WorldWideScience

Sample records for two-sided skin membranes

  1. The two sides of a double-skin facade: built intelligent skin or brand image scam?

    OpenAIRE

    Safamanesh, Bahare; Byrd, Hugh

    2012-01-01

    Double-Skin Facade (DSF) buildings regularly appear in popular architectural journals and claims are made that the buildings are either ‘sustainable’, ‘green’, ‘eco-friendly’ or ‘intelligent’. This results in myths about the performance of buildings that are perpetuated by designers eager to maintain a brand image. A literature review of research on the performance of DSFs reveals that the vast majority of the analysis is carried out by simulation methods and that there is a lack of empirical...

  2. Two-Sided Surface Oxidized Cellulose Membranes Modified with PEI: Preparation, Characterization and Application for Dyes Removal

    OpenAIRE

    Wei Wang; Qian Bai; Tao Liang; Huiyu Bai; Xiaoya Liu

    2017-01-01

    Porous regenerated cellulose (RC) membranes were prepared with cotton linter pulp as a raw material. These membranes were first oxidized on both sides by a modified (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) oxidation system using a controlled oxidation reaction technique. Then, the oxidized RC membranes were functionalized with polyethylenimine (PEI) via the glutaraldehyde crosslinking method to obtain bifunctional (carboxyl and amino) porous RC membranes, as revealed by Fourier transfo...

  3. Two-Sided Surface Oxidized Cellulose Membranes Modified with PEI: Preparation, Characterization and Application for Dyes Removal

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2017-09-01

    Full Text Available Porous regenerated cellulose (RC membranes were prepared with cotton linter pulp as a raw material. These membranes were first oxidized on both sides by a modified (2,2,6,6-tetramethylpiperidin-1-yloxyl (TEMPO oxidation system using a controlled oxidation reaction technique. Then, the oxidized RC membranes were functionalized with polyethylenimine (PEI via the glutaraldehyde crosslinking method to obtain bifunctional (carboxyl and amino porous RC membranes, as revealed by Fourier transform infrared spectroscopy (FT-IR, elemental analysis and zeta potential measurement. The scanning electron microscopy (SEM and the tests of the mechanical properties and permeability characteristics of modified RC membranes demonstrated that the porous structure and certain mechanical properties could be retained. The adsorption performance of the modified membranes towards dyes was subsequently investigated. The modified membranes displayed good adsorption capacities, rapid adsorption equilibrium and removal efficiencies towards both anionic (xylenol orange (XO and cationic (methylene blue (MB dyes, making them suitable bioadsorbents for wastewater treatment.

  4. Integrally skinned polysulfone hollow fiber membranes for pervaporation

    NARCIS (Netherlands)

    Koops, G.H.; Nolten, J.A.M.; Mulder, M.H.V.; Smolders, C.A.

    1994-01-01

    From polysulfone as polymer, integrally skinned hollow fiber membranes with a defect-free top layer have been spun. The spinning process described here differs from the traditional dry-wet spinning process where the fiber enters the coagulation bath after passing a certain air gap. In the present pr

  5. Integrally Skinned Polysulfone Hollow Fiber Membranes for Pervaporation

    NARCIS (Netherlands)

    Koops, G.H.; Nolten-Oude Hendrikman, J.A.M.; Nolten, J.A.M.; Mulder, M.H.V.; Smolders, C.A.; Smolders, C.A.

    1994-01-01

    From polysulfone as polymer, integrally skinned hollow fiber membranes with a defect-free top layer have been spun. The spinning process described here differs from the traditional dry-wet spinning process where the fiber enters the coagulation bath after passing a certain air gap. In the present pr

  6. Grammars with two-sided contexts

    Directory of Open Access Journals (Sweden)

    Mikhail Barash

    2014-05-01

    Full Text Available In a recent paper (M. Barash, A. Okhotin, "Defining contexts in context-free grammars", LATA 2012, the authors introduced an extension of the context-free grammars equipped with an operator for referring to the left context of the substring being defined. This paper proposes a more general model, in which context specifications may be two-sided, that is, both the left and the right contexts can be specified by the corresponding operators. The paper gives the definitions and establishes the basic theory of such grammars, leading to a normal form and a parsing algorithm working in time O(n^4, where n is the length of the input string.

  7. Ceramides in the skin lipid membranes: length matters.

    Science.gov (United States)

    Skolová, Barbora; Janůšová, Barbora; Zbytovská, Jarmila; Gooris, Gert; Bouwstra, Joke; Slepička, Petr; Berka, Pavel; Roh, Jaroslav; Palát, Karel; Hrabálek, Alexandr; Vávrová, Kateřina

    2013-12-17

    Ceramides are essential constituents of the skin barrier that allow humans to live on dry land. Reduced levels of ceramides have been associated with skin diseases, e.g., atopic dermatitis. However, the structural requirements and mechanisms of action of ceramides are not fully understood. Here, we report the effects of ceramide acyl chain length on the permeabilities and biophysics of lipid membranes composed of ceramides (or free sphingosine), fatty acids, cholesterol, and cholesterol sulfate. Short-chain ceramides increased the permeability of the lipid membranes compared to a long-chain ceramide with maxima at 4-6 carbons in the acyl. By a combination of differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, Langmuir monolayers, and atomic force microscopy, we found that the reason for this effect in short ceramides was a lower proportion of tight orthorhombic packing and phase separation of continuous short ceramide-enriched domains with shorter lamellar periodicity compared to native long ceramides. Thus, long acyl chains in ceramides are essential for the formation of tightly packed impermeable lipid lamellae. Moreover, the model skin lipid membranes are a valuable tool to study the relationships between the lipid structure and composition, lipid organization, and the membrane permeability.

  8. Fractionation of proteins with two-sided electro-ultrafiltration.

    Science.gov (United States)

    Käppler, Tobias; Posten, Clemens

    2007-03-10

    Downstream processing is a major challenge in bioprocess industry due to the high complexity of bio-suspensions itself, the low concentration of the product and the stress sensitivity of the valuable target molecules. A multitude of unit operations have to be joined together to achieve an acceptable purity and concentration of the product. Since each of the unit operations leads to a certain product loss, one important aim in downstream-research is the combination of different separation principles into one unit operation. In the current work a dead-end membrane process is combined with an electrophoresis operation. In the past this concept has proven successfully for the concentration of biopolymers. The present work shows that using different ultrafiltration membranes in a two-sided electro-filter apparatus with flushed electrodes brought significant enhancement of the protein fractionation process. Due to electrophoretic effects, the filtration velocity could be kept on a very high level for a long time, furthermore, the selectivity of a binary separation process carried out exemplarily for bovine serum albumin (BSA) and lysozyme (LZ) could be greatly increased; in the current case up to a value of more than 800. Thus the new two-sided electro-ultrafiltration technique achieves both high product purity and short separation times.

  9. [Application of amniotic membrane dressings in patients with skin damage].

    Science.gov (United States)

    Carrera González, Elier; Noa Hernández, Jose Eduardo; Marín Rojo, Carlos A

    2011-01-01

    The application of amniotic membranes in patients diagnosed with skin damage is a valid treatment option. A care plan following the Virginia Henderson model and NANDA, NOC and NIC taxonomy was applied to 36 patients admitted to the Dr. Miguel Enríquez hospital with different cutaneous lesions. This membrane has already been used for years due to its healing properties. These are attributed to antimicrobial properties reducing infection risk and promoting epithelial activity. They can decrease the need for the use of antibiotics, expendable materials, and can be applied during long periods of healing. This decreases the cost of wide spectrum antibiotic treatments, as well as the time patients spend in hospital. We present the results of this application in cases with several types of skin lesions.

  10. Areeda-turner in two-sided markets

    NARCIS (Netherlands)

    Behringer, S.; Filistrucchi, L.

    2015-01-01

    We extend the Areeda–Turner rule to two-sided markets. We show that a two-sided monopolist may find it short-run profit-maximizing to charge a price below marginal cost on one side of the market. Hence showing that the price is below marginal cost on one side of a two-sided market cannot be consider

  11. Areeda-turner in two-sided markets

    NARCIS (Netherlands)

    Behringer, S.; Filistrucchi, L.

    2015-01-01

    We extend the Areeda–Turner rule to two-sided markets. We show that a two-sided monopolist may find it short-run profit-maximizing to charge a price below marginal cost on one side of the market. Hence showing that the price is below marginal cost on one side of a two-sided market cannot be

  12. Areeda-turner in two-sided markets

    NARCIS (Netherlands)

    Behringer, S.; Filistrucchi, L.

    2015-01-01

    We extend the Areeda–Turner rule to two-sided markets. We show that a two-sided monopolist may find it short-run profit-maximizing to charge a price below marginal cost on one side of the market. Hence showing that the price is below marginal cost on one side of a two-sided market cannot be consider

  13. Superficial Dermal Fibroblasts Enhance Basement Membrane and Epidermal Barrier Formation in Tissue-Engineered Skin: Implications for Treatment of Skin Basement Membrane Disorders

    OpenAIRE

    2013-01-01

    Basement membrane is a highly specialized structure that binds the dermis and the epidermis of the skin, and is mainly composed of laminins, nidogen, collagen types IV and VII, and the proteoglycans, collagen type XVIII and perlecan, all of which play critical roles in the function and resilience of skin. Both dermal fibroblasts and epidermal keratinocytes contribute to the development of the basement membrane, and in turn the basement membrane and underlying dermis influence the development ...

  14. Investigation of the Efficacy of Transdermal Penetration Enhancers Through the Use of Human Skin and a Skin Mimic Artificial Membrane.

    Science.gov (United States)

    Balázs, Boglárka; Vizserálek, Gábor; Berkó, Szilvia; Budai-Szűcs, Mária; Kelemen, András; Sinkó, Bálint; Takács-Novák, Krisztina; Szabó-Révész, Piroska; Csányi, Erzsébet

    2016-03-01

    The aim of this study was to investigate the behavior of promising penetration enhancers through the use of 2 different skin test systems. Hydrogel-based transdermal formulations were developed with ibuprofen as a nonsteroidal anti-inflammatory drug. Transcutol and sucrose esters were used as biocompatible penetration enhancers. The permeability measurements were performed with ex vivo Franz diffusion cell methods and a newly developed Skin Parallel Artificial Membrane Permeability Assays (PAMPA) model. Franz diffusion measurement is commonly used as a research tool in studies of diffusion through synthetic membranes in vitro or penetration through ex vivo human skin, whereas Skin PAMPA involves recently published artificial membrane-based technology for the fast prediction of skin penetration. It is a 96-well plate-based model with optimized artificial membrane structure containing free fatty acid, cholesterol, and synthetic ceramide analog compounds to mimic the stratum corneum barrier function. Transdermal preparations containing 2.64% of different sucrose esters and/or Transcutol and a constant (5%) of ibuprofen were investigated to determine the effects of these penetration enhancers. The study demonstrated the good correlation of the permeability data obtained through use of human skin membrane and the in vitro Skin PAMPA system. The Skin PAMPA artificial membrane serves as quick and relatively deep tool in the early stages of transdermal delivery systems, through which the enhancing efficacy of excipients can be screened so as to facilitate the choice of effective penetration components.

  15. Agar/collagen membrane as skin dressing for wounds

    Energy Technology Data Exchange (ETDEWEB)

    Bao Lei; Yang Wei; Mao Xuan; Mou Shansong; Tang Shunqing [Biomedical Engineering Institute, Jinan University, Guangzhou (China)], E-mail: tshunqt@jnu.edu.cn, E-mail: tmuss@jnu.edu.cn

    2008-12-15

    Agar, a highly hydrophilic polymer, has a special gel property and favorable biocompatibility, but moderate intension strength in an aqueous condition and a low degradation rate. In order to tailor both properties of mechanical intension and degradation, type I collagen was composited with agar in a certain ratio by drying at 50 {sup 0}C or by a freeze-dry process. Glutaraldehyde was chosen as a crosslinking agent, and the most favorable condition for crosslinking was that the weight ratio of agar to glutaraldehyde was 66.7 and the pH value about 5. Dynamic mechanical analysis results showed that the single agar membrane had a modulus value between 640 MPa and 1064 MPa, but it was between 340 MPa and 819 MPa after being composited with type I collagen. It was discovered under an optical microscope that the pores were interconnected in the composite scaffolds instead of the honeycomb-like pores in a single type I collagen scaffold or the laminated gaps in a single agar scaffold. The results of an acute toxicity test disclosed that the composites were not toxic to mice although the composites were crosslinked with a certain concentration of glutaraldehyde. The results of gross examinations showed that when the composite membranes or scaffolds were applied to a repair rabbit skin lesion, the composites had a good repair effect without infection, liquid exudation or visible scar in the lesion covered with them. But in the control group, the autologous skin showed necrosis and there were a lot of scar tissues in the lesion site. H and E staining results showed that the repair tissue was similar to the normal one and very few scaffolds or membranes were left without degradation after 2 or 3 weeks. In conclusion, it is proved that type I collagen increases the toughness of the agar membrane, and the agar/type I collagen composites are promising biomaterials as wound dressings for healing burns or ulcers.

  16. Two-sided and alternating Jacobi-Davidson

    OpenAIRE

    Hochstenbach, Michiel Erik; Sleijpen, G.L.G.

    2001-01-01

    We discuss two variants of a two-sided Jacobi-Davidson method, which have asymptotically cubic convergence for nonnormal matrices and aim to find both right and left eigenvectors. These methods can be seen as Jacobi-Davidson analogs of Ostrowski’s two-sided Rayleigh Quotient Iteration. Some relations between (exact and inexact) two-sided Jacobi-Davidson and (exact and inexact) two-sided Rayleigh Quotient Iteration are given, together with convergence rates. Furthermore, we introduce an altern...

  17. Superficial dermal fibroblasts enhance basement membrane and epidermal barrier formation in tissue-engineered skin: implications for treatment of skin basement membrane disorders.

    Science.gov (United States)

    Varkey, Mathew; Ding, Jie; Tredget, Edward E

    2014-02-01

    Basement membrane is a highly specialized structure that binds the dermis and the epidermis of the skin, and is mainly composed of laminins, nidogen, collagen types IV and VII, and the proteoglycans, collagen type XVIII and perlecan, all of which play critical roles in the function and resilience of skin. Both dermal fibroblasts and epidermal keratinocytes contribute to the development of the basement membrane, and in turn the basement membrane and underlying dermis influence the development and function of the epidermal barrier. Disruption of the basement membrane results in skin fragility, extensive painful blistering, and severe recurring wounds as seen in skin basement membrane disorders such as epidermolysis bullosa, a family of life-threatening congenital skin disorders. Currently, there are no successful strategies for treatment of these disorders; we propose the use of tissue-engineered skin as a promising approach for effective wound coverage and to enhance healing. Fibroblasts and keratinocytes isolated from superficial and deep dermis and epidermis, respectively, of tissue from abdominoplasty patients were independently cocultured on collagen-glycosaminoglycan matrices, and the resulting tissue-engineered skin was assessed for functional differences based on the underlying specific dermal fibroblast subpopulation. Tissue-engineered skin with superficial fibroblasts and keratinocytes formed a continuous epidermis with increased epidermal barrier function and expressed higher levels of epidermal proteins, keratin-5, and E-cadherin, compared to that with deep fibroblasts and keratinocytes, which had an intermittent epidermis. Further, tissue-engineered skin with superficial fibroblasts and keratinocytes formed better basement membrane, and produced more laminin-5, nidogen, collagen type VII, compared to that with deep fibroblasts and keratinocytes. Overall, our results demonstrate that tissue-engineered skin with superficial fibroblasts and keratinocytes

  18. Two-sided and alternating Jacobi-Davidson

    NARCIS (Netherlands)

    Hochstenbach, Michiel Erik; Sleijpen, G.L.G.

    2001-01-01

    We discuss two variants of a two-sided Jacobi-Davidson method, which have asymptotically cubic convergence for nonnormal matrices and aim to find both right and left eigenvectors. These methods can be seen as Jacobi-Davidson analogs of Ostrowski’s two-sided Rayleigh Quotient Iteration. Some

  19. Market definition in two-sided markets : Theory and practice

    NARCIS (Netherlands)

    Filistrucchi, L.; Geradin, D.A.A.G.; van Damme, E.E.C.; Affeldt, P.

    2014-01-01

    Drawing from the economics of two-sided markets, we provide suggestions for the definition of the relevant market in cases involving two-sided platforms, such as media outlets, online intermediaries, payment cards companies, and auction houses. We also discuss when a one-sided approach may be harmle

  20. Market definition in two-sided markets : Theory and practice

    NARCIS (Netherlands)

    Filistrucchi, L.; Geradin, D.A.A.G.; van Damme, E.E.C.; Affeldt, P.

    2014-01-01

    Drawing from the economics of two-sided markets, we provide suggestions for the definition of the relevant market in cases involving two-sided platforms, such as media outlets, online intermediaries, payment cards companies, and auction houses. We also discuss when a one-sided approach may be

  1. Cdc42 expression in keratinocytes is required for the maintenance of the basement membrane in skin

    DEFF Research Database (Denmark)

    Wu, Xunwei; Quondamatteo, Fabio; Brakebusch, Cord

    2006-01-01

    , structure and number of hemidesomosomes were not significantly changed in the Cdc42 mutant skin compared with the control mice and no blister formation was observed in mutant skin. These data indicate that Cdc42 in keratinocytes is important for maintenance of the basement membrane of skin....

  2. Mathematical model to predict skin concentration of drugs: toward utilization of silicone membrane to predict skin concentration of drugs as an animal testing alternative.

    Science.gov (United States)

    Sugibayashi, Kenji; Todo, Hiroaki; Oshizaka, Takeshi; Owada, Yoko

    2010-01-01

    To calculate the skin concentration of active ingredients in cosmetics and topical pharmaceuticals using silicone membrane permeation. A series of parabens were used as model ingredients. Skin concentration of parabens was calculated using silicone membrane permeability. Their partition coefficient from formulations to the silicone membrane was determined by the membrane permeation profiles, and used to calculate their silicone membrane concentration, under an assumption that the membrane is one homogenous diffusion layer. The same procedure was applied for hairless rat skin. The calculated concentration of parabens in silicone membrane was very close to their observed values. However, the skin concentration calculated by skin permeability was not similar to the observed concentration. Re-calculation was performed under the assumption that the skin consists of two diffusion layers. This modification using permeation data through full-thickness and stripped skin enabled precise prediction of the skin concentration of parabens. In addition, the partition coefficient to the silicone membrane was useful to estimate their skin concentration. Ingredient concentration in skin can be precisely predicted using diffusion equations and partition coefficients through permeation experiments using a silicone membrane. The calculated in-skin concentration is useful for formulation studies of cosmetics and topical pharmaceuticals.

  3. Ortho-phthalaldehyde-induced skin mucous membrane damage from inadequate washing

    National Research Council Canada - National Science Library

    Horikiri, Masaru; Park, Susam; Matsui, Takahiro; Suzuki, Komei; Matsuoka, Takanori

    2011-01-01

    .... The authors report a patient with widespread, severe skin and mucous membrane damage of the lip, tongue, pharynx and oesophagus areas that was attributed to inadequate washing after the sterilisation...

  4. Numerical Tension Adjustment of X-Ray Membrane to Represent Goat Skin Kompang

    Science.gov (United States)

    Syiddiq, M.; Siswanto, W. A.

    2017-01-01

    This paper presents a numerical membrane model of traditional musical instrument kompang that will be used to find the parameter of membrane tension of x-ray membrane representing the classical goat-skin membrane of kompang. In this study, the experiment towards the kompang is first conducted in an acoustical anechoic enclosure and in parallel a mathematical model of the kompang membrane is developed to simulate the vibration of the kompang membrane in polar coordinate by implementing Fourier-Bessel wave function. The wave equation in polar direction in mode 0,1 is applied to provide the corresponding natural frequencies of the circular membrane. The value of initial and boundary conditions in the function is determined from experiment to allow the correct development of numerical equation. The numerical mathematical model is coded in SMath for the accurate numerical analysis as well as the plotting tool. Two kompang membrane cases with different membrane materials, i.e. goat skin and x-ray film membranes with fixed radius of 0.1 m are used in the experiment. An alternative of kompang’s membrane made of x-ray film with the appropriate tension setting can be used to represent the sound of traditional goat-skin kompang. The tension setting of the membrane to resemble the goat-skin is 24N. An effective numerical tool has been used to help kompang maker to set the tension of x-ray membrane. In the future application, any traditional kompang with different size can be replaced by another membrane material if the tension is set to the correct tension value. The numerical tool used is useful and handy to calculate the tension of the alternative membrane material.

  5. Harmony Search for Balancing Two-sided Assembly Lines

    Directory of Open Access Journals (Sweden)

    Hindriyanto Dwi Purnomo

    2012-01-01

    Full Text Available Two-sided assembly lines balancing problems are important problem for large-sized products such as cars and buses, in which, tasks operations can be performed in the two sides of the line. In this paper, Harmony Search algorithm is proposed to solve two-sided assembly lines balancing problems type-I (TALBP-I. The proposed method adopts the COMSOAL heuristic and specific features of TALBP in the Harmony operators – the harmony memory consideration, random selection and pitch adjustment – in order to maintain the local and global search. The proposed method is evaluated based on 6 benchmark problems that are commonly used in TALBP. The experiment results show that the proposed method work well and produces better solution than the heuristic method and genetic algorithm.

  6. Two-Sided Gravitational Mirror: Sealing off Curvature Singularities

    CERN Document Server

    Davidson, Aharon

    2012-01-01

    A gravitational mirror is a non-singular finite redshift surface which bounces all incident null geodesics. While a white mirror (outward bouncing) resembles 't Hooft's brick wall, a black mirror (inward bouncing) offers a novel mechanism for sealing off curvature singularities. The geometry underlying a two-sided mirror is characterized by a single signature change, to be contrasted with the signature flip which governs the black hole geometry. To demonstrate the phenomenon analytically, we derive an exact, static, radially symmetric, two-sided mirror solution, which asymptotes the massless BTZ black hole background, and then probe the local structure of a massive mirror.

  7. The Two-Sided Mind: Teaching and Suggestopedia.

    Science.gov (United States)

    Bancroft, W. Jane

    This paper explores how Georgi Lozanov's Suggestopedia incorporates elements of modern right-brain research. For example, issues in Linda VerLee Williams's "Teaching for the Two-Sided Mind" that are applicable to Suggestopedia include visual thinking, fantasy, multisensory learning, music, and direct experience. In Robert Ornstein's "The…

  8. Two-sided reflection of Markov-modulated Brownian motion

    NARCIS (Netherlands)

    D'Auria, B.; Ivanovs, J.; Kella, O.; Mandjes, M.

    2012-01-01

    This article considers a Markov-modulated Brownian motion with a two-sided reflection. For this doubly-reflected process we compute the Laplace transform of the stationary distribution, as well as the average loss rates at both barriers. Our approach relies on spectral properties of the matrix polyn

  9. Novel high torque bearingless two-sided rotary ultrasonic motor

    Institute of Scientific and Technical Information of China (English)

    LI Xia; CHEN Wei-shan; XIE Tao; LIU Jun-kao

    2007-01-01

    Applications are limited at present because the currently available ultrasonic motors (USMs) do not provide sufficiently high torque and power. The conventional travelling-wave USM needs the bearing to support, which required lubricant. To solve the above problem, a bearingless travelling-wave USM is designed. First, a novel structure of the two-sided USM consisting ora two-sided teeth stator and two disk-type rotors is designed. And the excitation principle of the two-sided travelling-wave USM is analyzed. Then, using ANSYS software, we set up the model of the stator to predict the excitation frequency and modal response of the stator. The shape of the vibration mode was obtained. Last, the load characteristics of the USM are measured using experimental method. The maximum stall torque and the no-load speed were obtained. The results showed that the characteristics of the two-sided USM are better than those of the conventional one-sided USM.

  10. Upward Pricing Pressure in Two-Sided Markets

    NARCIS (Netherlands)

    Affeldt, P.; Filistrucchi, L.; Klein, T.J.

    2012-01-01

    Abstract: Pricing pressure indices have recently been proposed as alternative screening devices for horizontal mergers involving differentiated products. We extend the concept of Upward Pricing Pressure (UPP) proposed by Farrell and Shapiro (2010) to two-sided markets. Examples of such markets are t

  11. Eubiosis and dysbiosis: the two sides of the microbiota.

    Science.gov (United States)

    Iebba, Valerio; Totino, Valentina; Gagliardi, Antonella; Santangelo, Floriana; Cacciotti, Fatima; Trancassini, Maria; Mancini, Carlo; Cicerone, Clelia; Corazziari, Enrico; Pantanella, Fabrizio; Schippa, Serena

    2016-01-01

    The microbial ecosystem of the gastrointestinal tract is characterized by a great number of microbial species living in balance by adopting mutualistic strategies. The eubiosis/dysbiosis condition of the gut microbiota strongly influences our healthy and disease status. This review briefly describes microbiota composition and functions, to then focus on eubiosis and dysbiosis status: the two sides of the microbiota.

  12. A Frame Nucleus on a Two-side Prequantale

    Institute of Scientific and Technical Information of China (English)

    XUShao-xian; WANGShun-qin; MAFei-fei

    2004-01-01

    In this paper, a Frame nucleus and prime elements in a Prequantale are defined. The concrete structure of a Frame prequantic quotient is considered, and the relation between the half-prime element and the Frame nucleus in a two-side Prequantale are obtained.

  13. Basement membrane proteoglycans are of epithelial origin in rodent skin

    DEFF Research Database (Denmark)

    Yamane, Y; Yaoita, H; Couchman, J R

    1996-01-01

    proteoglycan and rat and mouse perlecan. While the isolated rat epidermis was shown to completely lack rat basement membrane chondroitin sulfate proteoglycan and rat basement membrane heparan sulfate proteoglycans, including perlecan, immunofluorescence staining of tissue sections from the grafted sites......-epidermal junction and hair follicle epithelium are of epidermal (epithelial) origin in vivo. Stratified rat keratinocytes cultured on a collagen matrix at the air-liquid interface showed the synthesis of perlecan, laminin 1, and type IV collagen in basement membranes, but not clearly detectable basement membrane...

  14. Double-Skinned Forward Osmosis Membranes for Reducing Internal Concentration Polarization within the Porous Sublayer

    KAUST Repository

    Wang, Kai Yu

    2010-05-19

    A scheme to fabricate forward osmosis membranes comprising a highly porous sublayer sandwiched between two selective skin layers via phase inversion was proposed. One severe deficiency of existing composite and asymmetric membranes used in forward osmosis is the presence of unfavorable internal concentration polarization within the porous support layer that hinders both (i) separation (salt flux) and (ii) the performance (water flux). The double skin layers of the tailored membrane may mitigate the internal concentration polarization by preventing the salt and other solutes in the draw solution from penetrating into the membrane porous support. The prototype double-skinned cellulose acetate membrane displayed a water flux of 48.2 L·m-2·h -1 and lower reverse salt transport of 6.5 g·m -2·h-1 using 5.0 M MgCl2 as the draw solution in a forward osmosis process performed at 22 °C. This can be attributed to the effective salt rejection by the double skin layers and the low water transport resistance within the porous support layer. The prospects of utilizing the double-selective layer membranes may have potential application in forward osmosis for desalination. This study may help pave the way to improve the membrane design for the forward osmosis process. © 2010 American Chemical Society.

  15. Two-Sided Tests and One-Sided Confidence Bounds

    OpenAIRE

    1994-01-01

    Based on the duality between tests and confidence sets we introduce a new method to derive one-sided confidence bounds following the rejection of a null hypothesis with two-sided alternatives. This method imputes that the experimenter is only interested in confidence bounds if the null hypothesis is rejected. Furthermore, we suppose that he is only interested in the direction and a lower confidence bound concerning the distance of the true parameter value to the parameter values in the null h...

  16. Two-Sided Gravitational Mirror: Sealing off Curvature Singularities

    OpenAIRE

    Davidson, Aharon; Yellin, Ben

    2011-01-01

    A gravitational mirror is a non-singular finite redshift surface which bounces all incident null geodesics. While a white mirror (outward bouncing) resembles 't Hooft's brick wall, a black mirror (inward bouncing) offers a novel mechanism for sealing off curvature singularities. The geometry underlying a two-sided mirror is characterized by a single signature change, to be contrasted with the signature flip which governs the black hole geometry. To demonstrate the phenomenon analytically, we ...

  17. Strategic Trading in a Two-Sided Foreign Exchange Auction

    OpenAIRE

    Linda Goldberg; Rafael Tenorio

    1995-01-01

    The market microstructure chosen for foreign exchange markets can influence trading volumes and equilibrium exchange rates. With emerging markets and developing countries increasingly utilizing two- sided auctions, we show that the choice of the discrete 'tƒtonnement' auction creates incentives for strategic behavior among market participants. We provide theoretical predictions on strategic under- revelation of demand or supply positions that are supported empirically using detailed data from...

  18. Thermotropic phase transitions in model membranes of the outer skin layer based on ceramide 6

    Science.gov (United States)

    Gruzinov, A. Yu.; Kiselev, M. A.; Ermakova, E. V.; Zabelin, A. V.

    2014-01-01

    The lipid intercellular matrix stratum corneum of the outer skin layer is a multilayer membrane consisting of a complex mixture of different lipids: ceramides, fatty acids, cholesterol, and its derivatives. The basis of the multilayer membrane is the lipid bilayer, i.e., a two-dimensional liquid crystal. Currently, it is known that the main way of substance penetration through the skin is the lipid matrix. The complexity of the actual biological system does not allow reliable direct study of its properties; therefore, system modeling is often used. Phase transitions in the lipid system whose composition simulates the native lipid matrix are studied by the X-ray synchrotron radiation diffraction method.

  19. In vitro antioxidant properties of chicken skin enzymatic protein hydrolysates and membrane fractions.

    Science.gov (United States)

    Onuh, John O; Girgih, Abraham T; Aluko, Rotimi E; Aliani, Michel

    2014-05-01

    Chicken thigh and breast skin proteins were hydrolysed using alcalase or a combination of pepsin and pancreatin (PP), each at concentrations of 1-4%. The chicken skin protein hydrolysates (CSPHs) were then fractionated by membrane ultrafiltration into different molecular weight peptides (antioxidant properties. Results showed that the CSPHs had a significantly (pskin hydrolysates had significantly higher DPPH scavenging activity than the chicken thigh skin hydrolysates. DPPH scavenging and metal ion chelation increased significantly (pantioxidant properties decreased as peptide size increased. We conclude that CSPHs and their peptide fractions may be used as ingredients in the formulation of functional foods and nutraceuticals for the control and management of oxidative stress-related diseases.

  20. Wake flow behind two side-by-side square cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Yen, Shun C., E-mail: scyen@mail.ntou.edu.t [Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, Keelung 202, Taiwan (China); Liu, Jung H. [Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, Keelung 202, Taiwan (China)

    2011-02-15

    This study investigates the flow structures, form drag coefficients and vortex-shedding characteristics behind a single-square cylinder and two side-by-side cylinders in an open-loop wind tunnel. The Reynolds number (Re) and gap ratio (g*) are 2262 < Re < 28,000 and 0 {<=} g* {<=} 12, respectively. The flow patterns around the square cylinders are determined using the smoke-wire scheme. Experimental results indicate that the flow structures behind two side-by-side square cylinders are classified into three modes -single mode, gap-flow mode and couple vortex-shedding. The gap-flow mode displays anti-phase vortex shedding induced from the interference between the two square cylinders. However, the couple vortex-shedding mode exhibits in-phase vortex shedding that is caused by the independent flow behavior behind each square cylinder. The surface-pressure profile, form drag coefficient for each square cylinder (C{sub D}-bar) and vortex-shedding frequency were measured and calculated using a pressure transducer and a hot-wire anemometer. For two side-by-side cylinder configurations, the maximum C{sub D}-bar of 2.24 occurs in the single mode, while the minimum C{sub D}-bar of 1.68 occurs in the gap-flow mode. Additionally, the C{sub D}-bar in the coupled vortex-shedding mode is intermediate and approximately equal to that of a single (isolated) square cylinder. Moreover, the single mode has the highest Strouhal number (St) and the gap-flow mode has the lowest St.

  1. Peace and development: two sides of the same coin?

    Directory of Open Access Journals (Sweden)

    Viveros Tafur, Memphis Ronald

    2015-07-01

    Full Text Available There is the notion that peace and development are positively correlated, that peace drives development and that development drives peace, for Galtung (1985: 147 Peace and Development should be regarded as two sides of the same coin and considers development in relation to peace. This paper shows that peace and development are uncorrelated in several countries where there is peace without development or development without peace. The use of quantitative models as a tool for the analysis is a plus for the findings because most of the related theories are qualitative.

  2. Imageology and clinical examination: Two sides of the same coin

    Directory of Open Access Journals (Sweden)

    Deepa Das

    2011-01-01

    Full Text Available The continuous and rapid transition of techniques from research lab into clinical practice has been the pattern of development in radiology and imaging, and this has put the concept of clinical imaging into a different perspective. From a passive role of pattern recognition, distinguishing a radiograph from normal to abnormal, the task of a radiologist today has been elevated to reporting a comprehensive clinical imaging assay, giving information at a level profound enough to be useful for scientists working in allied fields. A peep into the literature shows how radiological and clinical examination can be two sides of the same coin.

  3. Experiments and Modeling of Boric Acid Permeation through Double-Skinned Forward Osmosis Membranes.

    Science.gov (United States)

    Luo, Lin; Zhou, Zhengzhong; Chung, Tai-Shung; Weber, Martin; Staudt, Claudia; Maletzko, Christian

    2016-07-19

    Boron removal is one of the great challenges in modern wastewater treatment, owing to the unique small size and fast diffusion rate of neutral boric acid molecules. As forward osmosis (FO) membranes with a single selective layer are insufficient to reject boron, double-skinned FO membranes with boron rejection up to 83.9% were specially designed for boron permeation studies. The superior boron rejection properties of double-skinned FO membranes were demonstrated by theoretical calculations, and verified by experiments. The double-skinned FO membrane was fabricated using a sulfonated polyphenylenesulfone (sPPSU) polymer as the hydrophilic substrate and polyamide as the selective layer material via interfacial polymerization on top and bottom surfaces. A strong agreement between experimental data and modeling results validates the membrane design and confirms the success of model prediction. The effects of key parameters on boron rejection, such as boron permeability of both selective layers and structure parameter, were also investigated in-depth with the mathematical modeling. This study may provide insights not only for boron removal from wastewater, but also open up the design of next generation FO membranes to eliminate low-rejection molecules in wider applications.

  4. Highly permeable double-skinned forward osmosis membranes for anti-fouling in the emulsified oil-water separation process

    KAUST Repository

    Duong, Hoang Hanh Phuoc

    2014-04-15

    Forward osmosis (FO) has attracted wide attention in recent years. However, the FO performance may be restricted due to internal concentration polarization (ICP) and fast fouling propensity that occurs in the membrane sublayer. Particularly, these problems significantly affect the membrane performance when treating highly contaminated oily wastewater. Recently, double-skinned flat sheet cellulose acetate (CA) membranes consisting of two selective skins via the phase inversion method have demonstrated less ICP and fouling propensity over typical single-skinned membranes. However, these membranes exhibit low water fluxes of <12 LMH under 2 M NaCl draw solution. Therefore, a novel double-skinned FO membrane with a high water flux has been aimed for in this study for emulsified oil-water treatment. The double-skinned FO membrane comprises a fully porous sublayer sandwiched between (i) a truly dense skin for salt rejection and (ii) a fairly loose dense skin for emulsified oil particle rejection. The former dense skin is a polyamide synthesized via interfacial polymerization, while the latter one is a self-assembled sulfonated pentablock copolymer (Nexar copolymer) layer. The resultant double-skinned membrane exhibits a high water flux of 17.2 LMH and a low reverse salt transport of 4.85 gMH using 0.5 M NaCl as the draw solution and DI water as the feed. The double-skinned membrane outperforms the single-skinned membrane with much lower fouling propensity for emulsified oil-water separation. © 2014 American Chemical Society.

  5. [The experimental application of chitosan membrane for treating chemical burns of the skin].

    Science.gov (United States)

    Pogorielov, M; Kalinkevich, O; Gortinskaya, E; Moskalenko, R; Tkachenko, Yu

    2014-01-01

    The basic method for skin damage treatment, including chemical wounds, is a topical application of different agents. Their objective is to repair structure of the skin and its functions. All dressings for treating wounds are classified as biological, artificial and composites containing both synthetic and natural materials. There are many studies concerning application of chitosan, which is a derivate of natural polymer chitin, as a basis for topical materials to treat burns. However, data are rather limited about application of chitosan for treating acid burns. Thus, the aim of research is to study the morphological futures of skin regeneration after the chemical burn applying chitosan membranes. We performed the experiment on 60 young rats (3 months old) with the chemical burns of third-degree (IIIA degree) to study the morphofunctional features of skin regeneration. Later we applied the chitosan membranes on the burns. We carried out a histologic investigation on the biopsy specimens of wound to determine the morphological features of wound regeneration. The results confirmed that earlier granulation and epithelialization of the skin surface happened as the chitosan membrane was applied on the acid effected surface. The final result of the application of chitosan film is to achieve full epithelialization, preserve the structure of tissues beneath the burn and prevent getting scars.

  6. The mechanism of formation of microporous or skinned membranes produced by immersion precipitation

    NARCIS (Netherlands)

    Wijmans, J.G.; Baaij, J.P.B.; Smolders, C.A.

    1983-01-01

    Cellulose acetate and polysulfone casting solutions were coagulated in water/solvent mixtures with differing solvent content. Precipitation in pure water yielded skinned membranes. Precipitation in water/solvent mixtures with solvent concentration exceeding a certain minimum value (which is differen

  7. Phytosphingosine, sphingosine and dihydrosphingosine ceramides in model skin lipid membranes: permeability and biophysics.

    Science.gov (United States)

    Školová, Barbora; Kováčik, Andrej; Tesař, Ondřej; Opálka, Lukáš; Vávrová, Kateřina

    2017-05-01

    Ceramides based on phytosphingosine, sphingosine and dihydrosphingosine are essential constituents of the skin lipid barrier that protects the body from excessive water loss. The roles of the individual ceramide subclasses in regulating skin permeability and the reasons for C4-hydroxylation of these sphingolipids are not completely understood. We investigated the chain length-dependent effects of dihydroceramides, sphingosine ceramides (with C4-unsaturation) and phytoceramides (with C4-hydroxyl) on the permeability, lipid organization and thermotropic behavior of model stratum corneum lipid membranes composed of ceramide/lignoceric acid/cholesterol/cholesteryl sulfate. Phytoceramides with very long C24 acyl chains increased the permeability of the model lipid membranes compared to dihydroceramides or sphingosine ceramides with the same chain lengths. Either unsaturation or C4-hydroxylation of dihydroceramides induced chain length-dependent increases in membrane permeability. Infrared spectroscopy showed that C4-hydroxylation of the sphingoid base decreased the relative ratio of orthorhombic chain packing in the membrane and lowered the miscibility of C24 phytoceramide with lignoceric acid. The phase separation in phytoceramide membranes was confirmed by X-ray diffraction. In contrast, phytoceramides formed strong hydrogen bonds and highly thermostable domains. Thus, the large heterogeneity in ceramide structures and in their aggregation mechanisms may confer resistance towards the heterogeneous external stressors that are constantly faced by the skin barrier. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Neutrophils in Cancer: Two Sides of the Same Coin

    Directory of Open Access Journals (Sweden)

    Eileen Uribe-Querol

    2015-01-01

    Full Text Available Neutrophils are the most abundant leukocytes in blood and are considered to be the first line of defense during inflammation and infections. In addition, neutrophils are also found infiltrating many types of tumors. Tumor-associated neutrophils (TANs have relevant roles in malignant disease. Indeed neutrophils may be potent antitumor effector cells. However, increasing clinical evidence shows TANs correlate with poor prognosis. The tumor microenvironment controls neutrophil recruitment and in turn TANs help tumor progression. Hence, TANs can be beneficial or detrimental to the host. It is the purpose of this review to highlight these two sides of the neutrophil coin in cancer and to describe recent studies that provide some light on the mechanisms for neutrophil recruitment to the tumor, for neutrophils supporting tumor progression, and for neutrophil activation to enhance their antitumor functions.

  9. Antimicrobial Brazilian Propolis (EPP-AF Containing Biocellulose Membranes as Promising Biomaterial for Skin Wound Healing

    Directory of Open Access Journals (Sweden)

    Hernane da Silva Barud

    2013-01-01

    Full Text Available Among remarkable discoveries concerning propolis, such as antifungal, antiviral, and antioxidant activities, its anti-inflammatory, and mainly its antibacterial, properties deserve special attention when skin wound healing is concerned. Based on this and knowing the distinctive performance of bacterial (BC membranes on wound healing, in this work it is proposed to demonstrate the potent antimicrobial activity and wound healing properties of a novel propolis containing biocellulose membrane. The obtained propolis/BC membrane was able to adsorb propolis not only on the surface, but also in its interstices demonstrated by scanning electron microscopy, X-ray diffraction, Fourier transform infrared (FT-IR spectroscopy, and thermogravidimetric assays. Additionally, the polyphenolic compounds determination and the prominent antibacterial activity in the membrane are demonstrated to be dose dependent, supporting the possibility of obtaining propolis/BC membranes at the desired concentrations, taking into consideration its application and its skin residence time. Finally, it could be suggested that propolis/BC membrane may favor tissue repair in less time and more effectively in contaminated wounds.

  10. Antimicrobial Brazilian Propolis (EPP-AF) Containing Biocellulose Membranes as Promising Biomaterial for Skin Wound Healing.

    Science.gov (United States)

    Barud, Hernane da Silva; de Araújo Júnior, Adalberto Miguel; Saska, Sybele; Mestieri, Letícia Boldrin; Campos, Juliana Alvares Duarte Bonini; de Freitas, Rubens Moreno; Ferreira, Nathália Ursoli; Nascimento, Andresa Piacezzi; Miguel, Felipe Galeti; Vaz, Mirela Mara de Oliveira Lima Leite; Barizon, Edna Aparecida; Marquele-Oliveira, Franciane; Gaspar, Ana Maria Minarelli; Ribeiro, Sidney José Lima; Berretta, Andresa Aparecida

    2013-01-01

    Among remarkable discoveries concerning propolis, such as antifungal, antiviral, and antioxidant activities, its anti-inflammatory, and mainly its antibacterial, properties deserve special attention when skin wound healing is concerned. Based on this and knowing the distinctive performance of bacterial (BC) membranes on wound healing, in this work it is proposed to demonstrate the potent antimicrobial activity and wound healing properties of a novel propolis containing biocellulose membrane. The obtained propolis/BC membrane was able to adsorb propolis not only on the surface, but also in its interstices demonstrated by scanning electron microscopy, X-ray diffraction, Fourier transform infrared (FT-IR) spectroscopy, and thermogravidimetric assays. Additionally, the polyphenolic compounds determination and the prominent antibacterial activity in the membrane are demonstrated to be dose dependent, supporting the possibility of obtaining propolis/BC membranes at the desired concentrations, taking into consideration its application and its skin residence time. Finally, it could be suggested that propolis/BC membrane may favor tissue repair in less time and more effectively in contaminated wounds.

  11. Production of an acellular matrix from amniotic membrane for the synthesis of a human skin equivalent.

    Science.gov (United States)

    Sanluis-Verdes, Anahí; Yebra-Pimentel Vilar, Maria Teresa; García-Barreiro, Juan Javier; García-Camba, Marta; Ibáñez, Jacinto Sánchez; Doménech, Nieves; Rendal-Vázquez, Maria Esther

    2015-09-01

    Human amniotic membrane (HAM) has useful properties as a dermal matrix substitute. The objective of our work was to obtain, using different enzymatic or chemical treatments to eliminate cells, a scaffold of acellular HAM for later use as a support for the development of a skin equivalent. The HAM was separated from the chorion, incubated and cryopreserved. The membrane underwent different enzymatic and chemical treatments to eliminate the cells. Fibroblasts and keratinocytes were separately obtained from skin biopsies of patients following a sequential double digestion with first collagenase and then trypsin-EDTA (T/E). A skin equivalent was then constructed by seeding keratinocytes on the epithelial side and fibroblasts on the chorionic side of the decellularizated HAM. Histological, immunohistochemical, inmunofluorescent and molecular biology studies were performed. Treatment with 1% T/E at 37 °C for 30 min totally removed epithelial and mesenchymal cells. The HAM thus treated proved to be a good matrix to support adherence of cells and allowed the achievement of an integral and intact scaffold for development of a skin equivalent, which could be useful as a skin substitute for clinical use.

  12. Breaching the skin barrier--insights from molecular simulation of model membranes.

    Science.gov (United States)

    Notman, Rebecca; Anwar, Jamshed

    2013-02-01

    Breaching the skin's barrier function by design is an important strategy for delivering drugs and vaccines to the body. However, while there are many proposed approaches for reversibly breaching the skin barrier, our understanding of the molecular processes involved is still rudimentary. Molecular simulation offers an unprecedented molecular-level resolution with an ability to reproduce molecular and bulk level properties. We review the basis of the molecular simulation methodology and give applications of relevance to the skin lipid barrier, focusing on permeation of molecules and chemical approaches for breaching the lipid barrier by design. The bulk kinetic model based on Fick's Law describing absorption of a drug through skin has been reconciled with statistical mechanical quantities such as the local excess chemical potential and local diffusion coefficient within the membrane structure. Applications of molecular simulation reviewed include investigations of the structure and dynamics of simple models of skin lipids, calculation of the permeability of molecules in simple model membranes, and mechanisms of action of the penetration enhancers, DMSO, ethanol and oleic acid. The studies reviewed illustrate the power and potential of molecular simulation to yield important physical insights, inform and rationalize experimental studies, and to predict structural changes, and kinetic and thermodynamic quantities. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Selective, ultrathin membrane skins prepared by deposition of novel polymer films on porous alumina supports

    Science.gov (United States)

    Balachandra, Anagi Manjula

    Membrane-based separations are attractive in industrial processes because of their low energy costs and simple operation. However, low permeabilities often make membrane processes uneconomical. Since flux is inversely proportional to membrane thickness, composite membranes consisting of ultrathin, selective skins on highly permeable supports are required to simultaneously achieve high throughput and high selectivity. However, the synthesis of defect-free skins with thicknesses less than 50 nm is difficult, and thus flux is often limited. Layer-by-layer deposition of oppositely charged polyelectrolytes on porous supports is an attractive method to synthesize ultrathin ion-separation membranes with high flux and high selectivity. The ion-transport selectivity of multilayer polyelectrolyte membranes (MPMs) is primarily due to Donnan exclusion; therefore increase in fixed charge density should yield high selectivity. However, control over charge density in MPMs is difficult because charges on polycations are electrostatically compensated by charges on polyanions, and the net charge in the bulk of these films is small. To overcome this problem, we introduced a templating method to create ion-exchange sites in the bulk of the membrane. This strategy involves alternating deposition of a Cu2+-poly(acrylic acid) complex and poly(allylamine hydrochloride) on a porous alumina support followed by removal of Cu2+ and deprotonation to yield free -COO- ion-exchange sites. Diffusion dialysis studies showed that the Cl-/SO42-. Selectivity of Cu2+-templated membranes is 4-fold higher than that of membranes prepared in the absence of Cu2+. Post-deposition cross-linking of these membranes by heat-induced amide bond formation further increased Cl-/SO42- selectivity to values as high as 600. Room-temperature, surface-initiated atom transfer radical polymerization (ATRP) provides another convenient method for formation of ultrathin polymer skins. This process involves attachment of

  14. NEW DYNAMICS OF THE CONFLICT BETWEEN TWO SIDES IN SCHOOLS

    Directory of Open Access Journals (Sweden)

    Pablo Ortega Gil

    2016-12-01

    Full Text Available This paper contains my own thoughts concerning what I have called new dynamics of the conflict between two sides in Schools. It begins by presenting the contrast between traditional conflicts, where both sides believed their argument was a private affair, and these new dynamics where one or both sides of the conflict tend to make it public and work to win support for their cause. The furious confrontation some people seek and the waves of indignation they set off bring to mind the frequent social media shitstorms we hear about. As a consequence, as the conflict festers, the inspector of education receives countless visits, phone calls and protest letters, an uproar designed to influence her decision. Next, some real cases are discussed, although no information is given of the people taking parts in the events to safeguard identities. Finally, I propose a checklist that involves a sequence of steps designed to protect the inspector from pressure and help her deal more efficiently with problems of this nature.

  15. Utilization of Shrimp Skin Waste (Sea Lobster) As Raw Material for the Membrane Filtration

    Science.gov (United States)

    Nyoman Rupiasih, Ni; Sumadiyasa, Made; Suyanto, Hery; Windari, Putri

    2017-05-01

    In view of the increasing littering of the sea banks by shells of crustaceans, a study was carried out to investigate the extraction and characterization of chitosan from skin waste of sea lobster i.e. ‘Bamboo Lobster’ (Panulirus versicolor). Chitosan was extracted using conventional methods such as pretreatment, demineralization, deprotienization, and deacetylation. The result showed that the degree of deacetylation of chitosan obtained is 70.02%. The FTIR spectra of the chitosan gave a characteristic of -NH2 band at 3447 cm-1 and carbonyl group band at 1655 cm-1. This chitosan has been used to prepare membrane. The chitosan membrane 2% has been prepared using phase inversion method with precipitation by solvent evaporation. The membranes were characterized by FTIR spectrophotometer, Nova 1200e using BJH method, and filtration method. The results show that thickness of the membrane is about 134 μm. The FTIR spectra show that functional groups present in the membrane are -NH, -CH, C=O, and -OH. Using BJH method obtained that the pore diameter is 3.382 nm with pore density is 8.95 x 105 pores/m3. By filtration method obtained that pure water flux (PWF) of the membrane are 386.662 and 489.627 1/m2.h at pressure 80-85 kPa and 90-100 kPa, respectively. These results show that skin waste of sea lobster was discovered as a raw material to prepare chitosan membrane. The membrane obtained is belonged to mesoporous group which may use in microfiltration process.

  16. Protein nanocoatings on synthetic polymeric nanofibrous membranes designed as carriers for skin cells

    Science.gov (United States)

    Bacakova, Marketa; Pajorova, Julia; Stranska, Denisa; Hadraba, Daniel; Lopot, Frantisek; Riedel, Tomas; Brynda, Eduard; Zaloudkova, Margit; Bacakova, Lucie

    2017-01-01

    Protein-coated resorbable synthetic polymeric nanofibrous membranes are promising for the fabrication of advanced skin substitutes. We fabricated electrospun polylactic acid and poly(lactide-co-glycolic acid) nanofibrous membranes and coated them with fibrin or collagen I. Fibronectin was attached to a fibrin or collagen nanocoating, in order further to enhance the cell adhesion and spreading. Fibrin regularly formed a coating around individual nanofibers in the membranes, and also formed a thin noncontinuous nanofibrous mesh on top of the membranes. Collagen also coated most of the fibers of the membrane and randomly created a soft gel on the membrane surface. Fibronectin predominantly adsorbed onto a thin fibrin mesh or a collagen gel, and formed a thin nanofibrous structure. Fibrin nanocoating greatly improved the attachment, spreading, and proliferation of human dermal fibroblasts, whereas collagen nanocoating had a positive influence on the behavior of human HaCaT keratinocytes. In addition, fibrin stimulated the fibroblasts to synthesize fibronectin and to deposit it as an extracellular matrix. Fibrin coating also showed a tendency to improve the ultimate tensile strength of the nanofibrous membranes. Fibronectin attached to fibrin or to a collagen coating further enhanced the adhesion, spreading, and proliferation of both cell types. PMID:28223803

  17. Direct visualization of lipid domains in human skin stratum corneum's lipid membranes

    DEFF Research Database (Denmark)

    Plasencia, I; Norlen, Lars; Bagatolli, Luis

    2007-01-01

    ; and iii), whether pH has a direct effect on the lipid matrix phase behavior. In this work the lateral structure of membranes composed of lipids extracted from human skin stratum corneum was studied in a broad temperature range (10 degrees C-90 degrees C) using different techniques such as differential......The main function of skin is to serve as a physical barrier between the body and the environment. This barrier capacity is in turn a function of the physical state and structural organization of the stratum corneum extracellular lipid matrix. This lipid matrix is essentially composed of very long...... scanning calorimetry, fluorescence spectroscopy, and two-photon excitation and laser scanning confocal fluorescence microscopy. Here we show that hydrated bilayers of human skin stratum corneum lipids express a giant sponge-like morphology with dimensions corresponding to the global three...

  18. Compact, Two-Sided Structural Cold Plate Configuration

    Science.gov (United States)

    Zaffetti, Mark

    2011-01-01

    In two-sided structural cold plates, typically there is a structural member, such as a honeycomb panel, that provides the structural strength for the cold plates that cool equipment. The cold plates are located on either side of the structural member and thus need to have the cooling fluid supplied to them. One method of accomplishing this is to route the inlet and outlet tubing to both sides of the structural member. Another method might be to supply the inlet to one side and the outlet to the other. With the latter method, an external feature such as a hose, tube, or manifold must be incorporated to pass the fluid from one side of the structural member to the other. Although this is a more compact design than the first option, since it eliminates the need for a dedicated supply and return line to each side of the structural member, it still poses problems, as these external features can be easily damaged and are now new areas for potential fluid leakage. This invention eliminates the need for an external feature and instead incorporates the feature internally to the structural member. This is accomplished by utilizing a threaded insert that not only connects the cold plate to the structural member, but also allows the cooling fluid to flow through it into the structural member, and then to the cold plate on the opposite side. The insert also employs a cap that acts as a cover to seal the open area needed to install the insert. There are multiple options for location of o-ring style seals, as well as the option to use adhesive for redundant sealing. Another option is to weld the cap to the cold plate after its installation, thus making it an integral part of the structural member. This new configuration allows the fluid to pass from one cold plate to the other without any exposed external features.

  19. Mechanical Stretch on Human Skin Equivalents Increases the Epidermal Thickness and Develops the Basement Membrane.

    Directory of Open Access Journals (Sweden)

    Eijiro Tokuyama

    Full Text Available All previous reports concerning the effect of stretch on cultured skin cells dealt with experiments on epidermal keratinocytes or dermal fibroblasts alone. The aim of the present study was to develop a system that allows application of stretch stimuli to human skin equivalents (HSEs, prepared by coculturing of these two types of cells. In addition, this study aimed to analyze the effect of a stretch on keratinization of the epidermis and on the basement membrane. HSEs were prepared in a gutter-like structure created with a porous silicone sheet in a silicone chamber. After 5-day stimulation with stretching, HSEs were analyzed histologically and immunohistologically. Stretch-stimulated HSEs had a thicker epidermal layer and expressed significantly greater levels of laminin 5 and collagen IV/VII in the basal layer compared with HSEs not subjected to stretch stimulation. Transmission electron microscopy revealed that the structure of the basement membrane was more developed in HSEs subjected to stretching. Our model may be relevant for extrapolating the effect of a stretch on the skin in a state similar to an in vivo system. This experimental system may be useful for analysis of the effects of stretch stimuli on skin properties and wound healing and is also expected to be applicable to an in vitro model of a hypertrophic scar in the future.

  20. Human skin basement membrane-associated heparan sulphate proteoglycan: distinctive differences in ultrastructural localization as a function of developmental age

    DEFF Research Database (Denmark)

    Horiguchi, Y; Fine, J D; Couchman, J R

    1991-01-01

    Recent studies have demonstrated that skin basement membrane components are expressed within the dermo-epidermal junction in an orderly sequence during human foetal development. We have investigated the ultrastructural localization of basement membrane-related antigens in human foetal skin...... was identical to that observed in neonatal and adult human skin. These findings demonstrate that active remodelling of the dermo-epidermal junction occurs during at least the first two trimesters, and affects not only basement membrane-associated structures but also specific antigens....... at different developmental ages using two monoclonal antibodies to a well-characterized basement membrane-associated heparan sulphate proteoglycan. A series of foetal skin specimens (range, 54-142 gestational days) were examined using an immunoperoxidase immunoelectron microscopic technique. In specimens...

  1. The potential of nanoporous anodic aluminium oxide membranes to influence skin wound repair.

    Science.gov (United States)

    Parkinson, Leigh G; Giles, Natalie L; Adcroft, Katharine F; Fear, Mark W; Wood, Fiona M; Poinern, Gerard E

    2009-12-01

    Cells respond to changes in the environment by altering their phenotype. The ability to influence cell behavior by modifying their environment provides an opportunity for therapeutic application, for example, to promote faster wound healing in response to skin injury. Here, we have modified the preparation of an aluminium oxide template to generate large uniform membranes with differing nano-pore sizes. Epidermal cells (keratinocytes) and dermal cells (fibroblasts) readily adhere to these nanoporous membranes. The pore size appears to influence the rate of cell proliferation and migration, important aspects of cell behavior during wound healing. The suitability of the membrane to act as a dressing after a burn injury was assessed in vivo; application of the membrane demonstrated adherence and conformability to the skin surface of a pig, with no observed degradation or detrimental effect on the repair. Our results suggest that keratinocytes are sensitive to changes in topography at the nanoscale level and that this property may be exploited to improve wound repair after tissue injury.

  2. DMPD: Targeting bacterial endotoxin: two sides of a coin. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17405910 Targeting bacterial endotoxin: two sides of a coin. Bosshart H, Heinzelman...n M. Ann N Y Acad Sci. 2007 Jan;1096:1-17. (.png) (.svg) (.html) (.csml) Show Targeting bacterial endotoxin:... two sides of a coin. PubmedID 17405910 Title Targeting bacterial endotoxin: two sides of a coin. Authors Bo

  3. The memory formalism in the diffusion of drugs through skin membrane

    Science.gov (United States)

    Caputo, Michele; Cametti, Cesare

    2009-06-01

    The diffusion of drugs across a composite structure such as a biological membrane is a rather complex phenomenon, where the assumptions on which the Fick equations are based are not always true, because of the inhomogeneous nature of the lipid membrane, the diffusion rate and the solubility of the drug being strongly dependent on the local position across the membrane. These problems are particularly strengthened in composite structures of a considerable thickness such as the human skin, where the high heterogeneity provokes the transport through different simultaneous pathways. In this note, we generalize the diffusion model based on Fick's second equation by the introduction of a space-dependent diffusion constant within the memory formalism (diffusion with memory) approach. The model predictions have been compared with experimental results concerning the permeation of two different compounds through human skin in vivo, such as piroxicam, an anti-inflammatory drug and 4-cyanophenol, a test chemical model compound. In both cases, reasonably good agreement has been found.

  4. The memory formalism in the diffusion of drugs through skin membrane

    Energy Technology Data Exchange (ETDEWEB)

    Caputo, Michele; Cametti, Cesare, E-mail: cesare.cametti@roma1.infn.i [Dipartimento di Fisica, Universita di Roma ' La Sapienza' , Piazzale A. Moro 2, I-00185 Rome (Italy) and CNR-INFM-SOFT, Unita di Roma1 Rome (Italy)

    2009-06-21

    The diffusion of drugs across a composite structure such as a biological membrane is a rather complex phenomenon, where the assumptions on which the Fick equations are based are not always true, because of the inhomogeneous nature of the lipid membrane, the diffusion rate and the solubility of the drug being strongly dependent on the local position across the membrane. These problems are particularly strengthened in composite structures of a considerable thickness such as the human skin, where the high heterogeneity provokes the transport through different simultaneous pathways. In this note, we generalize the diffusion model based on Fick's second equation by the introduction of a space-dependent diffusion constant within the memory formalism (diffusion with memory) approach. The model predictions have been compared with experimental results concerning the permeation of two different compounds through human skin in vivo, such as piroxicam, an anti-inflammatory drug and 4-cyanophenol, a test chemical model compound. In both cases, reasonably good agreement has been found.

  5. Octenidine dihydrochloride, a modern antiseptic for skin, mucous membranes and wounds.

    Science.gov (United States)

    Hübner, N-O; Siebert, J; Kramer, A

    2010-01-01

    Octenidine dihydrochloride (octenidine) was introduced for skin, mucous membrane and wound antisepsis more than 20 years ago. Until now, a wealth of knowledge has been gained, including in vitro and animal studies on efficacy, tolerance, safety and clinical experience both from case reports and prospective controlled trials. Nowadays, octenidine is an established antiseptic in a large field of applications and represents an alternative to older substances such as chlorhexidine, polyvidone-iodine or triclosan. The review is based on the current literature and unpublished original data as well. Copyright 2010 S. Karger AG, Basel.

  6. The human skin/chick chorioallantoic membrane model accurately predicts the potency of cosmetic allergens.

    Science.gov (United States)

    Slodownik, Dan; Grinberg, Igor; Spira, Ram M; Skornik, Yehuda; Goldstein, Ronald S

    2009-04-01

    The current standard method for predicting contact allergenicity is the murine local lymph node assay (LLNA). Public objection to the use of animals in testing of cosmetics makes the development of a system that does not use sentient animals highly desirable. The chorioallantoic membrane (CAM) of the chick egg has been extensively used for the growth of normal and transformed mammalian tissues. The CAM is not innervated, and embryos are sacrificed before the development of pain perception. The aim of this study was to determine whether the sensitization phase of contact dermatitis to known cosmetic allergens can be quantified using CAM-engrafted human skin and how these results compare with published EC3 data obtained with the LLNA. We studied six common molecules used in allergen testing and quantified migration of epidermal Langerhans cells (LC) as a measure of their allergic potency. All agents with known allergic potential induced statistically significant migration of LC. The data obtained correlated well with published data for these allergens generated using the LLNA test. The human-skin CAM model therefore has great potential as an inexpensive, non-radioactive, in vivo alternative to the LLNA, which does not require the use of sentient animals. In addition, this system has the advantage of testing the allergic response of human, rather than animal skin.

  7. Ibuprofen loaded PVA/chitosan membranes: A highly efficient strategy towards an improved skin wound healing.

    Science.gov (United States)

    Morgado, Patrícia I; Miguel, Sónia P; Correia, Ilídio J; Aguiar-Ricardo, Ana

    2017-03-01

    During wound healing, an early inflammation can cause an increase of the wound size and the healing process can be considerably belated if a disproportionate inflammatory response occurs. (S)-ibuprofen (IBP), a non-steroidal anti-inflammatory agent, has been used for muscle healing and to treat venous leg ulcers, but its effect in skin wound healing has not been thoroughly studied thus far. Herein, IBP-β-cyclodextrins carriers were designed to customise the release profile of IBP from poly(vinyl alcohol)/chitosan (PVA/CS) dressings in order to promote a faster skin regeneration. The dressings were produced using supercritical carbon dioxide (scCO2)-assisted technique. In vitro IBP release studies showed that β-cyclodextrins allowed a controlled drug release from the hydrogels which is crucial for their application in wound management. Moreover, the in vivo assays revealed that the presence of PVA/CS membranes containing IBP-β-cyclodextrins carriers avoided scab formation and an excessive inflammation, enabling an earlier skin healing. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. The role of ceramide chain length distribution on the barrier properties of the skin lipid membranes.

    Science.gov (United States)

    Mojumdar, E H; Kariman, Z; van Kerckhove, L; Gooris, G S; Bouwstra, J A

    2014-10-01

    The skin barrier function is provided by the stratum corneum (SC). The lipids in the SC are composed of three lipid classes: ceramides (CERs), cholesterol (CHOL) and free fatty acids (FFAs) which form two crystalline lamellar structures. In the present study, we investigate the effect of CER chain length distribution on the barrier properties of model lipid membranes mimicking the lipid composition and organization of SC. The membranes were prepared with either isolated pig CERs (PCERs) or synthetic CERs. While PCERs have a wide chain length distribution, the synthetic CERs are quite uniform in chain length. The barrier properties were examined by means of permeation studies using hydrocortisone as a model drug. Our studies revealed a reduced barrier in lipid membranes prepared with PCERs compared to synthetic CERs. Additional studies revealed that a wider chain length distribution of PCERs results in an enhanced hexagonal packing and increased conformational disordering of the lipid tails compared to synthetic CERs, while the lamellar phases did not change. This demonstrates that the chain length distribution affects the lipid barrier by reducing the lipid ordering and density within the lipid lamellae. In subsequent studies, the effect of increased levels of FFAs or CERs with a long acyl chain in the PCERs membranes was also studied. These changes in lipid composition enhanced the level of orthorhombic packing, reduced the conformational disordering and increased the barrier of the lipid membranes. In conclusion, the CER chain length distribution is an important key factor for maintaining a proper barrier. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Ceramides with a pentadecasphingosine chain and short acyls have strong permeabilization effects on skin and model lipid membranes.

    Science.gov (United States)

    Školová, Barbora; Janůšová, Barbora; Vávrová, Kateřina

    2016-02-01

    The composition and organization of stratum corneum lipids play an essential role in skin barrier function. Ceramides represent essential components of this lipid matrix; however, the importance of the individual structural features in ceramides is not fully understood. To probe the structure-permeability relationships in ceramides, we prepared analogs of N-lignoceroylsphingosine with shortened sphingosine (15 and 12 carbons) and acyl chains (2, 4 and 6 carbons) and studied their behavior in skin and in model lipid membranes. Ceramide analogs with pentadecasphingosine (15C) chains were more barrier-perturbing than 12C- and 18C-sphingosine ceramides; the greatest effects were found with 4 to 6C acyls (up to 15 times higher skin permeability compared to an untreated control and up to 79 times higher permeability of model stratum corneum lipid membranes compared to native very long-chain ceramides). Infrared spectroscopy using deuterated lipids and X-ray powder diffraction showed surprisingly similar behavior of the short ceramide membranes in terms of lipid chain order and packing, phase transitions and domain formation. The high- and low-permeability membranes differed in their amide I band shape and lamellar organization. These skin and membrane permeabilization properties of some short ceramides may be explored, for example, for the rational design of permeation enhancers for transdermal drug delivery. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Effect of ceramide acyl chain length on skin permeability and thermotropic phase behavior of model stratum corneum lipid membranes.

    Science.gov (United States)

    Janůšová, Barbora; Zbytovská, Jarmila; Lorenc, Petr; Vavrysová, Helena; Palát, Karel; Hrabálek, Alexandr; Vávrová, Kateřina

    2011-03-01

    Stratum corneum ceramides play an essential role in the barrier properties of skin. However, their structure-activity relationships are poorly understood. We investigated the effects of acyl chain length in the non-hydroxy acyl sphingosine type (NS) ceramides on the skin permeability and their thermotropic phase behavior. Neither the long- to medium-chain ceramides (8-24 C) nor free sphingosine produced any changes of the skin barrier function. In contrast, the short-chain ceramides decreased skin electrical impedance and increased skin permeability for two marker drugs, theophylline and indomethacin, with maxima in the 4-6C acyl ceramides. The thermotropic phase behavior of pure ceramides and model stratum corneum lipid membranes composed of ceramide/lignoceric acid/cholesterol/cholesterol sulfate was studied by differential scanning calorimetry and infrared spectroscopy. Differences in thermotropic phase behavior of these lipids were found: those ceramides that had the greatest impact on the skin barrier properties displayed the lowest phase transitions and formed the least dense model stratum corneum lipid membranes at 32°C. In conclusion, the long hydrophobic chains in the NS-type ceramides are essential for maintaining the skin barrier function. However, this ability is not shared by their short-chain counterparts despite their having the same polar head structure and hydrogen bonding ability. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. Price Competition in Two-Sided Markets with Heterogeneous Consumers and Network Effects

    NARCIS (Netherlands)

    Filistrucchi, L.; Klein, T.J.

    2013-01-01

    We model a two-sided market with heterogeneous customers and two heterogeneous network effects. In our model, customers on each market side care differently about both the number and the type of customers on the other side. Examples of two-sided markets are online platforms or daily newspapers. In t

  12. Mechanism of choline deficiency and membrane alteration in postural orthostatic tachycardia syndrome primary skin fibroblasts.

    Science.gov (United States)

    Schenkel, Laila C; Singh, Ratnesh K; Michel, Vera; Zeisel, Steven H; da Costa, Kerry-Ann; Johnson, Amy R; Mudd, Harvey S; Bakovic, Marica

    2015-05-01

    Fibroblasts from a patient with postural orthostatic tachycardia syndrome (POTS), who presented with low plasma choline and betaine, were studied to determine the metabolic characteristics of the choline deficiency. Choline is required for the synthesis of the phospholipid phosphatidylcholine (PC) and for betaine, an important osmoregulator. Here, choline transport, lipid homeostasis, and mitochondria function were analyzed in skin fibroblasts from POTS and compared with control cells. The choline transporter-like protein 1/solute carrier 44A1 (CTL1/SLC44A1) and mRNA expression were 2-3 times lower in POTS fibroblasts, and choline uptake was reduced 60% (P < 0.05). Disturbances of membrane homeostasis were observed by reduced ratios between PC:phosphatidylethanolamine and sphingomyelin:cholesterol, as well as by modified phospholipid fatty acid composition. Choline deficiency also impaired mitochondria function, which was observed by a reduction in oxygen consumption, mitochondrial potential, and glycolytic activity. When POTS cells were treated with choline, transporter was up-regulated, and uptake of choline increased, offering an option for patient treatment. The characteristics of the POTS fibroblasts described here represent a first model of choline and CTL1/SLC44A1 deficiency, in which choline transport, membrane homeostasis, and mitochondrial function are impaired.

  13. Basement membrane reconstruction in human skin equivalents is regulated by fibroblasts and/or exogenously activated keratinocytes

    NARCIS (Netherlands)

    El Ghalbzouri, A; Jonkman, MF; Dijkman, R; Ponec, M

    2005-01-01

    This study was undertaken to examine the role fibroblasts play in the formation of the basement membrane (BM) in human skin equivalents. For this purpose, keratinocytes were seeded on top of fibroblast-free or fibroblast-populated collagen matrix or de-epidermized dermis and cultured in the absence

  14. Bio-Inspired Aquaporinz Containing Double-Skinned Forward Osmosis Membrane Synthesized through Layer-by-Layer Assembly

    Directory of Open Access Journals (Sweden)

    Shuzheng Wang

    2015-08-01

    Full Text Available We demonstrated a novel AquaporinZ (AqpZ-incorporated double-skinned forward osmosis (FO membrane by layer-by-layer (LbL assembly strategy. Positively charged poly(ethyleneimine (PEI and negatively charged poly(sodium 4-styrenesulfonate (PSS were alternately deposited on both the top and bottom surfaces of a hydrolyzed polyacrylonitrile (H-PAN substrate. Subsequently, an AqpZ-embedded 1,2-dioleloyl-sn-glycero-3-phosphocholine (DOPC/1,2-dioleoyl-3-trimethylammonium- propane (chloride salt (DOTAP supported lipid bilayer (SLB was formed on PSS-terminated (T-PSS membrane via vesicle rupture method. The morphology and structure of the biomimetic membranes were characterized by in situ atomic force microscopy (AFM, scanning electron microscope (SEM, Fourier transform infrared spectrometer using the attenuated total reflection technique (ATR-FTIR, and contact angle. Moreover, the FO performance of the resultant membrane was measured by using 2 M MgCl2 solution as draw solution and deionized (DI water as feed solution, respectively. The membrane with a protein-to-lipid weight ratio (P/L of 1/50 exhibits 13.2 L/m2h water flux and 3.2 g/m2h reversed flux by using FO mode, as well as 15.6 L/m2h water flux and 3.4 L/m2h reversed flux for PRO mode (the draw solution is placed against the active layer. It was also shown that the SLB layer of the double-skinned FO membrane can increase the surface hydrophilicity and reduce the surface roughness, which leads to an improved anti-fouling performance against humic acid foulant. The current work introduced a new method of fabricating high performance biomimetic FO membrane by combining AqpZ and a double-skinned structure based on LbL assembly.

  15. IgE basement membrane zone antibodies induce eosinophil infiltration and histological blisters in engrafted human skin on SCID mice.

    Science.gov (United States)

    Zone, John J; Taylor, Ted; Hull, Christopher; Schmidt, Linda; Meyer, Laurence

    2007-05-01

    Bullous pemphigoid (BP) is characterized by the deposition of IgG in the basement membrane zone, infiltration of eosinophils, and blister formation. The purpose of this study was to evaluate a potential role of IgE basement membrane antibodies in the histological findings of BP. LABD97 is a component of the shed ectodomain of bullous pemphigoid antigen 2. We have developed an IgE hybridoma to LABD97 antigen. This hybridoma was injected subcutaneously in SCID mice with engrafted human skin. A subcutaneous hybridoma secreting IgE antibodies developed. An IgE mouse hybridoma to trinitrophenyl was used as a control. Human grafts and mouse skin were examined grossly over 21 days, histologically, and immunopathologically at day 21 after injection of the hybridoma. A visible subcutaneous tumor developed in 10-14 days. Erythema and intense scratching developed 2-3 days before the tumor in test mice, but not in controls. At day 21, 16/16 test mice developed intense eosinophil infiltration and degranulation of the human mast cells within the grafts and 13/16 developed histological, but not clinically visible, basement membrane blisters. Human skin grafts of control mice and normal mouse skin on the test mice and control mice did not develop any histological abnormalities. IgE antibodies to LABD97 recapitulate the histological inflammatory process seen in BP.

  16. [Monoclonal autoantibodies to the epithelial basement membrane cells of human skin and thymus obtained through immunization with Rickettsia prowazekii antigens].

    Science.gov (United States)

    Drobyshevskaia, E I; Spitsyn, S V; Nedialkov, Iu A; Shchekotikhina, Iu A; Tarasevich, I V

    1989-05-01

    As the result of immunization of BALB/c mice with the commercial preparation of typhus vaccine and R. prowazekii corpuscular antigen, in 29.2% and 40.3% of cases (respectively) the appearance of hybridomas synthesizing monoclonal antibodies (McAb) to different autologous structures (skin and thymic epithelium, cell nuclei, conjunctive tissue structures and vascular endothelium) has been revealed. The McAb under test have proved to be IgM-autoantibodies. McAb M-6, active against the basal membrane of human skin and thymic epithelium, produce quite a definite picture of disturbances in the differentiation of epithelium and can be used for the diagnosis of dyskeratosis.

  17. In vivo performance of chitosan/soy-based membranes as wound-dressing devices for acute skin wounds.

    Science.gov (United States)

    Santos, Tírcia C; Höring, Bernhard; Reise, Kathrin; Marques, Alexandra P; Silva, Simone S; Oliveira, Joaquim M; Mano, João F; Castro, António G; Reis, Rui L; van Griensven, Martijn

    2013-04-01

    Wound management represents a major clinical challenge on what concerns healing enhancement and pain control. The selection of an appropriate dressing plays an important role in both recovery and esthetic appearance of the regenerated tissue. Despite the wide range of available dressings, the progress in the wound care market relies on the increasing interest in using natural-based biomedical products. Herein, a rat wound-dressing model of partial-thickness skin wounds was used to study newly developed chitosan/soy (cht/soy)-based membranes as wound-dressing materials. Healing and repair of nondressed, cht/soy membrane-dressed, and Epigard(®)-dressed wounds were followed macroscopically and histologically for 1 and 2 weeks. cht/soy membranes performed better than the controls, promoting a faster wound repair. Re-epithelialization, observed 1 week after wounding, was followed by cornification of the outermost epidermal layer at the second week of dressing, indicating repair of the wounded tissue. The use of this rodent model, although in impaired healing conditions, may enclose some drawbacks regarding the inevitable wound contraction. Moreover, being the main purpose the evaluation of cht/soy-based membranes' performance in the absence of growth factors, the choice of a clinically relevant positive control was limited to a polymeric mesh, without any growth factor influencing skin healing/repair, Epigard. These new cht/soy membranes possess the desired features regarding healing/repair stimulation, ease of handling, and final esthetic appearance-thus, valuable properties for wound dressings.

  18. Stratum corneum model membranes : molecular organization in relation to skin barrier function

    NARCIS (Netherlands)

    Groen, Daniël

    2011-01-01

    The stratum corneum (SC), the thin uppermost layer of the skin, consists of dead flattened skin cells (corneocytes) embedded in a lipid matrix. The lipid matrix is considered to play a crucial role in the skin barrier function. It consists of ceramides (CER), cholesterol (CHOL) and free fatty acids

  19. Gyroid Nanoporous Membranes with Tunable Permeability

    DEFF Research Database (Denmark)

    Li, Li; Schulte, Lars; Clausen, Lydia D.

    2011-01-01

    Understanding the relevant permeability properties of ultrafiltration membranes is facilitated by using materials and procedures that allow a high degree of control on morphology and chemical composition. Here we present the first study on diffusion permeability through gyroid nanoporous cross......-sided skin membranes, much faster than expected by a naive resistance-in-series model; the flux through the two-sided skin membranes even increases with the membrane thickness. We propose a model that captures the physics behind the observed phenomena, as confirmed by flow visualization experiments...... the effective diffusion coefficients of a series of antibiotics, proteins, and other biomolecules; solute permeation is discussed in terms of hindered diffusion. The combination of uniform bulk morphology, isotropically percolating porosity, controlled surface chemistry, and tunable permeability is distinctive...

  20. Two-Sided Pyramid Wavefront Sensor in the Direct Phase Mode

    Energy Technology Data Exchange (ETDEWEB)

    Phillion, D; Baker, K

    2006-04-12

    The two-sided pyramid wavefront sensor has been extensively simulated in the direct phase mode using a wave optics code. The two-sided pyramid divides the focal plane so that each half of the core only interferes with the speckles in its half of the focal plane. A relayed image of the pupil plane is formed at the CCD camera for each half. Antipodal speckle pairs are separated so that a pure phase variation causes amplitude variations in the two images. The phase is reconstructed from the difference of the two amplitudes by transforming cosine waves into sine waves using the Hilbert transform. There are also other corrections which have to be applied in Fourier space. The two-sided pyramid wavefront sensor performs extremely well: After two or three iterations, the phase error varies purely in y. The two-sided pyramid pair enables the phase to be completely reconstructed. Its performance has been modeled closed loop with atmospheric turbulence and wind. Both photon noise and read noise were included. The three-sided and four-sided pyramid wavefront sensors have also been studied in direct phase mode. Neither performs nearly as well as does the two-sided pyramid wavefront sensor.

  1. Amniotic membrane as part of a skin substitute for full-thickness wounds: an experimental evaluation in a porcine model.

    Science.gov (United States)

    Loeffelbein, Denys J; Baumann, Claudia; Stoeckelhuber, Mechthild; Hasler, Rafael; Mücke, Thomas; Steinsträßer, Lars; Drecoll, Enken; Wolff, Klaus-Dietrich; Kesting, Marco R

    2012-07-01

    We evaluated the use of human amniotic membrane (HAM) as a graft material for the treatment of iatrogenic full-thickness (FT) skin wounds in a porcine model with a view to reducing donor site morbidity in free flap transfer. Forty experimental FT-wounds were covered with an autologous split-thickness skin graft (STSG) alone or in combination with a mono- or multilayer HAM or Integra(®). Untreated wounds served as controls. Clinical evaluation and biopsy-sampling for histological and immunohistochemical staining with von-Willebrand-factor (vWF) antibody, laminin antibody, Ki-67 antibody, and smooth muscle actin (αSMA) antibody were performed on days 5, 7, 10, 20, 40, and 60 after surgical intervention. Considerable disparities in the estimated criteria were observed between the various treatment groups of the FT-wounds. The use of HAM was found to have an accelerating impact on re-epithelialization. The multilayered amnion membrane showed better results than the Integra(®) and monolayer technique in terms of contraction rate, inflammation, and scarring and seemed useful as a dermal substitute in FT-wounds giving comparable results to STSG coverage alone. This study demonstrates the successful application of HAM as part of a skin substitute in FT-wounds in minipigs. The results offer promise as a simple and effective technique for the application of multilayer HAM in iatrogenic human skin defects and the acceleration of wound healing. Copyright © 2012 Wiley Periodicals, Inc.

  2. Experimental study on the near wake behind two side-by-side cylinders of unequal diameters

    Science.gov (United States)

    Gao, Yangyang; Yu, Dingyong; Tan, Soonkeat; Wang, Xikun; Hao, Zhiyong

    2010-10-01

    The wake structure behind two side-by-side circular cylinders with unequal diameter was investigated using the particle image velocimetry (PIV) technique. This investigation focused on the asymmetrical flow within the subcritical Reynolds number regime. A comparison between the time-averaged mean flow field of one cylinder and that of two side-by-side cylinders of unequal diameter was made for elucidating the mean flow characteristics attributable to the latter. The distribution of mean velocity behind two side-by-side unequal cylinders was distinctly different from that behind one cylinder, and an asymmetric combination was observed behind the two cylinders. The present paper also presents the authors' interpretation of the generation mechanism of gap flow deflection based on the instantaneous vorticity contours and velocity distribution. The effect of Reynolds number on flow structure was studied by analyzing the mean velocity distribution and time-averaged wake structures. The results showed that vortex formation length decreases with Reynolds number.

  3. On revenue and welfare dominance of ad valorem taxes in two-sided markets

    DEFF Research Database (Denmark)

    Kind, Hans Jarle; Köthenbürger, Marko; Schjelderup, Guttorm

    2009-01-01

    A benchmark result in public economics is that it is possible to increase both tax revenue and welfare by making a monopoly subject to ad valorem taxes rather than unit taxes. We show that such revenue and welfare dominance does not hold in two-sided markets.......A benchmark result in public economics is that it is possible to increase both tax revenue and welfare by making a monopoly subject to ad valorem taxes rather than unit taxes. We show that such revenue and welfare dominance does not hold in two-sided markets....

  4. Cationic membrane-active peptides - anticancer and antifungal activity as well as penetration into human skin.

    Science.gov (United States)

    Do, Nhung; Weindl, Günther; Grohmann, Lisa; Salwiczek, Mario; Koksch, Beate; Korting, Hans Christian; Schäfer-Korting, Monika

    2014-05-01

    Cationic antimicrobial peptides are ancient natural broad-spectrum antibiotics, and several compounds also exhibit anticancer activity. However, most applications pertain to bacterial infections, and treatment for skin cancer is less frequently considered. The cytotoxicity of melittin, cecropin A, protegrin-1 and histatin 5 against squamous skin cancer cell lines and normal human keratinocytes was evaluated and compared to established drugs. The results show that melittin clearly outperforms 5-fluorouracil regarding antitumor activity. Importantly, combined melittin and 5-fluorouracil enhanced cytotoxic effects on cancer cells and reduced toxicity on normal keratinocytes. Additionally, minimum inhibitory concentrations indicate that melittin also shows superior activity against clinical and laboratory strains of Candida albicans compared to amphotericin B. To evaluate its potential for topical applications, human skin penetration of melittin was investigated ex vivo and compared to two non-toxic cell-penetrating peptides (CPPs), low molecular weight protamine (LMWP) and penetratin. The stratum corneum prevents penetration into viable epidermis over 6 h; however, the peptides gain access to the viable skin after 24 h. Inhibition of digestive enzymes during skin penetration significantly enhances the availability of intact peptide. In conclusion, melittin may represent an innovative agent for non-melanoma skin cancer and infectious skin diseases. In order to develop a drug candidate, skin absorption and proteolytic digestion by skin enzymes need to be addressed. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Meta-heuristic algorithm to solve two-sided assembly line balancing problems

    Science.gov (United States)

    Wirawan, A. D.; Maruf, A.

    2016-02-01

    Two-sided assembly line is a set of sequential workstations where task operations can be performed at two sides of the line. This type of line is commonly used for the assembly of large-sized products: cars, buses, and trucks. This paper propose a Decoding Algorithm with Teaching-Learning Based Optimization (TLBO), a recently developed nature-inspired search method to solve the two-sided assembly line balancing problem (TALBP). The algorithm aims to minimize the number of mated-workstations for the given cycle time without violating the synchronization constraints. The correlation between the input parameters and the emergence point of objective function value is tested using scenarios generated by design of experiments. A two-sided assembly line operated in an Indonesia's multinational manufacturing company is considered as the object of this paper. The result of the proposed algorithm shows reduction of workstations and indicates that there is negative correlation between the emergence point of objective function value and the size of population used.

  6. Prices and Network Externalities in Two-Sided Markets: The Belgian Newspaper Industry

    NARCIS (Netherlands)

    van Cayseele, P.; Vanormelingen, S.

    2007-01-01

    This paper discusses the newspaper industry in Belgium from a two-sided market perspective. The reader and advertizing market for printed media are closely interlinked with each other by bilateral network externalities. This requires a specific structural model to estimate demand parameters for both

  7. Prices and network effects in two-sided markets: the Belgian newspaper industry

    NARCIS (Netherlands)

    Van Cayseele, P.; Vanormelingen, S.

    2009-01-01

    This paper investigates the two-sided nature of the newspaper industry. We explicitly take into account cross network effects that exist between advertisers and newspaper readers. On one side, advertisers' demand for publicity space depends on the number of newspaper readers and their

  8. A SSNIP Test for Two-sided Markets : The Case of Media

    NARCIS (Netherlands)

    Filistrucchi, L.

    2008-01-01

    I discuss the design and implementation of a SSNIP test in order to identify the relevant market in a media market. I argue that in such a two-sided market the traditional SSNIP test cannot be applied as it is usually conceived but rather should be modified in order to take into account indirect net

  9. A SSNIP Test for Two-sided Markets : The Case of Media

    NARCIS (Netherlands)

    Filistrucchi, L.

    2008-01-01

    I discuss the design and implementation of a SSNIP test in order to identify the relevant market in a media market. I argue that in such a two-sided market the traditional SSNIP test cannot be applied as it is usually conceived but rather should be modified in order to take into account indirect

  10. Prices and network effects in two-sided markets: the Belgian newspaper industry

    NARCIS (Netherlands)

    Van Cayseele, P.; Vanormelingen, S.

    2009-01-01

    This paper investigates the two-sided nature of the newspaper industry. We explicitly take into account cross network effects that exist between advertisers and newspaper readers. On one side, advertisers' demand for publicity space depends on the number of newspaper readers and their characteristic

  11. Merger Simulation in a Two-Sided Market : The Case of the Dutch Daily Newspapers

    NARCIS (Netherlands)

    Filistrucchi, L.; Klein, T.J.; Michielsen, T.O.

    2010-01-01

    We develop a structural econometric framework that allows us to simulate the effects of mergers among two-sided platforms selling differentiated products. We apply the proposed methodology to the Dutch newspaper industry. Our structural model encompasses demands for differentiated products on both s

  12. Computer program determines exact two-sided tolerance limits for normal distributions

    Science.gov (United States)

    Friedman, H. A.; Webb, S. R.

    1968-01-01

    Computer program determines by numerical integration the exact statistical two-sided tolerance limits, when the proportion between the limits is at least a specified number. The program is limited to situations in which the underlying probability distribution for the population sampled is the normal distribution with unknown mean and variance.

  13. Electromotive force and impedance studies of cellulose acetate membranes: Evidence for two binding sites for divalent cations and for an alveolar structure of the skin layer

    DEFF Research Database (Denmark)

    Smith Sørensen, T.; Jensen, J.B.; Malmgren-Hansen, B.

    1991-01-01

    . Alveoles in dense membranes or in the skin layer of asymmetric membranes seem to have a mean radius corresponding to ca. 70 angstrom. The dielectric constant in the alveoles is ca. 30 in contrast to a dielectric constant of ca. 16 in the >>lamellar phasealveoles. The dielectric constant...

  14. A Two-Sided Market Model of Optimal Price Structure for Instant Messenger

    Directory of Open Access Journals (Sweden)

    Jun Xu

    2013-01-01

    Full Text Available Instant messenger (IM is one of the most popular Internet applications all over the world. This paper examines the pricing problem of IM based on two-sided market model. IM serves as a two-sided platform, which gets both Internet users and advertisers on board. This paper concludes that IM operator adopts a heavily skewed price structure that favors IM users both under monopolistic case and under horizontal differentiated duopolistic case. When advertising revenue is large enough relatively to marginal cost for serving IM users, IM users can enjoy free service provided by IM operators. The competitive equilibrium of duopolistic case is not necessarily symmetric when advertisers choose singlehoming. Even in the symmetric equilibrium platform would rather deter all advertisers.

  15. Two-Sided Network Effects: A Theory of Information Product Design

    OpenAIRE

    Geoffrey G. Parker; Van Alstyne, Marshall W.

    2005-01-01

    How can firms profitably give away free products? This paper provides a novel answer and articulates trade-offs in a space of information product design. We introduce a formal model of two-sided network externalities based in textbook economics---a mix of Katz and Shapiro network effects, price discrimination, and product differentiation. Externality-based complements, however, exploit a different mechanism than either tying or lock-in even as they help to explain many recent strategies such ...

  16. Sparse two-sided rank-one updates for nonlinear equations

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The two-sided rank-one (TR1) update method was introduced by Griewank and Walther (2002) for solving nonlinear equations. It generates dense approximations of the Jacobian and thus is not applicable to large-scale sparse problems. To overcome this difficulty, we propose sparse extensions of the TR1 update and give some convergence analysis. The numerical experiments show that some of our extensions are superior to the TR1 update method. Some convergence analysis is also presented.

  17. Market segmentation in two-sided markets : tv rights for premier league

    OpenAIRE

    Kind, Hans Jarle; Sørgard, Lars

    2012-01-01

    This paper analyzes market segmentation in a two-sided market that consists of media consumers and advertisers. The analysis is motivated by a European Court of Justice Decision in October 2011, which allowed viewers to take advantage of international price differences and buy access to Premier League TV matches from whichever country they like. We compare complete market segmentation with the new situation where consumers can purchase from abroad (allowing for passive sales). Clearly, such a...

  18. Reproduced Giant Localization Length of Two-Side Surface Disordered Nanowires with Long-Range Correlation

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wei; DING Jian-Wen

    2011-01-01

    We numerically investigate the normalized localization length of two-side rough nanowires as functions of energy, magnetic field and correlation strength by using modular recursive Green's function method. It is found that in the absence of correlation, while in the presence of magnetic Reid, the localization length increases linearly for two-side roughness, which is different to diverging exponentially for one-side roughness. Moreover, the localization of electrons is suppressed in the low energy region, but enhanced in the high energy region. In the presence of correlation, especially, an exponential enhancement in the localization length resumes in high energy region, in contrast to that in low energy region, the long-range correlations abnormally enhance the localization of electrons. A competitive mechanism is proposed to explain this behavior.%We numerically investigate the normalized localization length of two-side rough nanowires as functions of energy,magnetic field and correlation strength by using modular recursive Green's function method.It is found that in the absence of correlation,while in the presence of magnetic field,the localization length increases linearly for two-side roughness,which is different to diverging exponentially for one-side roughness.Moreover,the localization of electrons is suppressed in the low energy region,but enhanced in the high energy region.In the presence of correlation,especially,an exponential enhancement in the localization length resumes in high energy region,in contrast to that in low energy region,the long-range correlations abnormally enhance the localization of electrons.A competitive mechanism is proposed to explain this behavior.Quantum dynamics of quasiparticles in random media has been a field of extensive study since the pioneering work by Anderson,[1] who argued that quasiparticle states become localized for sufficiently large disorder,thus giving rise to a localizationdelocalization transition (LDT) in three

  19. A Two-Sided Matching Decision Model Based on Uncertain Preference Sequences

    Directory of Open Access Journals (Sweden)

    Xiao Liu

    2015-01-01

    Full Text Available Two-sided matching is a hot issue in the field of operation research and decision analysis. This paper reviews the typical two-sided matching models and their limitations in some specific contexts, and then puts forward a new decision model based on uncertain preference sequences. In this model, we first design a data processing method to get preference ordinal value in uncertain preference sequence, then compute the preference distance of each matching pair based on these certain preference ordinal values, set the optimal objectives as maximizing matching number and minimizing total sum of preference distances of all the matching pairs under the lowest threshold constraint of matching effect, and then solve it with branch-and-bound algorithm. Meanwhile, we take two numeral cases as examples and analyze the different matching solutions with one-norm distance, two-norm distance, and positive-infinity-norm distance, respectively. We also compare our decision model with two other approaches, and summarize their characteristics on two-sided matching.

  20. Experimental study on the near wake behind two side-by-side cylinders of unequal diameters

    Energy Technology Data Exchange (ETDEWEB)

    Gao Yangyang; Yu Dingyong [College of Engineering, Ocean University of China, Qingdao 266100 (China); Tan, Soonkeat [School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Wang Xikun [Maritime Research Center, Nanyang Technological University, Singapore 639798 (Singapore); Hao Zhiyong, E-mail: gaoyangyangouc@163.co [Shanghai Maritime University, Shanghai 200135 (China)

    2010-10-15

    The wake structure behind two side-by-side circular cylinders with unequal diameter was investigated using the particle image velocimetry (PIV) technique. This investigation focused on the asymmetrical flow within the subcritical Reynolds number regime. A comparison between the time-averaged mean flow field of one cylinder and that of two side-by-side cylinders of unequal diameter was made for elucidating the mean flow characteristics attributable to the latter. The distribution of mean velocity behind two side-by-side unequal cylinders was distinctly different from that behind one cylinder, and an asymmetric combination was observed behind the two cylinders. The present paper also presents the authors' interpretation of the generation mechanism of gap flow deflection based on the instantaneous vorticity contours and velocity distribution. The effect of Reynolds number on flow structure was studied by analyzing the mean velocity distribution and time-averaged wake structures. The results showed that vortex formation length decreases with Reynolds number.

  1. Entactin: ultrastructural localization of an ubiquitous basement membrane glycoprotein in mouse skin

    DEFF Research Database (Denmark)

    Horiguchi, Y; Fine, J D; Ljubimov, A V;

    1989-01-01

    Entactin is a recently described sulfated glycoprotein component of mouse endodermal cell-derived extracellular matrix and is present in a number of basement membranes. It has been ultrastructurally localized to both lamina densa and adjacent epithelial cell membranes in rodent kidney. In the pre...

  2. Regenerative and Antibacterial Properties of Acellular Fish Skin Grafts and Human Amnion/Chorion Membrane: Implications for Tissue Preservation in Combat Casualty Care.

    Science.gov (United States)

    Magnusson, Skuli; Baldursson, Baldur Tumi; Kjartansson, Hilmar; Rolfsson, Ottar; Sigurjonsson, Gudmundur Fertram

    2017-03-01

    Improvised explosive devices and new directed energy weapons are changing warfare injuries from penetrating wounds to large surface area thermal and blast injuries. Acellular fish skin is used for tissue repair and during manufacturing subjected to gentle processing compared to biologic materials derived from mammals. This is due to the absence of viral and prion disease transmission risk, preserving natural structure and composition of the fish skin graft. The aim of this study was to assess properties of acellular fish skin relevant for severe battlefield injuries and to compare those properties with those of dehydrated human amnion/chorion membrane. We evaluated cell ingrowth capabilities of the biological materials with microscopy techniques. Bacterial barrier properties were tested with a 2-chamber model. The microstructure of the acellular fish skin is highly porous, whereas the microstructure of dehydrated human amnion/chorion membrane is mostly nonporous. The fish skin grafts show superior ability to support 3-dimensional ingrowth of cells compared to dehydrated human amnion/chorion membrane (p < 0.0001) and the fish skin is a bacterial barrier for 24 to 48 hours. The unique biomechanical properties of the acellular fish skin graft make it ideal to be used as a conformal cover for severe trauma and burn wounds in the battlefield. Reprint & Copyright © 2017 Association of Military Surgeons of the U.S.

  3. Dual-skinned polyamide/poly(vinylidene fluoride)/cellulose acetate membranes with embedded woven

    KAUST Repository

    Duong, Phuoc H.H.

    2016-08-31

    We propose multilayer membranes including (i) a thin selective polyamide (PA) layer prepared via interfacial polymerization, (ii) a poly (vinylidene fluoride) (PVDF) asymmetric porous support with high adhesion to the PA layer and high mechanical strength, (iii) a strong woven fabric, and (iv) fouling resistant porous cellulose acetate (CA) layer. The PA layer rejects solutes of the draw solution. The PVDF/woven fabric/CA (PVDF/CA) integrated layer performs as a mechanical support with unique properties for forward osmosis (FO) applications. It consists of a modified PVDF top layer suitable for the deposition of a PA layer and a highly hydrophilic bottom layer (CA) with a tunable pore size to minimize foulant deposition and intrusion onto and into the support. The experimental results using bovine serum albumin (BSA) as a model foulant show that the presence of the CA layer at the bottom of the FO membrane (PA/PVDF/CA) reduces 75% fouling propensity compared to the simple FO membrane made of PVDF, woven fabric and PA (PA/PVDF). Fouling tests with 2000 ppm oily feed faced the bottom of the FO membranes further indicate the superiority of the PA/PVDF/CA membrane compared to the PA/PVDF membrane. Moreover, the bottom CA layer can be adjusted with a flexible range of pore size, varied from sub-micron to sub-nanometer depending on the feed composition. The newly developed multilayer FO membrane has comparable performance to the state-of-the-art membrane with added tailored fouling resistance for specific wastewater feeds.

  4. Modelling the Penetration of Salicylates through Skin Using a Silicone Membrane

    Science.gov (United States)

    Wilkins, Andrew; Parmenter, Emily

    2012-01-01

    A diffusion cell to model the permeation of salicylate drugs through the skin using low-cost materials and a sensitive colorimetric analytical technique is described. The diffusion apparatus has been used at a further education college by a student for her AS-level Extended Project to investigate the permeation rates of salicylic acid…

  5. A note on P-values for two-sided tests.

    Science.gov (United States)

    Finner, Helmut; Strassburger, Klaus

    2007-12-01

    Based on uniformly most powerful unbiased (UMPU) tests for two-sided hypotheses and a short note in Lehmann (1959) on critical levels for randomized tests, Meulepas (1998, 1999) proposed (two-tailed) P -values taking into account the randomization constant(s) of the UMPU-tests. While UMPU-tests need an extra uniform observation if randomization is required, the P -values proposed by Meulepas need no extra uniform observation. At first glance, his idea looks very promising in order to define a suitable and powerful P -value. Unfortunately, such P -values are generally too conservative.

  6. Irradiance tailoring with two-sided Fresnel-type freeform optics

    Science.gov (United States)

    Bruneton, Adrien; Bäuerle, Axel; Traub, Martin; Wester, Rolf; Loosen, Peter

    2012-10-01

    Based on the Monge-Kantorovich theory of optimal mass transport, the computation of a ray mapping between source and target irradiances is used to design two-sided freeform lenses fulfilling the constraints of an automotive application: compactness and sharp bright-dark cutoff. A generic segmentation technic resulting in Fresnel-type optics is presented and the whole procedure is illustrated with the design of a fog light lens. Finally Monte Carlo simulation of the virtual model and measurements of a polycarbonate prototype are presented.

  7. Two-sided Mullins-Sekerka flow does not preserve convexity

    Directory of Open Access Journals (Sweden)

    Uwe F. Mayer

    1998-11-01

    Full Text Available The (two-sided Mullins-Sekerka model is a nonlocal evolution model for closed hypersurfaces, which was originally proposed as a model for phase transitions of materials of negligible specific heat. Under this evolution the propagating interfaces maintain the enclosed volume while the area of the interfaces decreases. We will show by means of an example that the Mullins-Sekerka flow does not preserve convexity in two space dimensions, where we consider both the Mullins-Sekerka model on a bounded domain, and the Mullins-Sekerka model defined on the whole plane.

  8. Evaluation of Human Amniotic Membrane as a Wound Dressing for Split-Thickness Skin-Graft Donor Sites

    Directory of Open Access Journals (Sweden)

    Denys J. Loeffelbein

    2014-01-01

    Full Text Available Human amniotic membrane (HAM has been used as a biomaterial in various surgical procedures and exceeds some qualities of common materials. We evaluated HAM as wound dressing for split-thickness skin-graft (STSG donor sites in a swine model (Part A and a clinical trial (Part B. Part A: STSG donor sites in 4 piglets were treated with HAM or a clinically used conventional polyurethane (PU foil (n=8 each. Biopsies were taken on days 5, 7, 10, 20, 40, and 60 and investigated immunohistochemically for alpha-smooth muscle actin (αSMA: wound contraction marker, von Willebrand factor (vWF: angiogenesis, Ki-67 (cell proliferation, and laminin (basement membrane integrity. Part B: STSG donor sites in 45 adult patients (16 female/29 male were treated with HAM covered by PU foam, solely by PU foam, or PU foil/paraffin gauze (n=15 each. Part A revealed no difference in the rate of wound closure between groups. HAM showed improved esthetic results and inhibitory effects on cicatrization. Angioneogenesis was reduced, and basement membrane formation was accelerated in HAM group. Part B: no difference in re-epithelialization/infection rate was found. HAM caused less ichor exudation and less pruritus. HAM has no relevant advantage over conventional dressings but might be a cost-effective alternative.

  9. NUMERICAL SIMULATION OF FLOW OVER TWO SIDE-BY-SIDE CIRCULAR CYLINDERS

    Institute of Scientific and Technical Information of China (English)

    SARVGHAD-MOGHADDAM Hesam; NOOREDIN Navid; GHADIRI-DEHKORDI Behzad

    2011-01-01

    In the present paper,the unsteady,viscous,incompressible and 2-D flow around two side-by-side circular cylinders was simulated using a Cartesian-staggered grid finite volume based method.A great-source term technique was employed to identify the solid bodies (cylinders) located in the flow field and boundary conditions were enforced by applying the ghost-cell technique.Finally,the characteristics of the flow around two side-by-side cylinders were comprehensively obtained through several computational simulations.The computational simulations were performed for different transverse gap ratios (1.5≤T/D≤4) in laminar (Re =100,200 ) and turbulent (Re =104) regimes,where T and D are the distance between the centers of cylinders and the diameter of cylinders,respectively.The Reynolds number is based on the diameter of cylinders,D.The pressure field and vorticity distributions along with the associated streamlines and the time histories of hydrodynamic forces were also calculated and analyzed for different gap ratios.Generally,different flow patterns were observed as the gap ratio and Reynolds number varied.Accordingly,the hydrodynamic forces showed irregular variations for small gaps while they took a regular pattern at higher spacing ratios.

  10. Detection of two-sided alternatives in a Brownian motion model

    CERN Document Server

    Hadjiliadis, Olympia

    2007-01-01

    This work examines the problem of sequential detection of a change in the drift of a Brownian motion in the case of two-sided alternatives. Applications to real life situations in which two-sided changes can occur are discussed. Traditionally, 2-CUSUM stopping rules have been used for this problem due to their asymptotically optimal character as the mean time between false alarms tends to $\\infty$. In particular, attention has focused on 2-CUSUM harmonic mean rules due to the simplicity in calculating their first moments. In this paper, we derive closed-form expressions for the first moment of a general 2-CUSUM stopping rule. We use these expressions to obtain explicit upper and lower bounds for it. Moreover, we derive an expression for the rate of change of this first moment as one of the threshold parameters changes. Based on these expressions we obtain explicit upper and lower bounds to this rate of change. Using these expressions we are able to find the best 2-CUSUM stopping rule with respect to the exten...

  11. Heuristics for Multiobjective Optimization of Two-Sided Assembly Line Systems

    Directory of Open Access Journals (Sweden)

    N. Jawahar

    2014-01-01

    Full Text Available Products such as cars, trucks, and heavy machinery are assembled by two-sided assembly line. Assembly line balancing has significant impacts on the performance and productivity of flow line manufacturing systems and is an active research area for several decades. This paper addresses the line balancing problem of a two-sided assembly line in which the tasks are to be assigned at L side or R side or any one side (addressed as E. Two objectives, minimum number of workstations and minimum unbalance time among workstations, have been considered for balancing the assembly line. There are two approaches to solve multiobjective optimization problem: first approach combines all the objectives into a single composite function or moves all but one objective to the constraint set; second approach determines the Pareto optimal solution set. This paper proposes two heuristics to evolve optimal Pareto front for the TALBP under consideration: Enumerative Heuristic Algorithm (EHA to handle problems of small and medium size and Simulated Annealing Algorithm (SAA for large-sized problems. The proposed approaches are illustrated with example problems and their performances are compared with a set of test problems.

  12. First Direct Two-Sided Bound on the B_s^0 Oscillation Frequency

    CERN Document Server

    Abazov, V M; Abolins, M; Acharya, B S; Adams, M; Adams, T; Agelou, M; Agram, J L; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Andeen, T; Anderson, S; Andrieu, B; Anzelc, M S; Arnoud, Y; Arov, M; Askew, A; Åsman, B; Assis-Jesus, A C S; Atramentov, O; Autermann, C; Avila, C; Ay, C; Badaud, F; Baden, A; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, P; Banerjee, S; Barberis, E; Bargassa, P; Baringer, P; Barnes, C; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellavance, A; Benítez, J A; Beri, S B; Bernardi, G; Bernhard, R; Berntzon, L; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Binder, M; Biscarat, C; Black, K M; Blackler, I; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Bloom, K; Blumenschein, U; Böhnlein, A; Boeriu, O; Bolton, T A; Borcherding, F; Borissov, G; Bos, K; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Buchanan, N J; Buchholz, D; Bühler, M; Büscher, V; Burdin, S; Burke, S; Burnett, T H; Busato, E; Buszello, C P; Butler, J M; Calvet, S; Cammin, J; Caron, S; Carvalho, W; Casey, B C K; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Chapin, D; Charles, F; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Claes, D; Clement, B; Clément, C; Coadou, Y; Cooke, M; Cooper, W E; Coppage, D; Corcoran, M; Cousinou, M C; Cox, B; Crepe-Renaudin, S; Cutts, D; Cwiok, M; Da Motta, H; Das, A; Das, M; Davies, B; Davies, G; Davis, G A; De, K; de Jong, P; De Jong, S J; De La Cruz-Burelo, E; De Oliveira Martins, C; Degenhardt, J D; Déliot, F; Demarteau, M; Demina, R; Demine, P; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Doidge, M; Dominguez, A; Dong, H; Dudko, L V; Duflot, L; Dugad, S R; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Edwards, T; Ellison, J; Elmsheuser, J; Elvira, V D; Eno, S; Ermolov, P; Estrada, J; Evans, H; Evdokimov, A; Evdokimov, V N; Fatakia, S N; Feligioni, L; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fleck, I; Ford, M; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; García, C; García-Bellido, A; Gardner, J; Gavrilov, V; Gay, A; Gay, P; Gelé, D; Gelhaus, R; Gerber, C E; Gershtein, Yu; Gillberg, D; Ginther, G; Gollub, N; Gómez, B; Gounder, K; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, P; Grivaz, J F; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutíerrez, G; Gutíerrez, P; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Hanagaki, K; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hong, S J; Hooper, R; Houben, P; Hu, Y; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jain, V; Jakobs, K; Jarvis, C; Jenkins, A; Jesik, R; Johns, K; Johnson, C; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Käfer, D; Kahn, S; Kajfasz, E; Kalinin, A M; Kalk, J M; Kalk, J R; Kappler, S; Karmanov, D; Kasper, J; Katsanos, I; Kau, D; Kaur, R; Kehoe, R; Kermiche, S; Kesisoglou, S; Khanov, A; Kharchilava, A I; Kharzheev, Yu M; Khatidze, D; Kim, H; Kim, T J; Kirby, M H; Klima, B; Kohli, J M; Konrath, J P; Kopal, M; Korablev, V M; Kotcher, J; Kothari, B; Koubarovsky, A; Kozelov, A V; Kozminski, J; Kryemadhi, A; Krzywdzinski, S; Kühl, T; Kumar, A; Kunori, S; Kupco, A; Kurca, T; Kvita, J; Lager, S; Lammers, S; Landsberg, G L; Lazoflores, J; Le Bihan, A C; Lebrun, P; Lee, W M; Leflat, A; Lehner, F; Leonidopoulos, C; Lesne, V; Lévêque, J; Lewis, P; Li, J; Li, Q Z; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Z; Lobo, L; Lobodenko, A; Lokajícek, M; Lounis, A; Love, P; Lubatti, H J; Lynker, M; Lyon, A L; Maciel, A K A; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Magnan, A M; Makovec, N; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martens, M; Mattingly, S E K; McCarthy, R; McCroskey, R; Meder, D; Melnitchouk, A; Mendes, A; Mendoza, L; Merkin, M; Merritt, K W; Meyer, A; Meyer, J; Michaut, M; Miettinen, H; Millet, T; Mitrevski, J; Molina, J; Mondal, N K; Monk, J; Moore, R W; Moulik, T; Muanza, G S; Mulders, M; Mulhearn, M; Mundim, L; Mutaf, Y D; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Nelson, S; Neustroev, P; Nöding, C; Nomerotski, A; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Oguri, V; Oliveira, N; Oshima, N; Otec, R; Oteroy-Garzon, G J; Owen, M; Padley, P; Parashar, N; Park, S J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Perea, P M; Pérez, E; Peters, K; Petroff, P; Petteni, M; Piegaia, R; Pleier, M A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M E; Pompos, A; Pope, B G; Popov, A V; Prado da Silva, W L; Prosper, H B; Protopopescu, S D; Qian, J; Quadt, A; Quinn, B; Rani, K J; Ranjan, K; Rapidis, P A; Ratoff, P N; Renkel, P; Reucroft, S; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F K; Robinson, S; Rodrigues, R F; Royon, C; Rubinov, P; Ruchti, R; Rud, V I; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santoro, A F S; Savage, G; Sawyer, L; Scanlon, T; Schaile, A D; Schamberger, R D; Scheglov, Y; Schellman, H; Schieferdecker, P; Schmitt, C; Schwanenberger, C; Schwartzman, A; Schwienhorst, R; Sen-Gupta, S; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shephard, W D; Shivpuri, R K; Shpakov, D; Siccardi, V; Sidwell, R A; Simák, V; Sirotenko, V I; Skubic, P L; Slattery, P F; Smith, R P; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Song, X; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Souza, M; Spurlock, B; Stark, J; Steele, J; Stevenson, K; Stolin, V; Stone, A; Stoyanova, D A; Strandberg, J; Strang, M A; Strauss, M; Ströhmer, R; Strom, D; Strovink, M; Stutte, L; Sumowidagdo, S; Sznajder, A; Talby, M; Tamburello, P; Taylor, W; Telford, P; Temple, J; Tiller, B; Titov, M; Tokmenin, V V; Tomoto, M; Toole, T; Torchiani, I; Towers, S; Trefzger, T; Trincaz-Duvoid, S; Tsybychev, D; Tuchming, B; Tully, C; Turcot, A S; Tuts, P M; Unalan, R; Uvarov, L; Uvarov, S; Uzunyan, S; Vachon, B; Vanden Berg, P J; Van Kooten, R; Van Leeuwen, W M; Varelas, N; Varnes, E W; Vartapetian, A H; Vasilyev, I A; Vaupel, M; Verdier, P; Vertogradov, L S; Verzocchi, M; Villeneuve-Séguier, F; Vint, P; Vlimant, J R; Von Törne, E; Voutilainen, M; Vreeswijk, M; Wahl, H D; Wang, L; Warchol, J; Watts, G; Wayne, M; Weber, M; Weerts, H; Wermes, N; Wetstein, M; White, A; Wicke, D; Wilson, G W; Wimpenny, S J; Wobisch, M; Womersley, J; Wood, D R; Wyatt, T R; Xie, Y; Xuan, N; Yacoob, S; Yamada, R; Yan, M; Yasuda, T; Yatsunenko, Y A; Yip, K; Yoo, H D; Youn, S W; Yu, C; Yu, J; Yurkewicz, A; Zatserklyaniy, A; Zeitnitz, C; Zhang, D; Zhao, T; Zhao, Z; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zutshi, V

    2006-01-01

    We report the first direct two-sided bound on the $B^0_s$ oscillation frequency using a large sample of $B^0_s$ semileptonic decays corresponding to approximately 1 fb$^{-1}$ of integrated luminosity collected by the \\dzer\\ experiment in 2002--2006 during Run II of the Fermilab Tevatron Collider. The flavor (i.e., $B^0_s$ or $\\bar{B}^0_s$) of the \\bs meson at the time of production was found using an opposite-side tagging technique, and the flavor at the time of decay was determined from the charge of the muon in the partially reconstructed decay $\\bs\\to \\mu^{+}D_{s}^{-}X$, $D_{s}^{-}\\to \\phi \\pi^{-}$, $\\phi\\to K^{+}K^{-}$. A likelihood scan over the oscillation frequency, $\\Delta m_s$, gives a most probable value of 19 ps$^{-1}$ and a range of $17 < \\Delta m_s < 21$ ps$^{-1}$ at the 90% C.L. At $\\Delta m_s=19$ ps$^{-1}$, the amplitude method yields a result that deviates from the hypothesis of an oscillation amplitude of zero by 2.5 standard deviations, corresponding to a two-sided C.L. of 1%.

  13. Interaction of Gap Flow With Flapping Dynamics of Two Side-by-Side Elastic Foils

    Science.gov (United States)

    Gurugubelli, Pardha S.; Jaiman, Rajeev K.

    2016-11-01

    We present a numerical analysis on the interaction between two side-by-side elastic foils with their leading edges clamped and the gap flow between them. We perform systematic parametric direct numerical simulations as a function of nondimensional bending rigidity, KB ∈ [ 1 ×10-4 , 3 ×10-3 ] and mass-ratio, m* ∈ [ 0 . 05 , 0 . 2 ] , for a fixed gap, dp = 0 . 2 / L , at the leading edge and Reynolds number, Re = 1000 to explain the underlying physical mechanism behind the in-phase and out-of-phase coupled flapping modes. The parametric simulations show that the parallel foil system exhibits predominant out-of-phase coupling for low mass-ratio m* 0 . 1 . We also show that the two side-by-side elastic foils always exhibit out-of-phase coupling initially irrespective of whether the fully developed flapping show out-of-phase or in-phase coupled mode. Finally, we show that the transition from the initial out-of-phase to stable in-phase is characterized by loss of gap flow symmetric stability to undergo oscillations at the gap exit.

  14. Chondroitin 6-sulfate proteoglycan but not heparan sulfate proteoglycan is abnormally expressed in skin basement membrane from patients with dominant and recessive dystrophic epidermolysis bullosa

    DEFF Research Database (Denmark)

    Fine, J D; Couchman, J R

    1989-01-01

    Two distinct groups of proteoglycans, chondroitin 6-sulfate (C6-S) proteoglycan and heparan sulfate proteoglycan (HSPG), have been recently shown to reside within the lamina densa of normal human skin basement membrane (BM). To determine whether either or both antigens are normally expressed in one...... junctional EB, and all control skin specimens. We have subsequently extracted a greater than 400 kD C6-S proteoglycan from normal skin BM and have found that the core protein may also contain heparan sulfate side chains. Our findings suggest that 3B3 monoclonal antibody recognizes a hybrid proteoglycan...... in human skin, and that its absent or reduced binding in dystrophic EB skin BM may reflect either absence of associated core protein or posttranslational alterations in the proteoglycan side chains....

  15. Diffusion of solvent from a cast cellulose acetate solution during the formation of skinned membranes

    NARCIS (Netherlands)

    Altena, F.W.; Smid, J.; van den Berg, J.W.A.; Wijmans, J.G.; Smolders, C.A.

    1985-01-01

    The transport of solvent out of a cast cellulose acetate (CA) solution into the coagulation bath during membrane formation is treated as a diffusion process. From the increase of solvent concentration in the bath with time (solvent leaching experiments) an overall solvent diffusion coefficient has b

  16. Membrane potential plays a dual role for chloride transport across toad skin

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Rasmussen, B E

    1983-01-01

    -dependent currents are not caused by a trivial Goldmand-type rectification and ion redistributions following transepithelial potential pertubations. Extended with a dynamic Cl- permeability in the apical membrane according to a Hodgkin-Huxley kinetic scheme, the model predicts voltage clamp data which closely...

  17. Diffusion of solvent from a cast cellulose acetate solution during the formation of skinned membranes

    NARCIS (Netherlands)

    Altena, F.W.; Smid, J.; Berg, van den J.W.A.; Wijmans, J.G.; Smolders, C.A.

    1985-01-01

    The transport of solvent out of a cast cellulose acetate (CA) solution into the coagulation bath during membrane formation is treated as a diffusion process. From the increase of solvent concentration in the bath with time (solvent leaching experiments) an overall solvent diffusion coefficient has b

  18. Hair Follicle Morphogenesis in the Treatment of Mouse Full-Thickness Skin Defects Using Composite Human Acellular Amniotic Membrane and Adipose Derived Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Wu Minjuan

    2016-01-01

    Full Text Available Early repair of skin injury and maximal restoration of the function and appearance have become important targets of clinical treatment. In the present study, we observed the healing process of skin defects in nude mice and structural characteristics of the new skin after transplantation of isolated and cultured adipose derived mesenchymal stem cells (ADMSCs onto the human acellular amniotic membrane (AAM. The result showed that ADMSCs were closely attached to the surface of AAM and grew well 24 h after seeding. Comparison of the wound healing rate at days 7, 14, and 28 after transplantation showed that ADMSCs seeded on AAM facilitated the healing of full-thickness skin wounds more effectively as compared with either hAM or AAM alone, indicating that ADMSCs participated in skin regeneration. More importantly, we noticed a phenomenon of hair follicle development during the process of skin repair. Composite ADMSCs and AAM not only promoted the healing of the mouse full-thickness defects but also facilitated generation of the appendages of the affected skin, thus promoting restoration of the skin function. Our results provide a new possible therapy idea for the treatment of skin wounds with respect to both anatomical regeneration and functional restoration.

  19. Hair Follicle Morphogenesis in the Treatment of Mouse Full-Thickness Skin Defects Using Composite Human Acellular Amniotic Membrane and Adipose Derived Mesenchymal Stem Cells

    Science.gov (United States)

    Minjuan, Wu; Jun, Xiong; Shiyun, Shao; Sha, Xu; Haitao, Ni

    2016-01-01

    Early repair of skin injury and maximal restoration of the function and appearance have become important targets of clinical treatment. In the present study, we observed the healing process of skin defects in nude mice and structural characteristics of the new skin after transplantation of isolated and cultured adipose derived mesenchymal stem cells (ADMSCs) onto the human acellular amniotic membrane (AAM). The result showed that ADMSCs were closely attached to the surface of AAM and grew well 24 h after seeding. Comparison of the wound healing rate at days 7, 14, and 28 after transplantation showed that ADMSCs seeded on AAM facilitated the healing of full-thickness skin wounds more effectively as compared with either hAM or AAM alone, indicating that ADMSCs participated in skin regeneration. More importantly, we noticed a phenomenon of hair follicle development during the process of skin repair. Composite ADMSCs and AAM not only promoted the healing of the mouse full-thickness defects but also facilitated generation of the appendages of the affected skin, thus promoting restoration of the skin function. Our results provide a new possible therapy idea for the treatment of skin wounds with respect to both anatomical regeneration and functional restoration. PMID:27597871

  20. Fatty acid composition of red blood cell membranes and risk of squamous cell carcinoma of the skin.

    Science.gov (United States)

    Harris, Robin B; Foote, Janet A; Hakim, Iman A; Bronson, Dan L; Alberts, David S

    2005-04-01

    Differential effects of fatty acids on carcinogenesis suggest that fatty acid composition is important in tumor development. Arachidonic acid and its metabolites elicit inflammation and promote tumor formation in mouse skin. Inhibitors of the arachidonic cascade inhibit tumor incidence. A population-based case control study in Southeastern Arizona tested the hypothesis that lower levels of arachidonic acid in RBC membranes were associated with decreased risk of skin squamous cell carcinoma (SCC; n = 335 SCC cases and 321 controls). Extracted and esterified RBC fatty acids were analyzed using capillary gas chromatography. Individual peaks for 14 fatty acids were measured as a percentage of total fatty acids. Logistic regression was used to estimate odds ratios (OR), adjusting for SCC risk factors (age, gender, actinic keratosis history, freckling, and tanning ability). Increased levels of arachidonic acid in RBC membranes were associated with increased risk of SCC [odds ratio (OR), 1.08 per mg/100 mL change; 95% confidence interval (95% CI), 1.02-1.15] and this association remained when controls with actinic keratosis precursor lesions were excluded. SCC risk was highest among the upper quartile of arachidonic acid (OR, 2.38; 95% CI, 1.37-4.12). In contrast, increasing proportions of palmitic acid (OR, 0.94; 95% CI, 0.89-1.00) and palmitoleicacid (OR, 0.49; 95% CI, 0.30-0.81) were associated with reduced SCC risk. More studies are needed to elucidate the function of RBC fatty acids so that recommendations can be made to alter the human diet for cancer prevention.

  1. Skin Basement Membrane: The Foundation of Epidermal Integrity—BM Functions and Diverse Roles of Bridging Molecules Nidogen and Perlecan

    Directory of Open Access Journals (Sweden)

    Dirk Breitkreutz

    2013-01-01

    Full Text Available The epidermis functions in skin as first defense line or barrier against environmental impacts, resting on extracellular matrix (ECM of the dermis underneath. Both compartments are connected by the basement membrane (BM, composed of a set of distinct glycoproteins and proteoglycans. Herein we are reviewing molecular aspects of BM structure, composition, and function regarding not only (i the dermoepidermal interface but also (ii the resident microvasculature, primarily focusing on the per se nonscaffold forming components perlecan and nidogen-1 and nidogen-2. Depletion or functional deficiencies of any BM component are lethal at some stage of development or around birth, though BM defects vary between organs and tissues. Lethality problems were overcome by developmental stage- and skin-specific gene targeting or by cell grafting and organotypic (3D cocultures of normal or defective cells, which allows recapitulating BM formation de novo. Thus, evidence is accumulating that BM assembly and turnover rely on mechanical properties and composition of the adjacent ECM and the dynamics of molecular assembly, including further “minor” local components, nidogens largely functioning as catalysts or molecular adaptors and perlecan as bridging stabilizer. Collectively, orchestration of BM assembly, remodeling, and the role of individual players herein are determined by the developmental, tissue-specific, or functional context.

  2. Diffusion of solvent from a cast cellulose acetate solution during the formation of skinned membranes

    OpenAIRE

    Altena, F.W.; Smid, J.; Berg, van den, G.J.; Wijmans, J.G.; Smolders, C.A.

    1985-01-01

    The transport of solvent out of a cast cellulose acetate (CA) solution into the coagulation bath during membrane formation is treated as a diffusion process. From the increase of solvent concentration in the bath with time (solvent leaching experiments) an overall solvent diffusion coefficient has been calculated. In size these coefficients compare well to mutual pseudo-binary solvent-non-solvent diffusion coefficients determined by means of a classical boundary broadening method applied to t...

  3. Slip effects on a generalized Burgers’ fluid flow between two side walls with fractional derivative

    Directory of Open Access Journals (Sweden)

    Shihao Han

    2016-01-01

    Full Text Available This paper presents a research for the 3D flow of a generalized Burgers’ fluid between two side walls generated by an exponential accelerating plate and a constant pressure gradient, where the no-slip assumption between the exponential accelerating plate and the Burgers’ fluid is no longer valid. The governing equations of the generalized Burgers’ fluid flow are established by using the fractional calculus approach. Exact analytic solutions for the 3D flow are established by employing the Laplace transform and the finite Fourier sine transform. Furthermore, some 3D and 2D figures for the fluid velocity and shear stress are plotted to analyze and discuss the effects of various parameters.

  4. Two sides of the same coin: stem cells in cancer and regenerative medicine.

    Science.gov (United States)

    Ilmer, Matthias; Vykoukal, Jody; Recio Boiles, Alejandro; Coleman, Michael; Alt, Eckhard

    2014-07-01

    Multipotent stromal cells (MSCs) derived from bone marrow, adipose tissue, cord blood, and other origins have recently received much attention as potential therapeutic agents with beneficial immunomodulatory and regenerative properties. In their native tissue environment, however, such cells also appear to have essential functions in building and supporting tumor microenvironments, providing metastatic niches, and maintaining cancer hallmarks. Here, we consider the varied roles of these tissue-resident stroma-associated cells, synthesize recent and emerging discoveries, and discuss the role, potential, and clinical applications of MSCs in cancer and regenerative medicine.-Ilmer, M., Vykoukal, J., Recio Boiles, A., Coleman, M., Alt, E. Two sides of the same coin: stem cells in cancer and regenerative medicine.

  5. Indirect-drive inertial fusion targets for two-sided heavy-ion illumination

    Science.gov (United States)

    Remizov, G. N.; Romanov, Yu. A.; Ryabikina, N. A.; Shagaliev, R. M.; Vakhlamova, L. L.; Vatulin, V. V.; Vinokurov, O. A.; Bock, R.; Kang, K.-H.; Maruhn, J. A.

    The properties of heavy-ion induced fusion targets with two-sided illumination and with the converters placed completely inside the hohlraum have been investigated using integrated simulations based on the SATURN and MIMOZA code packages in order to check the results obtained with the view factor method in previous work, which is briefly reviewed. Separate converter simulations show the importance of an accurate treatment of radiation transport and also demonstrate that a converter efficiency of 40 - 80% can be achieved easily depending on the detailed converter material and geometry. For the complete target, a gas fill is shown to be necessary and it turned out to be very important to allow some of the radiation shields to become partially transparent during the evolution. In the most favorable case, an asymmetry in the temperature on the capsule of about 5% was achieved, leading to a reduction of the neutron yield by a factor of 7 compared to an ideally symmetric situation.

  6. An Optimization of Granular Networks Based on PSO and Two-Sided Gaussian Contexts

    Directory of Open Access Journals (Sweden)

    Keun Chang Kwak

    2012-12-01

    Full Text Available This paper is concerned with an optimization of GN (Granular Networks based on PSO (Particle Swarm Optimization and Information granulation. The GN is designed by the linguistic model using context-based fuzzy c-means clustering algorithm performing relationship between fuzzy sets defined in the input and output space. The contexts used in this paper are based on two-sided Gaussian membership functions. The main goal of optimization based on PSO is to find the number of clusters obtained in each context and weighting factor. Finally, we apply to coagulant dosing process in a water purification plant to evaluate the predication performance and compare the proposed approach with other previous methods.

  7. The deinkability improvement of offset prints made from a two-side coated substrate

    Directory of Open Access Journals (Sweden)

    Zeljka Barbaric-Mikocevic

    2013-02-01

    Full Text Available This paper describes the improved removal of impurities (coating, ink/toner from offset prints produced by digital printing of two-side coated paper. The substrates were printed by conventional and digital offset processes. Based on image analysis results it was established that deinking flotation is an inefficient method for ink particle removal from digital offset printed paper, but it is efficient for ink removal from conventional offset printed paper. On the other hand, pre-treatment with hydrogen peroxide solution gives better results for ink particle removal from digital offset prints than from conventional offset prints. Optimal parameters for hydrogen peroxide pre-treatment for both offset prints were chosen based on unprinted substrate mass loss results in the preliminary investigation. These results showed that hydrogen peroxide pre-treatment is more successful at removal of impurities in comparison with flotation deinking without pre-treatment.

  8. Measured Data Processing Method For Relative Motions Between Two Side-by-side Ships

    Directory of Open Access Journals (Sweden)

    Ping-an Shi

    2013-01-01

    Full Text Available In order to design and implement a wave compensation system to reduce the relative motion between two side-by-side ships in waves, a new method to process measured data of ship model test with contact measurement to study the characteristics of relative motion was presented. The reference co-ordinate systems and relative motions were defined, and the scheme of the model test was described. Then the Empirical Mode Decomposition(EMD adaptive filter were designed, the frequency domain integration transform method based upon Fast Fourier Transform(FFT were established. The procedure to transform acceleration signal into displacement was proposed and verified, and the processing results with and without EMD adaptive filter were compared. Finally, the relative motions consistent with reality were acquired, which indicates this method is effective for measured data processing.

  9. Coupled resonator induced transparency in surface plasmon polariton gap waveguide with two side-coupled cavities

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhengren, E-mail: zhrenzhang@126.com [School of Science, Chongqing Jiaotong University, Chongqing 400074 (China); Zhang, Liwei [School of Physics and Chemistry, Henan Polytechnic University, Jiaozuo 454000 (China); Yin, Pengfei; Han, Xiangyu [School of Science, Chongqing Jiaotong University, Chongqing 400074 (China)

    2014-08-01

    We investigate theoretically the generation process of coupled resonator-induced transparency (CRIT) in surface plasmon polariton gap waveguide system containing two side-coupled cavities, which locate at a symmetric position. The CRIT is original from the destructive interference of the two detuned cavities. In contrast with the existing electromagnetically induced transparency (EIT) schemes, the occurrence of the CRIT is caused by the two radiative cavities in waveguide, instead of interference between a dark cavity and radiative cavity. This behavior mimics the quantum interference between two direct excitation pathways in a three-level V-type atom. The transmission lineshape can be tuned between an EIT-like resonant peak and a Lorentzian-like resonant dip by tailoring the detuning of the two cavities. Moreover, we also find that the transparency peak moves to high frequency with a line shift and its Q factor decreases with the increase of coupling distance between the cavities and waveguide.

  10. 19-DEJ-1, a hemidesmosome-anchoring filament complex-associated monoclonal antibody. Definition of a new skin basement membrane antigenic defect in junctional and dystrophic epidermolysis bullosa

    DEFF Research Database (Denmark)

    Fine, J D; Horiguchi, Y; Couchman, J R

    1989-01-01

    A murine monoclonal antibody (19-DEJ-1) was recently produced that recognizes a unique antigenic epitope of human skin basement membrane localized to the midlamina lucida exclusively in those areas bordered by overlying hemidesmosomes. To determine whether the antigen defined by 19-DEJ-1 is norma...

  11. Distribution, ultrastructural localization, and ontogeny of the core protein of a heparan sulfate proteoglycan in human skin and other basement membranes

    DEFF Research Database (Denmark)

    Horiguchi, Y; Couchman, J R; Ljubimov, A V;

    1989-01-01

    A variety of heparan sulfate proteoglycans (HSPG) have been identified on cell surfaces and in basement membrane (BM). To more fully characterize HSPG in human skin BM, we used two monoclonal antibodies (MAb) directed against epitopes of the core protein of a high molecular weight HSPG isolated...

  12. Membraner

    DEFF Research Database (Denmark)

    Bach, Finn

    2009-01-01

    Notatet giver en kort introduktion til den statiske virkemåde af membraner og membrankonstruktioner......Notatet giver en kort introduktion til den statiske virkemåde af membraner og membrankonstruktioner...

  13. [Irritative effect of aclacinomycin A on the eye mucous membrane, skin and muscle (author's transl)].

    Science.gov (United States)

    Ohmori, K; Hirano, S; Kiyosaki, T; Hori, S; Tone, H

    1980-04-01

    Aclacinomycin A, a new anthracycline antitumor antibiotic, was given to rabbits by single instillation or single intracutaneous injection and to guinea pigs by single subcutaneous or intramuscular injection to examine the irritative effect. Slight dilatation of blood vessel and swelling in the conjunctiva and nictitating membrane were observed in the eyes of rabbits given 1% solution. Edema in the bulbar conjunctiva, iris and cornea was histologically noted. Washing of the eyes after drug instillation prevented these damages. Subcutaneous and intracutaneous injections of 1% solution (0.2 ml) gave hyperemia, swelling and necrosis at injection site. Cellular infiltration, fibrosis and necrosis were histologically detected. Intramuscular injection of 1% solution (0.2 ml) also provided induration and swelling at injection site. Histologically cellular infiltration and necrosis were observed. These irritative effects were much slighter in administration of 0.1% solution. No change was observed with 0.01% solution.

  14. The stratified two-sided jet of Cygnus A. Acceleration and collimation

    CERN Document Server

    Boccardi, B; Bach, U; Mertens, F; Ros, E; Alef, W; Zensus, J A

    2016-01-01

    High-resolution Very-Long-Baseline Interferometry observations of relativistic jets are essential to constrain fundamental parameters of jet formation models. At a distance of 249 Mpc, Cygnus A is a unique target for such studies, being the only Fanaroff-Riley Class II radio galaxy for which a detailed sub-parsec scale imaging of the base of both jet and counter-jet can be obtained. Observing at millimeter wavelengths unveils those regions which appear self-absorbed at longer wavelengths and enables an extremely sharp view towards the nucleus to be obtained. We performed 7 mm Global VLBI observations, achieving ultra-high resolution imaging on scales down to 90 $\\mu$as. This resolution corresponds to a linear scale of only ${\\sim}$400 Schwarzschild radii (for $M_{\\mathrm{BH}}=2.5 \\times 10^9 M_{\\odot}$). We studied the kinematic properties of the main emission features of the two-sided flow and probed its transverse structure through a pixel-based analysis. We suggest that a fast and a slow layer, with differ...

  15. Chaotic-periodic transition in a two-sided minority game

    Science.gov (United States)

    Li, Xiao-Hui; Yang, Guang; Huang, Ji-Ping

    2016-08-01

    Phase transitions are being used increasingly to probe the collective behaviors of social human systems. In this study, we propose a different way of investigating such transitions in a human system by establishing a two-sided minority game model. A new type of agents who can actively transfer resources are added to our artificial bipartite resource-allocation market. The degree of deviation from equilibria is characterized by the entropy-like quantity of market complexity. Under different threshold values, Q th , two phases are found by calculating the exponents of the associated power spectra. For large values of Q th , the general motion of strategies for the agents is relatively periodic whereas for low values of Q th , the motion becomes chaotic. The transition occurs abruptly at a critical value of Q th . Our simulation results were also tested based on human experiments. The results of this study suggest that a chaotic-periodic transition related to the quantity of market information should exist in most bipartite markets, thereby allowing better control of such a transition and providing a better understanding of the endogenous emergence of business cycles from the perspective of quantum mechanics.

  16. Three--dimensional Instability in the Wake of Two Side--by--side Square Cylinders

    Science.gov (United States)

    Choi, Choon-Bum; Jang, Yong-Jun; Yang, Kyung-Soo

    2011-11-01

    Three-dimensional instability in the flow past two square cylinders in side-by-side arrangements has been numerically studied via a Floquet stability analysis. The distance between the neighboring faces of the two cylinders (G) is the key parameter which affects the secondary instability under consideration. In this talk, we present the critical Reynolds number for the 3D instability and the spanwise wave number corresponding to the most unstable (or least stable) wave for each G. When the two cylinders are close to each other, the Floquet mode resembles mode A of flow past a single cylinder. For large G, the Floquet mode for each cylinder is independent of the neighboring cylinder as expected. In the range of intermediate G, interference of the two wakes is clearly reflected in the Floquet mode. We also discuss about the effect of gap flow, and visualization of the dominant 3D vortical structures is provided by using Q contours. Our results shed light on a complete understanding of the onset of 3D instability in the presence of two side-by-side square cylinders. This work was supported by Korea Railroad Research Institute (Research Title: The study of standardization for urban railway facilities (SW 11002)).

  17. Low contrast detectability of a new CR system with two-sided reading

    Energy Technology Data Exchange (ETDEWEB)

    Katou, Toyoyuki; Ogawa, Kazuhisa; Umezu, Yoshiyuki; Kinoshita, Emi; Shinkai, Eishu [Kyushu Univ., Fukuoka (Japan). Hospital; Ohki, Masafumi; Toyofuku, Fukai; Higashida, Yoshiharu [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine

    2003-03-01

    A new imaging plate (IP) with a transparent support and reading system that can detect emissions from both sides of the IP has been developed and has already been introduced in some facilities. In this study, low contrast threshold detectability was investigated experimentally for a CR system with a two-sided reading system (new CR) and for a conventional CR system. Images of a Contrast-Detail phantom were obtained with the new and conventional CR systems at dose levels corresponding to 26%, 49%, 82%, 103%, and 164% of the dose used for the screen-film system. Using an observer performance study of Contrast-Detail phantom images, the threshold contrast of disk-shaped objects ranging from 0.3 mm to 4.0 mm in diameter was determined. We also calculated image quality figure (IQF) from the results of observation. The new CR system showed significantly better contrast detectability than the conventional CR system. The use of a new CR system provided a reduction of approximately 25% in radiographic dose while providing comparable IQF. (author)

  18. Behavioral and neural responses of toads to salt solutions correlate with basolateral membrane potential of epidermal cells of the skin.

    Science.gov (United States)

    Hillyard, Stanley D; Baula, Victor; Tuttle, Wendy; Willumsen, Niels J; Larsen, Erik H

    2007-10-01

    Dehydrated toads initiated water absorption response (WR) behavior and absorbed water from dilute NaCl solutions. With 200-250 mM NaCl, WR behavior and water absorption were both suppressed. With 200-250 mM Na-gluconate, WR initiation was significantly greater than with NaCl but water loss was greater. Neural recordings from spinal nerve #6 showed a greater integrated response to 250 mM NaCl than to 250 mM Na-gluconate, whereas a larger rinse response was seen with Na-gluconate. Studies with isolated epithelium showed a large increase in conductance (G(t)) when 250 mM NaCl replaced NaCl Ringer's as the apical bathing solution that was accompanied by depolarization of the transepithelial potential (V(t)) and basolateral membrane potential (V(b)). Depolarization of V(b) corresponded with the neural response to 250 mM NaCl. When 250 mM Na-gluconate replaced Ringer's as the apical solution G(t) remained low, V(b) transiently hyperpolarized to values near the equilibrium potential for K(+) and corresponded with the reduced neural response. These results support the hypothesis that chemosensory function of the skin is analogous to that of mammalian taste cells but utilizes paracellular ion transport to a greater degree.

  19. Effects of oxygen-containing terpenes as skin permeation enhancers on the lipoidal pathways of human epidermal membrane.

    Science.gov (United States)

    Chantasart, Doungdaw; Pongjanyakul, Thaned; Higuchi, William I; Li, S Kevin

    2009-10-01

    The present study investigated the effects of oxygen-containing terpenes as skin permeation enhancers on the lipoidal pathways of human epidermal membrane (HEM). The enhancement (E(HEM)) effects of menthol, thymol, carvacrol, menthone, and cineole on the transport of a probe permeant, corticosterone, across HEM were determined. It was found that the enhancer potencies of menthol, thymol, carvacrol, and menthone were essentially the same and higher than that of cineole based on their aqueous concentration in the diffusion cell chamber at E(HEM) = 4. Thymol and carvacrol also had the same E(HEM) = 10 concentration further supporting that they had the same enhancer potency based on the aqueous concentration. The uptake amounts of terpene into the HEM stratum corneum (SC) intercellular lipid under the same conditions indicate that the intrinsic potencies of the studied terpenes are the same based on their concentration in the SC and similar to those of n-alkanol and n-alkylphenyl alcohol. Moreover, they are all better enhancers compared to branched-chain alkanol. The approximately same uptake enhancement of beta-estradiol induced by the studied terpenes and alcohols at E(HEM) conditions into the SC intercellular lipids suggests that the mechanism of enhancement action for the terpenes and those of alcohols are essentially the same.

  20. Indirect two-sided relative ranking: a robust similarity measure for gene expression data

    Directory of Open Access Journals (Sweden)

    Licamele Louis

    2010-03-01

    Full Text Available Abstract Background There is a large amount of gene expression data that exists in the public domain. This data has been generated under a variety of experimental conditions. Unfortunately, these experimental variations have generally prevented researchers from accurately comparing and combining this wealth of data, which still hides many novel insights. Results In this paper we present a new method, which we refer to as indirect two-sided relative ranking, for comparing gene expression profiles that is robust to variations in experimental conditions. This method extends the current best approach, which is based on comparing the correlations of the up and down regulated genes, by introducing a comparison based on the correlations in rankings across the entire database. Because our method is robust to experimental variations, it allows a greater variety of gene expression data to be combined, which, as we show, leads to richer scientific discoveries. Conclusions We demonstrate the benefit of our proposed indirect method on several datasets. We first evaluate the ability of the indirect method to retrieve compounds with similar therapeutic effects across known experimental barriers, namely vehicle and batch effects, on two independent datasets (one private and one public. We show that our indirect method is able to significantly improve upon the previous state-of-the-art method with a substantial improvement in recall at rank 10 of 97.03% and 49.44%, on each dataset, respectively. Next, we demonstrate that our indirect method results in improved accuracy for classification in several additional datasets. These datasets demonstrate the use of our indirect method for classifying cancer subtypes, predicting drug sensitivity/resistance, and classifying (related cell types. Even in the absence of a known (i.e., labeled experimental barrier, the improvement of the indirect method in each of these datasets is statistically significant.

  1. Intrinsic features of flow around two side-by-side square cylinders

    Science.gov (United States)

    Alam, Md. Mahbub; Zhou, Y.

    2013-08-01

    The wake of two side-by-side square cylinders is investigated in detail based on flow visualization at a Reynolds number (Re) of 300. The cylinder center-to-center spacing ratio T* (= T/W, W is the cylinder width) is varied from 1.0 to 5.0. The intrinsic features of the wake are explored, including the gap vortices, flow switch, stability, merging of two streets into one, etc. The qualitative information on these features is further complemented by the quantitative information extracted from hotwire data at Re = 4.7 × 104 using both spectral and cross-wavelet analyses. Four flow regimes are identified: (i) the single bluff body regime (T* 2.4). The gap flow is found to switch at two distinct time scales, referred to as macro and micro switches. Macro switch occurs at 1.2 gap flow is slim in width and biased for a long duration ranging from several vortex shedding periods in the wide street to several hours. Micro switch is observed at 2.1 gap flow is thick in width and switches at a frequency of twice the frequency of vortex shedding from the free-stream side of the cylinders. The two streets formed immediately behind the cylinders merge to a single street at a downstream location x_c^* that depends on T*. A larger T* corresponds to a larger x_c^*. Regime (iv) is characterized by two streets either inphased or antiphased. The antiphased streets persist longer than the inphased.

  2. Laboratory Research on Effective Test Area of Short-Crested Waves Generated by Two-Sided Segmented Wavemakers

    Institute of Scientific and Technical Information of China (English)

    李俊; 陈刚; 杨建民; 彭涛

    2014-01-01

    The size and shape of the effective test area are crucial to consider when short-crested waves are created by segmented wavemakers. The range of the effective test area of short-crested waves simulated by two-sided segmented wavemakers is analyzed in this paper. The experimental investigation on the wave field distribution of short-crested waves generated by two-sided segmented wavemakers is conducted by using an array of wave gauges. Wave spectra and directional spreading function are analyzed and the results show that when the main direction is at a certain angle with the normal line of wave generators, the wave field of 3D short-crested waves generated by two-sided segmented wavemakers has good spatial uniformity within the model test area. The effective test area can provide good wave environments for seakeeping model tests of various ocean engineering structures in the deep ocean engineering basin.

  3. The role of the trans double bond in skin barrier sphingolipids: permeability and infrared spectroscopic study of model ceramide and dihydroceramide membranes.

    Science.gov (United States)

    Skolová, Barbora; Jandovská, Kateřina; Pullmannová, Petra; Tesař, Ondřej; Roh, Jaroslav; Hrabálek, Alexandr; Vávrová, Kateřina

    2014-05-20

    Dihydroceramides (dCer) are members of the sphingolipid family that lack the C4 trans double bond in their sphingoid backbone. In addition to being precursors of ceramides (Cer) and phytoceramides, dCer have also been found in the extracellular lipid membranes of the epidermal barrier, the stratum corneum. However, their role in barrier homeostasis is not known. We studied how the lack of the trans double bond in dCer compared to Cer influences the permeability, lipid chain order, and packing of multilamellar membranes composed of the major skin barrier lipids: (d)Cer, fatty acids, cholesterol, and cholesteryl sulfate. The permeability of the membranes with long-chain dCer was measured using various markers and was either comparable to or only slightly greater than (by up to 35%, not significant) that of the Cer membranes. The dCer were less sensitive to acyl chain shortening than Cer (the short dCer membranes were up to 6-fold less permeable that the corresponding short Cer membranes). Infrared spectroscopy showed that long dCer mixed less with fatty acids but formed more thermally stable ordered domains than Cer. The key parameter explaining the differences in permeability in the short dCer and Cer was the proportion of the orthorhombic phase. Our results suggest that the presence of the trans double bond in Cer is not crucial for the permeability of skin lipid membranes and that dCer may be underappreciated members of the stratum corneum lipid barrier that increase its heterogeneity.

  4. Development of a membrane impregnated with a poly(dimethylsiloxane)/poly(ethylene glycol) copolymer for a high-throughput screening of the permeability of drugs, cosmetics, and other chemicals across the human skin.

    Science.gov (United States)

    Miki, Ryotaro; Ichitsuka, Yasuna; Yamada, Takumi; Kimura, Soichiro; Egawa, Yuya; Seki, Toshinobu; Juni, Kazuhiko; Ueda, Hideo; Morimoto, Yasunori

    2015-01-23

    We aimed to develop a high-throughput screening (HTS) system for preliminary predictions of human skin permeability by using an artificial membrane that can mimic the permeation behaviour of lipophilic and hydrophilic compounds across the human skin. In this study, we synthesized a copolymer containing poly(dimethylsiloxane) (PDMS) and poly(ethylene glycol) (PEG) 6000 and impregnated it onto a supportive membrane filter to prepare a PDMS/PEG 6000 copolymer-impregnated membrane. In addition, we synthesized another polymer without PEG units and used it to prepare an impregnated membrane for determining the role of PEG 6000 units in the PDMS/PEG 6000 copolymer-impregnated membrane. The permeation characteristics of the impregnated membranes were evaluated on the basis of the permeability coefficients of 12 model compounds with different lipophilicities, by using a 2-chamber diffusion cell, and these permeability coefficients were compared with those across the human skin. We obtained a good correlation between the permeability coefficients across the PDMS/PEG 6000 copolymer-impregnated membrane and human skin. Further, we evaluated the permeation characteristics of a 96-well plate model of the PDMS/PEG 6000 copolymer by using 6 model compounds. We obtained an ideal correlation between the permeability coefficients across the PDMS/PEG 6000 copolymer using a 96-well plate and those across the human skin. Thus, the PDMS/PEG 6000 copolymer would be a good candidate for preliminary evaluation of the permeability of lipophilic and hydrophilic compounds across the human skin.

  5. Two Sides of the Same Coin: The Scope of Free Speech and Hate Speech in the College Community.

    Science.gov (United States)

    Schuett, Faye

    2000-01-01

    This article presents the Two Sides interviews, which confront the serious and immediate conflict between free speech and hate speech on college campuses. Dr. Robert O' Neil discusses the scope of free speech in the college community, while Dr. Timothy Shiell focuses on hate speech on campuses. Contains 12 references. (VWC)

  6. Two Sides of the Same Coin: The Scope of Free Speech and Hate Speech in the College Community.

    Science.gov (United States)

    Schuett, Faye

    2000-01-01

    This article presents the Two Sides interviews, which confront the serious and immediate conflict between free speech and hate speech on college campuses. Dr. Robert O' Neil discusses the scope of free speech in the college community, while Dr. Timothy Shiell focuses on hate speech on campuses. Contains 12 references. (VWC)

  7. Assessing Unilateral Merger Effects in a Two-Sided Market : An Application to the Dutch Daily Newspaper Market

    NARCIS (Netherlands)

    Filistrucchi, L.; Klein, T.J.; Michielsen, T.O.

    2011-01-01

    We compare different methods to assess unilateral merger effects in a two-sided market by applying them to a hypothetical merger in the Dutch newspaper industry. For this, we first specify and estimate a structural model of demand for differentiated products on both the readership and the advertisin

  8. 双边Prequantale中的Frame核映射%A Frame Nucleus on a Two-side Prequantale

    Institute of Scientific and Technical Information of China (English)

    徐少贤; 王顺钦; 马菲菲

    2004-01-01

    In this paper, a Frame nucleus and prime elements in a Prequantale are defined.The concrete structure of a Frame prequantic quotient is considered, and the relation between the half-prime element and the Frame nucleus in a two-side Prequantale are obtained.

  9. Use of a molecular form technique for the penetration of supersaturated solutions of salicylic acid across silicone membranes and human skin in vitro.

    Science.gov (United States)

    Leveque, N; Raghavan, S L; Lane, M E; Hadgraft, J

    2006-08-01

    Permeation enhancement of salicylic acid (SA) from supersaturated solutions formed using a 'molecular form' technique was investigated. In a conventional cosolvent technique, two solvents are used, one in which the drug is considerably more soluble than the other. Propylene glycol and water have been predominantly used as cosolvents to create supersaturation in skin permeation enhancement. In this paper, we report the use of buffer solutions with different pHs as media for producing different molecular forms. Supersaturated solutions were prepared using pH 8:pH 2 (80:20 v/v), which gave a nominal pH when mixed of around 5. Model silicone membranes and human skin were used. Hydroxypropyl methyl cellulose (HPMC) was employed to stabilise the supersaturated states. Stability data showed that while the SA supersaturated solutions without HPMC crystallised between 15 min and 46 h depending on the degree of supersaturation, the solutions with HPMC were stable for more than 2 months. The flux of SA increased with the degree of saturation for solutions prepared in a 80:20 buffer pH 8/buffer pH 2 mixture. Although the fluxes of SA with and without HPMC were similar both through silicone membrane and human skin, HPMC was found to be effective in increasing the stability of supersaturated solutions of SA.

  10. Evaluation of an Amniotic Membrane-Collagen Dermal Substitute in the Management of Full-Thickness Skin Defects in a Pig

    Directory of Open Access Journals (Sweden)

    Hyunji Kim

    2013-01-01

    Full Text Available BackgroundTo minimize the inflammatory reaction and improve healing, a new modified dermal substitute composed of an atelocollagen, chondroitin-6-sulfate, and amniotic membrane (AM was applied to full-thickness skin defects in a pig. Atelocollagen was extracted from bovine skin, and two modified dermal substitutes were generated according to the cross-linking type.MethodsThe AM-collagen dermal substitutes were characterized and compared with currently used dermal substitutes in a pig skin defect model. There were five experimental groups: dehydrothermal (DHT cross-linking atelocollagen with the AM on the top (AM-DHT, DHT and chemical cross-linking atelocollagen with the AM on the top (AM-DHT/chemical, Terudermis, Integra, and AlloDerm. After 3×3 cm full-thickness skin defects on the back of a pig were created, each dermal substitutes dermal substitutes was randomly grafted on the defects. Two weeks after grafting, autologous partial-thickness skin was over-grafted on the neodermis. The take rate of the dermal substitutes, skin, and histological sections were all assessed at 1, 2, and 4 weeks postoperatively.ResultsMore rapid healing and a higher take rate were evident in the AM-DHT and Terudermis groups. Histological examination revealed fewer inflammatory cells and more fibroblast hyperplasia in these two groups. Four weeks after surgery, the amount of newly formed collagen was significantly more appropriate in the AM-DHT group.ConclusionsThese observations provide supporting evidence that a newly developed amniotic-collagen dermal substitute may inhibit inflammatory reactions and promote wound healing.

  11. Matriptase and prostasin are expressed in human skin in an inverse trend over the course of differentiation and are targeted to different regions of the plasma membrane

    Directory of Open Access Journals (Sweden)

    Chih-Hsin Lai

    2016-10-01

    Full Text Available Matriptase and prostasin, acting as a tightly coupled proteolytic cascade, were reported to be required for epidermal barrier formation in mouse skin. Here we show that, in human skin, matriptase and prostasin are expressed with an inverse pattern over the course of differentiation. Matriptase was detected primarily in epidermal basal keratinocytes and the basaloid cells in the outer root sheath of hair follicles and the sebaceous gland, where prostasin was not detected. In contrast, prostasin was detected primarily in differentiated cells in the epidermal granular layer, the inner root sheath of hair follicles, and the sebaceous gland, where matriptase expression is negligible. While co-expressed in the middle stage of differentiation, prostasin was detected as polarized patches, and matriptase at intercellular junctions. Targeting to different subcellular localizations is also observed in HaCaT human keratinocytes, in which matriptase was detected primarily at intercellular junctions, and prostasin primarily on membrane protrusion. Furthermore, upon induction of zymogen activation, free active prostasin remains cell-associated and free active matriptase is rapidly shed into the extracellular milieu. Our data suggest that matriptase and prostasin likely function as independent entities in human skin rather than as a tightly coupled proteolytic cascade as observed in mouse skin.

  12. Matriptase and prostasin are expressed in human skin in an inverse trend over the course of differentiation and are targeted to different regions of the plasma membrane

    Science.gov (United States)

    Lai, Chih-Hsin; Chang, Shun-Cheng; Chen, Yen-Ju; Wang, Yi-Jie J.; Lai, Ying-Jun J.; Chang, Hsiang-Hua D.; Berens, Eric B.; Johnson, Michael D.; Wang, Jehng-Kang; Lin, Chen-Yong

    2016-01-01

    ABSTRACT Matriptase and prostasin, acting as a tightly coupled proteolytic cascade, were reported to be required for epidermal barrier formation in mouse skin. Here we show that, in human skin, matriptase and prostasin are expressed with an inverse pattern over the course of differentiation. Matriptase was detected primarily in epidermal basal keratinocytes and the basaloid cells in the outer root sheath of hair follicles and the sebaceous gland, where prostasin was not detected. In contrast, prostasin was detected primarily in differentiated cells in the epidermal granular layer, the inner root sheath of hair follicles, and the sebaceous gland, where matriptase expression is negligible. While co-expressed in the middle stage of differentiation, prostasin was detected as polarized patches, and matriptase at intercellular junctions. Targeting to different subcellular localizations is also observed in HaCaT human keratinocytes, in which matriptase was detected primarily at intercellular junctions, and prostasin primarily on membrane protrusion. Furthermore, upon induction of zymogen activation, free active prostasin remains cell-associated and free active matriptase is rapidly shed into the extracellular milieu. Our data suggest that matriptase and prostasin likely function as independent entities in human skin rather than as a tightly coupled proteolytic cascade as observed in mouse skin. PMID:27543057

  13. Chlamydia trachomatis infection and anti-Hsp60 immunity: the two sides of the coin.

    Directory of Open Access Journals (Sweden)

    Francesco Cappello

    2009-08-01

    Full Text Available Chlamydia trachomatis (CT infection is one of the most common causes of reproductive tract diseases and infertility. CT-Hsp60 is synthesized during infection and is released in the bloodstream. As a consequence, immune cells will produce anti-CT-Hsp60 antibodies. Hsp60, a ubiquitous and evolutionarily conserved chaperonin, is normally sequestered inside the cell, particularly into mitochondria. However, upon cell stress, as well as during carcinogenesis, the chaperonin becomes exposed on the cell surface (sf-Hsp60 and/or is secreted from cells into the extracellular space and circulation. Reports in the literature on circulating Hsp and anti-Hsp antibodies are in many cases short on details about Hsp60 concentrations, and about the specificity spectra of the antibodies, their titers, and their true, direct, pathogenetic effects. Thus, more studies are still needed to obtain a definitive picture on these matters. Nevertheless, the information already available indicates that the concurrence of persistent CT infection and appearance of sf-Hsp60 can promote an autoimmune aggression towards stressed cells and the development of diseases such as autoimmune arthritis, multiple sclerosis, atherosclerosis, vasculitis, diabetes, and thyroiditis, among others. At the same time, immunocomplexes composed of anti-CT-Hsp60 antibodies and circulating Hsp60 (both CT and human may form deposits in several anatomical locations, e.g., at the glomerular basal membrane. The opposite side of the coin is that pre-tumor and tumor cells with sf-Hsp60 can be destroyed with participation of the anti-Hsp60 antibody, thus stopping cancer progression before it is even noticed by the patient or physician.

  14. Chlamydia trachomatis infection and anti-Hsp60 immunity: the two sides of the coin.

    Directory of Open Access Journals (Sweden)

    Francesco Cappello

    2009-08-01

    Full Text Available Chlamydia trachomatis (CT infection is one of the most common causes of reproductive tract diseases and infertility. CT-Hsp60 is synthesized during infection and is released in the bloodstream. As a consequence, immune cells will produce anti-CT-Hsp60 antibodies. Hsp60, a ubiquitous and evolutionarily conserved chaperonin, is normally sequestered inside the cell, particularly into mitochondria. However, upon cell stress, as well as during carcinogenesis, the chaperonin becomes exposed on the cell surface (sf-Hsp60 and/or is secreted from cells into the extracellular space and circulation. Reports in the literature on circulating Hsp and anti-Hsp antibodies are in many cases short on details about Hsp60 concentrations, and about the specificity spectra of the antibodies, their titers, and their true, direct, pathogenetic effects. Thus, more studies are still needed to obtain a definitive picture on these matters. Nevertheless, the information already available indicates that the concurrence of persistent CT infection and appearance of sf-Hsp60 can promote an autoimmune aggression towards stressed cells and the development of diseases such as autoimmune arthritis, multiple sclerosis, atherosclerosis, vasculitis, diabetes, and thyroiditis, among others. At the same time, immunocomplexes composed of anti-CT-Hsp60 antibodies and circulating Hsp60 (both CT and human may form deposits in several anatomical locations, e.g., at the glomerular basal membrane. The opposite side of the coin is that pre-tumor and tumor cells with sf-Hsp60 can be destroyed with participation of the anti-Hsp60 antibody, thus stopping cancer progression before it is even noticed by the patient or physician.

  15. Analysis on Granular Two-sided Market%颗粒化双边市场分析

    Institute of Scientific and Technical Information of China (English)

    刘钰碧; 徐晓峰; 朱卫未

    2016-01-01

    The common value orientation makes the main reason that maintains stickiness of social network platform user. User with powerful stickiness creates granular two-sided market by design the business model elaborates on the social network. This thesis research the granular two-sided market,try discusses its generation, development, prospective and business model.%在社交平台中共同的价值取向是保持用户黏性的主要原因。在精确设计的商业模式引导下,具有强黏性的用户会通过社交平台形成颗粒化的双边市场。文章探讨了颗粒化双边市场的产生、发展以及前景,并对其商业模式进行了阐述。

  16. The role of two-sided splinting for recalcitrant paediatric post-burn hand flexion contracture: a case report.

    Science.gov (United States)

    Prasetyono, Toh; Caroline, I

    2017-07-01

    A 2-year-old boy presented to the plastic and reconstructive surgery outpatient clinic with bilateral post-burn hand flexion contracture. The contracture had been released twice elsewhere. The third surgical repair on one hand at a time was conducted by the author (TOHP). However, inadeq.uate compliance to the postoperative splinting and exercise led to the recurrence of the contracture in the following year. A customised two-sided splint was therefore created to ensure proper placement and compliance. Reinforcement to the parents to encourage the boy to practise active exercise on demand was also an integral part of the management. Good functional and cosmetic outcome were presented at 1-year follow-up. This case highlights the value of a two-sided splint for the management of post-burn hand flexion contracture in children whose compliance is inevitably cannot be guaranteed.

  17. The effect of curve sawing two-sided cants from small diameter hardwood sawlogs on lumber and pallet part yields

    Science.gov (United States)

    Peter Hamner; Marshall S. White; Philip A. Araman

    2006-01-01

    Curve sawing is a primary log breakdown process that incorporates gang-saw technology to allow two-sided cants from logs with sweep to be cut parallel to the log surface or log axis. Since curve-sawn logs with sweep are cut along the grain, the potential for producing high quality straight-grain lumber and cants increases, and strength, stiffness, and dimensional...

  18. Impurity-defect structure of anodic aluminum oxide produced by two-sided anodizing in tartaric acid

    Science.gov (United States)

    Chernyakova, K. V.; Vrublevsky, I. A.; Ivanovskaya, M. I.; Kotsikau, D. A.

    2012-03-01

    Porous aluminum oxide is prepared in a 0.4 M aqueous solution of tartaric acid by two-sided anodizing. Fourier Transform IR spectroscopy (FTIR) data reveal the presence, in the alumina, of unoxidized tartarate ions, as well as products of their partial (radical organic products and CO) and complete (CO2) oxidation. Carboxylate ions and elemental carbon contained in the anodic oxide impart a gray color to the films.

  19. Sagging Skin

    Science.gov (United States)

    ... Skin Scars Skin Growths Skin Lesions Spider Veins Stretch Marks Sun-damaged Skin Unwanted Hair Unwanted Tattoos Varicose ... Skin Scars Skin Growths Skin Lesions Spider Veins Stretch Marks Sun-damaged Skin Unwanted Hair Unwanted Tattoos Varicose ...

  20. Fit of fluxes of sunscreens and other compounds from propylene glycol:water (30:70) through human skin and silicone membrane to the Roberts-Sloan equation: the effect of polar vehicle (or water) solubility.

    Science.gov (United States)

    Sloan, Kenneth B; Devarajan-Ketha, Hemamalini; Synovec, Jennifer; Majumdar, Susruta

    2013-01-01

    It would be useful to develop a surrogate for animal skin, which could be use to predict flux through human skin. The fluxes (and physicochemical properties) of sunscreens and other compounds from propylene glycol (PG):water (AQ), 30:70, through human skin have previously been reported. We measured the fluxes of several of those sunscreens and other compounds from PG:AQ, 30:70, through silicone membrane and fit both sets of data to the Roberts-Sloan (RS) equation to determine any similarities. For both sets of data, the fluxes were directly dependent on their solubilities in a lipid solvent [octanol (OCT), in this case] and in a polar solvent (PG:AQ, 30:70, or AQ in this case) and inversely on their molecular weights. The fit of the experimental (EXP) fluxes through human skin in vivo to RS was excellent: r² = 0.92 if the vehicle (VEH) PG:AQ, 30:70 was the polar solvent (RS¹) or r² = 0.97 if water was the polar solvent (RS²). The fit of the EXP fluxes through silicone membrane to RS was good: r² = 0.80 if the VEH PG:AQ, 30:70, was the polar solvent (RS¹) or r² = 0.81 if water was the polar solvent (RS²). The correlations between their EXP fluxes through human skin in vivo and their EXP fluxes through silicone membrane were good (r² = 0.85). In addition, the correlation between EXP fluxes from PG:AQ, 30:70, through human skin in vivo and their fluxes calculated from the coefficients of the fit of solubilities, molecular weights and fluxes from water through silicone membranes from a previous n = 22 database to RS was even better (r² = 0.94). These results suggest that flux through human skin can be calculated from flux through a silicone membrane.

  1. Folded structure and insertion depth of the frog-skin antimicrobial Peptide esculentin-1b(1-18) in the presence of differently charged membrane-mimicking micelles.

    Science.gov (United States)

    Manzo, Giorgia; Casu, Mariano; Rinaldi, Andrea C; Montaldo, Nicola P; Luganini, Anna; Gribaudo, Giorgio; Scorciapino, Mariano A

    2014-11-26

    Antimicrobial peptides (AMPs) are effectors of the innate immunity of most organisms. Their role in the defense against pathogen attack and their high selectivity for bacterial cells make them attractive for the development of a new class of antimicrobial drugs. The N-terminal fragment of the frog-skin peptide esculentin-1b (Esc(1-18)) has shown broad-spectrum antimicrobial activity. Similarly to most cationic AMPs, it is supposed to act by binding to and damaging the negatively charged plasma membrane of bacteria. Differently from many other AMPs, Esc(1-18) activity is preserved in biological fluids such as serum. In this work, a structural investigation was performed through NMR spectroscopy. The 3D structure was obtained in the presence of either zwitterionic or negatively charged micelles as membrane models for eukaryotic and prokaryotic membranes, respectively. Esc(1-18) showed a higher affinity for and deeper insertion into the latter and adopted an amphipathic helical structure characterized by a kink at the residue G8. These findings were confirmed by measuring penetration into lipid monolayers. The presence of negatively charged lipids in the bilayer appears to be necessary for Esc(1-18) to bind, to fold in the right three-dimensional structure, and, ultimately, to exert its biological role as an AMP.

  2. Influence of Feed Speed on the Content of Fine Dust during Cutting of Two-Side-Laminated Particleboards

    Directory of Open Access Journals (Sweden)

    Luďka Hlásková

    2016-03-01

    Full Text Available This paper deals with the problems of wood dust production during the sawing of two-side-laminated particleboards. It points out the dangerous impact of wood dust particles on people´s health and other unfavourable influences in the working environment. The aim of the paper was to introduce the research of dustiness, to determine the content of fine particles in sawdust and analyse the influence of feed rate on the granularity of sawdust created in the process of sawing two-side-laminated particleboards using modern circular saw. Sawing parameters were chosen for the optimal cutting speed of the circular-saw blade Pilana TFZL, vc = 84.3 m·s-1 and for three feed rates of a workpiece with the cut vf = 10, 15, 20 m·min-1. The collected sawdust particles were subjected to the particle-size analysis under exactly defined conditions by sieving and the basic granulometric analysis was made. Sieve analysis gives only a general particle-size distribution without any information considering the mass concentration of fine fraction of dust. Therefore, laser particle sizer Analysette 22 Microtec Plus was used to specify details concerning the size of dust particles smaller than 63 μm, which were collected in the bottom collector.

  3. Preliminary Study on Heavy Metal Pollution Status of Farmland Soil at Two Sides of Cheng-Guan Expressway

    Institute of Scientific and Technical Information of China (English)

    Dongli; DUAN; Shuangyan; WANG; Zumin; ZHANG; Zhouping; YANG; Hua; ZHEN

    2013-01-01

    The heavy metal content of the farmland soil at two sides of Cheng-Guan Expressway is measured to make a preliminary evaluation on its heavy metal pollution status.After digestion and volume fixation of the soil samples collected,measure the Cu,Zn,Cd,Pb and Cr content with atomic absorption spectrophotometry and evaluate the measured data according to Level Two of National Soil Environmental Quality Standard to obtain the contamination status.Cu,Zn and Cd content of the farmland soil for sections of Cheng-Guan Expressway goes beyond Level Two of National Soil Environmental Quality Standard,while the Pb and Cr content meets Level Two of National Soil Environmental Quality Standard.Pb and Cr content of the farmland soil at two sides of Cheng-Guan Expressway is in safe state,while the Cu,Zn and Cd content is in a mild contamination state.Cu,Zn and Cd are the main pollution elements.

  4. Ultrastructural localization of the core protein of a basement membrane-specific chondroitin sulfate proteoglycan in adult rat skin

    DEFF Research Database (Denmark)

    McCarthy, K J; Horiguchi, Y; Couchman, J R

    1990-01-01

    Basement membranes are complex extracellular matrices present at epithelial/mesenchymal interfaces of tissues. The dermal-epidermal junction has been shown to contain numerous components, some of the most well known being laminin, types IV and VII collagens, heparan sulfate proteoglycan, fibronec...

  5. Complexation induced phase separation: preparation of composite membranes with a nanometer thin dense skin loaded with metal ions

    KAUST Repository

    Villalobos Vazquez de la Parra, Luis Francisco

    2015-04-21

    We present the development of a facile phase-inversion method for forming asymmetric membranes with a precise high metal ion loading capacity in only the dense layer. The approach combines the use of macromolecule-metal intermolecular complexes to form the dense layer of asymmetric membranes with nonsolvent-induced phase separation to form the porous support. This allows the independent optimization of both the dense layer and porous support while maintaining the simplicity of a phase-inversion process. Moreover, it facilitates control over (i) the thickness of the dense layer throughout several orders of magnitude—from less than 15 nm to more than 6 μm, (ii) the type and amount of metal ions loaded in the dense layer, (iii) the morphology of the membrane surface, and (iv) the porosity and structure of the support. This simple and scalable process provides a new platform for building multifunctional membranes with a high loading of well-dispersed metal ions in the dense layer.

  6. Complexation-induced phase separation: preparation of composite membranes with a nanometer-thin dense skin loaded with metal ions.

    Science.gov (United States)

    Villalobos, Luis Francisco; Karunakaran, Madhavan; Peinemann, Klaus-Viktor

    2015-05-13

    We present the development of a facile phase-inversion method for forming asymmetric membranes with a precise high metal ion loading capacity in only the dense layer. The approach combines the use of macromolecule-metal intermolecular complexes to form the dense layer of asymmetric membranes with nonsolvent-induced phase separation to form the porous support. This allows the independent optimization of both the dense layer and porous support while maintaining the simplicity of a phase-inversion process. Moreover, it facilitates control over (i) the thickness of the dense layer throughout several orders of magnitude from less than 15 nm to more than 6 μm, (ii) the type and amount of metal ions loaded in the dense layer, (iii) the morphology of the membrane surface, and (iv) the porosity and structure of the support. This simple and scalable process provides a new platform for building multifunctional membranes with a high loading of well-dispersed metal ions in the dense layer.

  7. Determinants of effective tax rates for firms listed on Chinese stock market: Panel models with two-sided censors

    Directory of Open Access Journals (Sweden)

    Yong-Ching Chiou

    2014-10-01

    Full Text Available This paper is to investigate the determinants effective tax rate for the firms listed on China’s stock markets. The panel data consists of 481 firms from 2007 to 2009 as our empirical data. In order to illustrate a country’s tax policies on firms’ real tax burdens, the dependent variable, ETR, is left-censored at 0 and right-censored at 1, the estimation for panel data model with two-sided censoring suggested by Alan, Honor´e, and Leth-Petersen (2014 is implemented in this paper. There are two important findings are obtained: first, this model can add more observations especially the observations with tax preferences. Second, theories suggest that ETR reflects outcomes of tax preference and this paper is the first time to consider the effective tax rates set between 0 and 1 and this range is more meaningful for the ETRs.

  8. Two sides of one coin: massive hepatic necrosis and progenitor cell-mediated regeneration in acute liver failure.

    Science.gov (United States)

    Weng, Hong-Lei; Cai, Xiaobo; Yuan, Xiaodong; Liebe, Roman; Dooley, Steven; Li, Hai; Wang, Tai-Ling

    2015-01-01

    Massive hepatic necrosis is a key event underlying acute liver failure, a serious clinical syndrome with high mortality. Massive hepatic necrosis in acute liver failure has unique pathophysiological characteristics including extremely rapid parenchymal cell death and removal. On the other hand, massive necrosis rapidly induces the activation of liver progenitor cells, the so-called "second pathway of liver regeneration." The final clinical outcome of acute liver failure depends on whether liver progenitor cell-mediated regeneration can efficiently restore parenchymal mass and function within a short time. This review summarizes the current knowledge regarding massive hepatic necrosis and liver progenitor cell-mediated regeneration in patients with acute liver failure, the two sides of one coin.

  9. Two-sided reflected Markov-modulated Brownian motion with applications to fluid queues and dividend payouts

    CERN Document Server

    D'Auria, Bernardo

    2011-01-01

    In this paper we study a reflected Markov-modulated Brownian motion with a two sided reflection in which the drift, diffusion coefficient and the two boundaries are (jointly) modulated by a finite state space irreducible continuous time Markov chain. The goal is to compute the stationary distribution of this Markov process, which in addition to the complication of having a stochastic boundary can also include jumps at state change epochs of the underlying Markov chain because of the boundary changes. We give the general theory and then specialize to the case where the underlying Markov chain has two states. Moreover, motivated by an application of optimal dividend strategies, we consider the case where the lower barrier is zero and the upper barrier is subject to control. In this case we generalized earlier results from the case of a reflected Brownian motion to the Markov modulated case.

  10. First 3 mm-VLBI imaging of the two-sided jet in Cygnus A. Zooming into the launching region

    CERN Document Server

    Boccardi, B; Bach, U; Bremer, M; Zensus, J A

    2016-01-01

    We present for the first time Very-Long-Baseline Interferometry images of the radio galaxy Cygnus A at the frequency of $86$ $\\rm GHz$. Thanks to the high spatial resolution of only ${\\sim}200$ Schwarzschild radii ($R_{\\bf S}$), such observations provide an extremely detailed view of the nuclear regions in this archetypal object and allow us to derive important constraints for theoretical models describing the launching of relativistic jets. A pixel-based analysis of the jet outflow, which still appears two-sided on the scales probed, was performed. By fitting Gaussian functions to the transverse intensity profiles, we could determine the jet width in the nuclear region. The base of the jets appears wide. The minimum measured transverse width of ${\\sim} (227\\pm98)$ $R_{\\bf S}$ is significantly larger than the radius of the Innermost Stable Circular Orbit, suggesting that the outer accretion disk is contributing to the jet launching. The existence of a faster and Doppler de-boosted inner section, powered eithe...

  11. Evasion and Immuno-Endocrine Regulation in Parasite Infection: Two Sides of the Same Coin in Chagas Disease?

    Science.gov (United States)

    Morrot, Alexandre; Villar, Silvina R.; González, Florencia B.; Pérez, Ana R.

    2016-01-01

    Chagas disease is a serious illness caused by the protozoan parasite Trypanosoma cruzi. Nearly 30% of chronically infected people develop cardiac, digestive, or mixed alterations, suggesting a broad range of host-parasite interactions that finally impact upon chronic disease outcome. The ability of T. cruzi to persist and cause pathology seems to depend on diverse factors like T. cruzi strains, the infective load and the route of infection, presence of virulence factors, the parasite capacity to avoid protective immune response, the strength and type of host defense mechanisms and the genetic background of the host. The host-parasite interaction is subject to a constant neuro-endocrine regulation that is thought to influence the adaptive immune system, and as the infection proceeds it can lead to a broad range of outcomes, ranging from pathogen elimination to its continued persistence in the host. In this context, T. cruzi evasion strategies and host defense mechanisms can be envisioned as two sides of the same coin, influencing parasite persistence and different outcomes observed in Chagas disease. Understanding how T. cruzi evade host's innate and adaptive immune response will provide important clues to better dissect mechanisms underlying the pathophysiology of Chagas disease. PMID:27242726

  12. Coupling Motion and Energy Harvesting of Two Side-by-Side Flexible Plates in a 3D Uniform Flow

    Directory of Open Access Journals (Sweden)

    Dibo Dong

    2016-05-01

    Full Text Available The fluid-structure interaction problems of two side-by-side flexible plates with a finite aspect ratio in a three-dimensional (3D uniform flow are numerically studied. The plates’ motions are entirely passive under the force of surrounding fluid. By changing the aspect ratio and transverse distance, the coupling motions, drag force and energy capture performance are analyzed. The mechanisms underlying the plates’ motion and flow characteristics are discussed systematically. The adopted algorithm is verified and validated by the simulation of flow past a square flexible plate. The results show that the plate’s passive flapping behavior contains transverse and spanwise deformation, and the flapping amplitude is proportional to the aspect ratio. In the side-by-side configuration, three distinct coupling modes of the plates’ motion are identified, including single-plate mode, symmetrical flapping mode and decoupled mode. The plate with a lower aspect ratio may suffer less drag force and capture less bending energy than in the isolated situation. The optimized selection for obtaining higher energy conversion efficiency is the plate flapping in single-plate mode, especially the plate with a higher aspect ratio. The findings of this work provide several new physical insights into the understanding of fish schooling and are expected to inspire the developments of underwater robots or energy harvesters.

  13. Two side liquid-cooled and passively Q-switched disk oscillator with nanosheets in flowing CCl4

    Science.gov (United States)

    Nie, Rongzhi; She, Jiangbo; Li, Dongdong; Li, Fuli; Peng, Bo

    2016-09-01

    A passively Q-switched and two side liquid-cooled Nd:YAG disk oscillator is demonstrated, which is operated at a pump pulse width of 300 μs and a pump repetition rate of 10 Hz. The coolant flows over the two large surfaces of the disk and will be passed through by laser beam, so it can also serve as a saturable absorber. For the unmodulated laser, the pure CCl4 was employed as coolant and a plane output mirror of 15 % transmission was employed. The maximum output energy of 795 mJ is realized corresponding to the optical-optical efficiency of 27.4 % and the slope efficiency of 30 %; for the graphene Q-switched laser, the CCl4 with graphene nanosheets was employed as coolant and a plane output mirror of 40 % transmission was employed. The maximum output energy of 376 mJ is realized corresponding to the optical-optical efficiency of 13 % and the slope efficiency of 18 %. The maximum average Q-switching repetition rate is 385 kHz, and the minimum average pulse width is 116 ns; for the MoS2 Q-switched laser, the CCl4 with MoS2 nanosheets was employed as coolant and a plane output mirror of 30 % transmission was employed. The maximum output energy of 486 mJ is realized corresponding to the optical-optical efficiency of 17 % and the slope efficiency of 22 %.The maximum average Q-switching repetition rate is 470 kHz, and the minimum average pulse width is 137 ns.

  14. 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 ...

  15. Hereditary skin diseases of hemidesmosomes

    NARCIS (Netherlands)

    Jonkman, MF

    1999-01-01

    Studies of hereditary blistering skin diseases (epidermolysis bullosa) and targeted gene mutation experiments in knockout mice have greatly improved our understanding of hemidesmosomes and their associated structures in the cytoskeleton and basement membrane of the skin and mucous membranes. At leas

  16. 皮肤中基底膜的结构与功能%The structure and functions of skin basement membrane

    Institute of Scientific and Technical Information of China (English)

    张丽丽; 李贤玉; 穆荣; 范春晖(综述); 北垣雅人; 高须; 惠美子(审校)

    2016-01-01

    Basement membranes (BE) are a kind of extracellular matrices in every tissue of the whole human body and play the most important role as keeping cellular functions and structures. It is the most important that BE in skin functionally connects and separates with epidermal and dermis containing of various proteins,such as type Ⅳ and Ⅶ collagen,laminins,nidogen and perlecan etc.Those interacted with themselves to form networks to support diverse bio functions in BE. And BE connects between epidermis and dermis signaling etc.It will lead the circulation smoothly among epidermis-basement membrane-dermis that healthy BE contributes diverse bio-functions,so that BE could maintain integrity and healthy of skin.Sunlight exposure may predominantly changes BE,such as sunburn, photoaging and photo-related skin cancers. On the other hand, some studies showed that various herbal extracts could protect BE well.It will be a new approach to develop functional cosmetics that how to utilize those active herbal ingredients.%基底膜是一类细胞外基质,存在于人体中所有的器官组织中,承担着重要的功能。皮肤的基底膜是表皮与真皮间重要的承接结构,主要成分有Ⅳ型和Ⅶ型胶原蛋白、层粘连蛋白、巢蛋白、串珠素等,通过它们交互形成的网状结构,构成了基底膜丰富多样的生物学功能,主要为表皮-真皮的连接功能、信号传导功能及渗透屏障功能等。健康的基底膜发挥多样生物学功能,使表皮-基底膜-真皮三者之间能够顺畅循环,保持皮肤的健康完整性。暴露于阳光下可引起基底膜的改变,可以引发多种肌肤烦恼,例如晒伤、光老化、皮肤癌等。研究发现一些植物提取物可以保护基底膜,如何运用这些活性成分对研究开发功能性化妆品可以提供更多的发展途径。

  17. Application of comfeel ulcer powder and 3 M painless skin membrane in intestinal fistula patients around the stoma damaged skin care%康惠尔溃疡粉及3 M无痛保肤膜在肠造瘘患儿造口周围受损皮肤护理中的应用

    Institute of Scientific and Technical Information of China (English)

    袁丽芬

    2013-01-01

    目的:探讨康惠尔溃疡粉及3M无痛保肤膜在肠造瘘患儿造口周围受损皮肤护理中的应用效果.方法:选择2007年8月~2011年8月肠造瘘造口周围皮肤受损患儿60例,将患儿随机分为观察组和对照组各30例,观察组使用康惠尔溃疡粉及3M无痛保肤膜护理肠造瘘患儿造口周围受损皮肤,对照组采用常规氯锌油及保鲜膜护理肠造瘘患儿造口周围受损皮肤,观察两组患儿造口周围受损皮肤恢复情况.结果:观察组疗效优于对照组(P<0.05).结论:应用康惠尔溃疡粉及3M无痛保肤膜能使水蒸气和氧气透过皮肤,更有效地促进了造口周围受损皮肤的恢复,且操作方便、简单,值得临床推广应用.%Objective:To investigate the application effect of comfeel ulcer powder and 3 M painless skin membrane in intestinal fistula patients around the stoma damaged skin care. Methods:From August 2007 to August 2011,chose the intestinal fistula peristomal skin damage in children with 60 cases, were randomly divided into observation group and control group with 30 cases in each group, the observation group used comfeel ulcer powder and 3 M painless nursing of colostomy patients skin membrane damaged skin around the stoma, the control group used conventional zinc chloride oil and wrap around the stoma nursing colostomy patients damaged skin around the stoma, observed two groups of children with skin damage recovery. Results:The curative effect of observation group was better than control group (P <0. 05 ). Conclusion: The application of comfeel ulcer powder and 3 M painless skin membrane can be made of water vapor and oxygen permeability of the skin, to more effectively promote the recovery of damaged skin around the stoma, and the operation is convenient and simplest is worthy of clinical application.

  18. Common channels for water and protons at apical and basolateral cell membranes of frog skin and urinary bladder epithelia. Effects of oxytocin, heavy metals, and inhibitors of H(+)-adenosine triphosphatase

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, B.; Lacoste, I.; Ehrenfeld, J. (Commissariat a l' Energie Atomique, Villefranche-sur-mer (France))

    1991-04-01

    We have compared the response of proton and water transport to oxytocin treatment in isolated frog skin and urinary bladder epithelia to provide further insights into the nature of water flow and H+ flux across individual apical and basolateral cell membranes. In isolated spontaneous sodium-transporting frog skin epithelia, lowering the pH of the apical solution from 7.4 to 6.4, 5.5, or 4.5 produced a fall in pHi in principal cells which was completely blocked by amiloride, indicating that apical Na+ channels are permeable to protons. When sodium transport was blocked by amiloride, the H+ permeability of the apical membranes of principal cells was negligible but increased dramatically after treatment with antidiuretic hormone (ADH). In the latter condition, lowering the pH of the apical solution caused a voltage-dependent intracellular acidification, accompanied by membrane depolarization, and an increase in membrane conductance and transepithelial current. These effects were inhibited by adding Hg2+ (100 microM) or dicyclohexylcarbodiimide (DCCD, 10(-5) M) to the apical bath. Net titratable H+ flux across frog skin was increased from 30 +/- 8 to 115 +/- 18 neq.h-1.cm-2 (n = 8) after oxytocin treatment (at apical pH 5.5 and serosal pH 7.4) and was completely inhibited by DCCD (10(-5) M). The basolateral membranes of the principal cells in frog skin epithelium were found to be spontaneously permeable to H+ and passive electrogenic H+ transport across this membrane was not affected by oxytocin. Lowering the pH of the basolateral bathing solution (pHb) produced an intracellular acidification and membrane depolarization (and an increase in conductance when the normal dominant K+ conductance of this membrane was abolished by Ba2+ 1 mM). These effects of low pHb were blocked by micromolar concentrations of heavy metals (Zn2+, Ni2+, Co2+, Cd2+, and Hg2+).

  19. On skin expansion.

    Science.gov (United States)

    Pamplona, Djenane C; Velloso, Raquel Q; Radwanski, Henrique N

    2014-01-01

    This article discusses skin expansion without considering cellular growth of the skin. An in vivo analysis was carried out that involved expansion at three different sites on one patient, allowing for the observation of the relaxation process. Those measurements were used to characterize the human skin of the thorax during the surgical process of skin expansion. A comparison between the in vivo results and the numerical finite elements model of the expansion was used to identify the material elastic parameters of the skin of the thorax of that patient. Delfino's constitutive equation was chosen to model the in vivo results. The skin is considered to be an isotropic, homogeneous, hyperelastic, and incompressible membrane. When the skin is extended, such as with expanders, the collagen fibers are also extended and cause stiffening in the skin, which results in increasing resistance to expansion or further stretching. We observed this phenomenon as an increase in the parameters as subsequent expansions continued. The number and shape of the skin expanders used in expansions were also studied, both mathematically and experimentally. The choice of the site where the expansion should be performed is discussed to enlighten problems that can lead to frustrated skin expansions. These results are very encouraging and provide insight into our understanding of the behavior of stretched skin by expansion. To our knowledge, this study has provided results that considerably improve our understanding of the behavior of human skin under expansion.

  20. A Dermal Equivalent Engineered with TGF-β3 Expressing Bone Marrow Stromal Cells and Amniotic Membrane: Cosmetic Healing of Full-Thickness Skin Wounds in Rats.

    Science.gov (United States)

    Samadikuchaksaraei, Ali; Mehdipour, Ahmad; Habibi Roudkenar, Mehryar; Verdi, Javad; Joghataei, Mohammad Taghi; As'adi, Kamran; Amiri, Fatemeh; Dehghan Harati, Mozhgan; Gholipourmalekabadi, Mazaher; Karkuki Osguei, Nushin

    2016-12-01

    Transforming growth factor beta-3 (TGF-β3) has been shown to decrease scar formation after scheduled topical applications to the cutaneous wounds. This study aimed to continuously deliver TGF-β3, during the early phase of wound healing, by engineering a dermal equivalent (DE) using TGF-β3 expressing bone marrow stromal cells (BM-SCs) and human dehydrated amniotic membrane (hDAM). To engineer a DE, rat BM-SCs were seeded on the hDAM and TGF-β3 was transiently transfected into the BM-SCs using a plasmid vector. Pieces of the dermal equivalent were transplanted onto the full-thickness excisional skin wounds in rats. The process of wound healing was assessed by image analysis, Manchester Scar Scale (MSS), and histopathological studies 7, 14, 21, and 85 days after the excision. The results confirmed accurate construction of recombinant pcDNA3.1-TGF-β3 expression system and showed that the transfected BM-SCs seeded on hDAM expressed TGF-β3 mRNA and protein from day 3 through day 7 after transfection. After implantation of the DE, contraction of the wounds was measured from day 7 through 21 and analyzed by linear regression, which revealed that the rate of wound contraction in all experimental groups was similar. Histologic evaluation demonstrated that transfected BM-SCs decreased retention and recruitment of the cells during the early stage of wound healing, decreased the formation of vascular structures and led to formation of uniformly parallel collagen bundles. MSS scores showed that TGF-β3 secreting cells significantly improved the cosmetic appearance of the healed skin and decreased the scar formation. From these results, it could be concluded that transient secretion of TGF-β3, during the early phase of healing, by BM-SCs seeded on hDAM can improve the cosmetic appearance of the scar in cutaneous wounds without negatively affecting the process of wound repair. Copyright © 2016 International Center for Artificial Organs and Transplantation and Wiley

  1. Molecular cloning of a cDNA encoding the porcine type XVII collagen noncollagenous 16 A domain and localization of the domain to the upper part of porcine skin basement membrane zone.

    Science.gov (United States)

    Xu, Luting; Olivry, Thierry; Chan, Lawrence S

    2004-06-01

    Bullous pemphigoid is an autoimmune blistering human skin disease mediated by immunoglobulin (Ig)G autoantibodies targeting skin basement membrane component type XVII collagen, a transmembrane protein. Also designated BP180 and BPAG2, type XVII collagen is an extracellular matrix element essential for the connection between the epidermis and the underlying dermis. In addition to being a target antigen in the human disease bullous pemphigoid, type XVII collagen is also targeted by autoantibodies of canine, feline, equine and porcine patients suffering from a similar blistering skin disease. Previously, enzyme-linked immunosorbent assay and Western blot analyses have shown that autoantibodies from pigs affected with bullous pemphigoid recognize the human NC16A domain of type XVII collagen. To facilitate the development of porcine model of bullous pemphigoid, we isolated cDNA encoding the porcine type XVII collagen NC16A domain using a reverse transcription-polymerase chain reaction technique. The amino acids deduced from the NC16A cDNA showed 61% identity with the sequence of human NC16A. An antibody generated against a 20-amino acid peptide within the porcine NC16A localized the NC16A epitope to the upper part of porcine skin basement membrane zone. Our data provide further information of the porcine bullous pemphigoid target antigen and may help investigators for their further studies of this disease.

  2. Minkowski spacetime and Lorentz invariance: The cart and the horse or two sides of a single coin?

    Science.gov (United States)

    Acuña, Pablo

    2016-08-01

    unnecessary, and that it actually obscures our understanding of the explanatory nature and power of the theory.Second, I argue that rather than a debate about what is the cart and what is the horse, the discussion between Brown and Janssen is an instance of the dispute about what was first, the egg or the chicken. I claim that Minkowski structure and Lorentz invariance need not be conceived in such a way that one must explain the other. Instead, they are better understood as the two sides of a single coin: the arrow between them is not explanatory, but analytic (in a sense that I explain below). Furthermore, I argue that this conception of the link between Lorentz invariance and Minkowski chronogeometry, unlike the conception that motivates the Janssen-Brown debate, sheds light on our understanding of the explanatory nature and power of special relativity. I claim that the aforementioned analytic connection between Minkowski structure and Lorentz grounds the explanatory foundations of Einstein's theory.The structure of this article is the following. In Section 2, I provide an overview of the debate, paying special attention to the aspects that are most relevant for my critical assessment. In Section 3, I underscore two crucial assumptions endorsed by Brown and Janssen-that the discussion is independent of questions about spacetime ontology, and that the arrow of explanation at stake must be constructive-and I ponder about the justification that the authors offer (and implicitly assume) for them. In Section 4, I show that both these assumptions are problematic and unjustified, thus tainting the whole debate. In Section 5, I argue that Minkowski structure and Lorentz invariance are analytically linked, and that this link-that is not itself explanatory-clarifies the source of the chronogeometric explanations of physical phenomena that special relativity provides. In Section 6, I conclude and value the lessons that we can draw from Janssen's and Brown's arguments in the light of

  3. Plasmoacanthoma of oral cavity and plasma cell cheilitis: two sides of same disorder “oral plasma cell mucositis” ?

    Directory of Open Access Journals (Sweden)

    Gayatri Khatri

    2014-04-01

    Full Text Available Plasmoacanthoma and plasma cell cheilitis are rare disorders of obscure etiology characterized by a plasma cell infiltrate an 80-year-old woman presented with a verrucous, fleshy, skin colored plaque over lips, gingiva, and the palate and painful swallowing for over a period of 6 months. Histopathology of the lesion showed dense infiltrate of plasma cells. The lesions resolved completely after intralesional triamcinolone acetonide. Another 52-year-old male had progressively enlarging, erosive lesion over vermilion border of lower lip for 6months resembling actinic cheilitis. Histology was diagnostic of plasma cell cheilitis. Treatment with topical clobetasol propionate was effective. Plasma cell cheilitis and plasmoacanthoma perhaps represent a spectrum of oral ”plasma cell mucositis” with plasmoacanthoma being an advanced version of the former.

  4. Your Skin

    Science.gov (United States)

    ... Room? What Happens in the Operating Room? Your Skin KidsHealth > For Kids > Your Skin Print A A ... are really dead skin cells. continue Bye-Bye Skin Cells These old cells are tough and strong, ...

  5. Roads may act as barriers to flying insects: species composition of bees and wasps differs on two sides of a large highway

    Directory of Open Access Journals (Sweden)

    Petter Andersson

    2017-07-01

    Full Text Available Roads may act as barriers to animal movements, but direct barrier effects on insects have rarely been studied. In this study we collected data on bees and wasps along two sides of a large road in Sweden using yellow pan traps. We then analyzed if the species composition differed between the two sides of the road; first for the whole community, and then only for the smallest species (which typically are poorer dispersers. As a complement, we analyzed if different vegetation variables differed between the two sides of the road, as this may also affect differences in species composition. Finally, we analyzed if species richness and abundance in general differed between the two sides and how these two response variables were explained by the vegetation variables. There was a significant difference in species composition between the eastern and the western side of the road when analyzing the whole community, and this relationship became even stronger when the largest species were excluded. The vegetation variables did not strongly differ between the two sides, and there was no difference in species richness and abundance of bees and wasps either. Abundance was, however, explained by the number of flowering plants in the surroundings of the trap. Even though using a rather limited data set, our results indicate that large roads may act as barriers on the movement of bees and wasps, especially for small species with poor dispersal ability. On the other hand, road verges may be important habitat for many species, which leads to a potential conflict that is important to consider in the planning of green infrastructure.

  6. Technology Licensing in Two-Sided Markets%双边市场条件下的技术许可策略研究

    Institute of Scientific and Technical Information of China (English)

    王怀祖; 熊中楷; 黄俊

    2011-01-01

    Two-sided markets include a system platform and two groups of clients who interact with each other via two-sided network externalities-the expansion of one market can increase customers' utilities in the other market. Technology licensing decisions are important in the network economy because two-sided network externalities are prevalent. The purpose of the paper is to investigate innovators' optimal technology licensing strategies under two-sided markets.We assume that an innovator has major patented technologies that are manufactured for Product I market, but licensed in Product II market. The scenario shows that two-sided network externalities between the two markets exist. We explore how factors, such as the intensity of two-sided network externalities, the number of potential licensees and the potential demand effect, can influence the technology licensing strategies of innovators. We establish a two-stage game model and adopt the fulfilled expectation equilibrium theory to analyze market equilibrium.First, we discuss the fixed-fee licensing strategy and analyze the optimal number of licenses for an innovator. We find that an innovator will not restrict the number of licenses in the licensed product market when the following conditions exist: strong two-sided network externalities, small potential licensee numbers, and relatively small potential demand scale in the licensed product market. Without the presence of these conditions, an innovator will restrict the number of licensees. Second, we discuss the royalty licensing strategy. We find that the innovator will decrease the royalty rate when two-sided network externalities and the potential number of licensees increase, and when the potential demand in the licensed product market decreases. Third, we discuss the probability of technological subsidies provided by innovators. An innovator may subsidize licensees with negative royalty rates. Furthermore, an innovator' s subsidizing strategy may promote

  7. Basement membrane zone remodeling during appendageal development in human fetal skin. The absence of type VII collagen is associated with gelatinase-A (MMP2) activity.

    Science.gov (United States)

    Karelina, T V; Bannikov, G A; Eisen, A Z

    2000-02-01

    Epithelial cell adhesion, migration, and differentiation are controlled by interactions at the basement membrane zone (BMZ). Type VII collagen is the major collagenous component of anchoring fibrils that are essential for the attachment of the epidermis to the dermis. Gelatinase A (MMP-2) is believed to be necessary for the degradation of type VII collagen. In this study we have examined the in vivo distribution of type VII collagen and gelatinase A (Gel A) in the developing human epidermis and its appendages. At 13-15 wk of gestation a marked decrease in type VII collagen immunoreactivity was seen in the BMZ surrounding invading appendageal buds; however, type VII collagen mRNA was strongly expressed in the budding epidermal keratinocytes adjacent to the BMZ. At these stages, Gel A-positive mesenchymal-like cells were found scattered throughout the stroma with numerous Gel A-containing cells in direct contact with the developing appendageal buds. In situ zymography was used to show Gel A-activity in vivo. Gel A-mediated lysis was present at the interface between the appendageal buds and the underlying BMZ. By 20-25 wk of gestational age, immunostaining for type VII collagen protein was absent from the BMZ surrounding the distal portion of invading appendageal epithelial cords of both hair follicles and sweat glands. In contrast, type VII collagen mRNA was present in the basal keratinocytes adjacent to the BMZ surrounding the distal portion of these invading appendageal epithelial cords. At these stages Gel A-positive cells were present in the stroma directly adjacent to the distal portion of developing appendageal cords that lacked type VII collagen. In situ zymography showed zones of Gel A-mediated stromal lysis at the distal portion of developing appendageal cords. Interestingly, no differences were seen in the distribution of type IV collagen in the BMZ of both budding and resting fetal epidermis. These observations suggest that the absence of type VII collagen

  8. Two Sides of the Same Coin? Analysis of the Web-Based Social Media with Regard to the Image of the Agri-Food Sector in Germany

    Directory of Open Access Journals (Sweden)

    Justus Boehm

    2010-10-01

    Full Text Available  Never before has food been as safe and secure as it is today, but simultaneously, society has become increasingly critical towards agricultural and food related issues. This two-sided development between society and agribusiness will be analyzed using Framing Theory. A quantitative semantic analysis was applied to evaluate the web-based social media in Germany. 50,931 web posts were collected covering 21 issues identified as relevant for the agri-food sector. The results show that all contentious issues are mainly framed in a two-sided way. The modern productivity-driven industry is judged as a negative development, trends returning to a more natural food production are seen as positive.

  9. Skin Biopsy

    Science.gov (United States)

    ... I Help Someone Who's Being Bullied? Volunteering Skin Biopsy KidsHealth > For Teens > Skin Biopsy Print A A ... español Biopsia de piel What Is a Skin Biopsy and Who Would Need One? In a biopsy, ...

  10. 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, ...

  11. 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 ...

  12. Wet spinning of integrally skinned hollow fiber membranes by a modified dual-bath coagulation method using a triple orifice spinneret

    NARCIS (Netherlands)

    Li, S.-G.; Koops, G.H.; Mulder, M.H.V.; Boomgaard, van den A.; Smolders, C.A.

    1994-01-01

    Three main routes are known to prepare hollow fiber membranes; melt spinning, dry spinning and wet spinning (or dry/wet spinning). The latter is the most important technique for the preparation of industrial hollow fiber membranes. In this process the extruded polymer solution is immersed in a nonso

  13. Wet spinning of integrally skinned hollow fiber membranes by a modified dual-bath coagulation method using a triple orifice spinneret

    NARCIS (Netherlands)

    Li, S.G.; Li, S.-G.; Koops, G.H.; Mulder, M.H.V.; van den Boomgaard, Anthonie; Smolders, C.A.; Smolders, C.A.

    1994-01-01

    Three main routes are known to prepare hollow fiber membranes; melt spinning, dry spinning and wet spinning (or dry/wet spinning). The latter is the most important technique for the preparation of industrial hollow fiber membranes. In this process the extruded polymer solution is immersed in a nonso

  14. Membrane Automata with Priorities

    Institute of Scientific and Technical Information of China (English)

    Luděk Cienciala; Lucie Ciencialová

    2004-01-01

    In this paper the one-way P automata with priorities are introduced. Such automata are P systemshere the membranes are only allowed to consume objects from parent membranes, under the given conditions. The result of computation of these systems is the set of multiset sequences consumed by skin membrane intc the system. The rules associated in some order with each membrane cannot modify any objects, they can only move them through membrane. We show that P automata with priorities and two membranes can accept every recursively enumerated language.

  15. Chitosan/TiO2 composite membrane improves proliferation and survival of L929 fibroblast cells: Application in wound dressing and skin regeneration.

    Science.gov (United States)

    Behera, Sudhanshu Shekhar; Das, Urmimala; Kumar, Awanish; Bissoyi, Akalabya; Singh, Abhishek Kumar

    2017-05-01

    The microbial infection and growth of fibroblasts are the critical factors for the effective wound healing. The natural polymer-based dressing membranes may mimic extracellular matrix to support the survival, proliferation and differentiation of fibroblasts. The present study deals with the preparation of chitosan/titanium dioxide (CS/TiO2) composite membranes with different degree of TiO2 incorporation, and their characterization in terms of morphology, ultrastructure, thermal behavior and mechanical properties with SEM, FTIR, XRD and tensile strength analyses. The data demonstrated the formation of strong O-Ti-O bonding between TiO2 and CS resulting in superior porosity, mechanical strength, crystallinity and flexibility of the composite membranes. Further, the cyto-compatibility, proliferation, oxidative stress, cell cycle and apoptosis analyses of fibroblast L929 cells demonstrated the enhanced proliferation and survival, and decreased oxidative stress and apoptosis in L929 cells grown on CS/TiO2 membrane incorporated with 025% TiO2. Next, we measured the significant up-regulation in the expression of fibroblast-markers in L929 cells cultured on CS/TiO2 (0.25%) membrane. Furthermore, the CS/TiO2 composite membranes exhibited a superior antibacterial activity against Staphylococcus aureus. Taken together, the data confirmed that CS/TiO2 (0.25%) membrane improved the growth, survival and functional integrity of fibroblasts, and exerted antibacterial activity which may be utilized as potential dressing materials.

  16. 双边市场中的搭售:问题与规制思路%Tying in Two-sided Markets:Problems and Regulations

    Institute of Scientific and Technical Information of China (English)

    王少南

    2016-01-01

    The unique market structure and operating mechanism of two-sided markets place great challenges on traditional ty-ing theories based on unilateral markets. It calls for a rational analysis to the tying subject’ s dominant market position and behav-ior characteristics, in terms of crossing network effects, non-neutral price structures, the mutual dependence and complementar-ity of platform products in two-sided markets. The key to regulating tying in two-sided markets by means of anti-monopoly laws is to take full account of both positive and negative competition effects. It is critically important that China take full advanta-ges of two-sided markets for technological innovation in the anti-monopoly legal practice, and to upgrade industrial develop-ment and promote consumer welfare by means of protecting innovation.%双边市场特有的结构和运行机制对基于传统单边市场的搭售理论提出了全新的挑战。应该围绕双边市场的交叉网络效应、非中性的价格结构及平台产品的相互依赖性和互补性等特征,理性分析搭售行为的主体市场支配地位和具体行为特征。反垄断法规制双边市场中的搭售行为的关键在于综合考量其积极的竞争效果和消极的竞争效果。我国在反垄断法实践中应充分注重双边市场在技术创新方面的突出优势,通过保护创新来促进产业发展和提升消费者福利。

  17. Skin Infections

    Science.gov (United States)

    ... Old Feeding Your 8- to 12-Month-Old Feeding Your 1- to 2-Year-Old First Aid: Skin ... (bacterial infection of the deeper layers of the skin and tissues beneath) are typical childhood skin infections. The usual bacterial culprits in skin ...

  18. Skin Biomes.

    Science.gov (United States)

    Fyhrquist, N; Salava, A; Auvinen, P; Lauerma, A

    2016-05-01

    The cutaneous microbiome has been investigated broadly in recent years and some traditional perspectives are beginning to change. A diverse microbiome exists on human skin and has a potential to influence pathogenic microbes and modulate the course of skin disorders, e.g. atopic dermatitis. In addition to the known dysfunctions in barrier function of the skin and immunologic disturbances, evidence is rising that frequent skin disorders, e.g. atopic dermatitis, might be connected to a dysbiosis of the microbial community and changes in the skin microbiome. As a future perspective, examining the skin microbiome could be seen as a potential new diagnostic and therapeutic target in inflammatory skin disorders.

  19. Filtering With Two Sided Filtrations

    Science.gov (United States)

    1990-01-01

    anid (4.12) must be the same. Equating the bounded variation terms we have -i = H(At(h(x,) + (t))) - 17(At)(Ifh(xt) + IfH(t)). (4.13) Similarly, forming...TRATIONS 535 Again, the decompositions (4.11) and (4.14) must be the same, so equating their bounded variation terms we see =H(Ait((t) - h(xj_,))) + fl...h (1 - 2t) -(B1 -B_) so dividing by h > 0 and letting h -+ 0 we see at = (-2t)(1 - 2t) Furthermore, because the quadratic variation of bounded

  20. Photothermal Radiometry for Skin Research

    Directory of Open Access Journals (Sweden)

    Perry Xiao

    2016-02-01

    Full Text Available Photothermal radiometry is an infrared remote sensing technique that has been used for skin and skin appendages research, in the areas of skin hydration, hydration gradient, skin hydration depth profiling, skin thickness measurements, skin pigmentation measurements, effect of topically applied substances, transdermal drug delivery, moisture content of bio-materials, membrane permeation, and nail and hair measurements. Compared with other technologies, photothermal radiometry has the advantages of non-contact, non-destructive, quick to make a measurement (a few seconds, and being spectroscopic in nature. It is also colour blind, and can work on any arbitrary sample surfaces. It has a unique depth profiling capability on a sample surface (typically the top 20 µm, which makes it particularly suitable for skin measurements. In this paper, we present a review of the photothermal radiometry work carried out in our research group. We will first introduce the theoretical background, then illustrate its applications with experimental results.

  1. Two-sided bounds on the mean vector and covariance matrix in linear stochastically excited vibration systems with application of the differential calculus of norms

    Directory of Open Access Journals (Sweden)

    Ludwig Kohaupt

    2015-12-01

    Full Text Available For a linear stochastic vibration model in state-space form, $ \\dot{x}(t = A x(t+b(t, \\, x(0=x_0, $ with system matrix A and white noise excitation $ b(t $, under certain conditions, the solution $ x(t $ is a random vector that can be completely described by its mean vector, $ m_x(t:=m_{x(t} $, and its covariance matrix, $ P_x(t:=P_{x(t} $. If matrix $ A $ is asymptotically stable, then $ m_x(t \\rightarrow 0 \\, (t \\rightarrow \\infty $ and $ P_x(t \\rightarrow P \\, (t \\rightarrow \\infty $, where $ P $ is a positive (semi-definite matrix. As the main new points, in this paper, we derive two-sided bounds on $ \\Vert m_x(t\\Vert _2 $ and $ \\Vert P_x(t- P\\Vert _2 $ as well as formulas for the right norm derivatives $ D_+^k \\Vert P_x(t- P\\Vert _2, \\, k=0,1,2 $, and apply these results to the computation of the best constants in the two-sided bounds. The obtained results are of special interest to applied mathematicians and engineers.

  2. Evaluation of percutaneous permeation of repellent DEET and sunscreen oxybenzone from emulsion-based formulations in artificial membrane and human skin

    Directory of Open Access Journals (Sweden)

    Tao Wang

    2014-02-01

    Full Text Available Insect repellent DEET and sunscreen ingredient oxybenzone play an essential role in minimizing vector-borne diseases and skin cancers. The purpose of this study was to investigate the effects of emulsion type, addition of thickening agent and droplet size in three emulsion-based lotions on percutaneous permeation of DEET and oxybenzone using in vitro diffusion experiments, in order to minimize overall systemic permeation of the substances. Formulation C (water-in-oil emulsion significantly increased overall permeation of DEET through human skin (56% compared to Formulation A (oil-in-water emulsion. Formulation B (oil-in-water emulsion with thickening agent xanthan gum significantly decreased the size of oil droplet containing DEET (16%, but no effect on oil droplets containing oxybenzone. Adding xanthan gum also increased overall permeation of DEET and oxybenzone (21% and 150% when compared to Formulation A; presence of both ingredients in Formulation B further increased their permeation (36% and 23% in comparison to its single counterparts. Overall permeation of oxybenzone through LDPE was significantly higher by 26%–628% than that through human skin; overall permeation of DEET through human skin was significantly higher by 64%–338% than that through LDPE.

  3. Utilization of reconstructed cultured human skin models as an alternative skin for permeation studies of chemical compounds

    OpenAIRE

    Kano, Satoshi; 藤堂, 浩明; 杉江, 謙一; 藤本, 英哲; 中田, 圭一; 徳留, 嘉寛; 橋本, フミ惠; 杉林, 堅次

    2010-01-01

    Two reconstructed human skin models, EpiskinSM and EpiDermTM, have been approved as alternative membranes for skin corrosive/irritation experiments due to their close correlation with animal skin. Such reconstructed human skin models were evaluated as alternative membranes for skin permeation experiments. Seven drugs with different lipophilicities and almost the same molecular weight were used as test penetrants. Relationships were investigated between permeability coefficients (P values) of ...

  4. Neuromodulators for Aging Skin

    Science.gov (United States)

    ... Skin Scars Skin Growths Skin Lesions Spider Veins Stretch Marks Sun-damaged Skin Unwanted Hair Unwanted Tattoos Varicose ... Skin Scars Skin Growths Skin Lesions Spider Veins Stretch Marks Sun-damaged Skin Unwanted Hair Unwanted Tattoos Varicose ...

  5. Array of planar membrane modules for producing hydrogen

    Science.gov (United States)

    Vencill, Thomas R [Albuquerque, NM; Chellappa, Anand S [Albuquerque, NM; Rathod, Shailendra B [Hillsboro, OR

    2012-05-08

    A shared or common environment membrane reactor containing a plurality of planar membrane modules with top and bottom thin foil membranes supported by both an intermediary porous support plate and a central base which has both solid extended members and hollow regions or a hollow region whereby the two sides of the base are in fluid communication. The membrane reactor operates at elevate temperatures for generating hydrogen from hydrogen rich feed fuels.

  6. Comparison of curative effects between chitosan artificial skin membrane and vaseline gauze in the treatment of medium-thick skin flap donor site%甲壳胺人工皮膜与凡士林纱布治疗中厚层皮片供区的疗效比较

    Institute of Scientific and Technical Information of China (English)

    黄秦邶; 陈陆平; 吕惠玲; 蔡建

    2015-01-01

    目的:比较甲壳胺人工皮膜与凡士林纱布治疗中厚层皮片供区的临床效果。方法骨外科具有完整临床资料以大腿部作为中厚层皮片供区的病例46例作为研究对象,随机分为观察组22例(采取甲壳胺人工皮膜治疗)和对照组24例(采取凡士林纱布治疗),对比两组治疗方法的临床效果。结果经过平均6个月随访,对照组瘙痒、皲裂或者溃疡以及脱屑的发生率为45.8%,高于观察组13.6%;色素脱失或沉着、瘢痕的发生率对照组明显高于观察组,观察组的两点辨别觉亦明显优于对照组,差异有统计学意义(P<0.01)。结论甲壳胺人工皮膜能有效地保护中厚层皮片供区创面,再生皮肤外形良好,质量高,并发症少,疗效确切,值得应用推广。%Objective To compare the curative effects between chitosan artificial skin membrane and vaseline gauze in the treatment of medium-thick skin flap donor site. Methods There were 46 patients with complete clinical data and medium-thick skin flap donor site in thigh as study subjects. They were randomly divided into observation group with 22 cases (received chitosan artificial skin membrane) and control group with 24 cases (received vaseline gauze). Clinical effects of the two groups were compared. Results After follow-up for average 6 months, the control group had higher incidences of pruritus, rahagades, anabrosis and desquamation as 45.8% than 13.6% of the observation group. The control group also had higher incidences of depigmentation, chromatosis, and scar then the observation group. The observation group had much better two-point identification feeling than the control group. Their difference had statistical significance (P<0.01). Conclusion Chitosan artificial skin membrane can effectively protect medium-thick skin flap donor site with good appearance and quality of regenerated skin. This method provides few complications and precise effect, and it is

  7. Effect of evidence-based nursing in nursing of skin mucosa membrane separation after undergoing enterostomy%循证护理在肠造口皮肤黏膜分离护理中的作用

    Institute of Scientific and Technical Information of China (English)

    裴新荣; 杜月娥

    2013-01-01

    目的:探讨缩短肠造口术后皮肤黏膜分离愈合时间、减少皮肤黏膜分离后并发症发生的最佳护理方法.方法:将发生肠造口术后皮肤黏膜分离的60例患者,运用循证护理和湿性愈合敷料进行切口护理,出院后门诊随诊2个月,观察其愈合时间,肠造口内陷及狭窄的发生情况.结果:运用循证护理和湿性愈合敷料进行切口护理后,患者7 ~28 d痊愈出院,造口内陷2例,造口狭窄1例,出院1个月后恢复正常.结论:将循证护理所获得的证据、护理经验和患者的实际情况相结合,能明显缩短患者的愈合时间及减少并发症的发生,缩短住院时间,提高肠造口患者的生活质量.%Objective:To investigate the healing time,and the beet methods of care to reduce complications after the separation of the skin and mucous membrane shorten the enterostomy postoperative skin and mucous membrane separation.Methods:After will have the intestines ostomy the skin mucous membrane separation 60 patients,used evidence-based nursing and the wet cicatrization surgical dressing carries on wound nursing,follow-up for two months after discharge,observed its cicatrization time,the intestines made the inside the mouth to fall and the narrow occurrence situation.Results:After follows card nursing and the wet cicatrization surgical dressing carried on wound nursing,hospitalizedpatients recovered and were discharged from hospital after 7-28 day,made the inside the mouth to fall 2 examples,after makes mouth narrow 1 example out of hospital after one month to restore normally.Conclusion:The evidence of evidence-based nursin care experience and the actual situation of the patients the combination can significantly shorten the healing time after the occurrence and reduce the incidence of other complications,shorter hospital stays,improve the quality of life of patients with enterostomy

  8. Membrane potentials and intracellular Cl- activity of toad skin epithelium in relation to activation and deactivation of the transepithelial Cl- conductance

    DEFF Research Database (Denmark)

    Willumsen, N J; Larsen, Erik Hviid

    1986-01-01

    M in skins from animals adapted to distilled water. Both Va and acCl were found to be positively correlated with Isc (r = 0.66 and r = 0.70, respectively). In eight epithelia from animals adapted to dry milieu/tap water Va and acCl were measured with KCl Ringer's on the outside during activation...... V was stepped back to 40 mV, Va instantaneously shifted to -67.8 +/- 3.9 mV while acCl and fRa remained constant during deactivation of GCl. Similar results were obtained in epithelia impaled from the serosal side. In 12 skins from animals adapted to either tap water or distilled water the density...... zero.(ABSTRACT TRUNCATED AT 400 WORDS)...

  9. One-sided or Two-sided Fee: The Choice of Pricing Modes in Media Two-sided Markets%单边收费还是双边收费:双边市场中媒体定价模式选择

    Institute of Scientific and Technical Information of China (English)

    程贵孙

    2011-01-01

    向一边用户收费还是向两边用户同时收费,是双边市场中众多平台企业在制定价格策略时面临的两难选择.本文以垄断媒体平台为例,考察了垄断媒体对单边收费和双边收费的最优定价模式选择问题.研究发现,媒体订阅量给广告商带来的网络效应强度和媒体内容产品质量参数,它们所形成的广告商与消费者之间的"相对价值比效应指数",将影响到垄断媒体对定价模式的选择.%Platform firms play an important role in e-business. Platform firms charge two groups of agents in exchange for their product and service offerings. Any platform firms in a two-sided market need to deal with the pricing dilemma of charging one-sided user or two-sided users. Advertisement can cause a negative externality on customers because customers usually dislike advertising. Different pricing models can be formulated to compare media platforms using advertisement, with platforms not using advertisement. This paper will present a model of a two-sided vertically differentiated market and use a model to find an optimal pricing model for charging onesided user or two-sided users in a monopolist media platform.This paper is organized as follows. Section 1 discusses related literature and research objectives. Section 2 describes our proposed model. Section 3 discusses the consumer payment pricing model and price equilibrium solutions. Media platforms do not use any advertisements and charge consumers a subscription fee in the consumer payment pricing model. Section 4 discusses the advertiser's payment pricing model and the price equilibrium solutions. In the advertiser's payment pricing model, media platforms allow advertisements and charge the advertisers an advertising fee. Consumers can subscribe to the advertising service for free. Section 5 discusses the two-sided payment pricing model and price equilibrium solutions. In this pricing model, media platforms charge consumers different

  10. Normal skin and hypertrophic scar fibroblasts differentially regulate collagen and fibronectin expression as well as mitochondrial membrane potential in response to basic fibroblast growth factor

    Directory of Open Access Journals (Sweden)

    Rui Song

    2011-05-01

    Full Text Available Basic fibroblast growth factor (bFGF regulates skin wound healing; however, the underlying mechanism remains to be defined. In the present study, we determined the effects of bFGF on the regulation of cell growth as well as collagen and fibronectin expression in fibroblasts from normal human skin and from hypertrophic scars. We then explored the involvement of mitochondria in mediating bFGF-inducedeffects on the fibroblasts. We isolated and cultivated normal and hypertrophic scar fibroblasts from tissue biopsies of patients who underwent plastic surgery for repairing hypertrophic scars. The fibroblasts were then treated with different concentrations of bFGF (ranging from 0.1 to 1000 ng/mL. The growth of hypertrophic scar fibroblasts became slower with selective inhibition of type I collagen production after exposure to bFGF. However, type III collagen expression was affected in both normal and hypertrophic scar fibroblasts. Moreover, fibronectin expression in the normal fibroblasts was up-regulated after bFGF treatment. bFGF (1000 ng/mL also induced mitochondrial depolarization in hypertrophic scar fibroblasts (P < 0.01. The cellular ATP level decreased in hypertrophic scar fibroblasts (P < 0.05, while it increased in the normal fibroblasts following treatment with bFGF (P < 0.01. These data suggest that bFGF has differential effects and mechanisms on fibroblasts of the normal skin and hypertrophic scars, indicating that bFGF may play a role in the early phase of skin wound healing and post-burn scar formation.

  11. MILP model for integrated balancing and sequencing mixed-model two-sided assembly line with variable launching interval and assignment restrictions

    Science.gov (United States)

    Azmi, N. I. L. Mohd; Ahmad, R.; Zainuddin, Z. M.

    2017-09-01

    This research explores the Mixed-Model Two-Sided Assembly Line (MMTSAL). There are two interrelated problems in MMTSAL which are line balancing and model sequencing. In previous studies, many researchers considered these problems separately and only few studied them simultaneously for one-sided line. However in this study, these two problems are solved simultaneously to obtain more efficient solution. The Mixed Integer Linear Programming (MILP) model with objectives of minimizing total utility work and idle time is generated by considering variable launching interval and assignment restriction constraint. The problem is analysed using small-size test cases to validate the integrated model. Throughout this paper, numerical experiment was conducted by using General Algebraic Modelling System (GAMS) with the solver CPLEX. Experimental results indicate that integrating the problems of model sequencing and line balancing help to minimise the proposed objectives function.

  12. Self-tuning wireless power transmission scheme based on on-line scattering parameters measurement and two-side power matching.

    Science.gov (United States)

    Luo, Yanting; Yang, Yongmin; Chen, Zhongsheng

    2014-04-10

    Sub-resonances often happen in wireless power transmission (WPT) systems using coupled magnetic resonances (CMR) due to environmental changes, coil movements or component degradations, which is a serious challenge for high efficiency power transmission. Thus self-tuning is very significant to keep WPT systems following strongly magnetic resonant conditions in practice. Traditional coupled-mode ways is difficult to solve this problem. In this paper a two-port power wave model is presented, where power matching and the overall systemic power transmission efficiency are firstly defined by scattering (S) parameters. Then we propose a novel self-tuning scheme based on on-line S parameters measurements and two-side power matching. Experimental results testify the feasibility of the proposed method. These findings suggest that the proposed method is much potential to develop strongly self-adaptive WPT systems with CMR.

  13. Skin Cancer

    Science.gov (United States)

    ... are round and lie directly under squamous cells. Melanocytes are specialized skin cells that produce pigment called melanin. The melanin pigment produced by melanocytes gives skin its color. It also protects the ...

  14. Skin turgor

    Science.gov (United States)

    ... arm or abdomen is checked. The skin is held for a few seconds then released. Skin with ... University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the ...

  15. Skin Cancer

    Science.gov (United States)

    Skin cancer is the most common form of cancer in the United States. The two most common types ... face, neck, hands, and arms. Another type of skin cancer, melanoma, is more dangerous but less common. Anyone ...

  16. Skin Aging

    Science.gov (United States)

    Your skin changes as you age. You might notice wrinkles, age spots and dryness. Your skin also becomes thinner and loses fat, making it ... heal, too. Sunlight is a major cause of skin aging. You can protect yourself by staying out ...

  17. INVESTIGATION ON PRODUCTION AND MANAGEMENT STATUS OF SKIN AND MUCOUS MEMBRANE ANTIBACTERIAL PREPARATIONS IN SHANGHAI%上海市皮肤黏膜抗(抑)菌产品生产与管理现状调查

    Institute of Scientific and Technical Information of China (English)

    孙玉卿; 毛洁; 周晓鹂

    2011-01-01

    Objective To know the production and management status of skin and mucous membrane antibacterial preparations in Shanghai, and to explore inspection and management methods to solve relevant problems. Methods Field sampling investigation was used to know the quality and manufactories management status of all the skin and mucous membrane antibacterial preparations in Shanghai. Results There are 17 types of skin and mucous membrane antibacterial preparations in Shanghai. The germicidal ingredient are mainly triclosan, biguanide and its compound preparations. The antibacterial ingredient contents of are qualified to national guidelines, and all the products have antibacterial effects on Escherichia coli and Staphylococcus aureus according to test results of certificated laboratory. Hygienic safety evaluation were made on 16 of the products, and 7 of the evaluation reports are qualified according to Hygienic Safety Evaluation Regulations on Disinfection Products of Ministry of Health. Conclusion All the skin and mucous membrane antibacterial preparations in Shanghai were manufactured under permission, and their antibacterial ingredient contents and antibacterial effects were qualified. However, there were defects concerning hygienic safety evaluation, and inspection should be strengthened accordingly.%目的 了解上海市皮肤黏膜抗(抑)菌产品的生产与管理现状,发现存在问题,探讨监管方法.方法 用现场抽样调查的方法,对本市所辖皮肤黏膜抗抑菌产品质量和生产企业管理情况进行了调查.结果 本市企业生产的皮肤黏膜抗(抑)菌产品共17种,这些产品的主要杀菌成分以三氯羟基二笨醚和双胍类化合物及其复方制剂为主,产品抗菌成分的含量值符合国家限量值规定.经过上海市认证实验室检测,17种产品对大肠杆菌和金黄色葡萄球菌均具有抗(抑)菌效果.17种产品中,有16种产品完成卫生安全评价,其中有7件产品的评价报告内容

  18. Platform strategy in vertically differentiated two-sided markets%纵向差异化双边市场中平台策略

    Institute of Scientific and Technical Information of China (English)

    万兴; 高觉民

    2013-01-01

    基于抽象函数建立了纵向差异化双边市场的一般模型,并利用一般模型讨论了垄断与双寡头情形下的市场均衡特征以及在双寡头情形下价格变动的战略效应.进一步在均匀分布的假设下分析了网络外部性参数与质量差距变量对市场均衡时价格与利润的影响.研究发现,在一般模型中,垄断平台能够比双寡头平台更加有效地协调两边的价格结构;双寡头平台的竞争呈现强者更强的效应;双寡头平台竞争中价格具有战略互补效应,而下游市场的战略互补效应要高于上游市场的战略互补效应.基于均匀分布假设可以得到,低质量平台宜采取“分而治之”的策略,高质量平台则宜“因时而动”.%A general-purpose model associated with vertically differentiated two-sided markets is established based on an function. Using the general-purpose model, the paper discusses the features of market equilibriums in both a monopoly and a duopoly markets, and explores strategic effects of price change in the duopoly market. The paper further studies the impact of the parameters of network externality and the variable of quality gap on equilibrium prices and profits under the assumption of uniform distribution of consumer preference. The following conclusions are obtained by using the general-purpose model. Firstly, a monopoly platform can coordinate the price structure of the two sides more effectively than duopoly platforms. Secondly, a positive feedback exists in competition between duopoly platforms. Thirdly, prices have strategic complementary effect in duopoly competition, and this effect is stronger on the downstream side than on the upstream side. Under the assumption of uniform distribution, the paper finds that the low-quality platform should take the strategy of "divide and conquer", while the high-quality platform should exert the strategy of "act according to circumstances".

  19. Numerical Study of Mixed Convection of the Nanofluids in Two-Sided Lid-Driven Square Cavity with a Pair of Triangular Heating Cylinders

    Directory of Open Access Journals (Sweden)

    Zoubair Boulahia

    2016-01-01

    Full Text Available A numerical study is carried out concerning mixed convection of the nanofluid in two-sided lid-driven square cavity with a pair of triangular heat sources. The upper and bottom moving walls are thermally insulated while the left and right walls are cooled at constant temperature. Two-dimensional Navier-Stokes and energy equations are solved using the finite volume discretization method with SIMPLE algorithm. The method used is validated against previous works. Two cases were considered depending on the direction of moving walls. Effects of various design parameters such as Richardson number (0.1≤Ri≤100, nanoparticle volume fraction (0≤φ≤0.05, and size (25 nm≤dp≤145 nm and type (Cu,Al2O3,TiO2 of nanoparticles on the heat transfer rate are investigated. The results of this investigation illustrate that, by reducing the diameter of the nanoparticles and Ri, the heat transfer rate increases. Moreover, it is found that by changing horizontal direction of the moving walls the heat transfer rate variation is negligible.

  20. Topological analysis of the periodic structures in a harmonically driven bubble oscillator near Blake's critical threshold: Infinite sequence of two-sided Farey ordering trees

    Energy Technology Data Exchange (ETDEWEB)

    Hegedűs, Ferenc, E-mail: hegedusf@hds.bme.hu

    2016-03-06

    The topology of the stable periodic orbits of a harmonically driven bubble oscillator, the Rayleigh–Plesset equation, in the space of the excitation parameters (pressure amplitude and frequency) has been revealed numerically. This topology is governed by a hierarchy of two-sided Farey trees initiated from a unique primary structure defined also by a simple asymmetric Farey tree. The sub-topology of each of these building blocks is driven by a homoclinic tangency of a periodic saddle. This self-similar organisation is a suitable basis for a general description, since it is in good agreement with partial results obtained in other periodically forced oscillators and iterated maps. The applied ambient pressure in the model is near but still below Blake's critical threshold. Therefore, this paper is also a straightforward continuation of the work of Hegedűs [1], who first found numerical evidence for the existence of stable, period 1 solutions beyond Blake's threshold. The present findings are crucial for the extension of the available numerical results from period 1 to arbitrary periodicity. - Highlights: • Spherical gas/vapour bubble in water has been examined numerically. • The bubble model was the Rayleigh–Plesset equation excited harmonically. • Topology of stable periodic solutions has been found near Blake's threshold.

  1. Oily skin

    Science.gov (United States)

    ... keep your skin clean using warm water and soap, or a soapless cleanser. Clean your face with astringent pads if frequent face washing causes irritation. Use only water-based or oil-free cosmetics if you have oily skin. Your ...

  2. Your Skin

    Science.gov (United States)

    ... your body. Without skin, people's muscles, bones, and organs would be hanging out all over the place. Skin holds everything together. It also: protects our bodies helps keep our bodies at just the right temperature allows us to have the sense of touch Don't Miss Your Epidermis The ...

  3. Effectiveness of two-sided UV-C treatments in inhibiting natural microflora and extending the shelf-life of minimally processed 'Red Oak Leaf' lettuce.

    Science.gov (United States)

    Allende, Ana; McEvoy, James L; Luo, Yaguang; Artes, Francisco; Wang, Chien Y

    2006-05-01

    The use of UV-C radiation treatments to inhibit the microbial growth and extend the shelf-life of minimally processed 'Red Oak Leaf' lettuce was investigated. Initially, UV-C resistance of 20 bacterial strains from different genera often associated with fresh produce (Enterobacter, Erwinia, Escherichia, Leuconostoc, Pantoea, Pseudomonas, Rahnela, Salmonella, Serratia and Yersinia) were tested in vitro. Most of the bacterial strains were inhibited with the minimum dose (30 J m(-2)). Erwinia carotovora, Leuconostoc carnosum, Salmonella typhimurium, and Yersinia aldovae were the most resistant strains requiring a UV-C dose of 85 J m(-2) to completely inhibit growth. An in vivo study consisted of treating minimally processed 'Red Oak Leaf' lettuce (Lactuca sativa) with UV-C at three radiation doses (1.18, 2.37 and 7.11 kJ m(-2)) on each side of the leaves and storing the product under passive MAP conditions at 5 degrees C for up to 10 days. The gas composition inside packages varied significantly among the treatments, with CO2 concentrations positively and O2 concentrations negatively correlating with the radiation dose. All the radiation doses were effective in reducing the natural microflora of the product, although the highest doses showed the greatest microbial inhibitions. Taking into account the microbial limit set by Spanish legislation [Boletín Oficial del Estado (BOE), 2001. Normas de higiene para la elaboración, distribución y comercio de comidas preparadas, Madrid, Spain, Real Decreto 3484/2000, pp. 1435-1441], all UV-C treatments extended the shelf-life of the product. However, the 7.11 kJ m(-2) dose induced tissue softening and browning after 7 days of storage at 5 degrees C. Therefore, the use of two sided UV-C radiation, at the proper dose, is effective in reducing the natural microflora and extending the shelf-life of minimally processed 'Red Oak Leaf' lettuce.

  4. 双边多工位装配线平衡问题%Heuristic algorithm of two-sided with multi-parallel stations assembly line balancing

    Institute of Scientific and Technical Information of China (English)

    张宏林; 殷复鹏; 吴爱华

    2013-01-01

    针对装配线上一个位置左右两边各有多个工位的装配线平衡问题建立数学模型,提出一种启发式平衡算法.该算法分为两个阶段,阶段1从未分配的作业元素中找出能够分配给某一位置的作业,构成集合W;阶段2按照不违背作业优先关系、方位约束和工位时间不超过节拍的原则,把W中的部分或全部作业元素分配到该位置内的各工位上;依此循环,直至所有作业元素分配完毕.以某重型汽车装配翻车前的装配线平衡为例,说明了所提算法的有效性.%To study the complex assembly line balancing problem, such as two-sided with multi-stations assembly line balancing problem, a mathematical model based on some assumptions to this problem was set up and a heuristic balancing algorithm was proposed. The algorithm had two phases. Phase one was to find out the operations which could be assigned to one position, corresponding to the constraint conditions in the mathematical model, and set up the set W with them. And phase two was to select and assign operations from W to the right station of the position without violating rules as precedence, position constraint and station time. All operations' assignments were completed based on this cycle. Finally, a truck assembly line balancing problem was provided as example to verify the effectiveness of the algorithm.

  5. 羧甲基壳聚糖膜对人皮肤黑素细胞的生物相容性研究%Biocompatibility of carboxymethyl chitosan membranes with human skin melanocytes

    Institute of Scientific and Technical Information of China (English)

    孔玉龙; 王克玉; 张秀文; 马伟元

    2014-01-01

    Objective To study the biocompatibility of carboxymethyl chitosan (CMCS) membrane with melanocytes from healthy human skin,and to investigate the feasibility to transport and carry melanocytes by using CMCS membrane.Methods CMCS membrane was prepared by a casting method combined with a glutaraldehydebased cross-linking method.Melanocytes were isolated from the foreskin of healthy men,and subjected to primary culture and subculture.The third-passage melanocytes were classified into two groups to be cultured on the CMCS membrane (test group) or traditional culture plates (control group).Methyl thiazolyl tetrazolium (MTT) assay was performed to evaluate the proliferative activity of melanocytes,and a sodium hydroxide-based lysis method to determine melanin content.HMB45 staining was conducted,and tyrosinase activity was estimated for melanocytes.Results Inverted microscopy showed that melanocytes were evenly distributed on the CMCS membrane with a normal shape.The melanocytes adherent to the CMCS membrane stained positive for anti-HMB45 monoclonal antibody.The growth curve of the melanocytes on the CMCS membrane,which was obtained from MTT assay,demonstrated that CMCS membrane could support the normal growth of melanocytes.No significant difference was observed between the test group and control group in melanin content (0.083 ± 0.015 vs.0.066 ± 0.008,t =2.38,P > 0.01) or tyrosinase activity (0.234 ± 0.083 vs.0.241 ± 0.061,t =0.23,P > 0.05).Conclusion CMCS membrane can maintain the normal biological activity of melanocytes and have good biocompatibility with skin melanocytes.%目的 探讨羧甲基壳聚糖膜对健康人黑素细胞的生物相容性,探索羧甲基壳聚糖膜搭载黑素细胞的可行性.方法 使用流延法联合戊二醛交联法制备羧甲基壳聚糖膜,黑素细胞分离培养技术分离培养健康人黑素细胞,使用HMB45染色、MTT法、NaOH裂解法、酪氨酸酶活性检测等方法检测羧甲基壳

  6. Study on Platform Ownership in Two-sided Markets%基于双边市场的平台所有权研究

    Institute of Scientific and Technical Information of China (English)

    王昭慧; 张洪

    2011-01-01

    There are many markets in which two groups of users interact with each other via electronic platforms. These platforms enable markets to have two - sided network externality. These platforms include payment systems, portals, search engines, Internet shops, operating systems, etc. The platform of two-sided markets may be owned by independent third parties, or vertically integrated buyers or suppliers. Different ownerships can lead to differences in platform size, profit distribution and social welfare. It is important to understand different forms of platform ownership structure and their external effects.This paper is to study the impact of different platform ownership arrangements on the market structure in two-sided markets. Two ownership structures and three market structures are examined in this study. The two examined ownership structures are the independent third party-owned platform and the supplier-owned platform. The three examined market structures are monopoly, duopoly with single-homing and multi-homing. This study compares the rankings of market size, consumer surplus, supplier's profit and social welfare for these two ownership structures and three market structures.Our findings show that in the monopoly market structure suppliers are motivated for profit to own platform if the density of suppliers is more than 1.0457. The ownership is not socially preferable and government should intervene in markets. Duopoly market structure has single-homing and multi-homing forms. Three cases were compared with each other: (1) two competing platforms owned by independent third parties, (2) one common platform jointly owned by two different suppliers, (3) one platform owned by an independent third party and the other co-owned by suppliers. Our analysis results show that independent third party ownership is a socially optimal ownership structure. Supplier-ownership should be regulated in order to maximize social welfare. Interactions between two platform ownership

  7. Synchronized vortex shedding and sound radiation from two side-by-side rectangular cylinders of different cross-sectional aspect ratios

    Energy Technology Data Exchange (ETDEWEB)

    Octavianty, Ressa, E-mail: ressa-octavianty@ed.tmu.ac.jp; Asai, Masahito, E-mail: masai@tmu.ac.jp [Department of Aerospace Engineering, Tokyo Metropolitan University, 6-6 Asahigaoka, Hino, Tokyo 191-0065 (Japan)

    2015-10-15

    Synchronized vortex shedding from two side-by-side cylinders and the associated sound radiation were examined experimentally at Reynolds numbers of the order of 10{sup 4} in low-Mach-number flows. In addition to a pair of square cylinders, a pair of rectangular cylinders, one with a square cross section (d × d) and the other with a rectangular cross section (d × c) having a cross-sectional aspect ratio (c/d) of 1.2–1.5, was considered. The center-to-center distance between the two cylinders L/d was 3.6, 4.5, and 6.0; these settings were within the non-biased flow regime for side-by-side square cylinders. In case of a square cylinder pair, anti-phase synchronized vortex shedding occurring for L/d = 3.6 and 4.5 generated a quadrupole-like sound source which radiated in-phase, planar-symmetric sound in the far field. Synchronized vortex shedding from the two rectangular cylinders with different c/d also occurred with almost the same frequency as the characteristic frequency of the square-cylinder wake in the case of the small center-to-center distance, L/d = 3.6, for all the cylinder pairs examined. The synchronized sound field was anti-phase and asymmetric in amplitude, unlike the case of a square cylinder pair. For larger spacing L/d = 4.5, synchronized vortex shedding and anti-phase sound still occurred, but only for close cross-sectional aspect ratios (c/d = 1.0 and 1.2), and highly modulated sound was radiated with two different frequencies due to non-synchronized vortex shedding from the two cylinders for larger differences in c/d. It was also found that when synchronized vortex shedding occurred, near-wake velocity fluctuations exhibited high spanwise-coherency, with a very sharp spectral peak compared with the single-cylinder case.

  8. Role of two-sided crosstalk between NO and H2S on improvement of mineral homeostasis and antioxidative defense in Sesamum indicum under lead stress.

    Science.gov (United States)

    Amooaghaie, Rayhaneh; Zangene-Madar, Faezeh; Enteshari, Shekoofeh

    2017-05-01

    H2S and NO are two important gasotransmitters that modulate stress responses in plants. There are the contradictory data on crosstalk between NO and H2S in the studies. Hence, in the present study, the role of interplay between NO and H2S was assessed on the Pb tolerance of Sesamum indicum using pharmacological and biochemical approaches. Results revealed that Pb stress reduced the plant growth and the content of photosynthetic pigments and Fv/Fm ratio, increased the lipid peroxidation and the H2O2 content, elevated the endogenous contents of nitric oxide (NO), H2S and enhanced the activities of antioxidant enzymes (except APX). Additionally, concentrations of most mineral ions (K, P, Mg, Fe, Mn and Zn) in both shoots and roots decreased. Pb accumulation in roots was more than it in shoots. Both sodium hydrosulfide (NaHS as a donor of H2S) and sodium nitroprusside (SNP as an NO donor) improved the plant growth, the chlorophyll and carotenoid contents and PSII efficiency, reduced oxidative damage, increased the activities of antioxidant enzymes and reduced the proline content in Pb-stressed plants. Furthermore, both NaHS and SNP significantly restricted the uptake and translocation of Pb, thereby minimizing antagonistic effects of Pb on essential mineral contents in sesame plants. NaHS increased the NO generation and many NaHS-induced responses were completely reversed by cPTIO, as the specific NO scavenger. Applying SNP also enhanced H2S release levels in roots of Pb-stressed plants and only some NO-driven effects were partially weakened by hypotuarine (HT), as the scavenger of H2S.These findings proposed for the first time that two-sided interplay between H2S and NO might confer an increased tolerance to Pb stress via activating the antioxidant systems, reducing the uptake and translocation of Pb, and harmonizing the balance of mineral nutrient. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Chloride channels in toad skin

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Rasmussen, B E

    1982-01-01

    A study of the voltage and time dependence of a transepithelial Cl- current in toad skin (Bufo bufo) by the voltage-clamp method leads to the conclusion that potential has a dual role for Cl- transport. One is to control the permeability of an apical membrane Cl-pathway, the other is to drive Cl...

  10. Preparation of Inactivated Human Skin Using High Hydrostatic Pressurization for Full-Thickness Skin Reconstruction.

    Directory of Open Access Journals (Sweden)

    Pham Hieu Liem

    Full Text Available We have reported that high-hydrostatic-pressure (HHP technology is safe and useful for producing various kinds of decellularized tissue. However, the preparation of decellularized or inactivated skin using HHP has not been reported. The objective of this study was thus to prepare inactivated skin from human skin using HHP, and to explore the appropriate conditions of pressurization to inactivate skin that can be used for skin reconstruction. Human skin samples of 8 mm in diameter were packed in bags filled with normal saline solution (NSS or distilled water (DW, and then pressurized at 0, 100, 150, 200 and 1000 MPa for 10 minutes. The viability of skin after HHP was evaluated using WST-8 assay. Outgrowth cells from pressurized skin and the viability of pressurized skin after cultivation for 14 days were also evaluated. The pressurized skin was subjected to histological evaluation using hematoxylin and eosin staining, scanning electron microscopy (SEM, immunohistochemical staining of type IV collagen for the basement membrane of epidermis and capillaries, and immunohistochemical staining of von Willebrand factor (vWF for capillaries. Then, human cultured epidermis (CE was applied on the pressurized skin and implanted into the subcutis of nude mice; specimens were subsequently obtained 14 days after implantation. Skin samples pressurized at more than 200 MPa were inactivated in both NSS and DW. The basement membrane and capillaries remained intact in all groups according to histological and immunohistological evaluations, and collagen fibers showed no apparent damage by SEM. CE took on skin pressurized at 150 and 200 MPa after implantation, whereas it did not take on skin pressurized at 1000 MPa. These results indicate that human skin could be inactivated after pressurization at more than 200 MPa, but skin pressurized at 1000 MPa had some damage to the dermis that prevented the taking of CE. Therefore, pressurization at 200 MPa is optimal for

  11. Aging skin.

    Science.gov (United States)

    Bolognia, J L

    1995-01-16

    Aging of the skin is a composite of actinic damage, chronologic aging, and hormonal influences. The majority of changes associated with aging, such as wrinkles and solar lentigines ("liver spots"), are due to photoaging and reflect cumulative sun exposure as well as skin pigmentation. Classically, chronologic aging includes those cutaneous changes that occur in non-sun-exposed areas, such as the buttocks, and are observed in both men and women. A clinical example would be soft tissue sagging due to elastic fiber degeneration. In women, investigations into the effect of hormones on aging of the skin have concentrated on estrogens; in men, there have been a limited number of studies on the influence of testosterone. The latter have shown an age-dependent decrease in tissue androgens in pubic skin, but not scrotal or thigh skin. To date, age has not been shown to have an effect on androgen receptor binding, although a decrease in foreskin 5 alpha-reductase activity with increasing age has been described. In fibroblast cultures from foreskins, there have been conflicting results as to whether 5 alpha-reductase activity decreases in an age-dependent manner. Some of the skin changes that have been categorized as secondary to chronologic aging, such as decreased sebaceous gland activity and decreased hair growth, may actually represent a decline in the concentration of tissue androgens with increasing age. The influence of androgens on age-related changes in keratinocyte and fibroblast function remains speculative.

  12. Skin Cancer Prevention

    Science.gov (United States)

    ... Genetics of Skin Cancer Skin Cancer Screening Research Skin Cancer Prevention (PDQ®)–Patient Version What is prevention? ... prevent cancer are being studied. General Information About Skin Cancer Key Points Skin cancer is a disease ...

  13. Skin Cancer Screening

    Science.gov (United States)

    ... Genetics of Skin Cancer Skin Cancer Screening Research Skin Cancer Screening (PDQ®)–Patient Version What is screening? ... These are called diagnostic tests . General Information About Skin Cancer Key Points Skin cancer is a disease ...

  14. Dry Skin Relief

    Science.gov (United States)

    ... Advocacy priorities AADA Health System Reform Principles Drug pricing and availability CVS dermatologic formulary restrictions Access to ... Skin care for men Skin care on a budget Skin care products Skin care secrets Skin of ...

  15. Finite Element Simulation of the Stretch-Forming of Aircraft Skins

    NARCIS (Netherlands)

    Wisselink, H.H.; Boogaard, van den A.H.

    2005-01-01

    In the aerospace industry stretch forming is often used to produce skin parts. During stretch forming a sheet is clamped at two sides and stretched over a die, such that the sheet gets the shape of the die. However for complex shapes it is necessary to use expensive intermediate heat-treatments in o

  16. The isolated perfused human skin flap model: A missing link in skin penetration studies?

    Science.gov (United States)

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

    2017-01-01

    Development of effective (trans)dermal drug delivery systems requires reliable skin models to evaluate skin drug penetration. The isolated perfused human skin flap remains metabolically active tissue for up to 6h during in vitro perfusion. We introduce the isolated perfused human skin flap as a close-to-in vivo skin penetration model. To validate the model's ability to evaluate skin drug penetration the solutions of a hydrophilic (calcein) and a lipophilic (rhodamine) fluorescence marker were applied. The skin flaps were perfused with modified Krebs-Henseleit buffer (pH7.4). Infrared technology was used to monitor perfusion and to select a well-perfused skin area for administration of the markers. Flap perfusion and physiological parameters were maintained constant during the 6h experiments and the amount of markers in the perfusate was determined. Calcein was detected in the perfusate, whereas rhodamine was not detectable. Confocal images of skin cross-sections shoved that calcein was uniformly distributed through the skin, whereas rhodamine accumulated in the stratum corneum. For comparison, the penetration of both markers was evaluated on ex vivo human skin, pig skin and cellophane membrane. The proposed perfused flap model enabled us to distinguish between the penetrations of the two markers and could be a promising close-to-in vivo tool in skin penetration studies and optimization of formulations destined for skin administration.

  17. Squamous cell skin cancer

    Science.gov (United States)

    ... that reflect light more, such as water, sand, concrete, and areas that are painted white. The higher ... - skin - squamous cell; Skin cancer - squamous cell; Nonmelanoma skin cancer - squamous ...

  18. 具有并发操作的双边装配线平衡问题研究%Study on balancing problem of two sided assembly line with concurrent operation

    Institute of Scientific and Technical Information of China (English)

    杨涛; 鲁建厦; 孔令革

    2011-01-01

    介绍了双边装配线以及双边装配线平衡问题的概念;阐述了并发操作的概念,以及在双边装配线上存在的并发操作情况;分析了并发操作对双边装配线平衡问题产生的重要性以及复杂性;指出前人对双边装配线平衡问题研究的不足,并在此基础上,追加考虑并发操作影响,建立了具有并发操作的双边装配线平衡模型;介于遗传算法全局搜索能力强、具有潜在的并行性、允许使用复杂的适应度函数等优点,采用遗传算法研究了具有并发操作的双边装配线平衡模型的求解过程,并给出了详细的求解步骤;最后,将研究成果应用于某企业冰箱装配线,实例证明了模型及其算法的有效性.%The concept of two sided assembly line and its balancing problem is introduced and the concept of concurrent operation is described, and its situation which is existed on two sided assembly line is also explained. Then the importance and the complexity which is concurrent operation on two sided assembly line balancing problem is analyzed and the lack of the predecessors' researches on two sided assembly line balancing problem is pointed out, based on which a two sided assembly line with concurrent operation balancing model is built considering the impact of concurrent operation. Since genetic algorithm has the advantages of strong global search ability, potential parallelism and allows to use a complex fitness function, it is used to solve two sided assembly line with concurrent operation balancing model, where the solving steps are given in detail. Finally the research results is applied on a company refrigerator assembly line, which proves the effectiveness of model and its algorithm.

  19. Membrane dynamics

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    Current topics include membrane-protein interactions with regard to membrane deformation or curvature sensing by BAR domains. Also, we study the dynamics of membrane tubes of both cells and simple model membrane tubes. Finally, we study membrane phase behavior which has important implications...... for the lateral organization of membranes as wells as for physical properties like bending, permeability and elasticity...

  20. Skin Cancer Treatment

    Science.gov (United States)

    ... of Skin Cancer Skin Cancer Screening Research Skin Cancer Treatment (PDQ®)–Patient Version General Information About Skin Cancer ... clinical trials before, during, or after starting their cancer treatment. Some clinical trials only include patients who have ...

  1. Skin Pigmentation Disorders

    Science.gov (United States)

    Pigmentation means coloring. Skin pigmentation disorders affect the color of your skin. Your skin gets its color from a pigment called melanin. Special cells in the skin make melanin. When these cells become damaged or ...

  2. Skin Cancer Foundation

    Science.gov (United States)

    ... Host a Fundraising Event | About Us | Store The Skin Cancer Foundation The Skin Cancer Foundation is the only ... Handbook A "Sunscreen Gene"? Skin Cancer Facts & Statistics Skin Cancer Treatment Glossary Information on medications and procedures The ...

  3. Multiphoton STED and FRET in human skin: Resolving the skin barrier

    DEFF Research Database (Denmark)

    Antonescu, Irina; Dreier, Jes; Brewer, Jonathan R.

    Understanding the penetration properties of substances across biological bar- riers and membranes is vital for many areas of research. In the case of human skin, the barrier is primarily found in the stratum corneum and consists of protein-enriched cells surrounded by a lipid membrane -enriched...... excited STED and Forster Resonance Energy Transfer (FRET) microscopy to probe the structure of human skin. Super resolution optical microscopy enables resolving structures in the skin below to 60 nm allowing visualization of the stratum corneum intercellular lipid matrix and individual proteins...

  4. Skin Bleaching

    OpenAIRE

    Ahmed, Samira M.

    2015-01-01

    In this project, I aim to investigate the reasoning behind the practice of skin bleaching by analyzing the documentary ”Dark Girls”, to gain a better understanding of race and colorism issues. Also this project tries to see if there is a connection with history and if this has been a part of making the european beauty ideal determine the choices black’s make in regards to beauty.

  5. Technical Regulations Comparative Analysis of Food Contact Materials in the Two Sides of the Taiwan Strait%海峡两岸食品接触材料技术法规对比分析研究

    Institute of Scientific and Technical Information of China (English)

    赖莺; 林睿; 普旭力; 董清木; 黄宗平

    2014-01-01

    In this paper, the framework, sanitary standards, testing methodologies, etc. of technical regulations for food contact materials in the two sides of the Taiwan Strait were described. And differences on hygiene standards, material classification, food simulants, limited requirements and other aspects of food contact materials between the two sides of the Taiwan Strait were studied.%本文介绍了海峡两岸食品接触材料技术法规的框架、卫生标准和检验方法体系等情况,并对二者在食品接触材料卫生标准体系、材质分类、食品模拟物和限量要求等方面的差异进行了分析研究。

  6. Study of the transmission of two-side internal level gear and spur gear%双联内锥齿轮和圆柱齿轮传动研究

    Institute of Scientific and Technical Information of China (English)

    王镇; 沈际春; 王飞

    2001-01-01

    This paper studies the contact lines of tooth surface of the transmission of two-sides level gear and spur gear and analyses the property of engagement.%计算和研究了双联锥形齿轮和圆柱齿轮啮合时的齿面接触线,并分析了啮合时的特点和性能。

  7. 单面与双面信息广告重复效应的实证研究%An Empirical Study on One-sided VS Two-sided Advertising's Repetition Effect

    Institute of Scientific and Technical Information of China (English)

    代祺; 梁樑

    2011-01-01

    By introducing the variable of business ethics perception and integrating Optimal Arousal Theory, Processing Fluency Model, Attribution Theory and Two Factor Theory, the study compares the repetition effects differences between one and two-sided advertisements. Using inter-group experiment design, the results suggest that two-sided advertisements are processed less fluently than one-sided ones, but the percentage of accurate recall and advertisement response are higher than its counterpart. The repetition effects are inverted U shape for one-side advertisements and monotonic increase for two-sided advertisements. Thus, the wearing out effects of two-sided advertisements is delayed. The diversity in perception of business ethics play important role in determining this differences.%通过引入企业道德感知变量,并在整合最优唤醒理论、加工流畅模型、归因理论和两因素理论的基础上,深入剖析了单、双面信息广告重复效应的差异.研究结果表明:双面信息广告比单面信息广告加工更困难,但消费者对其广告正确回忆率更高,广告反应也更积极.单面信息广告的重复效应呈现先增后减的倒U趋势,而双面信息广告的重复效应呈单调递增趋势,疲劳效应延迟出现.消费者对企业道德感知的差异在很大程度上决定了单、双面信息广告重复效应的差异.

  8. Cutaneous skin tag

    Science.gov (United States)

    Skin tag; Acrochordon; Fibroepithelial polyp ... have diabetes. They are thought to occur from skin rubbing against skin. ... The tag sticks out of the skin and may have a short, narrow stalk connecting it to the surface of the skin. Some skin tags are as long as ...

  9. Translocation of Single Polymer Chain from Nanopore on a Membrane: Solvent Effect

    Institute of Scientific and Technical Information of China (English)

    GU Fang; WANG Hai-Jun

    2005-01-01

    @@ We investigate the translocation of single polymer chain through a nanopore located on a membrane with different solvents in the two sides of the membrane. For the case under study, the effect of solvents on the translocation dynamics is significant, and as a result, the mean first passage time shortens remarkably compared with that calculated in the case of good solvents on both the sides of the membrane. In addition, we also discuss the condition such that the present result holds true.

  10. Skin Keratins.

    Science.gov (United States)

    Wang, Fengrong; Zieman, Abigail; Coulombe, Pierre A

    2016-01-01

    Keratins comprise the type I and type II intermediate filament-forming proteins and occur primarily in epithelial cells. They are encoded by 54 evolutionarily conserved genes (28 type I, 26 type II) and regulated in a pairwise and tissue type-, differentiation-, and context-dependent manner. Keratins serve multiple homeostatic and stress-enhanced mechanical and nonmechanical functions in epithelia, including the maintenance of cellular integrity, regulation of cell growth and migration, and protection from apoptosis. These functions are tightly regulated by posttranslational modifications as well as keratin-associated proteins. Genetically determined alterations in keratin-coding sequences underlie highly penetrant and rare disorders whose pathophysiology reflects cell fragility and/or altered tissue homeostasis. Moreover, keratin mutation or misregulation represents risk factors or genetic modifiers for several acute and chronic diseases. This chapter focuses on keratins that are expressed in skin epithelia, and details a number of basic protocols and assays that have proven useful for analyses being carried out in skin.

  11. Anyone Can Get Skin Cancer

    Science.gov (United States)

    ... of Skin Cancer Skin Cancer Screening Research Anyone Can Get Skin Cancer Order the free Anyone Can ... rarely, younger children can develop skin cancer. How can people with dark skin get skin cancer? Although ...

  12. 海峡两岸农业合作的政策演变、成效与对策%Policy Evolution, Effects and Countermeasures on Agricultural Cooperation between Two Sides across Taiwan Strait

    Institute of Scientific and Technical Information of China (English)

    陈灵; 赖文山; 董微; 庄佩芬

    2012-01-01

    The paper summarizes the policy evolution and effects of agricultural cooperation between two sides cross Taiwan Strait. The agricultural cooperation experimental zones and Taiwan farmer' s pioneer park are the major platforms between two sides cross Taiwan Strait, but the interaction cooperative mechanism in agricultural economic bodies between two sides cross Taiwan Strait hasn't yet formed. And the countermeasures including promoting the construction of the economic zone on the west side of the Taiwan Strait, strengthening policy guidance, building the Common Market, strengthening policy innovations and cooperation in science and technology, focusing on the exchanges and the introduction of the talented human resources, and optimizing the cooperation mechanism.%总结了海峡两岸农业合作发展的政策演变过程与成效,认为在两岸农业合作中两岸农业合作试验区和台湾农民创业园是主要的连接载体,但两岸农业经济主体的合作机制尚未形成双向互动;同时提出要加快海西经济区建设,强化政策引导,建立两岸“共同市场”;加强政策创新与科技合作,注重优秀资源和人才的交流与引进;优化配置,完善两岸农业合作机制。

  13. Membrane reactor. Membrane reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shindo, Y.; Wakabayashi, K. (National Chemical Laboratory for Industry, Tsukuba (Japan))

    1990-08-05

    Many reaction examples were introduced of membrane reactor, to be on the point of forming a new region in the field of chemical technology. It is a reactor to exhibit excellent function, by its being installed with membrane therein, and is generally classified into catalyst function type and reaction promotion type. What firstly belongs to the former is stabilized zirconia, where oxygen, supplied to the cathodic side of membrane with voltage, impressed thereon, becomes O {sup 2 {minus}} to be diffused through the membrane and supplied, as variously activated oxygenous species, on the anodic side. Examples with many advantages can be given such as methane coupling, propylene oxidation, methanating reaction of carbon dioxide, etc. Apart, palladium film and naphion film also belong to the former. While examples of the latter comprise, among others, decomposition of hydrogen sulfide by porous glass film and dehydrogenation of cyclohexane or palladium alloy film, which are expected to be developed and materialized in the industry. 33 refs., 8 figs.

  14. 基于双边市场理论的苹果App Store模式研究%The App Store Model of Apple Based on the Theory of Two- Sided Markets

    Institute of Scientific and Technical Information of China (English)

    张利斌; 张广霞

    2012-01-01

    从双边市场理论的定义、识别条件、特征、分类和平台企业战略等角度,分析了苹果App store模式的特征及平台战略.%From the viewpoints of definition, identification condition, characteristics, classification and strategy of platform enterprises based on the theory of two-sided markets, we analyze the characteristics and platform strategies of the App Store Model of Apple.

  15. Development of prosthetic skin

    Science.gov (United States)

    Kilaru, Rohit

    The objective of this research was to embed tactile sensors in polyimides. This novel method could be utilized to realize prosthetic skin for sensing different kinds of mechanical stimuli. Tactile sensors have an increasing demand in medical sectors: upper and lower-limb prosthetics and in the industrial sectors: robot end-effectors, grippers and manipulators. The sensors developed are targeted for prosthetic arm tactile sensing applications. Current work presents piezoresistive differential pressure sensors fabricated on flexible polyimide film or substrate. A unique technique to bond a flexible superstrate polyimide layer to a MEMS tactile sensor array is presented in this thesis. The sensor is made of aluminium oxide membrane layer with nichrome piezoresistors as the half-Wheatstone bridge elements. Four different types of sensor designs have been characterized to obtain gauge factor of thin film nichrome. The sensor arrays with and without the superstrate film were simulated for obtaining the maximum stress, average strain and deflection of the membrane. The maximum change in output voltage was 0.8 mV. The gauge factors calculated for tactile sensor with superstrate range between 2.2 to 7.8 and without superstrate range 1.5 to 5.7.

  16. Abnormally dark or light skin

    Science.gov (United States)

    Hyperpigmentation; Hypopigmentation; Skin - abnormally light or dark ... Normal skin contains cells called melanocytes. These cells produce melanin , the substance that gives skin its color. Skin with ...

  17. Skin color - patchy

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003224.htm Skin color - patchy To use the sharing features on this page, please enable JavaScript. Patchy skin color is areas where the skin color is irregular. ...

  18. Biobased Membrane

    NARCIS (Netherlands)

    Koenders, E.A.B.; Zlopasa, J.; Picken, S.J.

    2015-01-01

    The present invention is in the field of a composition for forming a bio-compatible membrane applicable to building material, such as concrete, cement, etc., to a meth od of applying said composition for forming a bio-compatible membrane, a biocompatible membrane, use of said membrane for various pu

  19. Membrane fusion

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    At Stanford University, Boxer lab, I worked on membrane fusion of small unilamellar lipid vesicles to flat membranes tethered to glass surfaces. This geometry closely resembles biological systems in which liposomes fuse to plasma membranes. The fusion mechanism was studied using DNA zippering...... between complementary strands linked to the two apposing membranes closely mimicking the zippering mechanism of SNARE fusion complexes....

  20. TWO SIDES OF THE SAME COIN

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    With trade of over $100 billion in 2009, the importance of China and Africa bilateral exchanges are growing daily. This blooming relationship increases the need of understanding the ways of doing business.This regular column will provide a practical insight of doing business in China, including tips and advice based on experience.

  1. THE TWO SIDES OF MONEY LAUNDERING

    Directory of Open Access Journals (Sweden)

    Corina – Maria ENE

    2014-12-01

    Full Text Available The mainly goal of money laundering is to carry out more and more illegal economic transactions or activities to produce individual or groups gains and then to legitimate them. Money laundering converts illicit source of money generated by criminal activities in order to hide the connection between money and their original illegal activities. This is one of money laundering side. The second side implies corruption. While money laundering is a passing channel for illicit funds due to its criminal origin source, such funds may derive from corruption offences. All corruption’s forms represent the most important illicit funds branches for money laundering process. Corrupt people methods used to exploit the national and international financial system reflect the relationship between those two criminal activities. Criminals achieve their personal interests by hiding their corruption proceeds and transfer these gains to official economies. Corruption spread in any society entails money laundering spread, and the converse, too. There is a quite “indecent” relationship between money laundering and corruption. This paper tries to identify the multiple connections between the two phenomenons showing the negative impacts these criminal behaviours are having on the national and international economy. We conclude by highlighting the necessity of a multidisciplinary approach in order to fight against money laundering and corruption by integrating these problem frameworks at national level. International community must focus their resources on money laundering and corruption risks areas and maximize their response impact.

  2. The Two Sides of the Representative Coin

    Directory of Open Access Journals (Sweden)

    Keith Sutherland

    2011-12-01

    Full Text Available In Federalist 10 James Madison drew a functional distinction between “parties” (advocates for factional interests and “judgment” (decision-making for the public good and warned of the corrupting effect of combining both functions in a “single body of men.” This paper argues that one way of overcoming “Madisonian corruption” would be by restricting political parties to an advocacy role, reserving the judgment function to an allotted (randomly-selected microcosm of the whole citizenry, who would determine the outcome of parliamentary debates by secret ballot—a division of labour suggested by James Fishkin’s experiments in deliberative polling. The paper then defends this radical constitutional proposal against Bernard Manin’s (1997 claim that an allotted microcosm could not possibly fulfil the “consent” requirement of Natural Right theory. Not only does the proposal challenge Manin’s thesis, but a 28th Amendment implementing it would finally reconcile the competing visions that have bedevilled representative democracy since the Constitutional Convention of 1787.

  3. The Two Sides of the Representative Coin

    Directory of Open Access Journals (Sweden)

    Keith Sutherland

    2011-12-01

    Full Text Available In Federalist 10 James Madison drew a functional distinction between “parties” (advocates for factional interests and “judgment” (decision-making for the public good and warned of the corrupting effect of combining both functions in a “single body of men.” This paper argues that one way of overcoming “Madisonian corruption” would be by restricting political parties to an advocacy role, reserving the judgment function to an allotted (randomly-selected microcosm of the whole citizenry, who would determine the outcome of parliamentary debates by secret ballot—a division of labour suggested by James Fishkin’s experiments in deliberative polling. The paper then defends this radical constitutional proposal against Bernard Manin’s (1997 claim that an allotted microcosm could not possibly fulfil the “consent” requirement of Natural Right theory. Not only does the proposal challenge Manin’s thesis, but a 28th Amendment implementing it would finally reconcile the competing visions that have bedevilled representative democracy since the Constitutional Convention of 1787.

  4. The two sides of silicon detectors

    CERN Document Server

    Devine, S R

    2001-01-01

    /p/n sup + and essentially two p-n junctions within one device. With increasing bias voltage, as the electric field is extending into the detector bulk from opposite sides of the silicon detector, there are two distinct depletion regions that collect charge signal independently. Summing the signal charge from the two regions, one is able to reconstruct the initial energy of the incident particle. From Transient Current measurements it is apparent that E-field manipulation is possible by excess carrier injection, enabling a high enough E-field to extend across the width of the detector, allowing for efficient charge collection. Results are presented on in situ irradiation of silicon detector's at cryogenic temperature. The results show that irradiation at cryogenic temperatures does not detrimentally effect a silicon detectors performance when compared to its irradiation at room temperature. Operation of silicon devices at cryogenic temperatures offers the advantage of reducing radiation-induced leakage curren...

  5. The Two Sides to the Internet Coin

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Since China hooked up to the Internet in 1994, Chinese netizenship has increased from the few hundreds of thousands recorded in 1995 to its present 87 million - second largest in the world. The Internet has streamlined daily life and also influenced life concepts. The voice of the“silent majority” now heard on the Internet, speaks of and searches for solutions to psychological problems exacerbated by a transitional society.

  6. 论双面信息策略在突发公共事件传播中的应用%On the Application of Two-sided Message Strategy in the Communication of Public Emergencies

    Institute of Scientific and Technical Information of China (English)

    刘中刚

    2015-01-01

    该研究基于归因理论、疫苗理论、锚定理论,结合相关文献分析了在突发公共事件传播中运用双面信息策略的必要性和可行性,阐述了双面信息策略在突发公共事件传播中提高可信度及抵制谣言的作用,探索具体的实施策略。该研究为突发公共事件的传播和谣言的抵制研究奠定了一定的理论基础,并能为相关应用研究提供理论指导。%Based on the attribution theory, vaccine theory and anchoring theory and taking in to account some relevant literatures, this paper analyzes the necessity and feasibility of applying two-sided message strategy in the communication of public emergencies, argues that the two-sided message strategy in the communication of public emergencies can be used to improve credibility and to resist to rumors and explores some specific implementation methods. The findings of this paper set a theoretic foundation for further researches into the communication of public emergencies and resistance to rumors and provide theoretic guidance to relevant application researches.

  7. Biologic and synthetic skin substitutes: An overview

    Directory of Open Access Journals (Sweden)

    Halim Ahmad

    2010-10-01

    Full Text Available The current trend of burn wound care has shifted to more holistic approach of improvement in the long-term form and function of the healed burn wounds and quality of life. This has demanded the emergence of various skin substitutes in the management of acute burn injury as well as post burn reconstructions. Skin substitutes have important roles in the treatment of deep dermal and full thickness wounds of various aetiologies. At present, there is no ideal substitute in the market. Skin substitutes can be divided into two main classes, namely, biological and synthetic substitutes. The biological skin substitutes have a more intact extracellular matrix structure, while the synthetic skin substitutes can be synthesised on demand and can be modulated for specific purposes. Each class has its advantages and disadvantages. The biological skin substitutes may allow the construction of a more natural new dermis and allow excellent re-epithelialisation characteristics due to the presence of a basement membrane. Synthetic skin substitutes demonstrate the advantages of increase control over scaffold composition. The ultimate goal is to achieve an ideal skin substitute that provides an effective and scar-free wound healing.

  8. Mathematical Model to Predict Skin Concentration after Topical Application of Drugs

    Directory of Open Access Journals (Sweden)

    Hiroaki Todo

    2013-12-01

    Full Text Available Skin permeation experiments have been broadly done since 1970s to 1980s as an evaluation method for transdermal drug delivery systems. In topically applied drug and cosmetic formulations, skin concentration of chemical compounds is more important than their skin permeations, because primary target site of the chemical compounds is skin surface or skin tissues. Furthermore, the direct pharmacological reaction of a metabolically stable drug that binds with specific receptors of known expression levels in an organ can be determined by Hill’s equation. Nevertheless, little investigation was carried out on the test method of skin concentration after topically application of chemical compounds. Recently we investigated an estimating method of skin concentration of the chemical compounds from their skin permeation profiles. In the study, we took care of “3Rs” issues for animal experiments. We have proposed an equation which was capable to estimate animal skin concentration from permeation profile through the artificial membrane (silicone membrane and animal skin. This new approach may allow the skin concentration of a drug to be predicted using Fick’s second law of diffusion. The silicone membrane was found to be useful as an alternative membrane to animal skin for predicting skin concentration of chemical compounds, because an extremely excellent extrapolation to animal skin concentration was attained by calculation using the silicone membrane permeation data. In this chapter, we aimed to establish an accurate and convenient method for predicting the concentration profiles of drugs in the skin based on the skin permeation parameters of topically active drugs derived from steady-state skin permeation experiments.

  9. Skin Care and Aging

    Science.gov (United States)

    ... version of this page please turn Javascript on. Skin Care and Aging How Aging Affects Skin Your skin changes with age. It becomes thinner, ... to make it feel and look better. Dry Skin and Itching Click for more information Many older ...

  10. Graphene membrane as a pressure gauge

    Science.gov (United States)

    Milovanović, S. P.; Tadić, M. Ž.; Peeters, F. M.

    2017-07-01

    Straining graphene results in the appearance of a pseudo-magnetic field which alters its local electronic properties. Applying a pressure difference between the two sides of the membrane causes it to bend/bulge resulting in a resistance change. We find that the resistance changes linearly with pressure for bubbles of small radius while the response becomes non-linear for bubbles that stretch almost to the edges of the sample. This is explained as due to the strong interference of propagating electronic modes inside the bubble. Our calculations show that high gauge factors can be obtained in this way which makes graphene a good candidate for pressure sensing.

  11. Basolateral Cl- channels in the larval bullfrog skin epithelium

    DEFF Research Database (Denmark)

    Hillyard, Stanley D.; Rios, K.; Larsen, Erik Hviid

    2002-01-01

    The addition of 150 U/ml nystatin to the mucosal surface of isolated skin from larval bullfrogs increases apical membrane permeability and allows a voltage clamp to be applied to the basolateral membrane. With identical Ringer's solutions bathing either side of the tissue the short-circuit current...

  12. 基于置信规则库推理的多属性双边匹配决策方法%Belief rule base inference methodology for two-sided matching decision with multi-attribute

    Institute of Scientific and Technical Information of China (English)

    方志坚; 杨隆浩; 傅仰耿; 陈建华

    2016-01-01

    This thesis presents a tentative study on a new two-sided matching approach,which is proposed to solve the two-sided matching problem with uncertain information and multiple attributes.The multi-attributes matching decision making(MAMDM)problem is one of the most important key points in the two-sided matching study,which has evoked great attention for the scholars in recent years.A belief rule-base inference methodology using the evidence reasoning approach(RIMER)has been introduced in this thesis to solve the problem of MAMDM.At the beginning of this thesis,the authors explain the reason why they choose to use belief degree.The current research on the problem of MAMDM is mainly restricted to the study of a kind of two-sided matching,whose evaluation information is linguistic values or interval values.But there exists a lack of study in belief degree as evaluation value. As belief degree can be used to deal with different kinds of uncertain and incomplete information,using it as evaluation value may trigger a new breakthrough in the study of MAMDM.Through the analysis of simulation ex-periments datas and the application of RIMER,belief degrees evaluation information is converted into different levels of confidence information.Then a 0-1 programming model is built by making use of different levels of confidence information to obtain a final matching scheme.It is also pointed out in the thesis that an output error may be caused when BRB(belief rule-base)input is higher than threshold value.To solve this problem,the authors propose that the input value can be incorporated into the uncertainty by the adoption of cutting method.If cutting method is not suitable,linear mapping method can be applied to reduce the influence of the results.The case study analysis shows that it is feasible and effective to adopt the new proposed approach to solve the problem of multi-attributes matching decision making.%针对具有不确定信息的多属性双边匹配决策问题,引

  13. Membranous nephropathy

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/000472.htm Membranous nephropathy To use the sharing features on this page, please enable JavaScript. Membranous nephropathy is a kidney disorder that leads to changes ...

  14. Fouling-induced enzyme immobilization for membrane reactors

    DEFF Research Database (Denmark)

    Luo, Jianquan; Meyer, Anne S.; Jonsson, Gunnar Eigil

    2013-01-01

    A simple enzyme immobilization method accomplished by promoting membrane fouling formation is proposed. The immobilization method is based on adsorption and entrapment of the enzymes in/on the membrane. To evaluate the concept, two membrane orientations, skin layer facing feed (normal mode......, but the reverse mode allowed for higher enzyme loading and stability, and irreversible fouling (i.e. pore blocking) developed more readily in the support structure than in the skin layer. Compared with an enzymatic membrane reactor (EMR) with free enzymes, the novel EMR with enzymes immobilized in membrane...... support improved the enzyme reusability (especially for ADH), and reduced the product inhibition (especially for GDH). © 2013 Elsevier Ltd....

  15. 双边市场中平台企业兼容策略选择研究%Research on Compatibility Strategy of Platforms in Two-sided Markets

    Institute of Scientific and Technical Information of China (English)

    刘大为; 李凯

    2011-01-01

    为了研究双边市场中平台企业的兼容策略选择,构建了反映不同兼容策略的双边市场模型.假设一个垄断者同时拥有两个存在横向差异的平台,运用两阶段博弈的思想分析了平台两边用户的兼容策略选择,发现两边都希望平台是完全兼容的;进而分析了平台企业的兼容策略选择,发现如果没有新用户的进入,平台之间的任何兼容策略都是无差异的,但如果存在新用户的进入,则完全兼容是垄断者的最优策略选择.%To analysis the compatibility strategy of platforms in two-sided markets, we introduce a two-sided market model which involves various compatibility regimes.We suppose there is a monopolist operating two platforms with horizontal differentiation.The whole situation is modeled as a two-stage game.Firstly we analyze the compatibility mode of two-type agents and find that both of them prefer full compatibility regimes.Then we analyze the compatibility mode of platforms owner and find that the monopolist' s profit is independent of the compatibility ' regime if there is no entry to the market, but if there is some new agent the monopolist' s best regime is also full compatibility.

  16. 求解双边装配线第二类平衡问题的一种蚁群算法∗%Ant Algorithm for Two-sided Assembly Line Balancing of Type-2

    Institute of Scientific and Technical Information of China (English)

    胡俊逸; 张则强; 金初云

    2016-01-01

    Two-sided assembly line problem is more difficult than one-sided assembly line problem as the task distribution procedure. In this problem, besides the precedence constraints among tasks, the operation directions constraints of tasks and the requirement of parallel work should also be taken into consideration. The mathematical model and an ant colony algorithm were constructed to solve the Two-sided Assembly Line Balancing Problem of type-2(TALBP-Ⅱ). A hybrid ant-based search rule and a heuristic task distribu-tion rule were used in order to establish a feasible solution, global pheromone trail update and the optimum solution search strategy were considered. The feasibility of this algorithm was indicated by a case of a loader final assembly line.%双边装配线在任务分配过程中,除考虑任务先后关系约束外还需兼顾任务操作方位约束及任务操作的并行性要求。针对双边装配线第二类平衡问题提出了数学模型并构建了一种蚁群算法。此算法采用蚁群综合搜索规则、启发式任务分配规则构造一个可行解,对最优解的搜索过程提出了可行的规划方案。最后,通过为某型装载机的实例提出多组较好的平衡方案,验证了此算法的有效性。

  17. Study on the pricing of smartphone operating system based on two-sided markets%基于双边市场理论智能手机操作系统定价研究

    Institute of Scientific and Technical Information of China (English)

    李文文

    2014-01-01

    Market of smartphone operating system has the characteristics of the two-sided mar-ket.Based on the theory of two-sided market,a Hotelling model is established to study the rela-tionships of smartphone operating system vendor,mobile phone application software developer and the terminal consumer.Three conclusions are reached.First,the deduction proportion that operating system vendors take from developers depends on the differences between the cross-group externalities of consumer and developer.Second,consumer price is negatively correlated with the cross-group externalities of consumer and developer and positively correlated with their appetite of operating system.Third,the profit of operating system vendor is positively correlated with the consumer and developer’s appetite of operating system and negatively with their cross-group externalities.%智能手机操作系统市场具有双边市场特征。借鉴双边市场理论,通过建立 Hotelling 模型来研究智能手机操作系统厂商,应用开发商以及消费者之间的关系。研究表明智能手机操作系统厂商的分成比例取决于消费者和开发商的交叉网络外部性;消费者价格和消费者以及开发商的交叉网络外部性负相关,而与两者的偏好程度正相关;操作系统厂商的利润与消费者和开发商的偏好程度正相关,而与两者的交叉网络外部性负相关。

  18. Fabrication of large flat gallium nitride templates with extremely low dislocation densities in the 106 cm-2 range by novel two-side hydride vapor-phase epitaxial growth

    Science.gov (United States)

    Fujikura, Hajime; Konno, Taichiro

    2017-10-01

    Large GaN templates with high flatness (i.e., negligible wafer bowing and smooth as-grown surfaces) and low threading dislocation densities (TTDs) were fabricated by a novel two-side hydride vapor-phase epitaxial (HVPE) growth, beginning with deposition of polycrystalline GaN on the rear side of the wafer. Appropriate gas-flow management realized by our homemade HVPE system permitted the growth of a GaN layer with a smooth as-grown surface and excellent thickness uniformity on the front surfaces of 4- or 6-inch patterned sapphire substrates (PSSs). However, when the grown thickness exceeded 20 μm, single-side HVPE-growth induced fractures in GaN crystals. The fracture resistance of the GaN increased markedly when it was in a cleavage-resistant polycrystalline form (poly-GaN), permitting its growth to a thickness of 100 μm. In the presence of a back-side poly-GaN layer, extremely thick GaN crystal layers could be grown on the front side without fractures. An 80-μm-thick GaN template fabricated by two-side growth on a 4-inch PSS had a device-quality surface, negligible bowing, and low TDD (7 × 106 cm-2). Issues of high fabrication costs, unavailability of large-size wafers, and large off-angle variations associated with native GaN wafers could be overcome by using our high-quality GaN templates as alternative substrates.

  19. Antiseptic skin agents for percutaneous procedures.

    Science.gov (United States)

    Lepor, Norman E; Madyoon, Hooman

    2009-01-01

    Infections associated with percutaneously implanted devices, such as pacemakers, internal cardiac defibrillators, and endovascular prostheses, create difficult and complex clinical scenarios because management can entail complete device removal, antibiotic therapy, and prolonged hospitalization. A source for pathogens is often thought to be the skin surface, making skin preparation at the time of the procedure a critical part of minimizing implantation of infected devices and prostheses. The most common skin preparation agents used today include products containing iodophors or chlorhexidine gluconate. Agents are further classified by whether they are aqueous-based or alcoholbased solutions. Traditional aqueous-based iodophors, such as povidone-iodine, are one of the few products that can be safely used on mucous membrane surfaces. Alcohol-based solutions are quick, sustained, and durable, with broader spectrum antimicrobial activity. These agents seem ideal for percutaneous procedures associated with prosthesis implantation, when it is critical to minimize skin colony counts to prevent hardware infection.

  20. [The many facets of inherited skin fragility].

    Science.gov (United States)

    Has, C; Kiritsi, D

    2014-06-01

    The inherited skin fragility encompasses a heterogeneous group of disorders, collectively designated as epidermolysis bullosa, characterized by recurrent mechanically induced blisters, erosions or wounds. The spectrum of clinical manifestations is broad, as well as the molecular background. Besides the skin, mucosal membranes and other organs can be affected. In real-world practice, patients with mild genetic skin fragility usually do not require medical care and often remain underdiagnosed. In contrast, the well-defined severe EB subtypes are recognized based on typical clinical features. The molecular diagnostics is usually performed in order to allow genetic counselling and prenatal diagnosis. Besides wound care and careful management of the disease complications, new experimental targeted therapies are being developed. New very rare forms of inherited skin fragility have been identified with modern sequencing methods.

  1. Influence of variation in eumelanin content on absorbance spectra of liquid skin-like phantoms

    CSIR Research Space (South Africa)

    Smit, Jacoba E

    2011-01-01

    Full Text Available The attenuation behaviour of two different types of skin-like phantoms representing the range of Skin Types I to VI were investigated and compared to real human skin. Intralipid and PheroidTM artificial lipid membrane vesicles respectively were...

  2. Firing membranes

    NARCIS (Netherlands)

    Kappert, Emiel Jan

    2015-01-01

    Thermal processing is commonly employed to alter the chemistry and microstructure of membrane layers. It can shape, strengthen, and give functionality to a membrane. A good understanding of the processes taking place during the thermal processing of a membrane material allows for optimization and tu

  3. Membrane Biophysics

    CERN Document Server

    Ashrafuzzaman, Mohammad

    2013-01-01

    Physics, mathematics and chemistry all play a vital role in understanding the true nature and functioning of biological membranes, key elements of living processes. Besides simple spectroscopic observations and electrical measurements of membranes we address in this book the phenomena of coexistence and independent existence of different membrane components using various theoretical approaches. This treatment will be helpful for readers who want to understand biological processes by applying both simple observations and fundamental scientific analysis. It provides a deep understanding of the causes and effects of processes inside membranes, and will thus eventually open new doors for high-level pharmaceutical approaches towards fighting membrane- and cell-related diseases.

  4. [Sarcoidosis of the skin].

    Science.gov (United States)

    Suga, Y; Ogawa, H

    1994-06-01

    Sarcoidosis is characterized by formation of epithelioid-cell tubercules, without caseation, of the affected organ systems. The mediastinum, peripheral lymph nodes and eyes, in addition to the skin, are most frequently affected. Between 10% and 30% of patients with systemic sarcoidosis in Japan have skin lesions. Skin sarcoidosis is morphologically classified into three basic groups, erythema nodosum, scar sarcoidosis and skin sarcoid. Skin sarcoid is characterized by specific cutaneous lesions of sarcoidosis, and may take nodular, plaque, angiolupoid, subcutaneous and some other forms. Clinical manifestations of the cutaneous lesions are usually asymptomatic and polymorphous. Skin biopsy is, however, often highly useful for confirming a diagnosis of sarcoidosis.

  5. Skin Stem Cells in Skin Cell Therapy

    Directory of Open Access Journals (Sweden)

    Mollapour Sisakht

    2015-12-01

    Full Text Available Context Preclinical and clinical research has shown that stem cell therapy is a promising therapeutic option for many diseases. This article describes skin stem cells sources and their therapeutic applications. Evidence Acquisition Compared with conventional methods, cell therapy reduces the surgical burden for patients because it is simple and less time-consuming. Skin cell therapy has been developed for variety of diseases. By isolation of the skin stem cell from the niche, in vitro expansion and transplantation of cells offers a surprising healing capacity profile. Results Stem cells located in skin cells have shown interesting properties such as plasticity, transdifferentiation, and specificity. Mesenchymal cells of the dermis, hypodermis, and other sources are currently being investigated to promote regeneration. Conclusions Because skin stem cells are highly accessible from autologous sources and their immunological profile is unique, they are ideal for therapeutic approaches. Optimization of administrative routes requires more investigation own to the lack of a standard protocol.

  6. Use of autologous tissue engineered skin to treat porcine full-thickness skin defects

    Institute of Scientific and Technical Information of China (English)

    CAI Xia; CAO Yi-lin; CUI Lei; LIU Wei; GUAN Wen-xiang

    2005-01-01

    Objective: To explore a feasible method to repair full-thickness skin defects utilizing tissue engineered techniques. Methods: The Changfeng hybrid swines were used and the skin specimens were cut from the posterior limb girdle region, from which the keratinocytes and fibroblasts were isolated and harvested by trypsin, EDTA, and type II collagenase. The cells were seeded in Petri dishes for primary culture. When the cells were in logarithmic growth phase, they were treated with trypsin to separate them from the floor of the tissue culture dishes. A biodegradable material, Pluronic F-127, was prefabricated and mixed with these cells, and then the cell-Pluronic compounds were seeded evenly into a polyglycolic acid (PGA). Then the constructs were replanted to the autologous animals to repair the full-thickness skin defects. Histology and immunohistochemistry of the neotissue were observed in 1, 2, 4, and 8 postoperative weeks. Results: The cell-Pluronic F-127-PGA compounds repaired autologous full-thickness skin defects 1 week after implantation. Histologically, the tissue engineered skin was similar to the normal skin with stratified epidermis overlying a moderately thick collageneous dermis. Three of the structural proteins in the epidermal basement membrane zone, type IV collagen, laminin, and type VII collagen were detected using immunohistochemical methods. Conclusions: By studying the histology and immunohistochemistry of the neotissue, the bioengineered skin graft holds great promise for improving healing of the skin defects.

  7. Learning about Skin Cancer

    Science.gov (United States)

    ... information, in skin cells, creating "misspellings" in their genetic code and, as a result, alter the function of those cells. Cancers generally are caused by a combination of environmental and genetic factors. With skin cancer, the environment plays a ...

  8. Examine Your Skin

    Medline Plus

    Full Text Available ... Items Awareness Store In Memory Melanoma Info Melanoma Facts Melanoma Prevention Sunscreen Suggestions Examine Your Skin Newly ... use this video. UPDATED: November 23, 2016 Melanoma Facts Melanoma Prevention Sunscreen Suggestions Examine Your Skin Newly ...

  9. Examine Your Skin

    Medline Plus

    Full Text Available ... Support Donate Share Facebook Twitter Newsletter Examine Your Skin Watch the video below and in only two minutes, you can learn to examine your skin. A special thanks to Dr. Martin Weinstock, MD, ...

  10. Examine Your Skin

    Medline Plus

    Full Text Available ... Support Donate Share Facebook Twitter Newsletter Examine Your Skin Watch the video below and in only two minutes, you can learn to examine your skin. A special thanks to Dr. Martin Weinstock, MD, ...

  11. Bleeding into the skin

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003235.htm Bleeding into the skin To use the sharing features on this page, please enable JavaScript. Bleeding into the skin can occur from broken blood ...

  12. Examine Your Skin

    Medline Plus

    Full Text Available ... Store In Memory Melanoma Info Melanoma Facts Melanoma Prevention Sunscreen Suggestions Examine Your Skin Newly Diagnosed? Understanding ... video. UPDATED: November 23, 2016 Melanoma Facts Melanoma Prevention Sunscreen Suggestions Examine Your Skin Newly Diagnosed? Understanding ...

  13. Examine Your Skin

    Medline Plus

    Full Text Available ... Store In Memory Melanoma Info Melanoma Facts Melanoma Prevention Sunscreen Suggestions Examine Your Skin Newly Diagnosed? Understanding ... video. UPDATED: November 23, 2016 Melanoma Facts Melanoma Prevention Sunscreen Suggestions Examine Your Skin Newly Diagnosed? Understanding ...

  14. Research on Pricing Strategy of Online Group Buying in Two-sided Network%双边网络环境下的网络团购定价策略研究

    Institute of Scientific and Technical Information of China (English)

    唐方成; 池坤鹏

    2013-01-01

    Online group buying is a business model characterized with two-sided market.The challenging problems that group buying firms face are how to meet the needs of consumers and suppliers and how to develop the right bilateral price structure and pricing level.According to the nature of two-sided markets group purchase site,this paper constructs the pricing models by considering multi-homing of consumers and suppliers.Furthermore,the pricing models under the monopoly pattern and competition equilibrium are presented.This study investigates the effect of some key factors of platform fixed cost,search matching,degree of service differentiation and cross-group network effects change on pricing mechanism.Finally,a case study of Lashou is employed to test the proposed pricing mechanism and tactics.%网络团购是一种典型的具有双边市场特征的商业模式,如何满足消费者和商户的需求,合理制定双边价格结构和定价水平已成为团购网站运营企业面临的挑战性问题.本文应用双边市场理论,构建了网络团购双边客户多归属条件下的定价模型,分析了垄断模式和竞争均衡状态下的定价机制,并讨论了网站固定成本、搜索匹配度、服务差异化程度以及交叉网络效应等关键因素变化对网络团购平台企业定价策略的影响.最后,通过拉手网的案例分析佐证了文中提出的定价机制与策略.

  15. Discussion on Development Strategy of Internet Recruitment Market in China Based on Two -sided Markets Theory%基于双边市场视角的我国网络招聘市场发展策略探讨

    Institute of Scientific and Technical Information of China (English)

    赵清斌; 纪汉霖

    2012-01-01

    China's internet recruitment industry developed fast although it started later than western eourtries. There is Great potential in China's in- ternet recruitment market which is in the golden age of its development. At present the enterprises compete fiercely in the market, meanwhile their homogenization is very serious. The intemet recruitment market is a two -sided market made up of job hunter, recruiting website and enterprise us- er in essence. Based on two - sided markets theory, the market pattern and characteristics of internet reernitment platform and enterprise competi- tion behavior were studied. And based on the understanding of current situation and the trend of China's internet recruitment market, we discussed and put forward competitive strategies and suggestions such as pricing, differentiation, entrance and bundling for interuet recruitment market of China so as to provide a new perspective for the research of internet recruiting and provide reference for China's network recruitment platform enterprises formulating business tactics and development strategies.%我国的网络招聘产业虽然起步较晚,但发展较快,中国网络招聘行业市场潜力巨大,正处于高速发展的黄金期,目前市场竞争激烈,同质化严重。网络招聘的产业实质,是一个由求职者、招聘网站和企业用户组成的双边市场。基于双边市场理论,对网络招聘平台的市场形态和特点、网络招聘市场中的企业竞争行为等问题展开研究,在对我国网络招聘市场发展现状和趋势认识的基础上,探讨并提出了定价、差异化、进入、捆绑策略等多方面的网络招聘市场竞争策略和建议,以期为网络招聘的研究提供一个新的视角,并为网络招聘平台企业制定企业策略和发展战略提供参考。

  16. 论海峡两岸刑事管辖的冲突及消解%On the Resolution of Criminal Jurisdiction Conflict between the Two Sides of the Taiwan Straits

    Institute of Scientific and Technical Information of China (English)

    江国华; 赖彦君

    2016-01-01

    The conflict of criminal jurisdiction between the two sides of the Taiwan Straits stem from their legisla⁃tive differences. The conflict caused by such differences result in the two sides ’failure to recognize each other ’s crimi⁃nal judgment and in dual decisions to repatriated criminals. This situation is contrary to the legal principle of prohibition against double jeopardy;it is also a hindrance to the development of the cross-strait judicial cooperation. To resolve this conflict ,it is time to put on the agenda the establishment of a mechanism for joint criminal jurisdiction;the key point is to specify the division of jurisdiction for each side so that both sides will recognize and implement the court ’s criminal de⁃cision of the other side. Thereby ,a coordinated cross-strait judicial system and a benign interaction are expected to be established.%两岸刑事管辖的冲突直接源自于各自立法上的差异。而这种由立法差异所导致的两岸刑事管辖权之冲突,使得海峡两岸互不承认对方法院刑事判决,从而造成罪犯遣返后出现双重判决之情形。如此,既有违禁止双重危险之法治原则,亦有碍两岸司法合作之发展。为解决这种冲突,建构海峡两岸刑事司法合作管辖机制应当提上议事议程,以具体划分两岸管辖权,并相互认可、执行对方法院的刑事判决为重点内容。借此,推动海峡两岸间协作管辖制度的建立,并最终促成两岸司法之良性互动。

  17. Human skin penetration of silver nanoparticles through intact and damaged skin.

    Science.gov (United States)

    Larese, Francesca Filon; D'Agostin, Flavia; Crosera, Matteo; Adami, Gianpiero; Renzi, Nadia; Bovenzi, Massimo; Maina, Giovanni

    2009-01-01

    There is a growing interest on nanoparticle safety for topical use. The benefits of nanoparticles have been shown in several scientific fields, but little is known about their potential to penetrate the skin. This study aims at evaluating in vitro skin penetration of silver nanoparticles. Experiments were performed using the Franz diffusion cell method with intact and damaged human skin. Physiological solution was used as receiving phase and 70 microg/cm2 of silver nanoparticles coated with polyvinylpirrolidone dispersed in synthetic sweat were applied as donor phase to the outer surface of the skin for 24h. The receptor fluid measurements were performed by electro thermal atomic absorption spectroscopy (ETAAS). Human skin penetration was also determined by using transmission electron microscope (TEM) to verify the location of silver nanoparticles in exposed membranes. Median silver concentrations of 0.46 ng cm(-2) (range skin (eight cells) and on damaged skin (eight cells), respectively. Twenty-four hours silver flux permeation in damaged skin was 0.62+/-0.2 ng cm(-2) with a lag time <1h. Our experimental data showed that silver nanoparticles absorption through intact and damaged skin was very low but detectable, and that in case of damaged skin it was possible an increasing permeation of silver applied as nanoparticles. Moreover, silver nanoparticles could be detected in the stratum corneum and the outermost surface of the epidermis by electron microscopy. We demonstrated for the first time that silver applied as nanoparticles coated with polyvinylpirrolidone is able to permeate the damaged skin in an in vitro diffusion cell system.

  18. Ultrasound skin imaging.

    Science.gov (United States)

    Alfageme Roldán, F

    2014-12-01

    The interaction of high-frequency ultrasound waves with the skin provides the basis for noninvasive, fast, and accessible diagnostic imaging. This tool is increasingly used in skin cancer and inflammatory conditions as well as in cosmetic dermatology. This article reviews the basic principles of skin ultrasound and its applications in the different areas of dermatology.

  19. Skin self-exam

    Science.gov (United States)

    Skin cancer - self-exam; Melanoma - self-exam; Basal cell cancer - self-exam; Squamous cell - self-exam; Skin mole - self-exam ... Experts do not agree on whether or not skin self-exams should be performed. So there is ...

  20. Microbiome and skin diseases

    NARCIS (Netherlands)

    Zeeuwen, P.L.J.M.; Kleerebezem, M.; Timmerman, H.M.; Schalkwijk, J.

    2013-01-01

    PURPOSE OF REVIEW: This article reviews recent findings on the skin microbiome. It provides an update on the current understanding of the role of microbiota in healthy skin and in inflammatory and allergic skin diseases. RECENT FINDINGS: Advances in computing and high-throughput sequencing technolog

  1. Microbiome and skin diseases

    NARCIS (Netherlands)

    Zeeuwen, P.L.; Kleerebezem, M.; Timmerman, H.M.; Schalkwijk, J.

    2013-01-01

    Purpose of review: This article reviews recent findings on the skin microbiome. It provides an update on the current understanding of the role of microbiota in healthy skin and in inflammatory and allergic skin diseases. Recent findings: Advances in computing and high-throughput sequencing technolog

  2. Microbiome and skin diseases

    NARCIS (Netherlands)

    Zeeuwen, P.L.J.M.; Kleerebezem, M.; Timmerman, H.M.; Schalkwijk, J.

    2013-01-01

    PURPOSE OF REVIEW: This article reviews recent findings on the skin microbiome. It provides an update on the current understanding of the role of microbiota in healthy skin and in inflammatory and allergic skin diseases. RECENT FINDINGS: Advances in computing and high-throughput sequencing

  3. Microbiome and skin diseases

    NARCIS (Netherlands)

    Zeeuwen, P.L.; Kleerebezem, M.; Timmerman, H.M.; Schalkwijk, J.

    2013-01-01

    Purpose of review: This article reviews recent findings on the skin microbiome. It provides an update on the current understanding of the role of microbiota in healthy skin and in inflammatory and allergic skin diseases. Recent findings: Advances in computing and high-throughput sequencing

  4. PPD skin test

    Science.gov (United States)

    ... test; Mantoux test Images Tuberculosis in the kidney Tuberculosis in the lung Positive PPD skin test PPD skin test References Chernecky CC, Berger ... test, purified protein derivative test, Tb test, tuberculin skin test, TST, tuberculosis test) - diagnostic. In: Chernecky CC, Berger BJ, eds. ...

  5. Psychoneuroimmunology and the Skin.

    Science.gov (United States)

    Honeyman, Juan F

    2016-08-23

    The nervous, immune, endocrine and integumentary systems are closely related and interact in a number of normal and pathological conditions. Nervous system mediators may bring about direct changes to the skin or may induce the release of immunological or hormonal mediators that cause pathological changes to the skin. This article reviews the psychological mechanisms involved in the development of skin diseases.

  6. The nature and biology of basement membranes.

    Science.gov (United States)

    Pozzi, Ambra; Yurchenco, Peter D; Iozzo, Renato V

    2017-01-01

    Basement membranes are delicate, nanoscale and pliable sheets of extracellular matrices that often act as linings or partitions in organisms. Previously considered as passive scaffolds segregating polarized cells, such as epithelial or endothelial cells, from the underlying mesenchyme, basement membranes have now reached the center stage of biology. They play a multitude of roles from blood filtration to muscle homeostasis, from storing growth factors and cytokines to controlling angiogenesis and tumor growth, from maintaining skin integrity and neuromuscular structure to affecting adipogenesis and fibrosis. Here, we will address developmental, structural and biochemical aspects of basement membranes and discuss some of the pathogenetic mechanisms causing diseases linked to abnormal basement membranes.

  7. Socio-motivational moderators – Two sides of the same coin?Testing the potential buffering role of socio-motivational relationships on achievement drive and test anxiety among German and Canadian secondary school students

    Directory of Open Access Journals (Sweden)

    Frances eHoferichter

    2015-10-01

    Full Text Available The current cross-national study investigates the potential buffering role of socio-motivational relationships for the association of achievement drive and test anxiety in secondary school students from Canada and Germany. One thousand eighty-eight students (54% girls, Mage = 13.71, SD = .53, age span 12–15 years from the state of Brandenburg and 389 students from Quebéc (55.9% girls, Mage = 13.43, SD = .82, age span 12–16 years were asked about their socio-motivational relationships with their teachers and peers, their drive for achievement, and test anxiety. Multigroup latent moderated structural equations (MGLMS were conducted to test for the moderator role of socio-motivational relationships that would buffer feelings of test anxiety related to the drive for achievement. The analyses revealed the two-sided role socio-motivational relationships can have for students with different levels of achievement drive; intensifying or mitigating feelings of test anxiety. Thereby, the results of this study extend the buffering hypothesis by Cohen and Wills (1985. Cross-national differences between Canada and Germany were found concerning the studied moderators on the association of achievement drive and test anxiety: While for German students teacher-student relationships acted as moderator, for Canadian students student-student relationships and teachers acting as positive motivators displayed a moderator role.

  8. 西秦岭北缘-拉脊山两侧地貌差异及地貌演化%TOPOGRAPHIC DIFFERENCE AND MORPHOLOGIC EVOLUTION BETWEEN THE TWO SIDES OF THE NORTHERN MARGIN OF WEST QINLING-LAJISHAN FAULT

    Institute of Scientific and Technical Information of China (English)

    高明星; 徐锡伟; 刘少峰

    2013-01-01

    The northern margin of West Qinling-Lajishan Fault is reckoned as an important geomorphologic and geological boundary.The elevation and local relief differences between the two sides of the boundary are distinct.The aim of this study is to understand the topographic differences and morphologic evolution mechanisms between the eastern and the western side of the northern margin of West Qinling-Lajishan Fault.The digital elevation model combined with geologic data has been used to:1) Extract local relief and swath profiles to quantitatively reveal the topographic characters of the eastern and the western side of the boundary; 2) Make statistics on the elevation modes of the Cenozoic sandstones on both sides of the fault.The results show that the older strata lie at higher elevations in the eastern region of the boundary; And for the west of the boundary,older strata (Paleogene and Neogene)perch on lower elevations,however,the Quaternary strata lie in the lowest elevation.The differential topographic evolution history of the two sides of the boundary indicates the complexity of Cenozoic strata development.Moreover,the lithological combination and sedimentary facies of the Cenozoic strata in the eastern and western side of the northern margin of West QinlingLajishan boundary are summarized,and the denudation and aggradation history of the two sides of the boundary are compared in this study.A longer constant denudation history in the eastern side than the western side has been suggested.The results also indicate the differential tectonic evolution history between the two sides of the boundary.Outward growth of the Tibetan plateau appears in the eastern side.The deformation and uplifting decrease as propagating northeastward.For the western side,the deformation pattern is more complex with different evolution histories of faults under stronger compression.The limited river erosion has enhanced the up-growth of this part of the plateau.%为了解西秦岭北缘-拉脊

  9. An Investigation of Pore Collapse in Asymmetric Polysulfone Membranes

    OpenAIRE

    Subrahmanyan, Sumitra

    2003-01-01

    Abstract Porous polysulfone membranes prepared by phase inversion can be tailored to suit filtration requirements by the choice of solvent and coagulant. In the current research polysulfone membranes were prepared by inverting a solution in N-methyl pyrrolidinone (NMP) in isopropanol to form uniform sized pores. Phase inversion resulted in the formation of an asymmetric membrane. The membranes have a characteristic "skin" which is supported by a highly porous substructure. Water-wet membra...

  10. Pursuing prosthetic electronic skin

    Science.gov (United States)

    Chortos, Alex; Liu, Jia; Bao, Zhenan

    2016-09-01

    Skin plays an important role in mediating our interactions with the world. Recreating the properties of skin using electronic devices could have profound implications for prosthetics and medicine. The pursuit of artificial skin has inspired innovations in materials to imitate skin's unique characteristics, including mechanical durability and stretchability, biodegradability, and the ability to measure a diversity of complex sensations over large areas. New materials and fabrication strategies are being developed to make mechanically compliant and multifunctional skin-like electronics, and improve brain/machine interfaces that enable transmission of the skin's signals into the body. This Review will cover materials and devices designed for mimicking the skin's ability to sense and generate biomimetic signals.

  11. Skin absorption through atopic dermatitis skin

    DEFF Research Database (Denmark)

    Halling-Overgaard, A-S; Kezic, S; Jakasa, I

    2017-01-01

    Patients with atopic dermatitis have skin barrier impairment in both lesional and non-lesional skin. They are typically exposed to emollients daily and topical anti-inflammatory medicaments intermittently, hereby increasing the risk of developing contact allergy and systemic exposed to chemicals...... ingredients found in these topical preparations. We systematically searched for studies that investigated skin absorption of various penetrants, including medicaments, in atopic dermatitis patients, but also animals with experimentally induced dermatitis. We identified 40 articles, i.e. 11 human studies...... examining model penetrants, 26 human studies examining atopic dermatitis drugs and 3 animal studies. We conclude that atopic dermatitis patients have nearly two-fold increased skin absorption when compared to healthy controls. There is a need for well-designed epidemiological and dermato...

  12. What Is Melanoma Skin Cancer?

    Science.gov (United States)

    ... Z About Melanoma Skin Cancer What Is Melanoma Skin Cancer? Key Statistics for Melanoma Skin Cancer What’s New in Melanoma ... Policy . About Melanoma Skin Cancer What Is Melanoma Skin Cancer? Key Statistics for Melanoma Skin Cancer What’s New in Melanoma ...

  13. In vitro permeation and disposition of niacinamide in silicone and porcine skin of skin barrier-mimetic formulations.

    Science.gov (United States)

    Haque, Tasnuva; Lane, Majella E; Sil, Bruno C; Crowther, Jonathan M; Moore, David J

    2017-03-30

    Niacinamide (NIA) is an amide form of vitamin B3 which is used in cosmetic formulations to improve various skin conditions and it has also been shown to increase stratum corneum thickness following repeated application. In this study, three doses (5, 20 and 50μL per cm(2)) of two NIA containing oil-in-water skin barrier-mimetic formulations were evaluated in silicone membrane and porcine ear skin and compared with a commercial control formulation. Permeation studies were conducted over 24h in Franz cells and at the end of the experiment membranes were washed and niacinamide was extracted. For the three doses, retention or deposition of NIA was generally higher in porcine skin compared with silicone membrane, consistent with the hydrophilic nature of the active. Despite the control containing a higher amount of active, comparable amounts of NIA were deposited in skin for all formulations for all doses; total skin absorption values (permeation and retention) of NIA were also comparable across all formulations. For infinite (50μL) and finite (5μL) doses the absolute permeation of NIA from the control formulation was significantly higher in porcine skin compared with both test formulations. This likely reflects differences in formulation components and/or presence of skin penetration enhancers in the formulations. Higher permeation for the 50 and 20μL dose was also evident in porcine skin compared with silicone membrane but the opposite is the case for the finite dose. The findings point to the critical importance of dose and occlusion when evaluating topical formulations in vitro and also the likelihood of exaggerated effects of excipients on permeation at infinite and pseudo-finite dose applications.

  14. In-vitro percutaneous absorption of losartan potassium in human skin and prediction of human skin permeability

    Directory of Open Access Journals (Sweden)

    Petkar K.C.

    2007-05-01

    Full Text Available This study describes the feasibility of transdermal controlled administration of Losartan potassium (LP across human cadaver skin. Study also defines the influence of capsaicin, sex and site of application on permeation characteristics and determined an appropriate animal model for human skin permeability. The permeation of LP of various formulations was studied using Keshary-Chein diffusion cell. Optimized controlled formulation (without capsaicin released 42.17% (±1.85 of LP in 12 hr whereas treatment formulation (with capsaicin 0.028 % w/v released 48.94% (±1.71 of LP with significant difference on null hypothesis. Influence of sex showed statistically significant difference for permeation of LP through male and female rats, as well as male and female mice across both the abdominal and dorsal sides of the skin (p<0.05. Similarly statistically significant differences were noted for permeation of LP across male and female mice abdomen-dorsal, but not for male rat abdomen-dorsal and female rat abdomen-dorsal. Furthermore, in-vitro permeation of LP across human skin was compared with the permeation across rat and mice skins. Male rat and male mice dorsal skin was found to have closer permeability characteristics to human than other skin membranes, but the Factor of Difference values were < 3 for all membranes which were used suggesting the membranes are good models for human skin permeability. In conclusion simple transdermal adhesive patches formulations incorporating high molecular weight of LP can deliver a dose in-vivo and proposed model skin membranes can be utilized for future pharmacokineic and toxicokinetic studies as well as metabolism studies of LP

  15. 下颌不对称后退术后两侧髁突位置变化的比较%Comparison of the Condylar Positional Changes between the Two Sides after Asymmetric Andibular Setback

    Institute of Scientific and Technical Information of China (English)

    王颖; 曲卫国; 丰鑫; 屈振宇

    2013-01-01

    目的:应用锥形束CT(cone-beam computed tomography,CBCT)比较双侧下颌支矢状劈开(SSRO)不对称后退下颌骨(asymmetric mandibular setback,AMS)术后两侧髁突位置的变化.方法:16例下颌偏突颌畸形患者,采用双侧下颌升支矢状劈开截骨术(BSSRO)后退下颌骨,小钛板坚固内固定(rigid internal fixation,RIF),分别于术前(T0)和术后1周(T1)做CBCT检查,利用InVivo dental软件测量双侧髁突的位置及角度变化,采用SPSS Statistics 17.0软件对数据进行统计分析.结果:术前除冠状位髁突头长轴的角度外,两侧髁突各观测指标均无统计学差异,术后1周两侧冠状位髁突颈的角度、轴位两侧髁突头的角度变化、冠状位后退距离小的一侧髁突颈的角度变化、矢状位后退距离大的一侧髁突前后向位置变化有统计学意义,两侧的改变程度仅轴位内外向变化和矢状位前后向变化具有统计学意义.结论:小钛板坚固内固定的SSRO不对称后退下颌骨可能会对两侧髁突产生不同的影响.%Objective:To compare the positional changes of the condylar between greater setback side(GSS) and lesser setback side (LSS) after asymmetric mandibular setback (AMS) using cone beam computed tomography (CBCT).Methods:16 skeletal class Ⅲ malocclusion patients with mandibular prognathism and facial asymmetry,who underwent bilateral sagittal split ramus osteotomy(BSSRO) with miniplate rigid internal fixation,were as sessed by CBCT before surgery(T0) and 1 week after surgery(T1).Results:At T0 stage,all the variables,except for coronal condylar head long axis angle(CHA),showed significant difference.At T1 stage,the coronal condylar neck long axis angle (CNA) showed significantly different between the two sides.The axial condylar head long axis angle(AHA) in both GSS and LSS,the CNA in the lesser setback side and the anteroposterior condylar position (AP) in GSS on the sagittal view showed statistically different from that at T0

  16. 双边截断型分布族参数函数的 渐近最优经验Bayes估计%Asymptotically Optimal Empirical Bayes Estimation for Parameter-functions Of Two-sided Truncation Distribution Families

    Institute of Scientific and Technical Information of China (English)

    张玲霞; 师义民

    2000-01-01

    Consider the two-sided truncation distribution families written in the form f(x|θ)= ω ( θ1, θ2) h (x) I[θ1,θ2] (x), where θ= ( θ1, θ2 ) T (x) = (t1 (x), t2 (x)) = ( min (x1,…, xm ), max (x1,… ,xm)) is a sufficient statistic, its marginal density is denoted by f(t). In this paper, by estimating f(t), we construct the empirical Bayes estimation (EBE) for parameter-function Q(θ), and prove the EBE is an asymptotically optimal that of Q(θ).%本文考虑一维双边截断型分布族参数函数在平方损失下的经验 Bayes 估计问题.给定θ,x的条件分布为 f(x|θ)=ω(θ1,θ2)h(x)I[θ1,θ2](x)dx其中 θ=(θ1,θ2) T(x)=(t1(x),t2(x))=(min(x1,…,xm),max(x1,…,xm))是充分统计量.其边缘密度为f(t),本文通过f(t)的核估计构造出θ的函数的经验 Bayes 估计,并证明在一定的条件下是渐近最优的(a.0.).

  17. 基于双边市场理论的金融超市竞争定价策略研究%Pricing Strategy of Financial Super-market Based on Two-sided Markets

    Institute of Scientific and Technical Information of China (English)

    王镭; 李一军; 张凯

    2014-01-01

    Based on two-sided market, this paper analyzs the pricing competition strategies of financial super-mar-ket under the case of duopoly , and is mainly focused on the price discrimination strategies .The paper builds price discrimination model by which the discriminatory criteria are transaction times on the platform , and analy-zes equilibrium price , equilibrium profit and market shares in two different cases:financial super-market pursues long term maximum profit or short term maximum one .Then we draw the conclusion that price discrimination is good for financial super-markets’ short term profit maximization but not short term or long term profit .So the pa-per suggests financial super-markets should take the strategies of price discrimination in development stage and maturation stage appropriately ,and be within a certain period of time and transactions , so as to get more profit .%基于双边市场理论,重点分析金融超市在双寡头垄断情形下的竞争定价策略。即在在一般定价模型的基础上,构建起加入金融超市双边用户交易次数为歧视标准的价格歧视竞争模型。并且围绕金融超市追求长期利益和短期利益两种不同动机,对采取该策略均衡时最终用户的均衡进入价格、金融超市利润和市场份额进行比较分析。最后,给出金融超市实施价格歧视策略的对策和建议。

  18. Calcipotriol delivery into the skin with PEGylated liposomes

    DEFF Research Database (Denmark)

    Knudsen, Nina Østergaard; Rønholt, Stine; Salte, Ragnhild Djønne

    2012-01-01

    The d-vitamin analogue calcipotriol is commonly used for topical treatment of psoriasis, but skin penetration is required for calcipotriol to reach its pharmacological target: the keratinocytes in the lower epidermis. Liposomes can enhance the delivery of drugs into the skin, but a major challenge...... for the development of dosage forms containing liposomes is to maintain the colloidal stability in the formulation. The purpose of this study was to investigate the effect of stabilising liposomes with the lipopolymer poly(ethylene glycol)-distearoylphosphoethanolamine (PEG-DSPE) on the physicochemical properties...... of the liposomes and the ability to deliver membrane-intercalated calcipotriol into the skin. Inclusion of 0.5, l and 5mol% PEG-DSPE in the membrane enhanced the colloidal stability of the liposomes without compromising the delivery of calcipotriol from the vehicle into excised pig skin. Calcipotriol...

  19. Skin barrier function

    DEFF Research Database (Denmark)

    2016-01-01

    Renowned experts present the latest knowledge Although a very fragile structure, the skin barrier is probably one of the most important organs of the body. Inward/out it is responsible for body integrity and outward/in for keeping microbes, chemicals, and allergens from penetrating the skin. Since...... the role of barrier integrity in atopic dermatitis and the relationship to filaggrin mutations was discovered a decade ago, research focus has been on the skin barrier, and numerous new publications have become available. This book is an interdisciplinary update offering a wide range of information...... on the subject. It covers new basic research on skin markers, including results on filaggrin and on methods for the assessment of the barrier function. Biological variation and aspects of skin barrier function restoration are discussed as well. Further sections are dedicated to clinical implications of skin...

  20. Aquaporins in the Skin.

    Science.gov (United States)

    Patel, Ravi; Kevin Heard, L; Chen, Xunsheng; Bollag, Wendy B

    2017-01-01

    The skin is the largest organ of the body, serving as an important barrier between the internal milieu and the external environment. The skin is also one of the first lines of defense against microbial infection and other hazards, and thus, the skin has important immune functions . This organ is composed of many cell types, including immune-active dendritic cells (epidermal Langerhans cells and dermal dendritic cells), connective tissue-generating dermal fibroblasts and pigment-producing melanocytes. Comprising the outer skin layer are the epidermal keratinocytes, the predominant cell of this layer, the epidermis , which provides both a mechanical barrier and a water -permeability barrier. Recent data suggest that aquaporins, a family of barrel-shaped proteins surrounding internal pores that allow the passage of water and, in some family members, small solutes such as glycerol , play critical roles in regulating various skin parameters. The involvement of different aquaporin family members in skin function is discussed.

  1. Electrospun superhydrophobic membranes with unique structures for membrane distillation.

    Science.gov (United States)

    Liao, Yuan; Loh, Chun-Heng; Wang, Rong; Fane, Anthony G

    2014-09-24

    With modest temperature demand, low operating pressure, and high solute rejection, membrane distillation (MD) is an attractive option for desalination, waste treatment, and food and pharmaceutical processing. However, large-scale practical applications of MD are still hindered by the absence of effective membranes with high hydrophobicity, high porosity, and adequate mechanical strength, which are important properties for MD permeation fluxes, stable long-term performance, and effective packing in modules without damage. This study describes novel design strategies for highly robust superhydrophobic dual-layer membranes for MD via electrospinning. One of the newly developed membranes comprises a durable and ultrathin 3-dimensional (3D) superhydrophobic skin and porous nanofibrous support whereas another was fabricated by electrospinning 3D superhydrophobic layers on a nonwoven support. These membranes exhibit superhydrophobicity toward distilled water, salty water, oil-in-water emulsion, and beverages, which enables them to be used not only for desalination but also for other processes. The superhydrophobic dual-layer membrane #3S-N with nanofibrous support has a competitive permeation flux of 24.6 ± 1.2 kg m(-2) h(-1) in MD (feed and permeate temperate were set as 333 and 293 K, respectively) due to the higher porosity of the nanofibrous scaffold. Meanwhile, the membranes with the nonwoven support exhibit greater mechanical strength due to this support combined with better long-term performance because of the thicker 3D superhydrophobic layers. The morphology, pore size, porosity, mechanical properties, and liquid enter pressure of water of these superhydrophobic composite membranes with two different structures are reported and compared with commercial polyvinylidene fluoride membranes.

  2. Intrinsic potential of cell membranes: opposite effects of lipid transmembrane asymmetry and asymmetric salt ion distribution

    DEFF Research Database (Denmark)

    Gurtovenko, Andrey A; Vattulainen, Ilpo

    2009-01-01

    Using atomic-scale molecular dynamics simulations, we consider the intrinsic cell membrane potential that is found to originate from a subtle interplay between lipid transmembrane asymmetry and the asymmetric distribution of monovalent salt ions on the two sides of the cell membrane. It turns out......Cl saline solution and the PE leaflet is exposed to KCl, the outcome is that the effects of asymmetric lipid and salt ion distributions essentially cancel one another almost completely. Overall, our study highlights the complex nature of the intrinsic potential of cell membranes under physiological...

  3. Basophils and skin disorders.

    Science.gov (United States)

    Borriello, Francesco; Granata, Francescopaolo; Marone, Gianni

    2014-05-01

    Since their discovery in 1879, basophils have been viewed as circulating blood granulocytes with limited immune function. New research tools for their functional analysis in vivo have revealed previously unrecognized roles for basophils in several skin disorders. Human basophils infiltrate different skin lesions and have been implicated in the pathogenesis of diseases ranging from chronic idiopathic urticaria to systemic lupus erythematosus. In mouse models, basophils participate in IgE-mediated chronic allergic inflammation of the skin and have a protective role in tick infestation. In this review, we discuss critical advances in our understanding of basophil biology and their roles in the pathophysiology of skin disorders.

  4. Skin Images Segmentation

    Directory of Open Access Journals (Sweden)

    Ali E. Zaart

    2010-01-01

    Full Text Available Problem statement: Image segmentation is a fundamental step in many applications of image processing. Skin cancer has been the most common of all new cancers detected each year. At early stage detection of skin cancer, simple and economic treatment can cure it mostly. An accurate segmentation of skin images can help the diagnosis to define well the region of the cancer. The principal approach of segmentation is based on thresholding (classification that is lied to the problem of the thresholds estimation. Approach: The objective of this study is to develop a method to segment the skin images based on a mixture of Beta distributions. We assume that the data in skin images can be modeled by a mixture of Beta distributions. We used an unsupervised learning technique with Beta distribution to estimate the statistical parameters of the data in skin image and then estimate the thresholds for segmentation. Results: The proposed method of skin images segmentation was implemented and tested on different skin images. We obtained very good results in comparing with the same techniques with Gamma distribution. Conclusion: The experiment showed that the proposed method obtained very good results but it requires more testing on different types of skin images.

  5. Ultrastructural changes of epidermal calcium gradient and lipid lamellar membrane in depigmented skin lesions of vitiligo patients%白癜风皮损表皮钙离子梯度与角质层板层脂膜超微结构观察

    Institute of Scientific and Technical Information of China (English)

    刘子重; 雷铁池

    2016-01-01

    目的 探讨白癜风皮损黑素脱失对表皮钙离子分布和角质层板层脂膜超微结构的影响.方法 2014年8月至2015年2月于武汉大学人民医院皮肤科门诊招募稳定期寻常型白癜风患者和健康对照各5例.四氧化钌(RuO4)电子特染结合透射电子显微镜技术观察皮肤标本角质层板层脂膜的超微结构;用钙离子化学捕捉技术结合透射电镜观察表皮钙沉淀颗粒的数量及分布.结果 健康对照皮肤角质层细胞间隙可见排列规整、电子致密带和电子透明带重复交替排列的板层结构;白癜风皮损角质层细胞间隙扩大,板层脂膜分离断裂,出现空泡,空泡内填充有无形电子致密物.健康对照皮肤的颗粒层可见到粗大密集的钙沉淀颗粒,基底层细胞间可见细小的钙沉淀颗粒与Ⅳ期黑素小体;而白癜风皮损的颗粒层钙沉淀颗粒大小和数目较正常对照明显减少,基底层几乎完全缺乏黑素小体.结论 白癜风皮损同时存在表皮钙离子梯度消失和板层脂膜结构紊乱,提示表皮黑素可能与表皮钙梯度形成与渗透性屏障结构完整性相关.%Objective To investigate the effects of melanin disappearance in vitiliginous skin on the ultrastructure of epidermal calcium distribution and the stratum corneum (SC) lipid lamellar membranes.Methods Five outpatients with stable vitiligo vulgaris and 5 healthy controls were recruited from August 2014 to February 2015 at Department of Dermatology,Renmin Hospital of Wuhan University.The ultrastructural changes of lipid lamellar membranes of the skin were assessed using transmission electron microscopy (TEM) technique in combination with ruthenium tetroxide (RuO4) staining.The concentration and distribution of calcium precipitates in the epidermis were studied using calcium ion-capture cytochemistry combined with TEM.Results The multilayered lipid lamellae existed within the intercellular space of the normal SC with a

  6. DNA vaccination in skin enhanced by electroporation.

    Science.gov (United States)

    Broderick, Kate E; Khan, Amir S; Sardesai, Niranjan Y

    2014-01-01

    DNA vaccines are a next generation branch of vaccines which offer major benefits over their conventional counterparts. However, to be effective in large mammals and humans, an enhancing delivery technology is required. Electroporation is a physical technique which results in improved delivery of large molecules through the cell membrane. In the case of plasmid DNA, electroporation enhances both the uptake and expression of the delivered DNA. The skin is an attractive tissue for DNA vaccination in a clinical setting due to the accessibility of the target, the ease of monitoring, and most importantly the immunocompetent nature of the dermis. Electroporation in the skin has the benefit of being minimally invasive and generally well tolerated. Previous studies have determined that optimized electroporation parameters (such as electrical field intensity, pulse length, pulse width, and plasmid formulation) majorly impact the efficiency of DNA delivery to the skin. We provide an overview of DNA vaccination in skin and muscle. In addition, we detail a protocol for the successful intradermal electroporation of plasmid DNA to guinea pig skin, an excellent dermatological animal model. The work detailed here suggests that the technique is safe and effective and could be highly applicable to a clinical setting.

  7. 基于双边市场的媒体跨媒介竞争效应分析∗%An Analysis on Cross-media Competition Effect in Media Based on Two-sided Markets

    Institute of Scientific and Technical Information of China (English)

    石莉萍

    2015-01-01

    Based on the current background of “Triple Play”and the concept of two-sided markets theo-ry,this essay constructs a media industry cross-media competition model.Model analysis shows that the expansion of cross-media platform would increase the number of consumers,advertisements,and advertis-ing expenses.However,there exists a critical point for cross-media platform expansion investment.The cross-media expansion would increase the profit of media platform only if the investment number is less than the critical point.By the increasing number of advertisement-averse consumer ratio,final equilibrium advertising fees and profits for both media platform will decrease,and the amount of cross-media expansion advertising media platforms and consumers will decrease.Comparatively,the amount of none-cross-media expansion advertisements media platforms and consumers will increase.The conclusion would benefit the cross-media expansion of enterprises and policy-making of the government.%基于三网融合的现实背景,在双边市场理论框架下,构建了媒体跨媒介竞争博弈模型。模型分析表明:媒体平台进行跨媒介扩张,可以增加自身消费者数量、广告投放数量以及广告费用;媒体平台跨媒介扩张存在一个投资临界,只有当投资成本小于这一临界时,跨媒介扩张才会增加媒体平台的利润;随着广告厌恶型消费者所占比例的增加,两家媒体平台最终的均衡广告收费和利润都会提升,进行跨媒介扩张的媒体平台广告量和消费者数量会减少,而没有进行跨媒介扩张的媒体平台广告量和消费者数量会增加。

  8. Research on Network Group-buying Platform Pricing Model Based on Two-sided Market%基于双边市场的网络团购平台定价模型研究

    Institute of Scientific and Technical Information of China (English)

    白莹; 李明杰; 袁冲; 邓舒; 胡春

    2012-01-01

    双边市场理论是近年来产业组织研究的热点问题,结合网络团购平台特点,可以推导出适合网络团购平台的定价模型,讨论交叉网络外部性、差异化程度、卖方信誉及平台搜索匹配度对网络团购平台定价的影响。结论表明,平台需要对网络外部性较强、信誉较高且差异化程度较小的一方收取较低的交易费甚至免费,相反则抽取较高佣金,同时提高平台的搜索匹配概率将对企业利润产生显著的正向影响。网络团购平台需通过不断提高差异化程度和卖方信誉等方式,来吸引更多用户并达成更多交易量,从而使团购企业真正获得盈利。%In recent years,two-sided market theory has been a hot spot in the field of industrial organization.Combining with the characteristics of network group-buying platform,a pricing model suitable for the network group-buying platform is established,and the impacts of crossover network externalities,differentiation degree,the sellers' reputation and search efficiency are discussed.The conclusions show that platform needs to charge lower fee or even be free on the side which has stronger network externalities,higher reputation and differentiation degree,and on the contrary charges higher commissions.At the same time,improving the search matching probability will have a significantly positive impact on the corporate profit.Network group-buying platform needs to attract more users and achieve more deals to make the enterprise gain profit by means of improving differentiation degree,sellers' credit and so on.

  9. A method for distinguishing WW and NW in the flow around two side by side circular cylinders%并列双圆柱绕流中宽窄尾流的识别方法

    Institute of Scientific and Technical Information of China (English)

    庞建华; 宗智; 周力; 邹丽

    2016-01-01

    采用基于边界瞬时涡量守恒(IVCBC)的纯拉格朗日涡方法,结合并列双圆柱的结构特点,建立双圆柱绕流数值计算模型。在间隙率T/D=1.1~2.6时,并列双圆柱绕流会出现宽尾流(WW)和窄尾流(NW)现象。利用两圆柱间隙中心点的诱导速度方向与间隙流的偏转方向同步的特性,提出一种区别宽、窄尾流的数值计算方法;比较间隙流的偏转方向与该间隙中点的速度偏转方向,并进行典型的算例分析。结果表明:该方法能准确区别宽尾流和窄尾流,可为数值研究这一特殊区域的流体特征提供重要的数值计算方法。%A pure-Lagrangian vortex method, based on Instantaneous Vorticity Conserved Boundary Condi⁃tions (IVCBC), is adopted to build the numerical calculation model of flow around double circular cylinders that have the same structure characteristics of two side by side circular cylinders. The Wide Wake(WW) and Narrow Wake(NW)appear in the range of pitch ratio T/D=1.1~2.6. A scheme is proposed to distin⁃guish the NW and WW through the direction synchronism between induced velocity at the middle of double circular cylinders and deflection of gap flow. By comparing the directions of the above two flowing condi⁃tions and analyzing the classic case, it is concluded that the proposed method could distinguish WW and NW accurately, which offers an important numerical calculation method for investigating the flow character⁃istics in this range.

  10. 以“供给侧”为重点推进粮食“两侧”结构改革的思考%On Promoting the Grain "Two Sides" Structural Reform Focused on the "Supply-side"

    Institute of Scientific and Technical Information of China (English)

    丁声俊

    2016-01-01

    推进“供给侧”结构性改革是一个重大的经济学理论和实践问题。在我国粮食领域存在着粮食品种产销结构、供需结构失衡问题。粮食“供给侧”是基础,“需求侧”是目标,二者存在相互依存、相互制约、相互促进的关系。根据对我国粮食宏观形势作出的客观评估,应以“五大发展新理念”为引领,坚守粮食总量安全、质量安全、农民增收、市场稳定“四条底线”,以粮食“供给侧”结构改革为主线,推动粮食“供给侧”与“需求侧”结构改革同步发力,促进粮食“两侧”结构相互协调与适应。%To promote the "supply-side structural reform" is a major economic theory and practical problems. In China′s grain field, the structural imbalance problems of the grain species can be seen in the process of production-marketing and supply-demand. Grain supply-side is the basis while the demand-side is the goal, both of them are mutual dependent, mutual restraint, and mutual promote. According to the objective assessment of China′s grain macro situation, we should take"the five new major development con⁃cepts" as the guiding principle, adhering to the" the four bottom lines" of the grain industry, such as adequate volume, safe quality, increased income and stable market. Take the grain "supply-side" structural reform as a main line to promote the grain supply-side and demand-side structural reform synchronously, making the "two sides" structure of mutual coordination and adaptation.

  11. Relación entre vitamina A y alteraciones mucocutáneas y pilosas en niños de zonas palúdicas State of the skin, mucous membranes, hair and vitamin A in children of endemic malaria zones of Antioquia (Colombia

    Directory of Open Access Journals (Sweden)

    Rosa Magdalena Uscátegui Peñuela

    2008-01-01

    ían el cabello sano, comparados con 9% de los que tenían el retinol en 20 o más µg/dL; tampoco se asoció con el riesgo de desnutrición, excepto por la asociación entre piel alterada y desnutrición crónica + global: 60% de los niños con piel anormal tenían desnutrición crónica + global, contra 20% de los que tenían la piel normal que presentaron esa desnutrición.

     

    Conclusiones: fueron muy frecuentes las alteraciones mucocutáneas y capilares en estos niños de zonas maláricas de Antioquia, quienes además presentaron elevada prevalencia de desnutrición crónica, global o ambas (61% y baja frecuencia de déficit de retinol sérico (4,5%. En general las alteraciones mucocutáneas y capilares no se asociaron con el estado del retinol ni con el estado nutricional.

    Objective: to know the class and frequency of skin, mucous membranes and hair alterations in children of endemic malaria zones of Antioquia (Colombia.

     

    Methodology: non-blind balanced experimental design. Ninety three children with malaria were included and followed up during 30 days.

     

    Skin Diseases: Skin and Sun—Not a good mix

    Science.gov (United States)

    Skip Navigation Bar Home Current Issue Past Issues Skin Diseases Skin and Sun —Not a good mix Past Issues / ... of this page please turn Javascript on. Good skin care begins with sun safety. Whether it is ...

  12. Dark Skin No Shield from Deadly Skin Cancer

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_166194.html Dark Skin No Shield From Deadly Skin Cancer Death rates from melanoma are higher for people of color, skin expert says To use the sharing features on ...

  13. Parasites and the skin

    African Journals Online (AJOL)

    2009-06-11

    Jun 11, 2009 ... remind you of those rare and wonderful infestations that you might never see. ... from a burrow, mounted on a glass slide. The findings are ... Parasitic infections may be confined to the skin or may have skin involvement as part ...

  14. Skin tribology: Science friction?

    NARCIS (Netherlands)

    Heide, van der E.; Zeng, X.; Masen, M.A.

    2013-01-01

    The application of tribological knowledge is not just restricted to optimizing mechanical and chemical engineering problems. In fact, effective solutions to friction and wear related questions can be found in our everyday life. An important part is related to skin tribology, as the human skin is fre

  15. Deformable skinning on bones

    DEFF Research Database (Denmark)

    Larsen, Bent Dalgaard; Petersen, Kim Steen; Jakobsen, Bjarke

    2001-01-01

    Applying skin to a model is a relatively simple task to implement. Nonetheless it seems that no good resource exists that describes both the concepts and math necessary to understand and implement skinning. The intention of this article is an attempt to give a thoroughly description...

  16. How Membrane-Active Peptides Get into Lipid Membranes.

    Science.gov (United States)

    Sani, Marc-Antoine; Separovic, Frances

    2016-06-21

    The structure-function relationship for a family of antimicrobial peptides (AMPs) from the skin of Australian tree frogs is discussed and compared with that of peptide toxins from bee and Australian scorpion venoms. Although these membrane-active peptides induce a similar cellular fate by disrupting the lipid bilayer integrity, their lytic activity is achieved via different modes of action, which are investigated in relation to amino acid sequence, secondary structure, and membrane lipid composition. In order to better understand what structural features govern the interaction between peptides and lipid membranes, cell-penetrating peptides (CPPs), which translocate through the membrane without compromising its integrity, are also discussed. AMPs possess membrane lytic activities that are naturally designed to target the cellular membrane of pathogens or competitors. They are extremely diverse in amino acid composition and often show specificity against a particular strain of microbe. Since our antibiotic arsenal is declining precariously in the face of the rise in multiantibiotic resistance, AMPs increasingly are seen as a promising alternative. In an effort to understand their molecular mechanism, biophysical studies of a myriad of AMPs have been reported, yet no unifying mechanism has emerged, rendering difficult the rational design of drug leads. Similarly, a wide variety of cytotoxic peptides are found in venoms, the best known being melittin, yet again, predicting their activity based on a particular amino acid composition or secondary structure remains elusive. A common feature of these membrane-active peptides is their preference for the lipid environment. Indeed, they are mainly unstructured in solution and, in the presence of lipid membranes, quickly adsorb onto the surface, change their secondary structure, eventually insert into the hydrophobic core of the membrane bilayer, and finally disrupt the bilayer integrity. These steps define the molecular

  17. Bionanomaterials for skin regeneration

    CERN Document Server

    Leonida, Mihaela D

    2016-01-01

    This book gives a concise overview of bionanomaterials with applications for skin regeneration. The advantages and challenges of nanoscale materials are covered in detail, giving a basic view of the skin structure and conditions that require transdermal or topical applications. Medical applications, such as wound healing, care for burns, skin disease, and cosmetic care, such as aging of the skin and photodamage, and how they benefit from bionanomaterials, are described in detail. A final chapter is devoted to the ethical and social issues related to the use of bionanomaterials for skin regeneration. This is an ideal book for researchers in materials science, medical scientists specialized in dermatology, and cosmetic chemists working in formulations. It can also serve as a reference for nanotechnologists, dermatologists, microbiologists, engineers, and polymer chemists, as well as students studying in these fields.

  18. Biomimetic shark skin: design, fabrication and hydrodynamic function.

    Science.gov (United States)

    Wen, Li; Weaver, James C; Lauder, George V

    2014-05-15

    Although the functional properties of shark skin have been of considerable interest to both biologists and engineers because of the complex hydrodynamic effects of surface roughness, no study to date has successfully fabricated a flexible biomimetic shark skin that allows detailed study of hydrodynamic function. We present the first study of the design, fabrication and hydrodynamic testing of a synthetic, flexible, shark skin membrane. A three-dimensional (3D) model of shark skin denticles was constructed using micro-CT imaging of the skin of the shortfin mako (Isurus oxyrinchus). Using 3D printing, thousands of rigid synthetic shark denticles were placed on flexible membranes in a controlled, linear-arrayed pattern. This flexible 3D printed shark skin model was then tested in water using a robotic flapping device that allowed us to either hold the models in a stationary position or move them dynamically at their self-propelled swimming speed. Compared with a smooth control model without denticles, the 3D printed shark skin showed increased swimming speed with reduced energy consumption under certain motion programs. For example, at a heave frequency of 1.5 Hz and an amplitude of ± 1 cm, swimming speed increased by 6.6% and the energy cost-of-transport was reduced by 5.9%. In addition, a leading-edge vortex with greater vorticity than the smooth control was generated by the 3D printed shark skin, which may explain the increased swimming speeds. The ability to fabricate synthetic biomimetic shark skin opens up a wide array of possible manipulations of surface roughness parameters, and the ability to examine the hydrodynamic consequences of diverse skin denticle shapes present in different shark species.

  19. 6 Common Cancers - Skin Cancer

    Science.gov (United States)

    ... Navigation Bar Home Current Issue Past Issues 6 Common Cancers - Skin Cancer Past Issues / Spring 2007 Table ... Gilbert Skin Cancer Skin cancer is the most common form of cancer in the United States. The ...

  1. Skin Cancer Can Strike Anyone

    Science.gov (United States)

    ... of this page please turn Javascript on. Feature: Skin Cancer Skin Cancer Can Strike Anyone Past Issues / Summer 2013 Table ... removed. That is the most common form of skin cancer and not as dangerous as melanoma. Photo: Corbis ...

  2. Polymer and Membrane Design for Low Temperature Catalytic Reactions

    KAUST Repository

    Villalobos, Luis Francisco

    2016-02-29

    Catalytically active asymmetric membranes have been developed with high loadings of palladium nanoparticles located solely in the membrane\\'s ultrathin skin layer. The manufacturing of these membranes requires polymers with functional groups, which can form insoluble complexes with palladium ions. Three polymers have been synthesized for this purpose and a complexation/nonsolvent induced phase separation followed by a palladium reduction step is carried out to prepare such membranes. Parameters to optimize the skin layer thickness and porosity, the palladium loading in this layer, and the palladium nanoparticles size are determined. The catalytic activity of the membranes is verified with the reduction of a nitro-compound and with a liquid phase Suzuki-Miyaura coupling reaction. Very low reaction times are observed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. 双边市场视角下操作系统平台定价策略研究%Pricing Strategies of Operating System Platform from the Perspective of Two-Sided Markets

    Institute of Scientific and Technical Information of China (English)

    邢明青

    2015-01-01

    越来越多有影响力开源操作系统平台的兴起(如 Linux ),对传统的专有操作系统平台(如微软的Windows)形成巨大的冲击。本文借用双边市场理论框架探讨专有操作系统平台在面对开源操作系统平台竞争时的定价策略问题。主要结论如下:①专有操作系统平台对平台用户收费和向应用软件开发商补贴的定价结构是由平台用户和应用软件开发商之间两类交叉网络外部性相对强弱决定的;②用户使用开源操作系统平台相对于专有操作系统平台需承担的额外费用(如较高的学习成本和维护费用)和获得的额外好处(如可个性化和较好的稳定性)均会间接影响专有操作系统平台的定价策略;③与专有操作系统平台独占市场的情形对比发现,两种市场结构下专有操作系统平台的定价结构可能存在差异,并且这种差异依赖于平台用户使用开源操作系统平台与使用专有操作系统平台相比额外需承担费用和额外获得好处的差距。%The emergence of more and more influential open-source operating system platforms ( such as Linux ) tremendously impacts the traditional proprietary operating system platforms ( such as Microsoft ’ s Windows ) . Based on two-sided markets framework, this paper studies the pricing strategies of proprietary platform in the face of competition from open-source platforms.It finds that the proprietary platform’ s pricing structure of charging users and subsiding for application software developers is decided by the relative strength of cross network exter-nalities between users and application software products, the additional costs ( such as higher learning and maintenance costs)and benefits(such as individuation and better stability)when users use open-source platform relative to proprietary platform will indirectly affect proprietary platform’ s pricing strategies, and proprietary plat-form’ s

  4. Skin Picking Disorder

    Directory of Open Access Journals (Sweden)

    Pinar Cetinay Aydin

    2014-08-01

    Full Text Available Skin picking disorder is not a dermatological disorder and it is a table characterized with picking skin excessively and repetitively, leading to damage in skin tissue. Unlike normal picking behaviour, psychogenic skin picking is repetitive and it can lead to severe damage in the skin and even complications which constitute vital danger. While some patients define frequent but short lasting picking attacks, others define rarer attacks which last a few hours. Skin picking disorder, which is not included in the classification systems up to DSM-5 as a separate diagnosis category, is included as an independent diagnosis in Obsessive Compulsive Disorder and Associated Disorders category in DSM-5. In case reports, open label studies and double blind studies selective serotonin reuptake inhibitors are shown to be effective in the treatment of skin picking disorder. Mostly, cognitive-behaviourial techniques are used and have been proven to be useful in psychotherapy. Habit reversal is one of the behaviourial techniques which are frequently applied, give positive results in which well-being state can be maintained. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2014; 6(4.000: 401-428

  5. Archaea on human skin.

    Directory of Open Access Journals (Sweden)

    Alexander J Probst

    Full Text Available The recent era of exploring the human microbiome has provided valuable information on microbial inhabitants, beneficials and pathogens. Screening efforts based on DNA sequencing identified thousands of bacterial lineages associated with human skin but provided only incomplete and crude information on Archaea. Here, we report for the first time the quantification and visualization of Archaea from human skin. Based on 16 S rRNA gene copies Archaea comprised up to 4.2% of the prokaryotic skin microbiome. Most of the gene signatures analyzed belonged to the Thaumarchaeota, a group of Archaea we also found in hospitals and clean room facilities. The metabolic potential for ammonia oxidation of the skin-associated Archaea was supported by the successful detection of thaumarchaeal amoA genes in human skin samples. However, the activity and possible interaction with human epithelial cells of these associated Archaea remains an open question. Nevertheless, in this study we provide evidence that Archaea are part of the human skin microbiome and discuss their potential for ammonia turnover on human skin.

  6. Skin and antioxidants.

    Science.gov (United States)

    Poljsak, Borut; Dahmane, Raja; Godic, Aleksandar

    2013-04-01

    It is estimated that total sun exposure occurs non-intentionally in three quarters of our lifetimes. Our skin is exposed to majority of UV radiation during outdoor activities, e.g. walking, practicing sports, running, hiking, etc. and not when we are intentionally exposed to the sun on the beach. We rarely use sunscreens during those activities, or at least not as much and as regular as we should and are commonly prone to acute and chronic sun damage of the skin. The only protection of our skin is endogenous (synthesis of melanin and enzymatic antioxidants) and exogenous (antioxidants, which we consume from the food, like vitamins A, C, E, etc.). UV-induced photoaging of the skin becomes clinically evident with age, when endogenous antioxidative mechanisms and repair processes are not effective any more and actinic damage to the skin prevails. At this point it would be reasonable to ingest additional antioxidants and/or to apply them on the skin in topical preparations. We review endogenous and exogenous skin protection with antioxidants.

  7. Chondroitin-6-sulfate-containing proteoglycan: a new component of human skin dermoepidermal junction

    DEFF Research Database (Denmark)

    Fine, J D; Couchman, J R

    1988-01-01

    as 54 gestational days. Indirect immunoelectron microscopy and NaCl-split skin studies were performed to ultrastructurally localize the antigen; immune deposits were detectable within the lamina densa in chondroitinase-treated skin. These findings demonstrate that chondroitin sulfate proteoglycan...... chondroitin sulfate proteoglycan is present in adult, neonatal, and/or fetal skin, and if present, its ultrastructural localization. Indirect immunofluorescence was performed on human adult, neonatal, and fetal skin. To detect the antigen, specimens were pretreated with chondroitinase ABC; absence of enzyme...... treatment served as negative control. Chondroitin sulfate proteoglycan was detectable in linear homogeneous array along the dermoepidermal junction and within vascular (and when present, adnexal) basement membranes in both adult and neonatal skin. In fetal skin, basement membrane staining was noted as early...

  8. Joint physical antimicrobial skin membrane treatment of syphilis chancre analysis of the effect of benzathine%苄星青霉素联合皮肤物理抗菌膜治疗梅毒硬下疳的效果分析

    Institute of Scientific and Technical Information of China (English)

    罗明

    2014-01-01

    two courses rapid plasma reagin test(RPR). The treatment group in the treatment of the first 5d,10d,15d healing rate than the control group,he difference was statistically significant (P>0.05). Conclusion:Benzathine joint physical antimicrobial skin membrane treatment of syphilis chancre can effectively shorten the healing time of skin lesions .

  9. Acellular amniotic membrane and small intestinal submucosa promote skin repair and vascularization in rats%脱细胞羊膜与小肠黏膜下层促进大鼠皮肤缺损修复和血管形成

    Institute of Scientific and Technical Information of China (English)

    霍艳丽; 马洁华; 柏树令; 王军

    2011-01-01

    Objective To observe the repairing effects and vascularization of the small intestinal submucosa and the acellular amnion for full-thickness skin defects in rats. Methods Two full-thickness skin defects, which were close to the vertebral column, were created on both sides of the dorsum of the SD rats.The skin defects were randomly divided into three groups covered by the acellular amniotic membrane in Group A, the small intestinal submucosa ( SIS) in Group B, and the physiological saline gauze in Group C (the control group) respectively. After two weeks, the sample were harvested for histological evaluation,immunohistochemical staining of K19 and VEGF, as well as for determination of expression levels of VEGF mRNA with RT-PCR. Results Immunohistochemical staining of K19 and VEGF showed that there were more positive cells in group A and B than in group C, and maximum in group A; RT-PCR results showed that the expression levels of VEGF mRNA were higher in group A and B than group C, and maximum in group A too. The results of the statistical analysis of the research data showed that there were statistically significant differences between the three groups (P< 0. 05). Conclusion The results indicate that HAM and SIS increases K19 positive cells and enhance expression levels of VEGF, thus promoting skin repair and vascularization in rats.%目的 观察脱细胞羊膜(HAM)与小肠黏膜下层(SIS)促进大鼠皮肤缺损修复和血管形成的作用.方法 SD大鼠24只,在两侧背部各做1个直径为1.8cm圆形全层皮肤缺损.创面随机分为A组、B组和C组.A组HAM覆盖,B组SIS覆盖,C组纱布覆盖.在2周时处死动物取材,HE染色观察皮肤缺损修复情况.免疫组织化学染色检测K19和VEGF,RT-PCR检测VEGF mRNA的表达.结果 A组、B组愈合较好.C组愈合较差.免疫组织化学染色显示,A、B组K19、VEGF阳性细胞显著多于C组,其中A组最多;RT-PCR结果显示,A、B组比C组表达更多的VEGF mRNA其中A组最多,

  10. 鼻咽癌同期放化疗中急性皮肤黏膜反应的临床观察及其相关因素分析%Clinical observation of acute skin and oral mucous membrane reactions in patients with nasopharyngeal carcinoma treated with concurrent radiochemotherapy and correlated factors

    Institute of Scientific and Technical Information of China (English)

    成灏; 吴慧; 卢晓旭; 徐靖

    2014-01-01

    目的 探讨鼻咽癌患者同期放化疗中急性皮肤及黏膜反应的影响因素,对主要相关因素进行分析.方法 对85例接受同期放化疗的鼻咽癌患者进行研究,观察并记录BMI、每周放疗剂量、口腔黏膜及颈部皮肤反应情况、血常规等15项临床指标及实验室指标,并进行单因素分析和多因素分析,筛选决定性影响因素.结果 与急性放射性口腔黏膜反应发生密切相关的危险因素,有吸烟史(OR=3.467,P<0.05)和原发灶GTV单次量>2.15 Gy(OR =3.393,P<0.05);与急性放射性皮肤反应发生密切相关的危险因素,有糖尿病史(OR=87.859,P<0.05),放疗前1周血红蛋白值> 130 g/L(OR=21.404,P<0.05).结论 对于同期放化疗的鼻咽癌患者,吸烟史和原发灶GTV单次量为急性放射性口腔黏膜反应的独立影响因素,糖尿病史和放疗前1周的血红蛋白值为急性放射性皮肤反应的独立影响因素.%Objective To observe the acute skin and mucous membrane reactions in patients treated with concurrent radiochemotherapy for nasopharyngeal carcinoma,and to analyze the influencing factors.Methods A total of 85 nasopharyngeal carcinoma cases treated with concurrent radiochemotherapy were enrolled in the study.Fifteen clinical and laboratory indexes,including BMI,radiation dose,degree of acute oral mucous and skin reactions and blood routine test were observed weekly.Univariate and multivariate regression analysis were performed to assess the factors,and screen the independent factors.Results Multiple-factor analysis showed that the risk factors cloesly related with acute radioactive oral mucosa reactions were smoking history(OR =3.467,P < 0.05),single-dose of gross tumor volume (GTV) >2.15 Gy(OR =3.393,P < 0.05),while those with acute radiation skin reactions were diabetes history(OR =87.859,P < 0.05) and hemoglobin values 1 week before radiotherapy > 130 g/L (OR =21.404,P < 0.05).Conclusions In the patients treated

  11. Analyses of changes on skin by aging.

    Science.gov (United States)

    Kazanci, A; Kurus, M; Atasever, A

    2017-02-01

    This study aimed to evaluate the histological changes occurring in rat skin with increasing age, starting from the intrauterine period. Thirty-two healthy female Sprague-Dawley rats were evaluated in four groups: group 1 - intrauterine day 19, group 2 - postpartum day 21, group 3 - postpartum day 60, and group 4 - postpartum month 19. Skin samples from the back, abdomen, head, and upper and lower limbs were obtained from each subject under anesthesia. Tissue specimens were evaluated statistically and morphologically for the thicknesses of the epidermis, dermis, and basement membrane; the number, height, and width of dermal papillae; and the mast cell and pilosebaceous counts per group. The changes in collagen/elastic fibers and glycosaminoglycans were also assessed. Epidermal thickness was the highest in the intrauterine group; it decreased in the postpartum period and increased again in the aged group. Basal membrane thickness increased steadily with age. The number, height, and width of dermal papillae and dermal thickness increased up to day 60 after birth although these decreased in the aged group. Mast cell count also reached the maximum in the intrauterine group and gradually decreased with age. Pilosebaceous units of the dermis were fewer in intrauterine specimens; they showed an increase during the postpartum period and a decrease in the aged group. Skin specimens obtained from rats showed striking differences between the intrauterine and postpartum groups. Moreover, the postpartum group showed considerable intra-group differences. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Primordial membranes

    DEFF Research Database (Denmark)

    Hanczyc, Martin M; Monnard, Pierre-Alain

    2017-01-01

    Cellular membranes, which are self-assembled bilayer structures mainly composed of lipids, proteins and conjugated polysaccharides, are the defining feature of cell physiology. It is likely that the complexity of contemporary cells was preceded by simpler chemical systems or protocells during the...

  13. Robotic membranes

    DEFF Research Database (Denmark)

    Ramsgaard Thomsen, Mette

    2008-01-01

    , Vivisection and Strange Metabolisms, were developed at the Centre for Information Technology and Architecture (CITA) at the Royal Danish Academy of Fine Arts in Copenhagen as a means of engaging intangible digital data with tactile physical material. As robotic membranes, they are a dual examination...

  14. Glycerol and urea can be used to increase skin permeability in reduced hydration conditions.

    Science.gov (United States)

    Björklund, Sebastian; Engblom, Johan; Thuresson, Krister; Sparr, Emma

    2013-12-18

    The natural moisturizing factor (NMF) is a group of hygroscopic molecules that is naturally present in skin and protects from severe drying. Glycerol and urea are two examples of NMF components that are also used in skin care applications. In the present study, we investigate the influence of glycerol and urea on the permeability of a model drug (metronidazole, Mz) across excised pig skin membranes at different hydrating conditions. The degree of skin hydration is regulated by the gradient in water activity across the membrane, which in turn depends on the water activity of the formulation in contact with the skin membrane. Here, we determine the water activity of all formulations employed using an isothermal calorimetric method. Thus, the gradient in water activity is controlled by a novel experimental set-up with well-defined boundary conditions on both sides of the skin membrane. The results demonstrate that glycerol and urea can retain high steady state flux of Mz across skin membranes at dehydrating conditions, which otherwise would decrease the permeability due to dehydration. X-ray diffraction measurements are performed to give insight into the effects of glycerol and urea on SC molecular organization. The novel steady state flux results can be related to the observation that water, glycerol, and urea all affect the structural features of the SC molecular components in a similar manner.

  15. Eicosanoids in skin inflammation.

    Science.gov (United States)

    Nicolaou, Anna

    2013-01-01

    Eicosanoids play an integral part in homeostatic mechanisms related to skin health and structural integrity. They also mediate inflammatory events developed in response to environmental factors, such as exposure to ultraviolet radiation, and inflammatory and allergic disorders, including psoriasis and atopic dermatitis. This review article discusses biochemical aspects related to cutaneous eicosanoid metabolism, the contribution of these potent autacoids to skin inflammation and related conditions, and considers the importance of nutritional supplementation with bioactives such as omega-3 and omega-6 polyunsaturated fatty acids and plant-derived antioxidants as means of addressing skin health issues.

  16. Ultrasound skin tightening.

    Science.gov (United States)

    Minkis, Kira; Alam, Murad

    2014-01-01

    Ultrasound skin tightening is a noninvasive, nonablative method that allows for energy deposition into the deep dermal and subcutaneous tissue while avoiding epidermal heating. Ultrasound coagulation is confined to arrays of 1-mm(3) zones that include the superficial musculoaponeurotic system and connective tissue. This technology gained approval from the Food and Drug Administration as the first energy-based skin "lifting" device, specifically for lifting lax tissue on the neck, submentum, and eyebrows. Ultrasound has the unique advantage of direct visualization of treated structures during treatment. Ultrasound is a safe and efficacious treatment for mild skin tightening and lifting.

  17. Leishmania Skin Test

    Science.gov (United States)

    2010-03-01

    2009, a dose of 50µg will be used in the design of a phase III clinical trial. 15. SUBJECT TERMS LtSTA = Leishmania tropica Skin Test Antigen 16...2010 on a Leishmania Skin Test (LtSTA) developed from the promastigotes of Leishmania tropica . During this period a phase IIB study was in progress...diluent. The final product is referred to as Leishmania tropica Skin Test Antigen (LtSTA). Figure 3 is a schematic diagram of the Drug Product

  18. Ion transport by mitochondria-rich cells in toad skin

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Ussing, H H; Spring, K R

    1987-01-01

    The optical sectioning video imaging technique was used for measurements of the volume of mitochondria-rich (m.r.) cells of the isolated epithelium of toad skin. Under short-circuit conditions, cell volume decreased by about 14% in response to bilateral exposure to Cl-free (gluconate substitution....... Unilateral exposure to a Cl-free solution did not prevent ouabain-induced cell swelling. It is concluded that m.r. cells have an amiloride-blockable Na conductance in the apical membrane, a ouabain-sensitive Na pump in the basolateral membrane, and a passive Cl permeability in both membranes. From...

  19. On the curvature effect of thin membranes

    Science.gov (United States)

    Wang, Duo; Jiao, Xiangmin; Conley, Rebecca; Glimm, James

    2013-01-01

    We investigate the curvature effect of a thin, curved elastic interface that separates two subdomains and exerts a pressure due to a curvature effect. This pressure, which we refer to as interface pressure, is similar to the surface tension in fluid mechanics. It is important in some applications, such as the canopy of parachutes, biological membranes of cells, balloons, airbags, etc., as it partially balances a pressure jump between the two sides of an interface. In this paper, we show that the interface pressure is equal to the trace of the matrix product of the curvature tensor and the Cauchy stress tensor in the tangent plane. We derive the theory for interfaces in both 2-D and 3-D, and present numerical discretizations for computing the quality over triangulated surfaces.

  20. [Skin-picking disorder].

    Science.gov (United States)

    Niemeier, V; Peters, E; Gieler, U

    2015-10-01

    The disorder is characterized by compulsive repetitive skin-picking (SP), resulting in skin lesions. The patients must have undertaken several attempts to reduce or stop SP. The disorder must have led to clinically significant limitations in social, professional, or other important areas of life. The symptoms cannot be better explained by another emotional disorder or any other dermatological disease. In the new DSM-V, skin-picking disorder has been included in the diagnostic system as an independent disorder and describes the self-injury of the skin by picking or scratching with an underlying emotional disorder. SP is classified among the impulse-control disorders and is, thus, differentiated from compulsive disorders as such. There are often emotional comorbidities. In cases of pronounced psychosocial limitation, interdisciplinary cooperation with a psychotherapist and/or psychiatrist is indicated.

  1. Skin picking disorder.

    Science.gov (United States)

    Grant, Jon E; Odlaug, Brian L; Chamberlain, Samuel R; Keuthen, Nancy J; Lochner, Christine; Stein, Dan J

    2012-11-01

    Although skin picking has been documented in the medical literature since the 19th century, only now is it receiving serious consideration as a DSM psychiatric disorder in discussions for DSM-5. Recent community prevalence studies suggest that skin picking disorder appears to be as common as many other psychiatric disorders, with reported prevalences ranging from 1.4% to 5.4%. Clinical evaluation of patients with skin picking disorder entails a broad physical and psychiatric examination, encouraging an interdisciplinary approach to evaluation and treatment. Approaches to treatment should include cognitive-behavioral therapy (including habit reversal or acceptance-enhanced behavior therapy) and medication (serotonin reuptake inhibitors, N-acetylcysteine, or naltrexone). Based on clinical experience and research findings, the authors recommend several management approaches to skin picking disorder.

  2. Aging changes in skin

    Science.gov (United States)

    ... Stress Other causes of skin changes: Allergies to plants and other substances Climate Clothing Exposures to industrial and household chemicals Indoor heating Sunlight can cause: Loss of elasticity (elastosis) ...

  3. Radiation therapy -- skin care

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000735.htm Radiation therapy - skin care To use the sharing features ... this page, please enable JavaScript. When you have radiation treatment for cancer, you may have some changes ...

  4. Scalded skin syndrome

    Science.gov (United States)

    ... Severe bloodstream infection ( septicemia ) Spread to deeper skin infection ( cellulitis ) When to Contact a Medical Professional Call your provider or go to the emergency room if you have symptoms of this disorder. Prevention ... Alternative Names Ritter disease; Staphylococcal ...

  5. Skin Cancer Trends

    Science.gov (United States)

    ... Potential Partners for Comprehensive Cancer Control Coalitions References Statistics Rates by Race and Ethnicity Rates by State Trends Behavior Rates What CDC Is Doing Skin Cancer Prevention Progress Report The Burning Truth Initiative A ...

  6. Skin, Hair, and Nails

    Science.gov (United States)

    ... Development Infections Diseases & Conditions Pregnancy & Baby Nutrition & Fitness Emotions & Behavior School & Family Life First Aid & Safety Doctors & ... produce melanin, the pigment that gives skin its color. All people have roughly the same number of ...

  7. Skin or nail culture

    Science.gov (United States)

    Mucosal culture; Culture - skin; Culture - mucosal; Nail culture; Culture - fingernail; Fingernail culture ... There, it is placed in a special dish (culture). It is then watched to see if bacteria, ...

  8. Allergy testing - skin

    Science.gov (United States)

    Patch tests - allergy; Scratch tests - allergy; Skin tests - allergy; RAST test; Allergic rhinitis - allergy testing; Asthma - allergy testing; Eczema - allergy testing; Hayfever - allergy testing; Dermatitis - allergy testing; Allergy testing; ...

  9. Skin graft - slideshow

    Science.gov (United States)

    ... ency/presentations/100100.htm Skin graft - series—Normal anatomy To use the sharing features on this page, ... 2017 Updated by: Debra G. Wechter, MD, FACS, general surgery practice specializing in breast cancer, Virginia Mason ...

  10. Impairments in Skin Integrity.

    Science.gov (United States)

    Murphree, Rose W

    2017-09-01

    Altered skin integrity increases the chance of infection, impaired mobility, and decreased function and may result in the loss of limb or, sometimes, life. Skin is affected by both intrinsic and extrinsic factors. Intrinsic factors can include altered nutritional status, vascular disease issues, and diabetes. Extrinsic factors include falls, accidents, pressure, immobility, and surgical procedures. Ensuring skin integrity in the elderly requires a team approach and includes the individual, caregivers, and clinicians. The twenty-first century clinician has several online, evidence-based tools to assist with optimal treatment plans. Understanding best practices in addressing skin integrity issues can promote positive outcomes with the elderly. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Designing pliable structural Skins

    DEFF Research Database (Denmark)

    Tamke, Martin; Peters, Brady; Nielsen, Stig Anton;

    2013-01-01

    Structural stability can be formed through structured or seemingly unstructured approaches to fold, plead or crumble paper. This paper reports on two projects that showcase how computational design approaches can help to widen the understanding and use of structural skins....

  12. An elastic second skin

    Science.gov (United States)

    Yu, Betty; Kang, Soo-Young; Akthakul, Ariya; Ramadurai, Nithin; Pilkenton, Morgan; Patel, Alpesh; Nashat, Amir; Anderson, Daniel G.; Sakamoto, Fernanda H.; Gilchrest, Barbara A.; Anderson, R. Rox; Langer, Robert

    2016-08-01

    We report the synthesis and application of an elastic, wearable crosslinked polymer layer (XPL) that mimics the properties of normal, youthful skin. XPL is made of a tunable polysiloxane-based material that can be engineered with specific elasticity, contractility, adhesion, tensile strength and occlusivity. XPL can be topically applied, rapidly curing at the skin interface without the need for heat- or light-mediated activation. In a pilot human study, we examined the performance of a prototype XPL that has a tensile modulus matching normal skin responses at low strain (<40%), and that withstands elongations exceeding 250%, elastically recoiling with minimal strain-energy loss on repeated deformation. The application of XPL to the herniated lower eyelid fat pads of 12 subjects resulted in an average 2-grade decrease in herniation appearance in a 5-point severity scale. The XPL platform may offer advanced solutions to compromised skin barrier function, pharmaceutical delivery and wound dressings.

  13. Occupational skin diseases

    DEFF Research Database (Denmark)

    Mahler, Vera; Aalto-Korte, Kristiina; Alfonso, Jose Hernan

    2017-01-01

    BACKGROUND: Work-related skin diseases (WSD) are caused or worsened by a professional activity. Occupational skin diseases (OSD) need to fulfil additional legal criteria which differ from country to country. OSD range amongst the five most frequently notified occupational diseases (musculoskeletal...... diseases, neurologic diseases, lung diseases, diseases of the sensory organs, skin diseases) in Europe. OBJECTIVE: To retrieve information and compare the current state of national frameworks and pathways to manage patients with occupational skin disease with regard to prevention, diagnosis, treatment...... in Science and Technology (COST) Action TD 1206 (StanDerm) (www.standerm.eu). RESULTS: Besides a national health service or a statutory health insurance, most European member states implemented a second insurance scheme specifically geared at occupational diseases [insurance against occupational risks...

  14. Skin lesion biopsy

    Science.gov (United States)

    ... procedure will leave a small indented area. This type of biopsy is often done when a skin cancer is ... may have stitches to close the area. This type of biopsy is often done to diagnose rashes . EXCISIONAL BIOPSY ...

  15. Examine Your Skin

    Medline Plus

    Full Text Available ... Doctor Glossary of Terms Resources Resources Global Resources Cancer Centers Online Resources The Melanoma Book Clinical Trials Download a Skin Self-Exam Card Download a Patient Navigation Card ...

  16. Skin Diseases: Cross-section of human skin

    Science.gov (United States)

    Skip Navigation Bar Home Current Issue Past Issues Skin Diseases Cross-section of human skin Past Issues / Fall 2008 Table of Contents For ... Logical Images, Inc. I n the areas of skin health and skin diseases, the NIH's National Institute ...

  17. Spiritual and religious aspects of skin and skin disorders

    Directory of Open Access Journals (Sweden)

    Shenefelt PD

    2014-08-01

    Full Text Available Philip D Shenefelt,1 Debrah A Shenefelt2 1Dermatology and Cutaneous Surgery, University of South Florida, Tampa, 2Congregation Or Ahavah, Lutz, FL, USA Abstract: Skin and skin disorders have had spiritual aspects since ancient times. Skin, hair, and nails are visible to self and others, and touchable by self and others. The skin is a major sensory organ. Skin also expresses emotions detectable by others through pallor, coldness, "goose bumps", redness, warmth, or sweating. Spiritual and religious significances of skin are revealed through how much of the skin has been and continues to be covered with what types of coverings, scalp and beard hair cutting, shaving and styling, skin, nail, and hair coloring and decorating, tattooing, and intentional scarring of skin. Persons with visible skin disorders have often been stigmatized or even treated as outcasts. Shamans and other spiritual and religious healers have brought about healing of skin disorders through spiritual means. Spiritual and religious interactions with various skin disorders such as psoriasis, leprosy, and vitiligo are discussed. Religious aspects of skin and skin diseases are evaluated for several major religions, with a special focus on Judaism, both conventional and kabbalistic. Keywords: skin, skin disorders, spiritual, religious

  18. Fabrication of bioinspired composite nanofiber membranes with robust superhydrophobicity for direct contact membrane distillation.

    Science.gov (United States)

    Liao, Yuan; Wang, Rong; Fane, Anthony G

    2014-06-03

    The practical application of membrane distillation (MD) for water purification is hindered by the absence of desirable membranes that can fulfill the special requirements of the MD process. Compared to the membranes fabricated by other methods, nanofiber membranes produced by electrospinning are of great interest due to their high porosity, low tortuosity, large surface pore size, and high surface hydrophobicity. However, the stable performance of the nanofiber membranes in the MD process is still unsatisfactory. Inspired by the unique structure of the lotus leaf, this study aimed to develop a strategy to construct superhydrophobic composite nanofiber membranes with robust superhydrophobicity and high porosity suitable for use in MD. The newly developed membrane consists of a superhydrophobic silica-PVDF composite selective skin formed on a polyvinylidene fluoride (PVDF) porous nanofiber scaffold via electrospinning. This fabrication method could be easily scaled up due to its simple preparation procedures. The effects of silica diameter and concentration on membrane contact angle, sliding angle, and MD performance were investigated thoroughly. For the first time, the direct contact membrane distillation (DCMD) tests demonstrate that the newly developed membranes are able to present stable high performance over 50 h of testing time, and the superhydrophobic selective layer exhibits excellent durability in ultrasonic treatment and a continuous DCMD test. It is believed that this novel design strategy has great potential for MD membrane fabrication.

  19. Skin and Liquid Crystal: A brief review on their similarities

    Directory of Open Access Journals (Sweden)

    Hamdan Suhaimi

    2016-08-01

    Full Text Available Looking oneself directly into a mirror and what does one see? The answer is of course one’s face. Taking good care of ones skin is synonymous to beauty and healthy life style. However, beauty last only as thick as a skin layer so the saying goes. While, liquid crystal, as the name implies, it looks like a crystal but flow like a liquid. Thus, how doesthis stucture called liquid crystal relate to skin and beauty? As most of us are aware skin and liquid crystalall around us, be it naturally or in technological applications. Our body body are covered with skin and liquid crystals. Surprise as it may seem but that is a fact, albeit peculiar to some. Classic example of natural liquid crystals are protein and cell membranes, while in industrial application such as electronic devices,for instance, screen of our laptop, digital watches and latest application in cosmeceuticals that isliquid crystal crystal emulsion. The question now arise is how does skin relate to liquid crystal? Why is it that this structure is crucial to the structure and function of skin? How does it relate to the delivery system of active ingredients which is important in many cosmeceuticals product? This paper will provide a brief review on the relationship of these two entities and present some work done in this area of interest. A model for the lipids of the top most layer of the skin namely stratum corneum will be highlighted.

  20. Nicotinamide and the skin.

    Science.gov (United States)

    Chen, Andrew C; Damian, Diona L

    2014-08-01

    Nicotinamide, an amide form of vitamin B3, boosts cellular energy and regulates poly-ADP-ribose-polymerase 1, an enzyme with important roles in DNA repair and the expression of inflammatory cytokines. Nicotinamide shows promise for the treatment of a wide range of dermatological conditions, including autoimmune blistering disorders, acne, rosacea, ageing skin and atopic dermatitis. In particular, recent studies have also shown it to be a potential agent for reducing actinic keratoses and preventing skin cancers.

  1. Mantoux Tuberculin Skin Test

    Centers for Disease Control (CDC) Podcasts

    2006-11-22

    Learn how to evaluate people for latent TB infection with the Mantoux tuberculin skin test. This podcast includes sections on administering and reading the Mantoux tuberculin skin test, the standard method for detecting latent TB infection since the 1930s.  Created: 11/22/2006 by National Center for HIV, STD and TB Prevention (NCHHSTP).   Date Released: 12/12/2006.

  2. Skin Cancer - Multiple Languages

    Science.gov (United States)

    ... Expand Section Skin Cancer: MedlinePlus Health Topic - English Cáncer de piel: Tema de salud de MedlinePlus - español (Spanish) National Library of Medicine Ukrainian (українська ) Expand Section Skin Cancer - українська (Ukrainian) Bilingual PDF Health Information Translations Characters ...

  3. Excised porcine skin experimental systems to validate quantitative microdialysis methods for determination of drugs in skin after topical application.

    Science.gov (United States)

    Seki, Toshinobu; Wang, Aiping; Yuan, Dan; Saso, Yuko; Hosoya, Osamu; Chono, Sumio; Morimoto, Kazuhiro

    2004-11-24

    Microdialysis is useful as a method to evaluate the disposition of drugs in the skin to design improved transdermal delivery systems (TDDSs). In this study, quantitative microdialysis methods were validated in excised porcine skin experimental systems in vitro. Flurbiprofen (FP), used as a model drug, showed high affinity for the skin tissues in equilibrium states between the medium and skin. The membrane clearances of FP for permeation through the membrane of a dialysis fiber placed in the skin (CL(m in S)) were lower than that in the medium. The adsorption of components in the skin to the membrane surface of the dialysis fiber and accumulation of FP near the dialysis fiber are the most likely reasons for this. When CL(m in S) was used to predict the extracellular FP concentration in skin (C(T)), the value obtained was lower than that expected from the FP concentration in the medium on the dermis side, which should be equal to C(T) at equilibrium. In the zero net flux (ZNF) method, in which the concentration difference of perfusate (DeltaC) between the inflow and outflow were used to obtain C(T), the predicted C(T) was similar to the expected value. In an in vitro skin permeation experiment, the ZNF method was used for the prediction of C(T) near the dialysis fiber. The predicted C(T) was over 10 times higher than the FP concentration in the medium on the dermis side, suggesting a concentration gradient in the dermis. Although the ZNF method is good for predicting the C(T) in skin, the mass balance has to be considered for the quantitative evaluation of the skin permeation of drugs. In this study, the effect of the mass transfer of FP from the perfusate to the skin on the cumulative amount of FP passing through the skin was relatively low because of the use of suitable solutions as perfusate. The perfusion conditions and schedules should be designed carefully for quantitative evaluations using the ZNF method. These results provide useful information for the in

  4. Poly/vinyl alcohol/ membranes for reverse osmosis

    Science.gov (United States)

    Katz, M. G.; Wydeven, T., Jr.

    1981-01-01

    A description is presented of the results of studies of the water and salt transport properties of PVA membranes, taking into account radiation crosslinked PVA membranes, diffusive salt permeability through PVA membranes, and heat treated PVA membranes. The experimental findings support an occurrence of independent water, and salt permeation processes. It is suggested that the salt permeation is governed by a solution-diffusion transport mechanism. The preparation of thin skinned, asymmetric PVA membranes is also discussed. The employed method has a certain similarity to the classical phase inversion method, which is widely applied in the casting of asymmetric reverse osmosis membranes. Instead of using a gelling bath composed of a nonsolvent for the membrane material and miscible with the solvent from which the membrane is cast, a 'complexing' bath is used, which is a solution of a complexing agent in water.

  5. Poly/vinyl alcohol/ membranes for reverse osmosis

    Science.gov (United States)

    Katz, M. G.; Wydeven, T., Jr.

    1981-01-01

    A description is presented of the results of studies of the water and salt transport properties of PVA membranes, taking into account radiation crosslinked PVA membranes, diffusive salt permeability through PVA membranes, and heat treated PVA membranes. The experimental findings support an occurrence of independent water, and salt permeation processes. It is suggested that the salt permeation is governed by a solution-diffusion transport mechanism. The preparation of thin skinned, asymmetric PVA membranes is also discussed. The employed method has a certain similarity to the classical phase inversion method, which is widely applied in the casting of asymmetric reverse osmosis membranes. Instead of using a gelling bath composed of a nonsolvent for the membrane material and miscible with the solvent from which the membrane is cast, a 'complexing' bath is used, which is a solution of a complexing agent in water.

  6. Systemic evening primrose oil improves the biophysical skin parameters of healthy adults.

    Science.gov (United States)

    Muggli, R

    2005-08-01

    Biophysical skin parameters are indicators of age-related structural and functional changes in skin tissues. This randomized, double-blind, placebo-controlled study in healthy adults tested the effect of Efamol evening primrose oil [EPO, a gamma-linolenic acid (GLA) containing vegetable oil] on skin moisture, transepidermal water loss (TEWL), redness, firmness, elasticity, fatigue resistance and roughness. Efamol EPO was administered orally in soft gel capsules, 3 x 500 mg b.i.d. for 12 weeks. Measurements were taken at baseline and at weeks 4 and 12. The two treatment groups did not differ at baseline and at week 4. At week 12, however, all measured variables, with the exception of skin redness, were significantly different in the EPO group compared with placebo. Skin moisture, TEWL, elasticity, firmness, fatigue resistance and roughness had significantly improved by 12.9, 7.7, 4.7, 16.7, 14.2 and 21.7%, respectively. The two-sided levels of significance in favor of the EPO treatment ranged between 0.034 and 0.001. These findings lend further support to the notion that GLA is a conditionally essential fatty acid for the skin, i.e. it is unable to synthesize GLA, and therefore depends on preformed GLA for optimal structure and function.

  7. Ultraflexible organic photonic skin.

    Science.gov (United States)

    Yokota, Tomoyuki; Zalar, Peter; Kaltenbrunner, Martin; Jinno, Hiroaki; Matsuhisa, Naoji; Kitanosako, Hiroki; Tachibana, Yutaro; Yukita, Wakako; Koizumi, Mari; Someya, Takao

    2016-04-01

    Thin-film electronics intimately laminated onto the skin imperceptibly equip the human body with electronic components for health-monitoring and information technologies. When electronic devices are worn, the mechanical flexibility and/or stretchability of thin-film devices helps to minimize the stress and discomfort associated with wear because of their conformability and softness. For industrial applications, it is important to fabricate wearable devices using processing methods that maximize throughput and minimize cost. We demonstrate ultraflexible and conformable three-color, highly efficient polymer light-emitting diodes (PLEDs) and organic photodetectors (OPDs) to realize optoelectronic skins (oe-skins) that introduce multiple electronic functionalities such as sensing and displays on the surface of human skin. The total thickness of the devices, including the substrate and encapsulation layer, is only 3 μm, which is one order of magnitude thinner than the epidermal layer of human skin. By integrating green and red PLEDs with OPDs, we fabricate an ultraflexible reflective pulse oximeter. The device unobtrusively measures the oxygen concentration of blood when laminated on a finger. On-skin seven-segment digital displays and color indicators can visualize data directly on the body.

  8. DOSHIC PHYSIOLOGY OF SKIN

    Directory of Open Access Journals (Sweden)

    Shivprasad Chiplunkar

    2013-06-01

    Full Text Available The balance of dosha  represents the healthy state and imbalance will cause various diseases. In normalcy doshas will be performing their own functions and individual doshas will be having their own specific sites. By telling the various sthana of each dosha, different function that is taken up by individual dosha in different sites has been highlighted.By mentioning ‘sparshanendriyam’ as one of the sthana of vata dosha the sensory functions of skin to vata dosha has been emphasised. By mentioning ‘sparshanam’ as one of the sthana of pittadosha, the function of colouring/pigmentation of skin, which is majorly carried out  by melanocytes by secreting melanin pigment has been highlighted. Meda is one among the sthanas of kapha dosha; this can be considered as the adipose tissue of skin/below skin. Since sweda is mala of meda it can be also considered as the secretions from the eccrine glands.With respect to skin, sensory functions, both tactile and thermal is carried out by vata dosha more specifically vyana vata, pigmentation to the skin carried out by meloncytes by secreting melanin, it is nothing but function of pitta dosha more specifically brajaka pitta with the help of udana vata and finally production of sweat in sweat glands is the function of kapha. So there is the need for further study and research regarding the sthanas of all three doshas in different structures/organs in the body and its physiology.

  9. Zinc and skin biology.

    Science.gov (United States)

    Ogawa, Youichi; Kawamura, Tatsuyoshi; Shimada, Shinji

    2016-12-01

    Of all tissues, the skin has the third highest abundance of zinc in the body. In the skin, the zinc concentration is higher in the epidermis than in the dermis, owing to a zinc requirement for the active proliferation and differentiation of epidermal keratinocytes. Here we review the dynamics and functions of zinc in the skin as well as skin disorders associated with zinc deficiency, zinc finger domain-containing proteins, and zinc transporters. Among skin disorders associated with zinc deficiency, acrodermatitis enteropathica is a disorder caused by mutations in the ZIP4 transporter and subsequent zinc deficiency. The triad acrodermatitis enteropathica is characterized by alopecia, diarrhea, and skin lesions in acral, periorificial, and anogenital areas. We highlight the underlying mechanism of the development of acrodermatitis because of zinc deficiency by describing our new findings. We also discuss the accumulating evidence on zinc deficiency in alopecia and necrolytic migratory erythema, which is typically associated with glucagonomas. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Effects of Essential Oils and Polyunsaturated Fatty Acids on Canine Skin Equivalents: Skin Lipid Assessment and Morphological Evaluation

    Directory of Open Access Journals (Sweden)

    S. Cerrato

    2013-01-01

    Full Text Available A canine skin equivalent model has been validated for the assessment of a topical formulation effects. Skin equivalents were developed from freshly isolated cutaneous canine fibroblasts and keratinocytes, after enzymatic digestion of skin samples (n=8 from different breeds. Fibroblasts were embedded into a collagen type I matrix, and keratinocytes were seeded onto its surface at air-liquid interface. Skin equivalents were supplemented with essential oils and polyunsaturated fatty acid formulation or with vehicle. Skin equivalents were histopathologically and ultrastructurally studied, and the three main lipid groups (free fatty acids, cholesterol, and ceramides were analyzed. Results showed that the culture method developed resulted in significant improvements in cell retrieval and confluence. Treated samples presented a thicker epidermis with increased number of viable cell layers, a denser and compact stratum corneum, and a more continuous basal membrane. Regarding lipid profile, treated skin equivalents showed a significant increase in ceramide content (51.7±1.3 when compared to untreated (41.6 ± 1.4 samples. Ultrastructural study evidenced a compact and well-organized stratum corneum in both treated and control skin equivalents. In conclusion, cell viability and ceramides increase, after lipid supplementation, are especially relevant for the treatment of skin barrier disruptions occurring in canine atopic dermatitis.

  11. 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.

  12. Personal observation of skin disorders in malnutrition.

    Science.gov (United States)

    Lee, Benjamin Y; Hogan, Daniel J; Ursine, Susonne; Yanamandra, Krishne; Bocchini, Joseph A

    2006-01-01

    This is a description of some unknown skin disorders found by a physician inmate in a concentration camp, 1958 to 1962. After prolonged semistarvation and ultraheavy physical labor, skin lesions developed among the inmates including cutaneous pigmentation overlying bony prominence, buccal membrane pigmentation, palmoplantar keratoderma with fissures, palmar crease clefts, nail layering, intra-nail hemorrhage, and so on. These lesions responded dramatically to nutrition therapy, including dietary improvement, yeast administration, or thiamin injection. Thiamin deficiency was confirmed to be one of major etiologic factors, whereas the deficiency of niacin or riboflavin also played a part. In the pediatric case with palmar crease clefts, both thiamin and niacin were dramatically effective. No laboratory data could be provided.

  13. New Polymeric Membranes for Organic Solvent Nanofiltration

    KAUST Repository

    Aburabie, Jamaliah

    2017-05-01

    The focus of this dissertation was the development, synthesis and modification of polymers for the preparation of membranes for organic solvent nanofiltration. High chemical stability in a wide range of solvents was a key requirement. Membranes prepared from synthesized polymers as well as from commercial polymers were designed and chemically modified to reach OSN requirements. A solvent stable thin-film composite (TFC) membrane is reported, which is fabricated on crosslinked polythiosemicarbazide (PTSC) as substrate. The membranes exhibited high fluxes towards solvents like THF, DMF and DMSO ranging around 20 L/m2 h at 5 bar with a MWCO of around 1000 g/mol. Ultrafiltration PTSC membranes were prepared by non-solvent induced phase separation and crosslinked with GPTMS. The crosslinking reaction was responsible for the formation of an inorganic-type-network that tuned the membrane pore size. The crosslinked membranes acquired high solvent stability in DMSO, DMF and THF with a MWCO above 1300 g/mol. Reaction Induced Phase Separation (RIPS) was introduced as a new method for the preparation of skinned asymmetric membranes. These membranes have two distinctive layers with different morphologies both from the same polymer. The top dense layer is composed of chemically crosslinked polymer chains while the bottom layer is a porous structure formed by non-crosslinked polymer chains. Such membranes were tested for vitamin B12 in solvents after either crosslinking the support or dissolving the support and fixing the freestanding membrane on alumina. Pebax® 1657 was utilized for the preparation of composite membranes by simple coating. Porous PAN membranes were coated with Pebax® 1657 which was then crosslinked using TDI. Crosslinked Pebax® membranes show high stability towards ethanol, propanol and acetone. The membranes were also stable in DMF once crosslinked PAN supports were used. Sodium alginate polymer was investigated for the preparation of thin film composite

  14. The potential applications of fibrin-coated electrospun polylactide nanofibers in skin tissue engineering.

    Science.gov (United States)

    Bacakova, Marketa; Musilkova, Jana; Riedel, Tomas; Stranska, Denisa; Brynda, Eduard; Zaloudkova, Margit; Bacakova, Lucie

    2016-01-01

    Fibrin plays an important role during wound healing and skin regeneration. It is often applied in clinical practice for treatment of skin injuries or as a component of skin substitutes. We prepared electrospun nanofibrous membranes made from poly(l-lactide) modified with a thin fibrin nanocoating. Fibrin surrounded the individual fibers in the membrane and also formed a thin fibrous mesh on several places on the membrane surface. The cell-free fibrin nanocoating remained stable in the cell culture medium for 14 days and did not change its morphology. On membranes populated with human dermal fibroblasts, the rate of fibrin degradation correlated with the degree of cell proliferation. The cell spreading, mitochondrial activity, and cell population density were significantly higher on membranes coated with fibrin than on nonmodified membranes, and this cell performance was further improved by the addition of ascorbic acid in the cell culture medium. Similarly, fibrin stimulated the expression and synthesis of collagen I in human dermal fibroblasts, and this effect was further enhanced by ascorbic acid. The expression of beta1-integrins was also improved by fibrin, and on pure polylactide membranes, it was slightly enhanced by ascorbic acid. In addition, ascorbic acid promoted deposition of collagen I in the form of a fibrous extracellular matrix. Thus, the combination of nanofibrous membranes with a fibrin nanocoating and ascorbic acid seems to be particularly advantageous for skin tissue engineering.

  15. Recent Progress in Electronic Skin

    OpenAIRE

    Wang, Xiandi; Dong, Lin; Zhang, Hanlu; Yu, Ruomeng; Pan, Caofeng; Wang, Zhong Lin

    2015-01-01

    The skin is the largest organ of the human body and can sense pressure, temperature, and other complex environmental stimuli or conditions. The mimicry of human skin's sensory ability via electronics is a topic of innovative research that could find broad applications in robotics, artificial intelligence, and human–machine interfaces, all of which promote the development of electronic skin (e‐skin). To imitate tactile sensing via e‐skins, flexible and stretchable pressure sensor arrays are co...

  16. Skin aging and oxidative stress

    OpenAIRE

    Sayeeda Ahsanuddin; Minh Lam; Baron, Elma D.

    2016-01-01

    Skin aging occurs through two main pathways, intrinsic and extrinsic. These pathways have significant interaction in contributing to the aging phenotype, which includes skin laxity, wrinkling, pigmentation irregularities, and the appearance of neoplastic skin lesions. Here, we review the critical role that oxidative stress plays in skin aging, including its effects on signaling pathways involved in skin matrix formation and degradation, proteasome activity, as well as DNA structure. Furthermo...

  17. Skin involvement in Dupuytren's disease.

    OpenAIRE

    Wade, R.; Igali, L; Figus, A

    2016-01-01

    Whether the palmar skin has a role in the development, propagation or recurrence of Dupuytren's disease remains unclear. Clinical assessment for skin involvement is difficult and its correlation with histology uncertain. We prospectively biopsied the palmar skin of consecutive patients undergoing single digit fasciectomy (for primary Dupuytren's disease without clinically involved skin) and dermofasciectomy (for clinically involved skin or recurrence) in order to investigate this relationship...

  18. Manifestações cutâneo-mucosas da coccidioidomicose: estudo de trinta casos procedentes dos estados do Piauí e Maranhão Skin and mucous membrane manifestations of coccidioidomycosis: a study of thirty cases in the Brazilian states of Piauí and Maranhão

    Directory of Open Access Journals (Sweden)

    Antônio de Deus Filho

    2010-02-01

    Full Text Available FUNDAMENTOS: A coccidioidomicose é micose sistêmica usualmente manifesta como infecção benigna de resolução espontânea; porém, uma pequena proporção dos infectados desenvolve quadros progressivos potencialmente fatais, podendo atingir a pele com lesões pleomórficas disseminadas. OBJETIVOS: Identificar e descrever as manifestações cutâneo-mucosas da coccidioidomicose, as ocupações de risco relacionadas à doença e o quadro clínico associado. MÉTODOS: Estudo realizado entre os anos 2003 e 2006 em 30 pacientes portadores de coccidioidomicose provenientes dos estados do Piauí e Maranhão e diagnosticados por exame microscópico direto, cultivo do escarro ou sorologia de triagem de imunodifusão dupla em gel de ágar, aliados à anamnese e exame físico. RESULTADOS: Identificaram-se lesões extrapulmonares em 13 casos (43,3%, com predomínio de manifestações dermatológicas de hipersensibilidade: eritema nodoso (26,6%, exantema com lesões eritemato-escamosas (26,6% e eritema multiforme (23,3%, além de úlceras de língua (13,3% e lábio (6,6% e abscesso subcutâneo (3,3%. Tais manifestações foram observadas na fase aguda da doença. CONCLUSÕES: As manifestações cutâneas associadas à infecção respiratória aguda fortalecem a hipótese diagnóstica desta doença, especialmente, em caçadores de tatus ou pessoas expostas à escavação do solo.BACKGROUND: Coccidioidomycosis is a systemic mycosis that usually presents as a benign infection. Patients generally recover spontaneously; however, a small proportion of infected individuals develop progressive complications that may affect the skin in the form of disseminated pleomorphic lesions and may become fatal. OBJECTIVES: To identify and describe skin and mucous membrane manifestations of coccidioidomycosis, to identify occupational hazards associated with the disease and to determine its associated clinical presentation. METHODS: A study conducted between 2003 and 2006

  19. Polymer and Membrane Design for Low Temperature Catalytic Reactions.

    Science.gov (United States)

    Villalobos, Luis Francisco; Xie, Yihui; Nunes, Suzana Pereira; Peinemann, Klaus-Viktor

    2016-04-01

    Catalytically active asymmetric membranes have been developed with high loadings of palladium nanoparticles located solely in the membrane's ultrathin skin layer. The manufacturing of these membranes requires polymers with functional groups, which can form insoluble complexes with palladium ions. Three polymers have been synthesized for this purpose and a complexation/nonsolvent induced phase separation followed by a palladium reduction step is carried out to prepare such membranes. Parameters to optimize the skin layer thickness and porosity, the palladium loading in this layer, and the palladium nanoparticles size are determined. The catalytic activity of the membranes is verified with the reduction of a nitro-compound and with a liquid phase Suzuki-Miyaura coupling reaction. Very low reaction times are observed.

  20. Spiritual and religious aspects of skin and skin disorders

    Science.gov (United States)

    Shenefelt, Philip D; Shenefelt, Debrah A

    2014-01-01

    Skin and skin disorders have had spiritual aspects since ancient times. Skin, hair, and nails are visible to self and others, and touchable by self and others. The skin is a major sensory organ. Skin also expresses emotions detectable by others through pallor, coldness, “goose bumps”, redness, warmth, or sweating. Spiritual and religious significances of skin are revealed through how much of the skin has been and continues to be covered with what types of coverings, scalp and beard hair cutting, shaving and styling, skin, nail, and hair coloring and decorating, tattooing, and intentional scarring of skin. Persons with visible skin disorders have often been stigmatized or even treated as outcasts. Shamans and other spiritual and religious healers have brought about healing of skin disorders through spiritual means. Spiritual and religious interactions with various skin disorders such as psoriasis, leprosy, and vitiligo are discussed. Religious aspects of skin and skin diseases are evaluated for several major religions, with a special focus on Judaism, both conventional and kabbalistic. PMID:25120377

  1. Skin cleansing in children.

    Science.gov (United States)

    Gelmetti, C

    2001-09-01

    The problems of skin cleansing in infants have been re-evaluated in recent years on the basis of current understanding of cosmetology and skin physiology. The anatomical and functional peculiarities of infant's skin have been elucidated and, although it is known that the barrier function is established at birth in normal babies, it remains the case that children's skin is more delicate and therefore more prone to irritant and allergic contact dermatitis. These factors determine the choice of cleansing agents during infancy. The products available on the market differ markedly. Indeed detergents, bath oils, bath powders, due to their distinctive properties, have different indications and different benefits. The method of cleansing the skin, i.e. bathing or showering, is also important. The frequency of cleansing should take into account the age and the degree of exposure to pollutants. For special purposes, e.g. impetiginized dermatoses, antiseptics such as potassium permanganate or chlorhexidine can be added to the water in appropriate concentrations. The ideal paediatric detergent should be very mild to avoid irritant dermatitis, and very simple to avoid allergic dermatitis.

  2. How to Choose the Best Skin Care Products

    Science.gov (United States)

    ... Skin Scars Skin Growths Skin Lesions Spider Veins Stretch Marks Sun-damaged Skin Unwanted Hair Unwanted Tattoos Varicose ... Skin Scars Skin Growths Skin Lesions Spider Veins Stretch Marks Sun-damaged Skin Unwanted Hair Unwanted Tattoos Varicose ...

  3. Extreme skin depth waveguides

    CERN Document Server

    Jahani, Saman

    2014-01-01

    Recently, we introduced a paradigm shift in light confinement strategy and introduced a class of extreme skin depth (e-skid) photonic structures (S. Jahani and Z. Jacob, "Transparent sub-diffraction optics: nanoscale light confinement without metal," Optica 1, 96-100 (2014)). Here, we analytically establish that figures of merit related to light confinement in dielectric waveguides are fundamentally tied to the skin depth of waves in the cladding. We contrast the propagation characteristics of the fundamental mode of e-skid waveguides and conventional waveguides to show that the decay constant in the cladding is dramatically larger in e-skid waveguides, which is the origin of sub-diffraction confinement. Finally, we propose an approach to verify the reduced skin depth in experiment using the decrease in the Goos-H\\"anchen phase shift.

  4. Skin Cancer Detection

    Directory of Open Access Journals (Sweden)

    N. Durga Rao

    2016-06-01

    Full Text Available : In recent days, skin cancer is seen as one of the most Hazardous form of the Cancers found in Humans. Skin cancer is found in various types such as Melanoma, Basal and Squamous cell Carcinoma among which Melanoma is the most unpredictable. The detection of Melanoma cancer in early stage can be helpful to cure it. Computer vision can play important role in Medical Image Diagnosis and it has been proved by many existing systems. In this paper, we present a survey on different steps which are being to detect the Melanoma Skin Cancer using Image Processing tools. In every step, what are the different methods are be included in our paper

  5. Smoking and skin disease.

    Science.gov (United States)

    Thomsen, S F; Sørensen, L T

    2010-06-01

    Tobacco smoking is a serious and preventable health hazard that can cause or exacerbate a number of diseases and shorten life expectancy, but the role of smoking as an etiologic factor in the development of skin disease is largely unknown. Although epidemiological evidence is sparse, findings suggest that tobacco smoking is a contributing factor in systemic lupus erythematosus, psoriasis, palmoplantar pustulosis, cutaneous squamous cell carcinoma, hidradenitis suppurativa, and genital warts. In contrast, smoking may confer some protective effects and mitigate other skin diseases, notably pemphigus vulgaris, pyoderma gangrenosum, aphthous ulcers, and Behçet's disease. Various degenerative dermatologic conditions are also impacted by smoking, such as skin wrinkling and dysregulated wound healing, which can result in post-surgical complications and delayed or even arrested healing of chronic wounds. Most likely, alteration of inflammatory cell function and extracellular matrix turnover caused by smoking-induced oxidative stress are involved in the pathophysiologic mechanisms.

  6. Sprayed skin turbine component

    Science.gov (United States)

    Allen, David B

    2013-06-04

    Fabricating a turbine component (50) by casting a core structure (30), forming an array of pits (24) in an outer surface (32) of the core structure, depositing a transient liquid phase (TLP) material (40) on the outer surface of the core structure, the TLP containing a melting-point depressant, depositing a skin (42) on the outer surface of the core structure over the TLP material, and heating the assembly, thus forming both a diffusion bond and a mechanical interlock between the skin and the core structure. The heating diffuses the melting-point depressant away from the interface. Subsurface cooling channels (35) may be formed by forming grooves (34) in the outer surface of the core structure, filling the grooves with a fugitive filler (36), depositing and bonding the skin (42), then removing the fugitive material.

  7. Smoking and skin disease

    DEFF Research Database (Denmark)

    Thomsen, S F; Sørensen, L T

    2010-01-01

    Tobacco smoking is a serious and preventable health hazard that can cause or exacerbate a number of diseases and shorten life expectancy, but the role of smoking as an etiologic factor in the development of skin disease is largely unknown. Although epidemiological evidence is sparse, findings...... suggest that tobacco smoking is a contributing factor in systemic lupus erythematosus, psoriasis, palmoplantar pustulosis, cutaneous squamous cell carcinoma, hidradenitis suppurativa, and genital warts. In contrast, smoking may confer some protective effects and mitigate other skin diseases, notably...... pemphigus vulgaris, pyoderma gangrenosum, aphthous ulcers, and Behçet's disease. Various degenerative dermatologic conditions are also impacted by smoking, such as skin wrinkling and dysregulated wound healing, which can result in post-surgical complications and delayed or even arrested healing of chronic...

  8. Evaluation of nicotinamide microemulsion on the skin penetration enhancement.

    Science.gov (United States)

    Boonme, Prapaporn; Boonthongchuay, Chalida; Wongpoowarak, Wibul; Amnuaikit, Thanaporn

    2016-01-01

    This study purposed to evaluate a microemulsion containing nicotinamide for its characteristics, stability, and skin penetration and retention comparing with a solution of nicotinamide in 2:1 mixture of water and isopropyl alcohol (IPA). The microemulsion system was composed of 1:1 mixture of Span80 and Tween80 as a surfactant mixture, isopropyl palmitate (IPP) as an oil phase, and 2:1 mixture of water and IPA as an aqueous phase. Nicotinamide microemulsion was prepared by dissolving the active in the aqueous phase before simply mixing with the other components. It was determined for its characteristics and stability under various conditions. The skin penetration and retention studies of nicotinamide microemulsion and solution were performed by modified Franz diffusion cells, using newborn pig skin as the membrane. The results showed that nicotinamide microemulsion could be obtained as clear yellowish liquid, was water-in-oil (w/o) type, possessed Newtonian flow, and exhibited physicochemical stability when kept at 4 °C and room temperature (≈30 ± 2 °C) during 3 months. From the skin penetration data, the microemulsion could enhance the skin penetration of nicotinamide comparing with the solution. Additionally, nicotinamide microemulsion could provide much higher amount of skin retention than that of skin penetration, resulting in suitability for a cosmeceutical product.

  9. Skin Temperature Measurement

    OpenAIRE

    Sarjoghian, Siamak

    2017-01-01

    This report represents the design and implementation of a skin temperature measurement system. The system aims to measure the skin temperature from a sensor and send it to the PC using a USB cable to display on screen. The data needs to be updated every second. The PIC18F4550 microcontroller has been used in this project to obtain data from the sensor and send it to the PC using USB 2.0 that has been built into the microcontroller. The microcontroller has a 10-bit Analog Digital Converting ac...

  10. Skin innate immune system

    Directory of Open Access Journals (Sweden)

    Berna Aksoy

    2013-06-01

    Full Text Available All multicellular organisms protect themselves from external universe and microorganisms by innate immune sytem that is constitutively present. Skin innate immune system has several different components composed of epithelial barriers, humoral factors and cellular part. In this review information about skin innate immune system and its components are presented to the reader. Innate immunity, which wasn’t adequately interested in previously, is proven to provide a powerfull early protection system, control many infections before the acquired immunity starts and directs acquired immunity to develop optimally

  11. Study of surfactant-skin interactions by skin impedance measurements.

    Science.gov (United States)

    Lu, Guojin; Moore, David J

    2012-02-01

    The stratum corneum (SC) plays a very critical physiological role as skin barrier in regulating water loss through the skin and protects the body from a wide range of physical and chemical exogenous insults. Surfactant-containing formulations can induce skin damage and irritation owing to surfactant absorption and penetration. It is generally accepted that reduction in skin barrier properties occurs only after surfactants have penetrated/permeated into the skin barrier. To mitigate the harshness of surfactant-based cleansing products, penetration/permeation of surfactants should be reduced. Skin impedance measurements have been taken in vitro on porcine skin using vertical Franz diffusion cells to investigate the impact of surfactants, temperature and pH on skin barrier integrity. These skin impedance results demonstrate excellent correlation with other published methods for assessing skin damage and irritation from different surfactant chemistry, concentration, pH, time of exposure and temperature. This study demonstrates that skin impedance can be utilized as a routine approach to screen surfactant-containing formulations for their propensity to compromise the skin barrier and hence likely lead to skin irritation.

  12. Deformation of Two-Dimensional Nonuniform-Membrane Red Blood Cells Simulated by a Lattice Boltzmann Model

    Institute of Scientific and Technical Information of China (English)

    LI Hua-Bing; JIN Li; QIU Bing

    2008-01-01

    To study two-dimensional red blood cells deforming in a shear flow with the membrane nonuniform on the rigidity and mass, the membrane is discretized into equilength segments. The fluid inside and outside the red blood cell is simulated by the D2Q9 lattice Boltzmann model and the hydrodynamic forces exerted on the membrane from the inner and outer of the red blood cell are calculated by a stress-integration method. Through the global deviation from the curvature of uniform-membrane, we find that when the membrane is nonuniform on the rigidity, the deviation first decreases with the time increases and implies that the terminal profile of the red blood cell is static. To a red blood cell with the mass nonuniform on the membrane, the deviation becomes more large, and the mass distribution affects the profile of the two sides of the flattened red blood cell in a shear flow.

  13. Therapeutic potential of the anti-diabetic agent metformin in targeting the skin cancer stem cell diaspora.

    Science.gov (United States)

    Reddi, Anand; Powers, Matthew A; Dellavalle, Robert P

    2014-05-01

    Type II diabetes is associated with increased prevalence of cancer including both melanoma and squamous cell carcinoma (SCC) of the skin. Emerging evidence from epidemiological studies suggest that diabetic patients on metformin have a lower risk of cancer incidence and mortality in a broad range of neoplasms. In both melanoma and SCC, populations of cancer stem cells (CSC) contribute to tumor initiation and metastasis. We propose that metformin constitutes a new class of targeted therapy that acts on the skin CSC diaspora. We posit that metformin selectively and simultaneously targets CSCs of the primary tumor as well as in metastatic niches thereby disrupting the dynamic dispersal of circulating CSCs between the primary tumor and metastatic site. This hypothesis suggests a new concept in dermato-oncology that treatment of type II diabetes and prevention of skin cancer are two sides of the same coin.

  14. Preparation of Gas Separation Membranes and their Evaluation

    Directory of Open Access Journals (Sweden)

    R. S. Chauhan

    2004-07-01

    Full Text Available Asymmetric membranes have been prepared form the polysulfone using dry-wet phase-inversion technique. These membranes show a thin dense skin at one surface and porous as well as the selectivity of membranes. In addition an online permeate composition analysis system has also been setup to quantify the concentration fo the two major components of atmospheric ari, namely oxygen and nitrogen using a gas chromatograph. Memvranes have been tested at various feed pressures. Teh developed membranes are capable of enriching atmospheric air to a level of 30 per cent and more.

  15. 交叉网络外部性还是单向网络外部性?——传媒业内的双边市场辨析%Cross-Product Network Externalities or Unilateral Network Externalities: Analysis of Two-Sided-Market in Media Industry

    Institute of Scientific and Technical Information of China (English)

    张辉锋

    2012-01-01

    This paper mainly discusses whether media industry has two-sided-market or not. It focuses on two categories which are mostly similar to two-sided-market: one is Internet advertising alliance, copyright exchange base, content products trade fair, etc., the other is the press and broadcasting markets. It finds that the former belongs to two-sided-market while the latter does not since there is no cross-product network externalities between advertiser and audience. It also argues that the former should refer to the pricing strategy of two-sided-market and there is no need for the latter to take care of the influence of the pricing strategy on audiences.%本论文利用双边市场理论对传媒业进行辨析,以厘清传媒业中是否存在双边市场。辨析主要集中在与双边市场最贴近的两类,一是互联网广告联盟、版权交易基地、内容产品展销会等,一是报刊广电等传媒。结论是前者属于双边市场,后者由于广告主与受众两边市场不存在交叉网络外部性而不是。论文还指出,前者的定价应多借鉴双边市场定价策略的相关内容,而后者对广告主的定价可不考虑对受众的影响。

  16. About Skin-to-Skin Care (Kangaroo Care)

    Science.gov (United States)

    ... Size Email Print Share About Skin-to-Skin Care Page Content Article Body You may be able ... care, also called kangaroo care. What is Kangaroo Care? Kangaroo care was developed in South America as ...

  17. Allergy Skin Tests

    Science.gov (United States)

    ... once. This test is usually done to identify allergies to pollen, mold, pet dander, dust mites and foods. In adults, the test is usually done on the forearm. Children may be tested on the upper back. Allergy skin tests aren't painful. This type of ...

  18. Preventing Skin Cancer

    Centers for Disease Control (CDC) Podcasts

    2016-05-18

    A man and a woman talk about how they’ve learned to protect their skin from the sun over the years. .  Created: 5/18/2016 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 5/18/2016.

  19. Skin-reducing mastectomy.

    Science.gov (United States)

    Nava, Maurizio B; Cortinovis, Umberto; Ottolenghi, Joseph; Riggio, Egidio; Pennati, Angela; Catanuto, Giuseppe; Greco, Marco; Rovere, Guidubaldo Querci Della

    2006-09-01

    The authors propose a combined flap technique to reconstruct large and medium-sized ptotic breasts in a single-stage operation by use of anatomical permanent implants. The authors enrolled 28 patients fulfilling criteria for skin-sparing mastectomy and presenting with ptotic breasts whose areola-to-inframammary fold distance was more than 8 cm. All reconstructions were performed as a single-stage procedure. After preoperative planning, a large area in the lower half of the breast was deepithelialized according to the conventional Wise pattern. Mastectomy was then carried out. To perform reconstructions, the inferomedial fibers of the pectoralis major muscle were dissected and sutured to the superior border of the inferior dermal flap. An anatomical implant was then inserted into the pouch, which was closed laterally with the previously harvested serratus anterior fascia. Skin flaps were finally closed down to the inframammary fold. The authors performed 30 procedures on 28 patients. The medium size anatomical implants was 433 cc. Twelve women achieved symmetrization in a single stage ending in a symmetric inverted-T scar. The overall complication rate was 20 percent, with four cases (13 percent) complicated by severe, extensive necrosis of the skin flaps requiring implant removal. Breast cancer treatment must nowadays optimize cosmetic results. This can be accomplished in selected cases by means of a single-stage operation that the authors call "skin-reducing mastectomy." The final scars imitate those of cosmetic surgery. Careful patient selection and improvement in the learning curve may reduce the complication rate.

  20. Tuberculin Skin Testing

    Science.gov (United States)

    ... Guidance for XDR Mycobacterium tuberculosis strains Data & Statistics Trends in Tuberculosis, 2015 TB Incidence in the United ... No. RR-17). CDC. Mantoux Tuberculin Skin Test: Training Materials Kit (2003). CDC. Targeted tuberculin testing and treatment of latent tuberculosis infection . MMWR 2000; 49 (No. ... CDC Jobs Funding LEGAL Policies Privacy FOIA No Fear Act ...

  1. Immunopathology of skin lesions

    Directory of Open Access Journals (Sweden)

    Khan Nazoora

    2001-09-01

    Full Text Available A study was conducted on 130 patients suffering from skin lesions which included psoriasis, lichen planus, DLE, pemphigus, vitiligo and alopecia areata. Forty age-and-sex-matched healthy individuals served as control. Serum IgG, IgM, and circulating immune complexes (CIC were estimated. Significant increase in serum IgG (1937.2 ± 1030.43 mg% and IgM (232.12 ± 136.98 mg% was observed in all the skin lesions when compared with controls except in lichen planus where they were significantly lowered, values being 580.61± 77.35 mg% and 66.88 ± 6.59mg% respectively. CIC levels were significantly raised (P<0.00 1 in various skin lesions (40.49±23.29 when compared with controls (17.68± 3.21, but no significance was observed in lichen planus( 17.72 ± 4.28. Serum IgG, IgM and CIC were statistically significantly altered depending on the extent of the lesion and lowered significantly to almost normal values following treatment, thereby confirming the role of immunity in the pathogenesis of these skin disorders.

  2. Frog skin function revisited

    DEFF Research Database (Denmark)

    Hviid Larsen, Erik; Ramløv, Hans

    2013-01-01

    of the epidermis. These mechanisms have evolved pari passu with life alternating between aquatic and terrestrial habitats associated with permeabilities of the skin controlled by external ion- and osmotic concentrations (loc. cit.). This allows for fast switching of the cutaneous uptake of chloride between active...

  3. Cryoglobulin induced skin ulceration

    Directory of Open Access Journals (Sweden)

    Fatima Razvi

    2015-01-01

    Full Text Available Lupus Erythematosus (LE is a multi-organ auto-immune disease which results from complex interaction of genetic and environmental factors. The clinical spectrum ranges from minor cutaneous lesions to life threatening multi-organ dysfunction. The skin manifestations are variable and common and range from LE specific to LE non-specific cutaneous disease. Vasculitis is one of the most common non-specific skin lesion of Systemic lupus erythematosus (SLE and appears as purpuric lesions, infarcts along lateral nail folds, peripheral gangrene, sub-cutaneous nodules and ulcers. Mixed cryoglobulinaemia (type II is associated with connective tissue disorders including SLE. Skin manifestations are seen in 60-100% patients and are more common in females. The most common manifestation is palpable purpura of lower extremities seen in 30-100% which often is triggered in winter or on cold exposure. Skin infarction, hemorrhagic crusts and ulcers are seen in 25% of patients. Wide spread necrotic ulcers are seen in 10-25% of patients which are often exacerbated by cold.

  4. Skin Conditions during Pregnancy

    Science.gov (United States)

    ... appear on the skin during pregnancy? • What are stretch marks? • Is acne common during pregnancy? • How can I ... runs from the navel to the pubic hair • Stretch marks •Acne • Spider veins • Varicose veins • Changes in nail ...

  5. Cytokines and the Skin Barrier

    Directory of Open Access Journals (Sweden)

    Jens Malte Baron

    2013-03-01

    Full Text Available The skin is the largest organ of the human body and builds a barrier to protect us from the harmful environment and also from unregulated loss of water. Keratinocytes form the skin barrier by undergoing a highly complex differentiation process that involves changing their morphology and structural integrity, a process referred to as cornification. Alterations in the epidermal cornification process affect the formation of the skin barrier. Typically, this results in a disturbed barrier, which allows the entry of substances into the skin that are immunologically reactive. This contributes to and promotes inflammatory processes in the skin but also affects other organs. In many common skin diseases, including atopic dermatitis and psoriasis, a defect in the formation of the skin barrier is observed. In these diseases the cytokine composition within the skin is different compared to normal human skin. This is the result of resident skin cells that produce cytokines, but also because additional immune cells are recruited. Many of the cytokines found in defective skin are able to influence various processes of differentiation and cornification. Here we summarize the current knowledge on cytokines and their functions in healthy skin and their contributions to inflammatory skin diseases.

  6. Skin color independent assessment of aging using skin autofluorescence

    NARCIS (Netherlands)

    Koetsier, M.; Nur, E.; Chunmao, H.; Lutgers, H.L.; Links, T.P.; Smit, A.J.; Rakhorst, G.; de Graaff, R.

    2010-01-01

    Skin autofluorescence (AF) for the non-invasive assessment of the amount of accumulated tissue Advanced Glycation Endproducts (AGEs) increases with aging. In subjects with darker skin colors, measurements typically result in lower AF values than in subjects with fair skin colors, e. g. due to select

  7. Skin color independent assessment of aging using skin autofluorescence

    NARCIS (Netherlands)

    Koetsier, M.; Nur, E.; Chunmao, H.; Lutgers, H.L.; Links, T.P.; Smit, A.J.; Rakhorst, G.; de Graaff, R.

    2010-01-01

    Skin autofluorescence (AF) for the non-invasive assessment of the amount of accumulated tissue Advanced Glycation Endproducts (AGEs) increases with aging. In subjects with darker skin colors, measurements typically result in lower AF values than in subjects with fair skin colors, e. g. due to

  8. Skin tissue engineering.

    Science.gov (United States)

    Mansbridge, Jonathan

    2008-01-01

    The major applications of tissue-engineered skin substitutes are in promoting the healing of acute and chronic wounds. Several approaches have been taken by commercial companies to develop products to address these conditions. Skin substitutes include both acellular and cellular devices. While acellular skin substitutes act as a template for dermal formation, this discussion mainly covers cellular devices. In addressing therapeutic applications in tissue engineering generally, a valuable precursor is an understanding of the mechanism of the underlying pathology. While this is straightforward in many cases, it has not been available for wound healing. Investigation of the mode of action of the tissue-engineered skin substitutes has led to considerable insight into the mechanism of formation, maintenance and treatment of chronic wounds. Four aspects mediating healing are considered here for their mechanism of action: (i) colonization of the wound bed by live fibroblasts in the implant, (ii) the secretion of growth factors, (iii) provision of a suitable substrate for cell migration, particularly keratinocytes and immune cells, and (iv) modification of the immune system by secretion of neutrophil recruiting chemokines. An early event in acute wound healing is an influx of neutrophils that destroy planktonic bacteria. However, if the bacteria are able to form biofilm, they become resistant to neutrophil action and prevent reepithelialization. In this situation the wound becomes chronic. In chronic wounds, fibroblasts show a senescence-like phenotype with decreased secretion of neutrophil chemoattractants that make it more likely that biofilms become established. Treatment of the chronic wounds involves debridement to eliminate biofilm, and the use of antimicrobials. A role of skin substitutes is to provide non-senescent fibroblasts that attract and activate neutrophils to prevent biofilm re-establishment. The emphasis of the conclusion is the importance of preventing

  9. The Roles of ADAMs Family Proteinases in Skin Diseases

    Directory of Open Access Journals (Sweden)

    Masakazu Kawaguchi

    2011-01-01

    Full Text Available A disintegrin and metalloproteinases (ADAMs are members of a new gene family of transmembrane and secreted proteins, which belong to the zinc proteinase superfamily. These molecules are involved in various biological events such as cell adhesion, cell fusion, cell migration, membrane protein shedding, and proteolysis. Growing evidence now attests to the potential involvement of ADAMs proteinases in diverse processes such as skin wound healing, inflammation, pigmentation, tumor development, cell proliferation, and metastasis. This paper focuses on the roles of ADAMs proteinases in a wide variety of skin diseases.

  10. In vitro selection and efficacy of topical skin protectants against the nerve agent VX.

    Science.gov (United States)

    Millerioux, J; Cruz, C; Bazire, A; Lallement, G; Lefeuvre, L; Josse, D

    2009-04-01

    Against highly toxic chemicals that are quickly absorbed in the skin, topical formulations could adequately complement specific protective suits and equipments. In this work, we evaluated in vitro and compared the skin protection efficacy against the nerve agent VX of four different topical formulations: oil-in-water and water-in-oil emulsions, a perfluorinated-based cream and a hydrogel. Semi-permeable silicone membrane, pig-ear and human abdominal split-thickness skin samples mounted in diffusion cells were compared as in vitro permeation tests. The results showed that silicone membrane could be used instead of skin samples to screen for potentially effective formulations. However, the results indicated that due to potentially significant interactions between formulations and skin, relevant ranking of formulations according to their protective efficacy could require tests with skin samples. The main phase of emulsions, water or oil, was not found to be critical for skin protective efficacy against VX. Instead, specific film-forming ingredients such as perfluorinated-based polymers and silicones could significantly affect the skin protective efficacy of formulations. We showed that a hydrogel containing specific hydrophilic polymers was by far the most effective of the formulations evaluated against VX skin permeation in vitro.

  11. SKIN DETECTION OF ANIMATION CHARACTERS

    Directory of Open Access Journals (Sweden)

    Kazi Tanvir Ahmed Siddiqui

    2015-02-01

    Full Text Available The increasing popularity of animes makes it vulnerable to unwanted usages like copyright violations and pornography. That’s why, we need to develop a method to detect and recognize animation characters. Skin detection is one of the most important steps in this way. Though there are some methods to detect human skin color, but those methods do not work properly for anime characters. Anime skin varies greatly from human skin in color, texture, tone and in different kinds of lighting. They also vary greatly among themselves. Moreover, many other things (for example leather, shirt, hair etc., which are not skin, can have color similar to skin. In this paper, we have proposed three methods that can identify an anime character’s skin more successfully as compared with Kovac, Swift, Saleh and Osman methods, which are primarily designed for human skin detection. Our methods are based on RGB values and their comparative relations.

  12. Staining of skin with dihydroxyacetone.

    Science.gov (United States)

    WITTGENSTEIN, E; BERRY, H K

    1960-09-30

    The reaction of skin with dihydroxyacetone to produce a brown "artificial tan" appears to proceed through combination with free amino groups in skin proteins, and particularly by combination of dihydroxyacetone with the free guanido group in arginine.

  13. Candida infection of the skin

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000880.htm Candida infection of the skin To use the sharing features on this page, please enable JavaScript. Candida infection of the skin is a yeast infection ...

  14. Maintaining Healthy Skin -- Part 2

    Science.gov (United States)

    ... from seams or elastic binding. Check also for blisters, bumps, insect bites, dry flaky skin or pimples. ... always check your skin carefully after wearing new shoes or clothing. Too loose — Loose clothing can form ...

  15. Tissue Engineered Human Skin Equivalents

    Directory of Open Access Journals (Sweden)

    Zheng Zhang

    2012-01-01

    Full Text Available Human skin not only serves as an important barrier against the penetration of exogenous substances into the body, but also provides a potential avenue for the transport of functional active drugs/reagents/ingredients into the skin (topical delivery and/or the body (transdermal delivery. In the past three decades, research and development in human skin equivalents have advanced in parallel with those in tissue engineering and regenerative medicine. The human skin equivalents are used commercially as clinical skin substitutes and as models for permeation and toxicity screening. Several academic laboratories have developed their own human skin equivalent models and applied these models for studying skin permeation, corrosivity and irritation, compound toxicity, biochemistry, metabolism and cellular pharmacology. Various aspects of the state of the art of human skin equivalents are reviewed and discussed.

  16. Drugs Approved for Skin Cancer

    Science.gov (United States)

    ... Ask about Your Treatment Research Drugs Approved for Skin Cancer This page lists cancer drugs approved by the Food and Drug Administration (FDA) for skin cancer, including drugs for basal cell carcinoma, melanoma, and ...

  17. Skin Cancers of the Feet

    Science.gov (United States)

    ... cracking, bleeding, or ulceration. Frequently, individuals discover their skin cancer after unrelated ailments near the affected site. Causes We often view the sun's harmful rays as the primary cause of skin cancer; the condition is often found on parts of ...

  18. Nicotinamide for skin cancer chemoprevention.

    Science.gov (United States)

    Damian, Diona L

    2017-03-20

    Nicotinamide (vitamin B3 ) has a range of photoprotective effects in vitro and in vivo; it enhances DNA repair, reduces UV radiation-induced suppression of skin immune responses, modulates inflammatory cytokine production and skin barrier function and restores cellular energy levels after UV exposure. Pharmacological doses of nicotinamide have been shown to reduce actinic keratoses and nonmelanoma skin cancer incidence in high-risk individuals, making this a nontoxic and accessible option for skin cancer chemoprevention in this population.

  19. A REVIEW ON SKIN CANCER

    OpenAIRE

    S. Ramya Silpa; Chidvila V

    2013-01-01

    Skin cancer can be of 2 types mainly. They are malignant melanoma and non-malignant melanoma. Skin cancer mainly occurs due to exposure of sunlight. Ozone depletion and chemical exposures are other factors involved in precipitating skin cancer. Mutations of p53 gene are involved in UV- induced carcinogenesis. P53 gene acts vital in development of SCC. So, prevention of skin cancer is the main criteria. Regular application of sunscreens could be one of the primary prevention. The purpose of pr...

  20. From biological membranes to biomimetic model membranes

    Directory of Open Access Journals (Sweden)

    Eeman, M.

    2010-01-01

    Full Text Available Biological membranes play an essential role in the cellular protection as well as in the control and the transport of nutrients. Many mechanisms such as molecular recognition, enzymatic catalysis, cellular adhesion and membrane fusion take place into the biological membranes. In 1972, Singer et al. provided a membrane model, called fluid mosaic model, in which each leaflet of the bilayer is formed by a homogeneous environment of lipids in a fluid state including globular assembling of proteins and glycoproteins. Since its conception in 1972, many developments were brought to this model in terms of composition and molecular organization. The main development of the fluid mosaic model was made by Simons et al. (1997 and Brown et al. (1997 who suggested that membrane lipids are organized into lateral microdomains (or lipid rafts with a specific composition and a molecular dynamic that are different to the composition and the dynamic of the surrounding liquid crystalline phase. The discovery of a phase separation in the plane of the membrane has induced an explosion in the research efforts related to the biology of cell membranes but also in the development of new technologies for the study of these biological systems. Due to the high complexity of biological membranes and in order to investigate the biological processes that occur on the membrane surface or within the membrane lipid bilayer, a large number of studies are performed using biomimicking model membranes. This paper aims at revisiting the fundamental properties of biological membranes in terms of membrane composition, membrane dynamic and molecular organization, as well as at describing the most common biomimicking models that are frequently used for investigating biological processes such as membrane fusion, membrane trafficking, pore formation as well as membrane interactions at a molecular level.

  1. Skin cancer: Etiology and management.

    Science.gov (United States)

    Qadir, Muhammad Imran

    2016-05-01

    Nowadays, occurrence of skin cancer is very common in humans. It is reported that the most common cause of the skin cancer is excessive exposure to sunlight as it contains harmful radiations; the ultra violet rays. Different management strategies are used for different types of skin cancers, which are chemotherapy, radiation therapy.

  2. Skin Pedagogies and Abject Bodies

    Science.gov (United States)

    Kenway, Jane; Bullen, Elizabeth

    2011-01-01

    How does the beauty industry "narrate the skin"? What does it teach women from different cultural groups about the female body? How does skin function as a site where female subjection and abjection are produced and reproduced? In this paper we examine the skin industry pointing to its extreme commodification of the female body and to the…

  3. Skin Pedagogies and Abject Bodies

    Science.gov (United States)

    Kenway, Jane; Bullen, Elizabeth

    2011-01-01

    How does the beauty industry "narrate the skin"? What does it teach women from different cultural groups about the female body? How does skin function as a site where female subjection and abjection are produced and reproduced? In this paper we examine the skin industry pointing to its extreme commodification of the female body and to the…

  4. Electrospun polyvinyl alcohol-polyvinyl pyrrolidone nanofibrous membranes for interactive wound dressing application.

    Science.gov (United States)

    Shankhwar, Nisha; Kumar, Manishekhar; Mandal, Biman B; Robi, P S; Srinivasan, A

    2016-01-01

    Cross-linked polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) composite nanofibrous membranes have been prepared by electrospinning. Mechanical properties of the membranes improved significantly with PVP addition. PVP improved hydrophilicity and sustainable degradation of the membranes. Biocompatibility of the membranes was assessed by in vitro culture of native skin cells (L929 fibroblast and HaCaT keratinocytes). Tests showed sustained release of the antibiotic ciprofloxacin hydrochloride monohydrate by the membranes. Further, zone of inhibition study against Staphylococcus aureus growth demonstrated protective action against external pathogenic microbes. These studies show these simple PVA-PVP nanofibrous membranes are promising interactive antibiotic-eluting wound dressing materials.

  5. Microporous Inorganic Membranes as Proton Exchange Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Vichi, F.M. Tejedor-Tejedor, M.I. Anderson, Marc A

    2002-08-28

    Porous oxide electrolyte membranes provide an alternative approach to fabricating proton exchange membrane fuel cells based on inorganic materials. This study focused on elucidating the properties of these inorganic membranes that make them good electrolyte materials in membrane electrode assemblies; in particular, we investigated several properties that affect the nature of proton conductivity in these membranes. This report discusses our findings on the effect of variables such as site density, amount of surface protonation and surface modification on the proton conductivity of membranes with a fixed pore structure under selected conditions. Proton conductivities of these inorganic membranes are similar to conductivities of nafion, the polymeric membrane most commonly used in low temperature fuel cells.

  6. Skin Cancer: Biology, Risk Factors & Treatment

    Science.gov (United States)

    ... turn Javascript on. Feature: Skin Cancer Skin Cancer: Biology, Risk Factors & Treatment Past Issues / Summer 2013 Table ... Articles Skin Cancer Can Strike Anyone / Skin Cancer: Biology, Risk Factors & Treatment / Timely Healthcare Checkup Catches Melanoma ...

  7. How Is Melanoma Skin Cancer Diagnosed?

    Science.gov (United States)

    ... Early Detection, Diagnosis, and Staging Tests for Melanoma Skin Cancer Most melanomas are brought to a doctor’s attention ... Melanoma Skin Cancer, by Stage More In Melanoma Skin Cancer About Melanoma Skin Cancer Causes, Risk Factors, and ...

  8. Serotonin in human skin

    Institute of Scientific and Technical Information of China (English)

    Jianguo Huang; Qiying Gong; Guiming Li

    2005-01-01

    In this review the authors summarize data of a potential role for serotonin in human skin physiology and pathology. The uncovering of endogenous serotonin synthesis and its transformation to melatonin underlines a putative important role of this pathway in melanocyte physiology and pathology. Pathways of the biosynthesis and biodegradation of serotonin have been characterized in human beings and its major cellular populations. Moreover, receptors of serotonin are expressed on keratinocytes, melanocytes, and fibroblasts and these mediate phenotypic actions on cellular proliferation and differentiation. And the widespread expression of a cutaneous seorotoninergic system indicates considerable selectivity of action to facilitate intra-, auto-, or paracrine mechanisms that define and influence skin function in a highly compartmentalized manner. Melatonin, in turn, can also act as a hormone, neurotransmitter, cytokine, biological modifier and immunomodulator. Thus, Serotonin local synthesis and cellular localization could thus become of great importance in the diagnosis and management of cutaneous pathology.

  9. Skin contamination dosimeter

    Science.gov (United States)

    Hamby, David M.; Farsoni, Abdollah T.; Cazalas, Edward

    2011-06-21

    A technique and device provides absolute skin dosimetry in real time at multiple tissue depths simultaneously. The device uses a phoswich detector which has multiple scintillators embedded at different depths within a non-scintillating material. A digital pulse processor connected to the phoswich detector measures a differential distribution (dN/dH) of count rate N as function of pulse height H for signals from each of the multiple scintillators. A digital processor computes in real time from the differential count-rate distribution for each of multiple scintillators an estimate of an ionizing radiation dose delivered to each of multiple depths of skin tissue corresponding to the multiple scintillators embedded at multiple corresponding depths within the non-scintillating material.

  10. Double-Skin Facade

    DEFF Research Database (Denmark)

    Kalyanova, Olena

    difficulties experienced by scientists when attempting to model DSF thermal and energy performance were examined. In addition, the lack of experimental studies and empirical validation of models was realized, many numerical models have not been empirically validated and most of them require an expert knowledge...... IEA Annex 34/43, subtask E "Double-Skin Facade". The results of empirical validation are discussed in this work. Discussion and analysis of experimental results is carried out. It has lead to hypothesis of recirculation flow phenomenon in the DSF cavity. Finally, a suggestion of a new numerical model......Double-Skin Facades (DSF) are gaining popularity that, in fact, appears to be independent from sturdy critics of the concept in the past years. DSF buildings are being built in Europe and worldwide, DSF concept is being taught at schools of architecture and fully glazed office buildings are being...

  11. Echo: skin stress test

    Science.gov (United States)

    1960-01-01

    Skin Stress Test of the 12-foot satellite built as a prototype of the full-scale Echo satellite. The 12-foot diameter of the sphere was chosen because that was the ceiling height in the Langley model shop. The proposal to build the 12-foot satellite was made in November 1957. - Published in James R. Hansen, Spaceflight Revolution: NASA Langley Research Center From Sputnik to Apollo, NASA SP-4308, pp. 170-171.

  12. Smoking and skin disease

    DEFF Research Database (Denmark)

    Thomsen, S F; Sørensen, L T

    2010-01-01

    pemphigus vulgaris, pyoderma gangrenosum, aphthous ulcers, and Behçet's disease. Various degenerative dermatologic conditions are also impacted by smoking, such as skin wrinkling and dysregulated wound healing, which can result in post-surgical complications and delayed or even arrested healing of chronic...... wounds. Most likely, alteration of inflammatory cell function and extracellular matrix turnover caused by smoking-induced oxidative stress are involved in the pathophysiologic mechanisms....

  13. Anaerobic membrane bioreactors: Are membranes really necessary?

    NARCIS (Netherlands)

    Davila, M.; Kassab, G.; Klapwijk, A.; Lier, van J.B.

    2008-01-01

    Membranes themselves represent a significant cost for the full scale application of anaerobic membrane bioreactors (AnMBR). The possibility of operating an AnMBR with a self-forming dynamic membrane generated by the substances present in the reactor liquor would translate into an important saving. A

  14. Development of human skin equivalents to unravel the impaired skin barrier in atopic dermatitis skin

    NARCIS (Netherlands)

    Eweje, M.O.

    2016-01-01

    The studies in this thesis describes the barrier defects in Atopic Dermatitis (AD) skin and various techniques to develop AD Human Skin Equivalents (HSEs) which can be used to better understand the role of several factors in the pathogenesis of AD skin. The results described show that Inflammation p

  15. Skin changes in menopause.

    Science.gov (United States)

    Bolognia, J L; Braverman, I M; Rousseau, M E; Sarrel, P M

    1989-12-01

    Skin signs and symptoms were examined in 46 menopausal women prior to estrogen replacement therapy. Several symptoms such as pruritus, bruising, dryness and thinning were seen more frequently in sun-exposed skin emphasizing the contribution of photoaging. At the end of a 6-mth treatment period, no significant difference was observed in the prevalence or severity of the cutaneous signs and symptoms when patients receiving transdermal 17 beta-estradiol (Estraderm) were compared with controls (the only exception was cutaneous flushing). Elastic fibers from sun-protected (buttock) skin of menopausal women were studied by light and electron microscopy. In 3 women (ages 30-37) with a history of premature menopause, the elastic fibers had several degenerative changes including coalescence of cystic spaces into lacunae, peripheral fragmentation, granular degeneration and splitting of the fibers into strands. Similar age-related ultrastructural changes are normally found in individuals that are at least 20 yrs older than these patients. These findings are suggestive of a relationship between premature aging of the dermal elastic fibers and estrogen deprivation.

  16. SKIN RADIATION IN PANORAMIC

    Directory of Open Access Journals (Sweden)

    Herry Irawan

    2015-06-01

    Full Text Available Dental panoramic radiograph in Indonesia has been widely used. Modern diagnostic imaging equipment with minimum radiation is still very limited. One of the conditions in nuclear safety law, UU 10/1997, is an optimization of all radiation sources with DRL through skin dose measurements. In Indonesia, the national DRL has not been established yet, and there were no reports on the study of panoramic skin dose in Indonesia. The aim of this preliminary study was to obtain a panoramic skin dose radiation as reference to establish DRL in Indonesia. Panoramic radiographs of sixteen female and fifteen male patients, aged 4 – 48 years, were taken using the standard conventional method, with TLD chips attached in location groups. The chips were then read with the detector and integrator of BATAN, in high and low temperature condition at the same time. It was revealed that behind the right and left ear were the regions with the highest radiation dose received, followed by the back of the neck, left jaw, right jaw, and chin. The result of this study has shown the importance of DRL in Indonesia since the use of modern diagnostic imaging equipement that limits radiation dose to the minimum level is still very limited.

  17. An investigation of pore collapse in asymmetric polysulfone membranes

    Science.gov (United States)

    Subrahmanyan, Sumitra

    2003-06-01

    Porous polysulfone membranes prepared by phase inversion can be tailored to suit filtration requirements by the choice of solvent and coagulant. In the current research polysulfone membranes were prepared by inverting a solution in N-methyl pyrrolidinone (NMP) in isopropanol to form uniform sized pores. Phase inversion resulted in the formation of an asymmetric membrane. The membranes have a characteristic "skin" which is supported by a highly porous substructure. Water-wet membranes experience capillary force during water evaporation. Since the modulus of the membranes is lower than the capillary force, the membrane walls shrink and thicken giving rise to a condensed structure. The "skin" regulates permeation through the membranes which is essential for filtration. A change in the pore structure of the skin alters the permeability. The current research investigates the influence of amine plasma treatments on the surface pore structure of polysulfone membranes. The permeation of a rhodamine dye through the plasma treated membranes and through non-plasma treated membranes is used to examine the influence of the plasma treatment. Furthermore, the influence of plasma treatment on the loss of water from the membranes leading to pore collapse is also explored. The study revealed that a plasma ablates the skin, increasing the permeation. An ammonia plasma treatment produced more etching, and hence increased permeation compared to permeation for an aniline plasma-treated membrane. A one-minute aniline plasma treatment only caused a moderate increase in permeation. Plasma treatments introduced significant surface modification by the introduction of new functionalities. However, permeation was not influenced by the surface modification. Water trapped in the pores is essential to maintain the pore structure of the membrane. The surface treatment dictates the pore size and therefore, the convection allowing water evaporation, leading to pore collapse. Heat treating also

  18. Model cell membranes

    DEFF Research Database (Denmark)

    Günther-Pomorski, Thomas; Nylander, Tommy; Cardenas Gomez, Marite

    2014-01-01

    The high complexity of biological membranes has motivated the development and application of a wide range of model membrane systems to study biochemical and biophysical aspects of membranes in situ under well defined conditions. The aim is to provide fundamental understanding of processes...... controlled by membrane structure, permeability and curvature as well as membrane proteins by using a wide range of biochemical, biophysical and microscopic techniques. This review gives an overview of some currently used model biomembrane systems. We will also discuss some key membrane protein properties...... that are relevant for protein-membrane interactions in terms of protein structure and how it is affected by membrane composition, phase behavior and curvature....

  19. Ultraviolet radiation and skin cancer.

    Science.gov (United States)

    Narayanan, Deevya L; Saladi, Rao N; Fox, Joshua L

    2010-09-01

    Skin cancer is the most common type of cancer in fair-skinned populations in many parts of the world. The incidence, morbidity and mortality rates of skin cancers are increasing and, therefore, pose a significant public health concern. Ultraviolet radiation (UVR) is the major etiologic agent in the development of skin cancers. UVR causes DNA damage and genetic mutations, which subsequently lead to skin cancer. A clearer understanding of UVR is crucial in the prevention of skin cancer. This article reviews UVR, its damaging effects on the skin and its relationship to UV immunosuppression and skin cancer. Several factors influence the amount of UVR reaching the earth's surface, including ozone depletion, UV light elevation, latitude, altitude, and weather conditions. The current treatment modalities utilizing UVR (i.e. phototherapy) can also predispose to skin cancers. Unnecessary exposure to the sun and artificial UVR (tanning lamps) are important personal attributable risks. This article aims to provide a comprehensive overview of skin cancer with an emphasis on carefully evaluated statistics, the epidemiology of UVR-induced skin cancers, incidence rates, risk factors, and preventative behaviors & strategies, including personal behavioral modifications and public educational initiatives. © 2010 The International Society of Dermatology.

  20. Erythrocyte membrane proteins and membrane skeleton

    Institute of Scientific and Technical Information of China (English)

    LU Yiqin; LIU Junfan

    2007-01-01

    Considerable advances in the research field of erythrocyte membrane were achieved in the recent two decades.New findings in the structure-function correlation and interactions of erythrocyte membrane proteins have attracted extensive attention.Interesting progress was also made in the molecular pathogenesis of erythrocyte membrane disorders.Advances in the composition,function and interaction of erythrocyte membrane proteins,erythrocyte membrane skeleton,and relevant diseases are briefly described and summarized here on the basis of domestic and world literatures.

  1. Comparison of synthetic membranes in the development of an in vitro feeding system for Dermanyssus gallinae.

    Science.gov (United States)

    Harrington, D W J; Guy, J H; Robinson, K; Sparagano, O A E

    2010-04-01

    Although artificial feeding models for the poultry red mite (Dermanyssus gallinae) most frequently use biological membranes consisting of day-old chick skin, there are ethical considerations associated with the use of skin. The few studies reported in the literature that have investigated the use of synthetic membranes to feed D. gallinae in vitro have reported limited success. The current study describes an investigation into the use of synthetic membranes made from either Nescofilm or rayon and silicone, used either alone or in combination with different feather or skin extracts, as well as the use of capillary tubes. In all, 12 different treatments were used, and the feeding rate of D. gallinae was compared to that of day-old chick skin. Allowing mites to feed on a membrane consisting of Nescofilm with a skin extract resulted in the highest proportion of mites feeding (32.3%), which was not significantly different to the feeding rate of mites on day-old chick skin (38.8%). This study confirms that synthetic membranes can be used to feed D. gallinae artificially. Further optimization of the membrane and mite storage conditions is still necessary, but the study demonstrates a proof of concept.

  2. A non-invasive method for in vivo skin volatile compounds sampling.

    Science.gov (United States)

    Jiang, Ruifen; Cudjoe, Erasmus; Bojko, Barbara; Abaffy, Tatjana; Pawliszyn, Janusz

    2013-12-04

    The use of volatile organic compounds (VOCs) emanating from human skin presents great potential for skin disease diagnosis. These compounds are emitted at very low concentrations. Thus, the sampling preparation step needs to be implemented before gas chromatography-mass spectrometry (GC-MS) analysis. In this work, a simple, non-invasive headspace sampling method for volatile compounds emanating from human skin is presented, using thin film as the extraction phase format. The proposed method was evaluated in terms of reproducibility, membrane size, extraction mode and storage conditions. First, the in vial sampling showed an intra- and inter-membrane RSD% less than 9.8% and 8.2%, respectively, which demonstrated that this home-made skin volatiles sampling device was highly reproducible with regard to intra-, inter-membrane sampling. The in vivo sampling was influenced not only by the skin metabolic status, but also by environmental conditions. The developed sampling set-up (or "membrane sandwich") was used to compare two different modes of sampling: headspace and direct sampling. Results demonstrated that headspace sampling had significantly reduced background signal intensity, indicating minimized contamination from the skin surface. In addition, membrane storage conditions both before and after sampling were fully investigated. Membranes stored in dry ice for up to 72 h after collection were tested and showed no or minimal change in volatile profiles. This novel skin volatile compounds sampling approach coupled with gas chromatography-mass spectrometry (GC-MS) can achieve reproducible analysis. This technique was applied to identify the biomarkers of garlic intake and alcohol ingestion. Dimethyl sulphone, allyl methyl sulfide and allyl mercaptan, as metabolites of garlic intake, were detected. In addition, alcohol released from skin was also detected using our "membrane-sandwich" sampling. Using the same approach, we analyzed skin VOCs from upper back, forearm and

  3. Development of human skin equivalents to unravel the impaired skin barrier in atopic dermatitis skin

    OpenAIRE

    Eweje, M.O.

    2016-01-01

    The studies in this thesis describes the barrier defects in Atopic Dermatitis (AD) skin and various techniques to develop AD Human Skin Equivalents (HSEs) which can be used to better understand the role of several factors in the pathogenesis of AD skin. The results described show that Inflammation plays a pivotal role in the development of epidermal and SC features of AD skin and that AD epidermal features can be maintained in vitro when AD skin biopsies are used to generate explant-HSEs. The...

  4. Comparative attenuation spectra of liquid skin-like phantoms

    CSIR Research Space (South Africa)

    Singh, A

    2010-09-01

    Full Text Available Intralipid (IL) (20% fat emulsion) and (b) the same eumelanin concentrations but with added bilipid membrane artificial vesicles (PheroidTM). Transmittance spectra of the samples were measured with a UV-VIS spectrophotometer (Shimazdu UV-1650 PC) using... is the fraction of photons removed from the sample due to the scattering and absorption processes occurring in the sample, using both methods. Two different skin-like phantom sets investigated: (a) Different concentrations of synthetic eumelanin and added...

  5. HUMAN AMNIOTIC MEMBRANE GRAFTING: A BOON IN OCULAR CHEMICAL INJURIES

    Directory of Open Access Journals (Sweden)

    Shashikala

    2013-03-01

    Full Text Available INTRODUCTION: Amniotic membrane is the innermost layer of the f etal membranes. It has a stromal matrix, a collagen layer, and an overlying basement membrane with a single layer of epithelium. (1 Amniotic membrane has unique properties including an ti-adhesive effects, bacterio-static properties, wound protection, pain redu ction, and epithelialisation effects. Another characteristic of amniotic membrane is the lack of imunogenicity. (2 Amniotic membranes have been used as a dressing to promote he aling of chronic ulcers of the leg and as a biological dressing for burned skin and skin woun ds. (3, 4 It has also been used in surgical reconstruction of artificial vagina, for repairing o mphaloceles, and to prevent tissue adhesion in surgeries of the abdomen, head, or pelvis. (5, 6 Amniotic membrane has been successfully used in ocular conditions like persistent epithelial defects (7, pterygium, (8 Symblepharon (9 and for ocular surface reconstruction. (10, 11 The purpose of this study was to evaluate the use of cryo- preserved Human amniotic membrane graft( HAMT, with or without limbal autograft transplantation (LAT in patients with previous and fr esh chemical eye injuries respectively. Institutional ethical committee approval was obtained .

  6. Immunoarchitectural characterization of a human skin model reconstructed in vitro

    Directory of Open Access Journals (Sweden)

    Luís Ricardo Martinhão Souto

    Full Text Available CONTEXT AND OBJECTIVE: Over the last few years, different models for human skin equivalent reconstructed in vitro (HSERIV have been reported for clinical usage and applications in research for the pharmaceutical industry. Before release for routine use as human skin replacements, HSERIV models need to be tested regarding their similarity with in vivo skin, using morphological (architectural and immunohistochemical (functional analyses. A model for HSERIV has been developed in our hospital, and our aim here was to further characterize its immunoarchitectural features by comparing them with human skin, before it can be tested for clinical use, e.g. for severe burns or wounds, whenever ancillary methods are not indicated. DESIGN AND SETTING: Experimental laboratory study, in the Skin Cell Culture Laboratory, School of Medical Sciences, Universidade Estadual de Campinas. METHODS: Histological sections were stained with hematoxylin-eosin, Masson's trichrome for collagen fibers, periodic acid-Schiff reagent for basement membrane and glycogen, Weigert-Van Gieson for elastic fibers and Fontana-Masson for melanocytes. Immunohistochemistry was used to localize cytokeratins (broad spectrum of molecular weight, AE1/AE3, high molecular weight cytokeratins (34βE12, low molecular weight cytokeratins (35βH11, cytokeratins 7 and 20, vimentin, S-100 protein (for melanocytic and dendritic cells, CD68 (KP1, histiocytes and CD34 (QBend, endothelium. RESULTS: Histology revealed satisfactory similarity between HSERIV and in vivo skin. Immunohistochemical analysis on HSERIV demonstrated that the marker pattern was similar to what is generally present in human skin in vivo. CONCLUSION: HSERIV is morphologically and functionally compatible with human skin observed in vivo.

  7. In vitro percutaneous absorption of chromium powder and the effect of skin cleanser.

    Science.gov (United States)

    Larese Filon, Francesca; D'Agostin, Flavia; Crosera, Matteo; Adami, Gianpiero; Bovenzi, Massimo; Maina, Giovanni

    2008-09-01

    The present study tried to investigate, using a synthetic sweat at pH 4.5, whether metallic chromium can pass through the skin (in vitro) and the effect of rapid skin decontamination with a common detergent. A suspension of chromium powder in synthetic sweat at pH 4.5 was prepared and shaken with a stirring plate at room temperature for 30 min. Human skin membranes were set up in Franz-diffusion cells and 1 ml of the freshly made suspension was applied to the outer surface of the skin for 24h. The tests were performed without and with decontamination using the cleanser 30 min after the start of exposure. The appearance of metal ions in the aqueous receptor phase was quantified by Electro Thermal Atomic Absorption Spectroscopy (ETAAS) and Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). Speciation analysis and measurements of chromium skin content were also performed. Chromium skin permeation was demonstrated in in vitro experiments using the Franz cell system, giving a permeation flux of 0.84+/-0.25 ng cm(-2)h(-1) and a lag time of 1.1+/-0.7h. The cleaning procedure stop Cr permeation but its concentration into the skin significantly increased (Mann-Whitney U test P<0.03). The results revealed that chromium applied as powder can pass through the skin and that decontamination, done after 30 min of exposure, prevent Cr skin permeation but increase Cr content into the skin.

  8. Preparation, anti-biofouling and drag-reduction properties of a biomimetic shark skin surface

    Directory of Open Access Journals (Sweden)

    Xia Pu

    2016-04-01

    Full Text Available Shark skin surfaces show non-smoothness characteristics due to the presence of a riblet structure. In this study, biomimetic shark skin was prepared by using the polydimethylsiloxane (PDMS-embedded elastomeric stamping (PEES method. Scanning electron microscopy (SEM was used to examine the surface microstructure and fine structure of shark skin and biomimetic shark skin. To analyse the hydrophobic mechanism of the shark skin surface microstructure, the effect of biomimetic shark skin surface microstructure on surface wettability was evaluated by recording water contact angle. Additionally, protein adhesion experiments and anti-algae adhesion performance testing experiments were used to investigate and evaluate the anti-biofouling properties of the surface microstructure of biomimetic shark skin. The recorded values of the water contact angle of differently microstructured surfaces revealed that specific microstructures have certain effects on surface wettability. The anti-biofouling properties of the biomimetic shark skin surface with microstructures were superior to a smooth surface using the same polymers as substrates. Moreover, the air layer fixed on the surface of the biomimetic shark skin was found to play a key role in their antibiont adhesion property. An experiment into drag reduction was also conducted. Based on the experimental results, the microstructured surface of the prepared biomimetic shark skin played a significant role in reducing drag. The maximum of drag reduction rate is 12.5%, which is higher than the corresponding maximum drag reduction rate of membrane material with a smooth surface.

  9. Skin moisturization mechanisms: new data.

    Science.gov (United States)

    Bonté, F

    2011-05-01

    The main function of the skin is to protect the body against exogenous substances and excessive water loss. The skin barrier is located in the outermost layer of the skin, called the stratum corneum, which is composed of corneocytes, originating from the keratinocytes differentiation process, embedded in organized complex lipid domains. Moisturizing of the skin is recognized as the first anti-aging skin care. Skin moisturization is essential for its appearance, protection, complexion, softness and the reinforcement of its barrier properties against deleterious and exogenous environmental factors. The intrinsic water binding capacity of skin is not only due to the complex natural moisturizing factor present in corneocytes, but also to hyaluronic acid and a regulated water transport within the skin. Recent data shows that the water movements between the cells at the different levels of the epidermis are due to dedicated water and glycerol transport proteins named aquaporins. Their role in the skin moisturization is completed by corneodesmosomes and tight junctions. Water and pH are now shown to be of prime importance in the regulation of the epidermal enzymes linked to corneocytes desquamation and lipid synthesis. Furthermore, the level of moisturization of the skin is important in its protection against repeated exposure to various irritant agents or phenomena such as very frequent washing with strong tensioactive materials.

  10. Magnetically controlled permeability membranes

    KAUST Repository

    Kosel, Jurgen

    2013-10-31

    A bioactive material delivery system can include a thermoresponsive polymer membrane and nanowires distributed within the thermoresponsive polymer membrane. Magnetic activation of a thermoresponsive polymer membrane can take place via altering the magnetization or dimensions of nanowires dispersed or ordered within the membrane matrix.

  11. Compositional asynchronous membrane systems

    Institute of Scientific and Technical Information of China (English)

    Cosmin Bonchis; Cornel Izbasa; Gabriel Ciobanu

    2007-01-01

    This paper presents an algorithmic way of building complex membrane systems by coupling elementary membranes. Its application seems particularly valuable in the case of asynchronous membrane systems, since the resulting membrane system remains asynchronous. The composition method is based on a handshake mechanism implemented by using antiport rules and promoters.

  12. Composite sensor membrane

    Science.gov (United States)

    Majumdar, Arun; Satyanarayana, Srinath; Yue, Min

    2008-03-18

    A sensor may include a membrane to deflect in response to a change in surface stress, where a layer on the membrane is to couple one or more probe molecules with the membrane. The membrane may deflect when a target molecule reacts with one or more probe molecules.

  13. Climate change and skin.

    Science.gov (United States)

    Balato, N; Ayala, F; Megna, M; Balato, A; Patruno, C

    2013-02-01

    Global climate appears to be changing at an unprecedented rate. Climate change can be caused by several factors that include variations in solar radiation received by earth, oceanic processes (such as oceanic circulation), plate tectonics, and volcanic eruptions, as well as human-induced alterations of the natural world. Many human activities, such as the use of fossil fuel and the consequent accumulation of greenhouse gases in the atmosphere, land consumption, deforestation, industrial processes, as well as some agriculture practices are contributing to global climate change. Indeed, many authors have reported on the current trend towards global warming (average surface temperature has augmented by 0.6 °C over the past 100 years), decreased precipitation, atmospheric humidity changes, and global rise in extreme climatic events. The magnitude and cause of these changes and their impact on human activity have become important matters of debate worldwide, representing climate change as one of the greatest challenges of the modern age. Although many articles have been written based on observations and various predictive models of how climate change could affect social, economic and health systems, only few studies exist about the effects of this change on skin physiology and diseases. However, the skin is the most exposed organ to environment; therefore, cutaneous diseases are inclined to have a high sensitivity to climate. For example, global warming, deforestation and changes in precipitation have been linked to variations in the geographical distribution of vectors of some infectious diseases (leishmaniasis, lyme disease, etc) by changing their spread, whereas warm and humid environment can also encourage the colonization of the skin by bacteria and fungi. The present review focuses on the wide and complex relationship between climate change and dermatology, showing the numerous factors that are contributing to modify the incidence and the clinical pattern of many

  14. Epidemiology of skin cancer.

    Science.gov (United States)

    Leiter, Ulrike; Eigentler, Thomas; Garbe, Claus

    2014-01-01

    Melanoma and nonmelanoma skin cancer (NMSC) are now the most common types of cancer in white populations. Both tumor entities show an increasing incidence rate worldwide but a stable or decreasing mortality rate. NMSC is the most common cancer in white-skinned individuals with a worldwide increasing incidence. NMSC is an increasing problem for health care services worldwide which causes significant morbidity. The rising incidence rates of NMSC are probably caused by a combination of increased exposure to ultraviolet (UV) or sun light, increased outdoor activities, changes in clothing style, increased longevity, ozone depletion, genetics and in some cases, immune suppression. An intensive UV exposure in childhood and adolescence was causative for the development of basal cell carcinoma (BCC) whereas for the etiology of SCC a chronic UV exposure in the earlier decades was accused. Cutaneous melanoma is the most rapidly increasing cancer in white populations, in the last 3 decades incidence rates have risen up to 5-fold. In 2008 melanoma was on place 5 in women and on place 8 in men of the most common solid tumor entities in Germany. The frequency of its occurrence is closely associated with the constitutive color of the skin, and the geographical zone. Changes in outdoor activities and exposure to sunlight during the past 50 years are an important factor for the increasing incidence of melanoma. Mortality rates of melanoma show a stabilization in the USA, Australia and also in European countries. In contrast to SCC, melanoma risk seems to be associated with an intermittent exposure to sunlight. Prevention campaigns aim on reducing incidence and achieving earlier diagnosis, which resulted in an ongoing trend toward thin melanoma since the last two decades. However, the impact of primary prevention measures on incidence rates of melanoma is unlikely to be seen in the near future, rather increasing incidence rates to 40-50/100,000 inhabitants/year should be expected in

  15. Skin and bones. I.

    Science.gov (United States)

    Orlow, S J; Watsky, K L; Bolognia, J L

    1991-08-01

    Skin disorders in which a radiograph may detect associated bony changes or abnormalities of calcification are discussed. They are grouped into eight categories: (1) inherited diseases (e.g., alkaptonuria, neurofibromatosis); (2) congenital disorders (e.g., Sturge-Weber and Proteus syndromes); (3) inflammatory conditions (e.g., dermatomyositis, sarcoidosis); (4) infections (e.g., dental sinus, syphilis); (5) neoplasias (e.g., histiocytosis, mastocytosis); (6) drug- and environment-induced (e.g., acroosteolysis, retinoid toxicity); (7) calcinosis cutis; and (8) osteoma cutis. Part I of our review discusses the first two categories.

  16. Skin and bones. II.

    Science.gov (United States)

    Orlow, S J; Watsky, K L; Bolognia, J L

    1991-09-01

    Skin disorders in which a radiograph may detect associated bony changes or abnormalities of calcification are discussed. They are grouped into eight categories: (1) inherited diseases (e.g., alkaptonuria, neurofibromatosis); (2) congenital disorders (e.g., Sturge-Weber and Proteus syndromes); (3) inflammatory conditions (e.g., dermatomyositis, sarcoidosis); (4) infections (e.g., dental sinus, syphilis); (5) neoplasias (e.g., histiocytosis, mastocytosis); (6) drug- and environment-induced (e.g., acroosteolysis, retinoid toxicity); (7) calcinosis cutis; and (8) osteoma cutis. The first part of this review, published in the August 1991 issue of this JOURNAL, dealt with the first two categories; part II discusses categories 3 through 8.

  17. 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 skin sensitisation above and below the LogKow = 1 threshold. Reaction chemistry considerations could explain the skin sensitisation observed for the 38 sensitisers with a LogKow 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

  18. Pathophysiological Study of Sensitive Skin.

    Science.gov (United States)

    Buhé, Virginie; Vié, Katell; Guéré, Christelle; Natalizio, Audrey; Lhéritier, Céline; Le Gall-Ianotto, Christelle; Huet, Flavien; Talagas, Matthieu; Lebonvallet, Nicolas; Marcorelles, Pascale; Carré, Jean-Luc; Misery, Laurent

    2016-03-01

    Sensitive skin is a clinical syndrome characterized by the occurrence of unpleasant sensations, such as pruritus, burning or pain, in response to various factors, including skincare products, water, cold, heat, or other physical and/or chemical factors. Although these symptoms suggest inflammation and the activation of peripheral innervation, the pathophysiogeny of sensitive skin remains unknown. We systematically analysed cutaneous biopsies from 50 healthy women with non-sensitive or sensitive skin and demonstrated that the intraepidermal nerve fibre density, especially that of peptidergic C-fibres, was lower in the sensitive skin group. These fibres are involved in pain, itching and temperature perception, and their degeneration may promote allodynia and similar symptoms. These results suggest that the pathophysiology of skin sensitivity resembles that of neuropathic pruritus within the context of small fibre neuropathy, and that environmental factors may alter skin innervation.

  19. The 'beauty' of skin neurobiology.

    Science.gov (United States)

    Pincelli, C; Bonté, F

    2003-07-01

    The skin is the most densely innervated organ in the body and there is a close relationship between the skin and the nervous system. Most skin cells express receptors for neuromediators (NM) and skin cells themselves are an important source of NM. In particular, human keratinocytes synthesize neurotrophins and endorphins and express their receptors. In addition to neurotrophic activity, NM are involved in skin homeostasis, trophism and stress responses. NM released from keratinocytes also function in a paracrine fashion on other skin cells, such as Langerhans cells, melanocytes and fibroblasts. We discuss the influence of NM on these cells, which may be involved in major cosmetic problems like ageing, baldness and dyspigmentation. Based on this correlation, it seems reasonable to target neural factors for cosmetic purposes.

  20. In vitro techniques to assess the proficiency of skin care cosmetic formulations

    OpenAIRE

    Amit Roy; Ram Kumar Sahu; Munglu Matlam; Vinay Kumar Deshmukh; Jaya Dwivedi; Arvind Kumar Jha

    2013-01-01

    Cosmetics comprising either natural or synthetic components are used almost regularly and universally in different forms to enhance the beauty. The utmost disclosure of human membrane to sunlight and environmental pollution results in the exhibition of free radical, that react with deoxyribonucleic acid, proteins and fatty acids, causation oxidative destruction dysfunction of the antioxidant system. In skin, the formation of reactive oxygen species leads to skin diseases, predominantly cutane...

  1. Cobalt Oxide Nanoparticles: Behavior towards Intact and Impaired Human Skin and Keratinocytes Toxicity

    OpenAIRE

    Marcella Mauro; Matteo Crosera; Marco Pelin; Chiara Florio; Francesca Bellomo; Gianpiero Adami; Piero Apostoli; Giuseppe Palma; Massimo Bovenzi; Marco Campanini; Francesca Larese Filon

    2015-01-01

    Skin absorption and toxicity on keratinocytes of cobalt oxide nanoparticles (Co3O4NPs) have been investigated. Co3O4NPs are commonly used in industrial products and biomedicine. There is evidence that these nanoparticles can cause membrane damage and genotoxicity in vitro, but no data are available on their skin absorption and cytotoxicity on keratinocytes. Two independent 24 h in vitro experiments were performed using Franz diffusion cells, using intact (experiment 1) and needle-abraded huma...

  2. H-Ras Expression in Immortalized Keratinocytes Produces an Invasive Epithelium in Cultured Skin Equivalents

    OpenAIRE

    Vaughan, Melville B.; Ruben D Ramirez; Andrews, Capri M.; Woodring E Wright; Jerry W Shay

    2009-01-01

    BACKGROUND: Ras proteins affect both proliferation and expression of collagen-degrading enzymes, two important processes in cancer progression. Normal skin architecture is dependent both on the coordinated proliferation and stratification of keratinocytes, as well as the maintenance of a collagen-rich basement membrane. In the present studies we sought to determine whether expression of H-ras in skin keratinocytes would affect these parameters during the establishment and maintenance of an in...

  3. [Thermal lasers and skin cicatrization].

    Science.gov (United States)

    Mordon, Serge; Capon, Alexandre; Fournier, Nathalie; Iarmarcovai, Gwen

    2010-01-01

    Any cutaneous damage triggers a cascade of biological effects in the skin responsible for re-establishing skin integrity. Wound healing is a complex biological process inducing dermal remodelling leading at least to a visible scar, and sometimes to hypertrophic or keloid scars. Recent studies suggest that using a laser generates a precisely defined thermal effect in the skin, improving the wound healing process and potentially opening the door to scarless healing.

  4. Protecting the skin during thyroidectomy

    Directory of Open Access Journals (Sweden)

    Renan Bezerra Lira

    2014-01-01

    Full Text Available In this note we describe the standard technical maneuver used in our department to protect the skin during thyroidectomy in order to get the best aesthetic result. We use surgical gloves to protect the skin during these operations to reduce the negative impact of thermal trauma and mechanical retractors and energy delivery devices at the edges of the skin incised. This practice is effective, inexpensive, rapid, reproducible and showed no complication in our experience of over 2,500 thyroidectomies.

  5. Propofol and arrhythmias: two sides of the coin

    Science.gov (United States)

    Liu, Qiang; Kong, Ai-ling; Chen, Rong; Qian, Cheng; Liu, Shao-wen; Sun, Bao-gui; Wang, Le-xin; Song, Long-sheng; Hong, Jiang

    2011-01-01

    The hypnotic agent propofol is effective for the induction and maintenance of anesthesia. However, recent studies have shown that propofol administration is related to arrhythmias. Propofol displays both pro- and anti-arrhythmic effects in a concentration-dependent manner. Data indicate that propofol can convert supraventricular tachycardia and ventricular tachycardia and may inhibit the conduction system of the heart. The mechanism of the cardiac effects remains poorly defined and may involve ion channels, the autonomic nervous system and cardiac gap junctions. Specifically, sodium, calcium and potassium currents in cardiac cells are suppressed by clinically relevant concentrations of propofol. Propofol shortens the action potential duration (APD) but lessens the ischemia-induced decrease in the APD. Furthermore, propofol suppresses both sympathetic and parasympathetic tone and preserves gap junctions during ischemia. All of these effects cumulatively contribute to the antiarrhythmic and proarrhythmic properties of propofol. PMID:21642950

  6. Hypercholesterolemia and Hypertension: Two Sides of the Same Coin.

    Science.gov (United States)

    Ivanovic, Branislava; Tadic, Marijana

    2015-12-01

    The aim of this review article is to summarize the current knowledge about mechanisms that connect blood pressure regulation and hypercholesterolemia, the mutual interaction between hypertension and hypercholesterolemia, and their influence on atherosclerosis development. Our research shows that at least one-third of the population of Western Europe has hypertension and hypercholesterolemia. Several biohumoral mechanisms could explain the relationship between hypertension and hypercholesterolemia and the association between these risk factors and accelerated atherosclerosis. The most investigated mechanisms are the renin-angiotensin-aldosterone system, oxidative stress, endothelial dysfunction, and increased production of endothelin-1. Arterial hypertension is frequently observed in combination with hypercholesterolemia, and this is related to accelerated atherosclerosis. Understanding the mechanisms behind this relationship could help explain the benefits of therapy that simultaneously reduce blood pressure and cholesterol levels.

  7. Refeeding and metabolic syndromes: two sides of the same coin

    Science.gov (United States)

    Obeid, O A; Hachem, D H; Ayoub, J J

    2014-01-01

    Refeeding syndrome describes the metabolic and clinical changes attributed to aggressive rehabilitation of malnourished subjects. The metabolic changes of refeeding are related to hypophosphatemia, hypokalemia, hypomagnesemia, sodium retention and hyperglycemia, and these are believed to be mainly the result of increased insulin secretion following high carbohydrate intake. In the past few decades, increased consumption of processed food (refined cereals, oils, sugar and sweeteners, and so on) lowered the intake of several macrominerals (mainly phosphorus, potassium and magnesium). This seems to have compromised the postprandial status of these macrominerals, in a manner that mimics low grade refeeding syndrome status. At the pathophysiological level, this condition favored the development of the different components of the metabolic syndrome. Thus, it is reasonable to postulate that metabolic syndrome is the result of long term exposure to a mild refeeding syndrome. PMID:24979149

  8. Reputation and Reward: Two Sides of the Same Bitcoin.

    Science.gov (United States)

    Delgado-Segura, Sergi; Tanas, Cristian; Herrera-Joancomartí, Jordi

    2016-05-27

    In Mobile Crowd Sensing (MCS), the power of the crowd, jointly with the sensing capabilities of the smartphones they wear, provides a new paradigm for data sensing. Scenarios involving user behavior or those that rely on user mobility are examples where standard sensor networks may not be suitable, and MCS provides an interesting solution. However, including human participation in sensing tasks presents numerous and unique research challenges. In this paper, we analyze three of the most important: user participation, data sensing quality and user anonymity. We tackle the three as a whole, since all of them are strongly correlated. As a result, we present PaySense, a general framework that incentivizes user participation and provides a mechanism to validate the quality of collected data based on the users' reputation. All such features are performed in a privacy-preserving way by using the Bitcoin cryptocurrency. Rather than a theoretical one, our framework has been implemented, and it is ready to be deployed and complement any existing MCS system.

  9. Fixed Points of Two-Sided Fractional Matrix Transformations

    Directory of Open Access Journals (Sweden)

    Handelman David

    2007-01-01

    Full Text Available Let and be complex matrices, and consider the densely defined map on matrices. Its fixed points form a graph, which is generically (in terms of nonempty, and is generically the Johnson graph ; in the nongeneric case, either it is a retract of the Johnson graph, or there is a topological continuum of fixed points. Criteria for the presence of attractive or repulsive fixed points are obtained. If and are entrywise nonnegative and is irreducible, then there are at most two nonnegative fixed points; if there are two, one is attractive, the other has a limited version of repulsiveness; if there is only one, this fixed point has a flow-through property. This leads to a numerical invariant for nonnegative matrices. Commuting pairs of these maps are classified by representations of a naturally appearing (discrete group. Special cases (e.g., is in the radical of the algebra generated by and are discussed in detail. For invertible size two matrices, a fixed point exists for all choices of if and only if has distinct eigenvalues, but this fails for larger sizes. Many of the problems derived from the determination of harmonic functions on a class of Markov chains.

  10. T and NK cells: two sides of tumor immunoevasion.

    Science.gov (United States)

    Fruci, Doriana; Lo Monaco, Elisa; Cifaldi, Loredana; Locatelli, Franco; Tremante, Elisa; Benevolo, Maria; Giacomini, Patrizio

    2013-02-04

    Natural Killer (NK) cells are known to reject several experimental murine tumors, but their antineoplastic activity in humans is not generally agreed upon, as exemplified by an interesting correspondence recently appeared in Cancer Research. In the present commentary, we join the discussion and bring to the attention of the readers of the Journal of Translational Medicine a set of recent, related reports. These studies demonstrate that effectors of the adaptive and innate immunity need to actively cooperate in order to reject tumors and, conversely, tumors protect themselves by dampening both T and NK cell responses. The recently reported ability of indoleamine 2,3-dioxygenase (IDO) and prostaglandin E2 (PGE2) expressed by melanoma cells to down-regulate activating NK receptors is yet another piece of evidence supporting combined and highly effective T/NK cell disabling. Major Histocompatibility Complex class I (MHC-I) molecules, including Human Leukocyte Antigen E (HLA-E), represent another class of shared activating/inhibitory ligands. Ongoing clinical trials with small molecules interfering with IDO and PGE2 may be exploiting an immune bonus to control cancer. Conversely, failure to simultaneously engage effectors of both the innate and the adaptive immunity may contribute to explain the limited clinical efficacy of T cell-only vaccination trials. Shared (T/NK cells) natural immunosuppressants and activating/inhibitory ligands expressed by tumor cells may provide mechanistic insight into impaired gathering and function of immune effectors at the tumor site.

  11. Acetylcholine, Histamine, and Cognition: Two Sides of the Same Coin

    Science.gov (United States)

    Blandina, Patrizio; Efoudebe, Marcel; Cenni, Gabriele; Mannaioni, Pierfrancesco; Passani, Maria Beatrice

    2004-01-01

    The forebrain cholinergic neurons are localized in the nucleus basalis magnocellularis (NBM), the major source of cholinergic innervation to the neocortex and to the amygdala, and in the medium septum-banda diagonalis complex, which provides cholinergic inputs to the hippocampus (Mesulam et al. 1983; Woolf et al. 1984; Nicoll 1985). Basic and…

  12. Information Congestion: open access in a two-sided market

    OpenAIRE

    Anderson, Simon P.; André De Palma

    2007-01-01

    Advertising messages compete for scarce attention. “Junk” mail, “spam” e-mail, and telemarketing calls need both parties to exert effort to generate transactions. Message recipients supply attention depending on average message benefit, while senders are motivated by profits. Costlier message transmission may improve message quality so more messages are examined. Too many messages may be sent, or the wrong ones. A Do-Not-Call policy beats a ban, but too many individuals opt out. A monopoly ga...

  13. Young successors : A Two-Sided Story in Renewing SMEs

    NARCIS (Netherlands)

    Kleingeld, Karin; Teeffelen, Lex van

    2016-01-01

    Entrepreneurship is often used as a synonym for starting up a new business. Existing SMEs — from purchasing to succession — are all too often left out of the picture. This booklet tells the stories of those involved in handing over their businesses to the next generation. It’s an honest and straight

  14. Measuring Political Polarization: Twitter shows the two sides of Venezuela

    CERN Document Server

    Morales, A J; Losada, J C; Benito, R M

    2015-01-01

    We say that a population is perfectly polarized when divided in two groups of the same size and opposite opinions. In this paper, we propose a methodology to study and measure the emergence of polarization from social interactions. We begin by proposing a model to estimate opinions in which a minority of influential individuals propagate their opinions through a social network. The result of the model is an opinion probability density function. Next, we propose an index to quantify the extent to which the resulting distribution is polarized. Finally, we apply the proposed methodology to a Twitter conversation about the late Venezuelan president, Hugo Ch\\'avez, finding a good agreement between our results and offline data. Hence, we show that our methodology can detect different degrees of polarization, depending on the structure of the network.

  15. CDKN1C mutations: two sides of the same coin.

    Science.gov (United States)

    Eggermann, Thomas; Binder, Gerhard; Brioude, Frédéric; Maher, Eamonn R; Lapunzina, Pablo; Cubellis, Maria Vittoria; Bergadá, Ignacio; Prawitt, Dirk; Begemann, Matthias

    2014-11-01

    Cyclin-dependent kinase (CDK)-inhibitor 1C (CDKN1C) negatively regulates cellular proliferation and it has been shown that loss-of-function mutations in the imprinted CDKN1C gene (11p15.5) are associated with the overgrowth disorder Beckwith-Wiedemann syndrome (BWS). With recent reports of gain-of-function mutations of the PCNA domain of CDKN1C in growth-retarded patients with IMAGe syndrome or Silver-Russell syndrome (SRS), its key role for growth has been confirmed. Thereby, the last gap in the spectrum of molecular alterations in 11p15.5 in growth-retardation and overgrowth syndromes could be closed. Recent functional studies explain the strict association of CDKN1C mutations with clinically opposite phenotypes and thereby contribute to our understanding of the function and regulation of the gene in particular and epigenetic regulation in general.

  16. PRIVATIZATION OF BRAZILIAN PRISONS: THE TWO SIDES OF THE CURRENCY

    Directory of Open Access Journals (Sweden)

    Hilderline Câmara de Oliveira

    2017-09-01

    Full Text Available Since the beginning of the 1990s, in Brazil, privatization has proved to be an emergency exit to crisis of services that the State cannot offer efficiently, such as Education, Health, Transportation, and more recently Social Security. The agenda in question is now Public Safety. Failing to meet the demand for lawsuits that pass through the Judiciary, Brazilian prisons are becoming increasingly overcrowded; the services lagged; Constant rebellions, high crime rate, denial of human rights and structural violence, glaring. Thus, this article aims to reflect on both sides of the 'currency' of prisons privatizations in the Brazilian scenario. He used the research with a qualitative approach and bibliographical character with the support of theoretical references from the specialized literature in the area, besides the technical documents, official reports from the Government and NGOs that carry out social control works. The research has shown that privatization seems to be the best way out in the short term and can solve a number of social problems, but how can one think of the profitable return that all privatization requires if its main objective is to reduce the target population? So either this alternative will create a market that, if it turns out, will end itself, or we will end up creating an even more perverse logic of incarceration.

  17. Measuring political polarization: Twitter shows the two sides of Venezuela

    Science.gov (United States)

    Morales, A. J.; Borondo, J.; Losada, J. C.; Benito, R. M.

    2015-03-01

    We say that a population is perfectly polarized when divided in two groups of the same size and opposite opinions. In this paper, we propose a methodology to study and measure the emergence of polarization from social interactions. We begin by proposing a model to estimate opinions in which a minority of influential individuals propagate their opinions through a social network. The result of the model is an opinion probability density function. Next, we propose an index to quantify the extent to which the resulting distribution is polarized. Finally, we apply the proposed methodology to a Twitter conversation about the late Venezuelan president, Hugo Chávez, finding a good agreement between our results and offline data. Hence, we show that our methodology can detect different degrees of polarization, depending on the structure of the network.

  18. Areeda-Turner in Two-Sided Markets

    NARCIS (Netherlands)

    Behringer, S.; Filistrucchi, L.

    2014-01-01

    Areeda and Turner (1975) were the first to argue that a price below marginal costs should be considered a sign of predation. Recognizing that marginal cost data were typically unavailable, the authors concluded that a price below average variable cost should be presumed unlawful. This socalled Areed

  19. Hormesis: Decoding Two Sides of the Same Coin

    Directory of Open Access Journals (Sweden)

    Dipita Bhakta-Guha

    2015-12-01

    Full Text Available In the paradigm of drug administration, determining the correct dosage of a therapeutic is often a challenge. Several drugs have been noted to demonstrate contradictory effects per se at high and low doses. This duality in function of a drug at different concentrations is known as hormesis. Therefore, it becomes necessary to study these biphasic functions in order to understand the mechanistic basis of their effects. In this article, we focus on different molecules and pathways associated with diseases that possess a duality in their function and thus prove to be the seat of hormesis. In particular, we have highlighted the pathways and factors involved in the progression of cancer and how the biphasic behavior of the molecules involved can alter the manifestations of cancer. Because of the pragmatic role that it exhibits, the imminent need is to draw attention to the concept of hormesis. Herein, we also discuss different stressors that trigger hormesis and how stress-mediated responses increase the overall adaptive response of an individual to stress stimulus. We talk about common pathways through which cancer progresses (such as nuclear factor erythroid 2-related factor 2-Kelch-like ECH-associated protein 1 (Nrf2-Keap1, sirtuin-forkhead box O (SIRT-FOXO and others, analyzing how diverse molecules associated with these pathways conform to hormesis.

  20. Areeda-Turner in Two-Sided Markets

    NARCIS (Netherlands)

    Behringer, S.; Filistrucchi, L.

    2014-01-01

    Areeda and Turner (1975) were the first to argue that a price below marginal costs should be considered a sign of predation. Recognizing that marginal cost data were typically unavailable, the authors concluded that a price below average variable cost should be presumed unlawful. This socalled