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Sample records for multiple consecutive adhesive

  1. Percutaneous Vertebroplasty in Multiple Myeloma: Prospective Long-Term Follow-Up in 106 Consecutive Patients

    International Nuclear Information System (INIS)

    Anselmetti, Giovanni Carlo; Manca, Antonio; Montemurro, Filippo; Hirsch, Joshua; Chiara, Gabriele; Grignani, Giovanni; Carnevale Schianca, Fabrizio; Capaldi, Antonio; Rota Scalabrini, Delia; Sardo, Elena; Debernardi, Felicino; Iussich, Gabriella; Regge, Daniele

    2012-01-01

    Purpose: Percutaneous vertebroplasty (PV) is a minimally invasive procedure involving the injection of bone cement within a collapsed vertebral body. Although this procedure was demonstrated to be effective in osteoporosis and metastases, few studies have been reported in cases of multiple myeloma (MM). We prospectively evaluated the safety and efficacy of PV in the treatment of vertebral compression fractures (VCFs) resulting from MM. Materials and Methods: PV was performed in 106 consecutive MM patients who had back pain due to VCFs, the treatment of which had failed conservative therapies. Follow-up (28.2 ± 12.1 months) was evaluated at 7 and 15 days as well as at 1, 3, 6, 12, 18, and every 6 months after PV. Visual analog scale (VAS) pain score, opioid use, external brace support, and Oswestry Disability Index (ODI) score were recorded. Results: The median pretreatment VAS score of 9 (range 4–10) significantly (P < 0.001) decreased to 1 (range 0–9) after PV. Median pre-ODI values of 82% (range 36–89%) significantly improved to 7% (range 0–82%) (P < 0.001). Differences in pretreatment and posttreatment use of analgesic drug were statistically significant (P < 0.001). The majority of patients (70 of 81; 86%) did not use an external brace after PV (P < 0.001). Conclusion: PV is a safe, effective, and long-lasting procedure for the treatment of vertebral compression pain resulting from MM.

  2. Adhesion

    Science.gov (United States)

    ... Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Adhesion URL of this page: //medlineplus.gov/ency/article/001493.htm Adhesion To use the sharing features on this page, please enable JavaScript. Adhesions are bands of scar-like tissue that form between two ...

  3. Dystroglycan versatility in cell adhesion: a tale of multiple motifs

    Directory of Open Access Journals (Sweden)

    Winder Steve J

    2010-02-01

    Full Text Available Abstract Dystroglycan is a ubiquitously expressed heterodimeric adhesion receptor. The extracellular α-subunit makes connections with a number of laminin G domain ligands including laminins, agrin and perlecan in the extracellular matrix and the transmembrane β-subunit makes connections to the actin filament network via cytoskeletal linkers including dystrophin, utrophin, ezrin and plectin, depending on context. Originally discovered as part of the dystrophin glycoprotein complex of skeletal muscle, dystroglycan is an important adhesion molecule and signalling scaffold in a multitude of cell types and tissues and is involved in several diseases. Dystroglycan has emerged as a multifunctional adhesion platform with many interacting partners associating with its short unstructured cytoplasmic domain. Two particular hotspots are the cytoplasmic juxtamembrane region and at the very carboxy terminus of dystroglycan. Regions which between them have several overlapping functions: in the juxtamembrane region; a nuclear localisation signal, ezrin/radixin/moesin protein, rapsyn and ERK MAP Kinase binding function, and at the C terminus a regulatory tyrosine governing WW, SH2 and SH3 domain interactions. We will discuss the binding partners for these motifs and how their interactions and regulation can modulate the involvement of dystroglycan in a range of different adhesion structures and functions depending on context. Thus dystroglycan presents as a multifunctional scaffold involved in adhesion and adhesion-mediated signalling with its functions under exquisite spatio-temporal regulation.

  4. Split-Volume Treatment Planning of Multiple Consecutive Vertebral Body Metastases for Cyberknife Image-Guided Robotic Radiosurgery

    International Nuclear Information System (INIS)

    Sahgal, Arjun; Chuang, Cynthia; Larson, David; Huang, Kim; Petti, Paula; Weinstein, Phil; Ma Lijun

    2008-01-01

    Cyberknife treatment planning of multiple consecutive vertebral body metastases is challenging due to large target volumes adjacent to critical normal tissues. A split-volume treatment planning technique was developed to improve the treatment plan quality of such lesions. Treatment plans were generated for 1 to 5 consecutive thoracic vertebral bodies (CVBM) prescribing a total dose of 24 Gy in 3 fractions. The planning target volume (PTV) consisted of the entire vertebral body(ies). Treatment plans were generated considering both the de novo clinical scenario (no prior radiation), imposing a dose limit of 8 Gy to 1 cc of spinal cord, and the retreatment scenario (prior radiation) with a dose limit of 3 Gy to 1 cc of spinal cord. The split-volume planning technique was compared with the standard full-volume technique only for targets ranging from 2 to 5 CVBM in length. The primary endpoint was to obtain best PTV coverage by the 24 Gy prescription isodose line. A total of 18 treatment plans were generated (10 standard and 8 split-volume). PTV coverage by the 24-Gy isodose line worsened consistently as the number of CVBM increased for both the de novo and retreatment scenario. Split-volume planning was achieved by introducing a 0.5-cm gap, splitting the standard full-volume PTV into 2 equal length PTVs. In every case, split-volume planning resulted in improved PTV coverage by the 24-Gy isodose line ranging from 4% to 12% for the de novo scenario and, 8% to 17% for the retreatment scenario. We did not observe a significant trend for increased monitor units required, or higher doses to spinal cord or esophagus, with split-volume planning. Split-volume treatment planning significantly improves Cyberknife treatment plan quality for CVBM, as compared to the standard technique. This technique may be of particular importance in clinical situations where stringent spinal cord dose limits are required

  5. Formal Derivation of Lotka-Volterra-Haken Amplitude Equations of Task-Related Brain Activity in Multiple, Consecutively Performed Tasks

    Science.gov (United States)

    Frank, T. D.

    The Lotka-Volterra-Haken equations have been frequently used in ecology and pattern formation. Recently, the equations have been proposed by several research groups as amplitude equations for task-related patterns of brain activity. In this theoretical study, the focus is on the circular causality aspect of pattern formation systems as formulated within the framework of synergetics. Accordingly, the stable modes of a pattern formation system inhibit the unstable modes, whereas the unstable modes excite the stable modes. Using this circular causality principle it is shown that under certain conditions the Lotka-Volterra-Haken amplitude equations can be derived from a general model of brain activity akin to the Wilson-Cowan model. The model captures the amplitude dynamics for brain activity patterns in experiments involving several consecutively performed multiple-choice tasks. This is explicitly demonstrated for two-choice tasks involving grasping and walking. A comment on the relevance of the theoretical framework for clinical psychology and schizophrenia is given as well.

  6. Controlled multiple neutral planes by low elastic modulus adhesive for flexible organic photovoltaics.

    Science.gov (United States)

    Kim, Wansun; Lee, Inhwa; Yoon Kim, Dong; Yu, Youn-Yeol; Jung, Hae-Yoon; Kwon, Seyeoul; Seo Park, Weon; Kim, Taek-Soo

    2017-05-12

    To protect brittle layers in organic photovoltaic devices, the mechanical neutral plane strategy can be adopted through placing the brittle functional materials close to the neutral plane where stress and strain are zero during bending. However, previous research has been significantly limited in the location and number of materials to protect through using a single neutral plane. In this study, multiple neutral planes are generated using low elastic modulus adhesives and are controlled through quantitative analyses in order to protect the multiple brittle materials at various locations. Moreover, the protection of multiple brittle layers at various locations under both concave and convex bending directions is demonstrated. Multilayer structures that have soft adhesives are further analyzed using the finite element method analysis in order to propose guidelines for structural design when employing multiple neutral planes.

  7. Characterisation of cellular adhesion reinforcement by multiple bond force spectroscopy in alveolar epithelial cells.

    Science.gov (United States)

    Nguyen, Ngoc-Minh; Angely, Christelle; Andre Dias, Sofia; Planus, Emmanuelle; Filoche, Marcel; Pelle, Gabriel; Louis, Bruno; Isabey, Daniel

    2017-07-01

    Integrin-mediated adhesion is a key process by which cells physically connect with their environment, and express sensitivity and adaptation through mechanotransduction. A critical step of cell adhesion is the formation of the first bonds which individually generate weak contacts (∼tens pN) but can sustain thousand times higher forces (∼tens nN) when associated. We propose an experimental validation by multiple bond force spectroscopy (MFS) of a stochastic model predicting adhesion reinforcement permitted by non-cooperative, multiple bonds on which force is homogeneously distributed (called parallel bond configuration). To do so, spherical probes (diameter: 6.6 μm), specifically coated by RGD-peptide to bind integrins, are used to statically indent and homogenously stretch the multiple bonds created for short contact times (2 s) between the bead and the surface of epithelial cells (A549). Using different separation speeds (v = 2, 5, 10 μm/s) and measuring cellular Young's modulus as well as the local stiffness preceding local rupture events, we obtain cell-by-cell the effective loading rates both at the global cell level and at the local level of individual constitutive bonds. Local rupture forces are in the range: f*=60-115 pN , whereas global rupture (detachment) forces reach F*=0.8-1.7 nN . Global and local rupture forces both exhibit linear dependencies with the effective loading rate, the slopes of these two linear relationships providing an estimate of the number of independent integrin bonds constituting the tested multiple bond structure (∼12). The MFS method enables to validate the reinforcement of integrin-mediated adhesion induced by the multiple bond configuration in which force is homogeneously distributed amongst parallel bonds. Local rupture events observed in the course of a spectroscopy manoeuver (MFS) lead to rupture force values considered in the literature as single-integrin bonds. Adhesion reinforcement permitted by the parallel

  8. Nonimmune immunoglobulin binding and multiple adhesion characterize Plasmodium falciparum-infected erythrocytes of placental origin

    DEFF Research Database (Denmark)

    Rasti, Niloofar; Namusoke, Fatuma; Chêne, Arnaud

    2006-01-01

    The harmful effects of pregnancy-associated malaria (PAM) are engendered by the heavy sequestration of Plasmodium falciparum-parasitized RBCs in the placenta. It is well documented that this process is mediated by interactions of parasite-encoded variant surface antigens and placental receptors...... and adhesion to multiple receptors (IgG/IgM/HA/CSA) rather than the exclusive binding to CSA is a characteristic of fresh Ugandan placental isolates. These findings are of importance for the understanding of the pathogenesis of placental malaria and have implications for the ongoing efforts to develop a global...

  9. A gene pathway analysis highlights the role of cellular adhesion molecules in multiple sclerosis susceptibility

    DEFF Research Database (Denmark)

    Damotte, V; Guillot-Noel, L; Patsopoulos, N A

    2014-01-01

    adhesion molecule (CAMs) biological pathway using Cytoscape software. This network is a strong candidate, as it is involved in the crossing of the blood-brain barrier by the T cells, an early event in MS pathophysiology, and is used as an efficient therapeutic target. We drew up a list of 76 genes...... in interaction with other genes as a group. Pathway analysis is an alternative way to highlight such group of genes. Using SNP association P-values from eight multiple sclerosis (MS) GWAS data sets, we performed a candidate pathway analysis for MS susceptibility by considering genes interacting in the cell...... belonging to the CAM network. We highlighted 64 networks enriched with CAM genes with low P-values. Filtering by a percentage of CAM genes up to 50% and rejecting enriched signals mainly driven by transcription factors, we highlighted five networks associated with MS susceptibility. One of them, constituted...

  10. Multiple cell adhesion molecules shaping a complex nicotinic synapse on neurons.

    Science.gov (United States)

    Triana-Baltzer, Gallen B; Liu, Zhaoping; Gounko, Natalia V; Berg, Darwin K

    2008-09-01

    Neuroligin, SynCAM, and L1-CAM are cell adhesion molecules with synaptogenic roles in glutamatergic pathways. We show here that SynCAM is expressed in the chick ciliary ganglion, embedded in a nicotinic pathway, and, as shown previously for neuroligin and L1-CAM, acts transcellularly to promote synaptic maturation on the neurons in culture. Moreover, we show that electroporation of chick embryos with dominant negative constructs disrupting any of the three molecules in vivo reduces the total amount of presynaptic SV2 overlaying the neurons expressing the constructs. Only disruption of L1-CAM and neuroligin, however, reduces the number of SV2 puncta specifically overlaying nicotinic receptor clusters. Disrupting L1-CAM and neuroligin together produces no additional decrement, indicating that they act on the same subset of synapses. SynCAM may affect synaptic maturation rather than synapse formation. The results indicate that individual neurons can express multiple synaptogenic molecules with different effects on the same class of nicotinic synapses.

  11. Adhesion molecules levels in blood correlate with MRI activity and clinical activity in multiple sclerosis

    International Nuclear Information System (INIS)

    Millers, A.; Enina, G.; Platkajis, A.; Metra, M.; Kukaine, R.

    2002-01-01

    Research into pathogenesis of multiple sclerosis (MS) has prompted efforts to identify immunological markers associated with disease activity. Adhesion molecules ICAM-1 and VCAM-1 are associated with inflammatory mediated blood-brain barrier (BBB) dysfunction. In this study investigates the correlation between blood level of circulating ICAM-1 and VCAM-1 and magnetic resonance imaging (MRI) activity in different clinical phases of patients with MS. We show that RRMS and SPMS patients in clinically active phase with Gd-enhancing lesions in CNS had higher blood levels of cICAM-1 and cVCAM-1 compared these parameters levers of RRMS patients in remission stage. These results suggest that cICAM-1 and cVCAM-1 is a sensitive indicator of disease activity associated with BBB inflammatory dysfunction. Elevated blood level of cICAM-1 more strongly correlated with clinical activity and BBB damage, than cVCAM-1 and that could be used as biological marker of disease activity. Circulating VCAM-1 as an early indicator of BBB disturbance, may also serve as marker of beneficial activity in relapses phase of MS course. (authors)

  12. Buried interfaces - A systematic study to characterize an adhesive interface at multiple scales

    Science.gov (United States)

    Haubrich, Jan; Löbbecke, Miriam; Watermeyer, Philipp; Wilde, Fabian; Requena, Guillermo; da Silva, Julio

    2018-03-01

    A comparative study of a model adhesive interface formed between laser-pretreated Ti15-3-3-3 and the thermoplastic polymer PEEK has been carried out in order to characterize the interfaces' structural details and the infiltration of the surface nano-oxide by the polymer at multiple scales. Destructive approaches such as scanning and transmission electron microscopy of microsections prepared by focused ion beam, and non-destructive imaging approaches including laser scanning and scanning electron microscopy of pretreated surfaces as well as synchrotron computed tomography techniques (micro- and ptychographic tomographies) were employed for resolving the large, μm-sized melt-structures and the fine nano-oxide substructure within the buried interface. Scanning electron microscopy showed that the fine, open-porous nano-oxide homogeneously covers the larger macrostructure features which in turn cover the joint surface. The open-porous nano-oxide forming the interface itself appears to be fully infiltrated and wetted by the polymer. No voids or even channels were detected down to the respective resolution limits of scanning and transmission electron microscopy.

  13. Multiple integrin-ligand interactions synergize in shear-resistant platelet adhesion at sites of arterial injury in vivo

    DEFF Research Database (Denmark)

    Grüner, Sabine; Prostredna, Miroslava; Schulte, Valerie

    2003-01-01

    by intravital fluorescence microscopy that platelet adhesion and thrombus growth on the exposed ECM of the injured carotid artery is not significantly altered in alpha2-null mice and even in mice with a Cre/loxP-mediated loss of all beta1 integrins on their platelets. In contrast, inhibition of alphaIIbbeta3...... integrin on platelets in wild-type mice blocked aggregate formation and reduced platelet adhesion by 60.0%. Strikingly, alphaIIbbeta3 inhibition had a comparable effect in alpha2-null mice, demonstrating that other receptors mediate shear-resistant adhesion in the absence of functional alpha2beta1...... and alphaIIbbeta3. These were identified to be alpha5beta1 and/or alpha6beta1 as alphaIIbbeta3 inhibition abrogated platelet adhesion in beta1-null mice. We conclude that shear-resistant platelet adhesion on the injured vessel wall in vivo is a highly integrated process involving multiple integrin...

  14. Multiple-Approach Evaluation of WSP Coatings Adhesion/Cohesion Strength

    Czech Academy of Sciences Publication Activity Database

    Mušálek, Radek; Pejchal, V.; Vilémová, Monika; Matějíček, Jiří

    2013-01-01

    Roč. 22, 2-3 (2013), s. 221-232 ISSN 1059-9630. [International Thermal Spray Conference (ITSC). Houston, 21.05.2012-24.05.2012] R&D Projects: GA ČR(CZ) GPP108/12/P552 Institutional research plan: CEZ:AV0Z20430508 Keywords : adhesion testing * adhesive strength * alumina * cohesion * stainless steel * water-stabilized plasma Subject RIV: JI - Composite Materials Impact factor: 1.491, year: 2013 http://link.springer.com/content/pdf/10.1007%2Fs11666-012-9850-2.pdf

  15. Podocalyxin Is a Novel Polysialylated Neural Adhesion Protein with Multiple Roles in Neural Development and Synapse Formation

    Science.gov (United States)

    Vitureira, Nathalia; Andrés, Rosa; Pérez-Martínez, Esther; Martínez, Albert; Bribián, Ana; Blasi, Juan; Chelliah, Shierley; López-Doménech, Guillermo; De Castro, Fernando; Burgaya, Ferran; McNagny, Kelly; Soriano, Eduardo

    2010-01-01

    Neural development and plasticity are regulated by neural adhesion proteins, including the polysialylated form of NCAM (PSA-NCAM). Podocalyxin (PC) is a renal PSA-containing protein that has been reported to function as an anti-adhesin in kidney podocytes. Here we show that PC is widely expressed in neurons during neural development. Neural PC interacts with the ERM protein family, and with NHERF1/2 and RhoA/G. Experiments in vitro and phenotypic analyses of podxl-deficient mice indicate that PC is involved in neurite growth, branching and axonal fasciculation, and that PC loss-of-function reduces the number of synapses in the CNS and in the neuromuscular system. We also show that whereas some of the brain PC functions require PSA, others depend on PC per se. Our results show that PC, the second highly sialylated neural adhesion protein, plays multiple roles in neural development. PMID:20706633

  16. Cytokines and adhesion molecules in multiple sclerosis patients treated with interferon-beta1b

    DEFF Research Database (Denmark)

    Jensen, Jakob; Krakauer, Martin; Sellebjerg, Finn

    2005-01-01

    inconsistent. We found decreases in CD4 and CD8 T cell expression of the CD49d/VLA-4 molecule, increases in plasma concentrations of soluble vascular cell adhesion molecule (sVCAM-1), and increases in plasma concentrations of tumor necrosis factor and interleukin (IL)-12 p40 chain in patients with MS who were...

  17. Normalizing the bone marrow microenvironment with p38 inhibitor reduces multiple myeloma cell proliferation and adhesion and suppresses osteoclast formation

    International Nuclear Information System (INIS)

    Nguyen, Aaron N.; Stebbins, Elizabeth G.; Henson, Margaret; O'Young, Gilbert; Choi, Sun J.; Quon, Diana; Damm, Debby; Reddy, Mamatha; Ma, Jing Y.; Haghnazari, Edwin; Kapoun, Ann M.; Medicherla, Satyanarayana; Protter, Andy; Schreiner, George F.; Kurihara, Noriyoshi; Anderson, Judy; Roodman, G. David; Navas, Tony A.; Higgins, Linda S.

    2006-01-01

    The multiple myeloma (MM) bone marrow (BM) microenvironment plays a critical role in supporting tumor growth and survival as well as in promoting formation of osteolytic lesions. Recent results suggest that the p38 mitogen-activated protein kinase (MAPK) is an important factor in maintaining this activated environment. In this report, we demonstrate that the p38α MAPK inhibitor, SCIO-469, suppresses secretion of the tumor-supportive factors IL-6 and VEGF from BM stromal cells (BMSCs) as well as cocultures of BMSCs with MM cells, resulting in reduction in MM cell proliferation. Additionally, we show that SCIO-469 prevents TNFα-induced adhesion of MM cells to BMSCs through an ICAM-1- and VCAM-1-independent mechanism. Microarray analysis revealed a novel set of TNFα-induced chemokines in BMSCs that is strongly inhibited by SCIO-469. Furthermore, reintroduction of chemokines CXCL10 and CCL8 to BMSCs overcomes the inhibitory effect of SCIO-469 on TNFα-induced MM adhesion. Lastly, we show that SCIO-469 inhibits secretion and expression of the osteoclast-activating factors IL-11, RANKL, and MIP-1α as well as prevents human osteoclast formation in vitro. Collectively, these results suggest that SCIO-469 treatment can suppress factors in the bone marrow microenvironment to inhibit MM cell proliferation and adhesion and also to alleviate osteolytic activation in MM

  18. Rationally engineered nanoparticles target multiple myeloma cells, overcome cell-adhesion-mediated drug resistance, and show enhanced efficacy in vivo

    International Nuclear Information System (INIS)

    Kiziltepe, T; Ashley, J D; Stefanick, J F; Qi, Y M; Alves, N J; Handlogten, M W; Suckow, M A; Navari, R M; Bilgicer, B

    2012-01-01

    In the continuing search for effective cancer treatments, we report the rational engineering of a multifunctional nanoparticle that combines traditional chemotherapy with cell targeting and anti-adhesion functionalities. Very late antigen-4 (VLA-4) mediated adhesion of multiple myeloma (MM) cells to bone marrow stroma confers MM cells with cell-adhesion-mediated drug resistance (CAM-DR). In our design, we used micellar nanoparticles as dynamic self-assembling scaffolds to present VLA-4-antagonist peptides and doxorubicin (Dox) conjugates, simultaneously, to selectively target MM cells and to overcome CAM-DR. Dox was conjugated to the nanoparticles through an acid-sensitive hydrazone bond. VLA-4-antagonist peptides were conjugated via a multifaceted synthetic procedure for generating precisely controlled number of targeting functionalities. The nanoparticles were efficiently internalized by MM cells and induced cytotoxicity. Mechanistic studies revealed that nanoparticles induced DNA double-strand breaks and apoptosis in MM cells. Importantly, multifunctional nanoparticles overcame CAM-DR, and were more efficacious than Dox when MM cells were cultured on fibronectin-coated plates. Finally, in a MM xenograft model, nanoparticles preferentially homed to MM tumors with ∼10 fold more drug accumulation and demonstrated dramatic tumor growth inhibition with a reduced overall systemic toxicity. Altogether, we demonstrate the disease driven engineering of a nanoparticle-based drug delivery system, enabling the model of an integrative approach in the treatment of MM

  19. Loss of laminin alpha 1 results in multiple structural defects and divergent effects on adhesion during vertebrate optic cup morphogenesis

    Science.gov (United States)

    Bryan, Chase D.; Chien, Chi-Bin; Kwan, Kristen M.

    2016-01-01

    The vertebrate eye forms via a complex set of morphogenetic events. The optic vesicle evaginates and undergoes transformative shape changes to form the optic cup, in which neural retina and retinal pigmented epithelium enwrap the lens. It has long been known that a complex, glycoprotein-rich extracellular matrix layer surrounds the developing optic cup throughout the process, yet the functions of the matrix and its specific molecular components have remained unclear. Previous work established a role for laminin extracellular matrix in particular steps of eye development, including optic vesicle evagination, lens differentiation, and retinal ganglion cell polarization, yet it is unknown what role laminin might play in the early process of optic cup formation subsequent to the initial step of optic vesicle evagination. Here, we use the zebrafish lama1 mutant (lama1UW1) to determine the function of laminin during optic cup morphogenesis. Using live imaging, we find, surprisingly, that loss of laminin leads to divergent effects on focal adhesion assembly in a spatiotemporally-specific manner, and that laminin is required for multiple steps of optic cup morphogenesis, including optic stalk constriction, invagination, and formation of a spherical lens. Laminin is not required for single cell behaviors and changes in cell shape. Rather, in lama1UW1 mutants, loss of epithelial polarity and altered adhesion lead to defective tissue architecture and formation of a disorganized retina. These results demonstrate that the laminin extracellular matrix plays multiple critical roles regulating adhesion and polarity to establish and maintain tissue structure during optic cup morphogenesis. PMID:27339294

  20. Modeling and Elucidation of the Kinetics of Multiple Consecutive Photoreactions AB4(4Φ) With Φ-order Kinetics. Application to the Photodegradation of Riboflavin.

    Science.gov (United States)

    Maafi, Mounir; Maafi, Wassila

    2016-12-01

    New semi-empirical rate-law system of equations is proposed for the first time for consecutive photoreactions that involve up to 4 photoreaction steps, AB 4 (4Φ). The equation system was developed, tested, and validated against synthetic kinetic traces generated by fifth-order Runge-Kutta calculations. The model accurately fitted the kinetic traces of Riboflavin photodegradation in ethanol which decomposes via the AB 2 (2Φ) mechanism involving 2 consecutive photoreaction steps. A kinetic elucidation methodology useful for consecutive photoreactions was also proposed to determine all the kinetic parameters and reaction attributes defining AB 2 (2Φ) reactions. The quantum yields of photodegradation, determined for wavelengths in the visible region 400-480 nm, ranged from 0.005 to 0.00756 and 0.0012 to 8 10 -5 for the first and second photoreaction steps, respectively. They were found to increase with wavelength in defined sigmoid functions. For this monochromatic irradiation range, riboflavin proved to be a useful actinometer. Finally, a photodegradation scale based on pseudo-rate-constant values was also proposed for drugs. This scale (including 4 groups) is thought to contribute to rationalizing photodegradation testing and might prove useful in categorizing drugs' photodegradation reactivity. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  1. Tempo and mode of performance evolution across multiple independent origins of adhesive toe pads in lizards.

    Science.gov (United States)

    Hagey, Travis J; Uyeda, Josef C; Crandell, Kristen E; Cheney, Jorn A; Autumn, Kellar; Harmon, Luke J

    2017-10-01

    Understanding macroevolutionary dynamics of trait evolution is an important endeavor in evolutionary biology. Ecological opportunity can liberate a trait as it diversifies through trait space, while genetic and selective constraints can limit diversification. While many studies have examined the dynamics of morphological traits, diverse morphological traits may yield the same or similar performance and as performance is often more proximately the target of selection, examining only morphology may give an incomplete understanding of evolutionary dynamics. Here, we ask whether convergent evolution of pad-bearing lizards has followed similar evolutionary dynamics, or whether independent origins are accompanied by unique constraints and selective pressures over macroevolutionary time. We hypothesized that geckos and anoles each have unique evolutionary tempos and modes. Using performance data from 59 species, we modified Brownian motion (BM) and Ornstein-Uhlenbeck (OU) models to account for repeated origins estimated using Bayesian ancestral state reconstructions. We discovered that adhesive performance in geckos evolved in a fashion consistent with Brownian motion with a trend, whereas anoles evolved in bounded performance space consistent with more constrained evolution (an Ornstein-Uhlenbeck model). Our results suggest that convergent phenotypes can have quite distinctive evolutionary patterns, likely as a result of idiosyncratic constraints or ecological opportunities. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  2. Wood : adhesives

    Science.gov (United States)

    A.H. Conner

    2001-01-01

    This chapter on wood adhesives includes: 1) Classification of wood adhesives 2) Thermosetting wood adhesives 3) Thermoplastic adhesives, 4) Wood adhesives based on natural sources 5) Nonconventional bonding of wood 6) Wood bonding.

  3. The adhesive strength and initial viscosity of denture adhesives.

    Science.gov (United States)

    Han, Jian-Min; Hong, Guang; Dilinuer, Maimaitishawuti; Lin, Hong; Zheng, Gang; Wang, Xin-Zhi; Sasaki, Keiichi

    2014-11-01

    To examine the initial viscosity and adhesive strength of modern denture adhesives in vitro. Three cream-type denture adhesives (Poligrip S, Corect Cream, Liodent Cream; PGS, CRC, LDC) and three powder-type denture adhesives (Poligrip Powder, New Faston, Zanfton; PGP, FSN, ZFN) were used in this study. The initial viscosity was measured using a controlled-stress rheometer. The adhesive strength was measured according to ISO-10873 recommended procedures. All data were analyzed independently by one-way analysis of variance combined with a Student-Newman-Keuls multiple comparison test at a 5% level of significance. The initial viscosity of all the cream-type denture adhesives was lower than the powder-type adhesives. Before immersion in water, all the powder-type adhesives exhibited higher adhesive strength than the cream-type adhesives. However, the adhesive strength of cream-type denture adhesives increased significantly and exceeded the powder-type denture adhesives after immersion in water. For powder-type adhesives, the adhesive strength significantly decreased after immersion in water for 60 min, while the adhesive strength of the cream-type adhesives significantly decreased after immersion in water for 180 min. Cream-type denture adhesives have lower initial viscosity and higher adhesive strength than powder type adhesives, which may offer better manipulation properties and greater efficacy during application.

  4. End-range mobilization techniques in adhesive capsulitis of the shoulder joint: a multiple-subject case report.

    NARCIS (Netherlands)

    Vermeulen, H.M.; Obermann, W.R.; Burger, B.J.; Kok, G.J.; Rozing, P.M.; Ende, C.H.M. van den

    2000-01-01

    BACKGROUND AND PURPOSE: The purpose of this case report is to describe the use of end-range mobilization techniques in the management of patients with adhesive capsulitis. CASE DESCRIPTION: Four men and 3 women (mean age=50.2 years, SD=6.0, range=41-65) with adhesive capsulitis of the glenohumeral

  5. Denture Adhesives

    Science.gov (United States)

    ... Devices Products and Medical Procedures Dental Devices Denture Adhesives Share Tweet Linkedin Pin it More sharing options ... Wearers Reporting Problems to the FDA Background Denture adhesives are pastes, powders or adhesive pads that may ...

  6. Serum levels of tumor necrosis factor-α and soluble adhesion molecules in relation to magnetic resonance imaging results and clinical activity in multiple sclerosis

    International Nuclear Information System (INIS)

    Millers, A.; Metra, M.; Mastina, M.; Platkajis, A.; Kukaine, R.

    2001-01-01

    One direction of research in pathogenesis of multiple sclerosis (MS) has been to identify immunological markers associated with disease activity that are capable of predicting subsequent course of disease and are sensitive to intervention by immunomodulatory therapies. Adhesion molecules and tumor necrosis factor-α of the cytokine superfamily are associated with inflammation-mediated blood-brain barrier dysfunction and demyelination in the central nervous system (CNS). This study investigates the relationship between the serum level of soluble vascular adhesion molecule-1 (sVCAM), soluble intercellular adhesion molecule-1 (alCAM), tumor necrosis factor-α (TNF-α) and magnetic resonance imaging (MRI) activity in 18 patients with relapsing-remitting (RR) MS with different clinical activity. Patients with active gadolinium (Gd)-enhanced lesions on MRI showed a higher serum level of TNF-α, sVCA-1, slCAM-1 than RR MS patients without Gd-enhanced lesions. Control individuals (n=10) without MRI abnormalities had significantly lower serum levels of the above immunological parameters. These results suggest that serum levels of TNF-α and adhesion molecules slCAM-1 in RR MS patients are correlated with Gd-enhanced MRI and disease clinical activity and that they can be used as biological markers of disease activity. The soluble form of VCAM levels in peripheral blood did not correlate with disease activity and Gd-enhanced lesions of MRI. sVCAM as an early indicator of blood-brain barrier dysfunction may also serve as marker of beneficial activity in the relapsing phase of MS course. (authors)

  7. A non-randomized study in consecutive patients with postcholecystectomy refractory biliary leaks who were managed endoscopically with the use of multiple plastic stents or fully covered self-expandable metal stents (with videos).

    Science.gov (United States)

    Canena, Jorge; Liberato, Manuel; Meireles, Liliane; Marques, Inês; Romão, Carlos; Coutinho, António Pereira; Neves, Beatriz Costa; Veiga, Pedro Mota

    2015-07-01

    Endoscopic management of postcholecystectomy biliary leaks is widely accepted as the treatment of choice. However, refractory biliary leaks after a combination of biliary sphincterotomy and the placement of a large-bore (10F) plastic stent can occur, and the optimal rescue endotherapy for this situation is unclear. To compare the clinical effectiveness of the use of a fully covered self-expandable metal stent (FCSEMS) with the placement of multiple plastic stents (MPS) for the treatment of postcholecystectomy refractory biliary leaks. Prospective study. Two tertiary-care referral academic centers and one general district hospital. Forty consecutive patients with refractory biliary leaks who underwent endoscopic management. Temporary placement of MPS (n = 20) or FCSEMSs (n = 20). Clinical outcomes of endotherapy as well as the technical success, adverse events, need for reinterventions, and prognostic factors for clinical success. Endotherapy was possible in all patients. After endotherapy, closure of the leak was accomplished in 13 patients (65%) who received MPS and in 20 patients (100%) who received FCSEMSs (P = .004). The Kaplan-Meier (log-rank) leak-free survival analysis showed a statistically significant difference between the 2 patient populations (χ(2) [1] = 8.30; P stents (P = .024), a plastic stent diameter <20F (P = .006), and a high-grade biliary leak (P = .015) were shown to be significant predictors of treatment failure with MPS. The 7 patients in whom placement of MPS failed were retreated with FCSEMSs, resulting in closure of the leaks in all cases. Non-randomized design. In our series, the results of the temporary placement of FCSEMSs for postcholecystectomy refractory biliary leaks were superior to those from the use of MPS. A randomized study is needed to confirm our results before further recommendations. Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  8. Protein adhesives

    Science.gov (United States)

    Charles R. Frihart; Linda F. Lorenz

    2018-01-01

    Nature uses a wide variety of chemicals for providing adhesion internally (e.g., cell to cell) and externally (e.g., mussels to ships and piers). This adhesive bonding is chemically and mechanically complex, involving a variety of proteins, carbohydrates, and other compounds.Consequently,the effect of protein structures on adhesive properties is only partially...

  9. Consecutive opposed interactions of light waves

    International Nuclear Information System (INIS)

    Volkov, V V; Chirkin, Anatolii S

    1999-01-01

    The conditions were determined for the occurrence of the opposed interaction of waves having multiple frequencies in two consecutive three-frequency processes in periodically inhomogeneous nonlinear optical crystals. The necessary nonlinear susceptibility modulation period was calculated for an MgO:LiNbO 3 crystal. The characteristic features of the energy exchange between counterpropagating waves with parametric amplification in a low-frequency pump field were investigated. (nonlinear optical phenomena)

  10. Appearance of Tissue Transglutaminase in Astrocytes in Multiple Sclerosis Lesions: A Role in Cell Adhesion and Migration?

    NARCIS (Netherlands)

    van Strien, M.; Drukarch, B.; Bol, J.G.J.M.; van der Valk, P.; van Horssen, J.; Gerritsen, W.H.; Breve, J.J.P.; van Dam, A.M.

    2011-01-01

    Multiple Sclerosis (MS) is a neuroinflammatory disease mainly affecting young adults. A major pathological hallmark of MS is the presence of demyelinated lesions in the central nervous system. In the active phase of the disease, astrocytes become activated, migrate and contribute to local tissue

  11. Cellular Adhesion and Adhesion Molecules

    OpenAIRE

    SELLER, Zerrin

    2014-01-01

    In recent years, cell adhesion and cell adhesion molecules have been shown to be important for many normal biological processes, including embryonic cell migration, immune system functions and wound healing. It has also been shown that they contribute to the pathogenesis of a large number of common human disorders, such as rheumatoid arthritis and tumor cell metastasis in cancer. In this review, the basic mechanisms of cellular adhesion and the structural and functional features of adhes...

  12. Adhesion science

    CERN Document Server

    Comyn, John

    1997-01-01

    The use of adhesives is widespread and growing, and there are few modern artefacts, from the simple cereal packet, to the jumbo jet, that are without this means of joining. Adhesion Science provides an illuminating account of the science underlying the use of adhesives, a branch of chemical technology which is fundamental to the science of coatings and composite materials and to the performance of all types of bonded structures. This book guides the reader through the essential basic polymer science, and the chemistry of adhesives in use at present. It discusses surface preparation for adhesive bonding, and the use of primers and coupling agents. There is a detailed chapter on contact angles and what can be predicted from them. A simple guide on stress distribution joints and how this relates to testing is included. It also examines the interaction of adhesives and the environment, including an analysis of the resistance of joints to water, oxygen and ultra-violet light. Adhesion Science provides a comprehens...

  13. Adhesion molecules

    CERN Document Server

    Preedy, Victor R

    2016-01-01

    This book covers the structure and classification of adhesion molecules in relation to signaling pathways and gene expression. It discusses immunohistochemical localization, neutrophil migration, and junctional, functional, and inflammatory adhesion molecules in pathologies such as leukocyte decompression sickness and ischemia reperfusion injury. Highlighting the medical applications of current research, chapters cover diabetes, obesity, and metabolic syndrome; hypoxia; kidney disease; smoking, atrial fibrillation, and heart disease, the brain and dementia; and tumor proliferation. Finally, it looks at molecular imaging and bioinformatics, high-throughput technologies, and chemotherapy.

  14. Cellular prion protein is required for neuritogenesis: fine-tuning of multiple signaling pathways involved in focal adhesions and actin cytoskeleton dynamics

    Directory of Open Access Journals (Sweden)

    Alleaume-Butaux A

    2013-07-01

    Full Text Available Aurélie Alleaume-Butaux,1,2 Caroline Dakowski,1,2 Mathéa Pietri,1,2 Sophie Mouillet-Richard,1,2 Jean-Marie Launay,3,4 Odile Kellermann,1,2 Benoit Schneider1,2 1INSERM, UMR-S 747, 2Paris Descartes University, Sorbonne Paris Cité, UMR-S 747, 3Public Hospital of Paris, Department of Biochemistry, INSERM UMR-S 942, Lariboisière Hospital, Paris, France; 4Pharma Research Department, Hoffmann La Roche Ltd, Basel, Switzerland Abstract: Neuritogenesis is a dynamic phenomenon associated with neuronal differentiation that allows a rather spherical neuronal stem cell to develop dendrites and axon, a prerequisite for the integration and transmission of signals. The acquisition of neuronal polarity occurs in three steps: (1 neurite sprouting, which consists of the formation of buds emerging from the postmitotic neuronal soma; (2 neurite outgrowth, which represents the conversion of buds into neurites, their elongation and evolution into axon or dendrites; and (3 the stability and plasticity of neuronal polarity. In neuronal stem cells, remodeling and activation of focal adhesions (FAs associated with deep modifications of the actin cytoskeleton is a prerequisite for neurite sprouting and subsequent neurite outgrowth. A multiple set of growth factors and interactors located in the extracellular matrix and the plasma membrane orchestrate neuritogenesis by acting on intracellular signaling effectors, notably small G proteins such as RhoA, Rac, and Cdc42, which are involved in actin turnover and the dynamics of FAs. The cellular prion protein (PrPC, a glycosylphosphatidylinositol (GPI-anchored membrane protein mainly known for its role in a group of fatal neurodegenerative diseases, has emerged as a central player in neuritogenesis. Here, we review the contribution of PrPC to neuronal polarization and detail the current knowledge on the signaling pathways fine-tuned by PrPC to promote neurite sprouting, outgrowth, and maintenance. We emphasize that Pr

  15. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    , which influence the transition from a planktonic lifestyle to a sessile lifestyle, have been studied. Protein conditioning film formation was found to influence bacterial adhesion and subsequent biofilm formation considerable, and an aqueous extract of fish muscle tissue was shown to significantly...... tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion...... is the first committing step in biofilm formation, and has therefore been intensely scrutinized. Much however, still remains elusive. Bacterial adhesion is a highly complex process, which is influenced by a variety of factors. In this thesis, a range of physico-chemical, molecular and environmental parameters...

  16. Consecutive cycles of hospital accreditation

    DEFF Research Database (Denmark)

    Falstie-Jensen, Anne Mette; Bogh, Søren Bie; Johnsen, Søren Paaske

    2018-01-01

    Objective: To examine the association between compliance with consecutive cycles of accreditation and patient-related outcomes. Design: A Danish nationwide population-based study from 2012 to 2015. Setting: In-patients admitted with one of the 80 diagnoses at public, non-psychiatric hospitals....... Participants: In-patients admitted with one of 80 primary diagnoses which accounted for 80% of all deaths occuring within 30 dyas after admission. Intervention: Admission to a hospital with high (n = 125 485 in-patients) or low compliance (n = 152 074 in-patients) in both cycles of accreditation by the Danish...... admission (adjusted OR: 1.26 (95% CI: 1.11-1.43) and a longer LOS (adjusted HR of discharge: 0.89 (95% CI: 0.82-0.95) than in-patients at high compliant hospitals. No difference was seen for acute readmission (adjusted HR: 0.98 (95% CI: 0.90-1.06)). Focusing on the second cycle alone, in...

  17. Fifty consecutive pancreatectomies without mortality

    Directory of Open Access Journals (Sweden)

    Enio Campos Amico

    Full Text Available Objective: to report the group's experience with a series of patients undergoing pancreatic resection presenting null mortality rates. Methods: we prospectively studied 50 consecutive patients undergoing pancreatic resections for peri-ampullary or pancreatic diseases. Main local complications were defined according to international criteria. In-hospital mortality was defined as death occurring in the first 90 postoperative days. Results: patients' age ranged between 16 and 90 years (average: 53.3. We found anemia (Hb < 12g/dl and preoperative jaundice in 38% and 40% of cases, respectively. Most patients presented with peri-ampullary tumors (66%. The most common surgical procedure was the Kausch - Whipple operation (70%. Six patients (12% needed to undergo resection of a segment of the mesenteric-portal axis. The mean operative time was 445.1 minutes. Twenty two patients (44% showed no clinical complications and presented mean hospital stay of 10.3 days. The most frequent complications were pancreatic fistula (56%, delayed gastric emptying (17.1% and bleeding (16%. Conclusion : within the last three decades, pancreatic resection is still considered a challenge, especially outside large specialized centers. Nevertheless, even in our country (Brazil, teams seasoned in such procedure can reach low mortality rates.

  18. α2-macroglobulin can crosslink multiple Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) molecules and may facilitate adhesion of parasitized erythrocytes

    DEFF Research Database (Denmark)

    Stevenson, Liz; Laursen, Erik; Cowan, Graeme J

    2015-01-01

    -macroglobulin (α2M), which is both required and sufficient for rosetting mediated by the PfEMP1 protein HB3VAR06 and some other rosette-mediating PfEMP1 proteins. We map the α2M binding site to the C terminal end of HB3VAR06, and demonstrate that α2M can bind at least four HB3VAR06 proteins, plausibly....... Together, our results are evidence that P. falciparum parasites exploit α2M (and IgM) to expand the repertoire of host receptors available for PfEMP1-mediated IE adhesion, such as the erythrocyte carbohydrate moieties that lead to formation of rosettes. It is likely that this mechanism also affects IE...

  19. Adhesion in microelectronics

    CERN Document Server

    Mittal, K L

    2014-01-01

    This comprehensive book will provide both fundamental and applied aspects of adhesion pertaining to microelectronics in a single and easily accessible source. Among the topics to be covered include; Various theories or mechanisms of adhesionSurface (physical or chemical) characterization of materials as it pertains to adhesionSurface cleaning as it pertains to adhesionWays to improve adhesionUnraveling of interfacial interactions using an array of pertinent techniquesCharacterization of interfaces / interphasesPolymer-polymer adhesionMetal-polymer adhesion  (metallized polymers)Polymer adhesi

  20. Consecutive dynamic resolutions of phosphine oxides

    NARCIS (Netherlands)

    Kortmann, Felix A.; Chang, Mu-Chieh; Otten, Edwin; Couzijn, Erik P. A.; Lutz, Martin; Minnaard, Adriaan J.

    2013-01-01

    A crystallization-induced asymmetric transformation (CIAT) involving a radical-mediated racemization provides access to enantiopure secondary phosphine oxides. A consecutive CIAT is used to prepare enantio-and diastereo-pure tert-butyl(hydroxyalkyl)phenylphosphine oxides.

  1. On the last digits of consecutive primes

    OpenAIRE

    Holt, Fred B.

    2016-01-01

    Recently Oliver and Soundararajan made conjectures based on computational enumerations about the frequency of occurrence of pairs of last digits for consecutive primes. By studying Eratosthenes sieve, we have identified discrete dynamic systems that exactly model the populations of gaps across stages of Eratosthenes sieve. Our models provide some insight into the observed biases in the occurrences of last digits in consecutive primes, and the models suggest that the biases will ultimately be ...

  2. Reflections about Adhesive Systems

    OpenAIRE

    de Freitas Borges, Marciano; Diesel, Pâmela Gutheil; Corrêa, Fernanda Gomez; Bernardi, Eledana; Fernandes Montagner, Anelise; Skupien, Jovito Adiel; Susin, Alexandre Henrique

    2010-01-01

    The adhesive systems are responsible for an efficient union between teeth and resin, resulting in a longevity restoration. They are organic molecules di or multifunctional that contain reactive groups that interact with dentin and with the resin monomer of composite resin. The adhesive systems are characterized by wet adhesion, which is a result of presence of hidrophylics radicals in their compositions, to promote a better bond and the best properties of the adhesion. Adhesive systems may us...

  3. Human climbing with efficiently scaled gecko-inspired dry adhesives.

    Science.gov (United States)

    Hawkes, Elliot W; Eason, Eric V; Christensen, David L; Cutkosky, Mark R

    2015-01-06

    Since the discovery of the mechanism of adhesion in geckos, many synthetic dry adhesives have been developed with desirable gecko-like properties such as reusability, directionality, self-cleaning ability, rough surface adhesion and high adhesive stress. However, fully exploiting these adhesives in practical applications at different length scales requires efficient scaling (i.e. with little loss in adhesion as area grows). Just as natural gecko adhesives have been used as a benchmark for synthetic materials, so can gecko adhesion systems provide a baseline for scaling efficiency. In the tokay gecko (Gekko gecko), a scaling power law has been reported relating the maximum shear stress σmax to the area A: σmax ∝ A(-1/4). We present a mechanical concept which improves upon the gecko's non-uniform load-sharing and results in a nearly even load distribution over multiple patches of gecko-inspired adhesive. We created a synthetic adhesion system incorporating this concept which shows efficient scaling across four orders of magnitude of area, yielding an improved scaling power law: σmax ∝ A(-1/50). Furthermore, we found that the synthetic adhesion system does not fail catastrophically when a simulated failure is induced on a portion of the adhesive. In a practical demonstration, the synthetic adhesion system enabled a 70 kg human to climb vertical glass with 140 cm(2) of adhesive per hand. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  4. Chapter 9:Wood Adhesion and Adhesives

    Science.gov (United States)

    Charles R. Frihart

    2013-01-01

    The recorded history of bonding wood dates back at least 3000 years to the Egyptians (Skeist and Miron 1990, River 1994a), and adhesive bonding goes back to early mankind (Keimel 2003). Although wood and paper bonding are the largest applications for adhesives, some of the fundamental aspects leading to good bonds are not fully understood. Better understanding of these...

  5. Consecutive dynamic resolutions of phosphine oxides

    NARCIS (Netherlands)

    Kortmann, Felix A.; Chang, Mu Chieh; Otten, Edwin; Couzijn, Erik P A; Lutz, Martin|info:eu-repo/dai/nl/304828971; Minnaard, Adriaan J.

    2014-01-01

    A crystallization-induced asymmetric transformation (CIAT) involving a radical-mediated racemization provides access to enantiopure secondary phosphine oxides. A consecutive CIAT is used to prepare enantio- and diastereo-pure tert-butyl(hydroxyalkyl)phenylphosphine oxides. © 2014 The Royal Society

  6. THz Properties of Adhesives

    Science.gov (United States)

    Stübling, E.; Gomell, L.; Sommer, S.; Winkel, A.; Kahlmeyer, M.; Böhm, S.; Koch, M.

    2018-06-01

    We determined the THz properties of 12 different adhesives which are mainly used for industrial purposes. The adhesives applied can be classified according to their chemical structure: epoxy resins, acrylic resins, and polyurethane based materials. This work represents a basis for future studies, which will concentrate on aging effects, including the absorption of water of adhesive joints. Thus, the dielectric properties of the unaged adhesives are investigated and the results of these measurements are described herein.

  7. PH dependent adhesive peptides

    Science.gov (United States)

    Tomich, John; Iwamoto, Takeo; Shen, Xinchun; Sun, Xiuzhi Susan

    2010-06-29

    A novel peptide adhesive motif is described that requires no receptor or cross-links to achieve maximal adhesive strength. Several peptides with different degrees of adhesive strength have been designed and synthesized using solid phase chemistries. All peptides contain a common hydrophobic core sequence flanked by positively or negatively charged amino acids sequences.

  8. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    . As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will become...

  9. Particle adhesion and removal

    CERN Document Server

    Mittal, K L

    2015-01-01

    The book provides a comprehensive and easily accessible reference source covering all important aspects of particle adhesion and removal.  The core objective is to cover both fundamental and applied aspects of particle adhesion and removal with emphasis on recent developments.  Among the topics to be covered include: 1. Fundamentals of surface forces in particle adhesion and removal.2. Mechanisms of particle adhesion and removal.3. Experimental methods (e.g. AFM, SFA,SFM,IFM, etc.) to understand  particle-particle and particle-substrate interactions.4. Mechanics of adhesion of micro- and  n

  10. Analyte variations in consecutive 24-hour urine collections in children.

    Science.gov (United States)

    Ellison, Jonathan S; Hollingsworth, John M; Langman, Craig B; Asplin, John R; Schwaderer, Andrew L; Yan, Phyllis; Bierlein, Maggie; Barraza, Mark A; Defoor, William R; Figueroa, T Ernesto; Jackson, Elizabeth C; Jayanthi, Venkata R; Johnson, Emilie K; Joseph, David B; Shnorhavorian, Margarett

    2017-12-01

    The metabolic evaluation of children with nephrolithiasis begins with a 24-h urine collection. For adults, the diagnostic yield increases with consecutive collections; however, little is known regarding the variability of multiple 24-h studies in the pediatric population. We sought to evaluate the variability of consecutive 24-h urine collection in children through a multi-institutional study hypothesizing that compared with a single collection, consecutive 24-h urine collections would reveal a greater degree of clinically useful information in the evaluation of children at risk for nephrolithiasis. Including data from six institutions, we identified children less than 18 years of age considered at risk for recurrent nephrolithiasis, undergoing metabolic evaluation. We evaluated a subset of patients performing two collections with urine creatinine varying by 10% or less during a 7-day period. Discordance between repeat collections based on normative urine chemistry values was evaluated. A total of 733 children met inclusion criteria, and in over a third both urine calcium and urine volume differed by 30% or more between samples. Urine oxalate demonstrated greater variation between collections in children collections prior to targeted intervention to modify stone risk are advised to increase diagnostic yield in children at risk for nephrolithiasis. Copyright © 2017 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

  11. Radiation curable adhesive compositions and composite structures

    International Nuclear Information System (INIS)

    Brenner, W.

    1984-01-01

    This disclosure relates to novel adhesive compositions and composite structures utilizing the same, wherein said adhesive compositions contain an elastomer, a chemically compatible ethylenically unsaturated monomer, a tackifier, an adhesion promoter, and optionally, pigments, fillers, thickeners and flow control agents which are converted from the liquid to the solid state by exposure to high energy ionizing radiation such as electron beam. A particularly useful application for such adhesive compositions comprises the assembly of certain composite structures or laminates consisting of, for example, a fiber flocked rubber sheet and a metal base with the adhesive fulfilling the multiple functions of adhering the flocked fiber to the rubber sheet as well as adhering the rubber sheet to the metal base. Optionally, the rubber sheet itself may also be cured at the same time as the adhesive composition with all operations being carried out at ambient temperatures and in the presence of air, with exposure of said assembly to selected dosages of high energy ionizing radiation. These adhesive compositions contain no solvents thereby almost eliminating air pollution or solvent toxicity problems, and offer substantial savings in energy and labor as they are capable of curing in very short time periods without the use of external heat which might damage the substrate

  12. Energetics of bacterial adhesion

    International Nuclear Information System (INIS)

    Loosdrecht, M.C.M. van; Zehnder, A.J.B.

    1990-01-01

    For the description of bacterial adhesion phenomena two different physico-chemical approaches are available. The first one, based on a surface Gibbs energy balance, assumes intimate contact between the interacting surfaces. The second approach, based on colloid chemical theories (DLVO theory), allows for two types of adhesion: 1) secondary minimum adhesion, which is often weak and reversible, and 2) irreversible primary minimum adhesion. In the secondary minimum adhesion a thin water film remains present between the interacting surface. The merits of both approaches are discussed in this paper. In addition, the methods available to measure the physico-chemical surface characteristics of bacteria and the influence of adsorbing (in)organic compounds, extracellular polymers and cell surface appendages on adhesion are summarized. (author) 2 figs., 1 tab., 50 refs

  13. Radiation-curable adhesives

    International Nuclear Information System (INIS)

    Woods, J.G.

    1992-01-01

    Radiation-curable adhesives may be classified into two broad categories. In the first category, adhesive bonding occurs as a direct result of irradiation. The second category includes pressure-sensitive and hot-melt adhesives, which are composed of linear or lightly cross-linked polymers prepared by a radiation-induced polymerization reaction. This chapter is mainly concerned with radiation-curable adhesives of the first category. The various adhesive types are discussed and adhesive performance is examined, particularly in relation to the chemistry and chemical technology which underlies the individual materials. A description of a limited number of representative applications is included as is an outline of recent developments of curing and dispensing equipment. 268 refs., 14 figs., 13 tabs

  14. Synaptic Cell Adhesion

    OpenAIRE

    Missler, Markus; Südhof, Thomas C.; Biederer, Thomas

    2012-01-01

    Chemical synapses are asymmetric intercellular junctions that mediate synaptic transmission. Synaptic junctions are organized by trans-synaptic cell adhesion molecules bridging the synaptic cleft. Synaptic cell adhesion molecules not only connect pre- and postsynaptic compartments, but also mediate trans-synaptic recognition and signaling processes that are essential for the establishment, specification, and plasticity of synapses. A growing number of synaptic cell adhesion molecules that inc...

  15. Hierarchical capillary adhesion of microcantilevers or hairs

    International Nuclear Information System (INIS)

    Liu Jianlin; Feng Xiqiao; Xia Re; Zhao Hongping

    2007-01-01

    As a result of capillary forces, animal hairs, carbon nanotubes or nanowires of a periodically or randomly distributed array often assemble into hierarchical structures. In this paper, the energy method is adopted to analyse the capillary adhesion of microsized hairs, which are modelled as clamped microcantilevers wetted by liquids. The critical conditions for capillary adhesion of two hairs, three hairs or two bundles of hairs are derived in terms of Young's contact angle, elastic modulus and geometric sizes of the beams. Then, the hierarchical capillary adhesion of hairs is addressed. It is found that for multiple hairs or microcantilevers, the system tends to take a hierarchical structure as a result of the minimization of the total potential energy of the system. The level number of structural hierarchy increases with the increase in the number of hairs if they are sufficiently long. Additionally, we performed experiments to verify our theoretical solutions for the adhesion of microbeams

  16. Reversible Thermoset Adhesives

    Science.gov (United States)

    Mac Murray, Benjamin C. (Inventor); Tong, Tat H. (Inventor); Hreha, Richard D. (Inventor)

    2016-01-01

    Embodiments of a reversible thermoset adhesive formed by incorporating thermally-reversible cross-linking units and a method for making the reversible thermoset adhesive are provided. One approach to formulating reversible thermoset adhesives includes incorporating dienes, such as furans, and dienophiles, such as maleimides, into a polymer network as reversible covalent cross-links using Diels Alder cross-link formation between the diene and dienophile. The chemical components may be selected based on their compatibility with adhesive chemistry as well as their ability to undergo controlled, reversible cross-linking chemistry.

  17. Adhesive interactions with wood

    Science.gov (United States)

    Charles R. Frihart

    2004-01-01

    While the chemistry for the polymerization of wood adhesives has been studied systematically and extensively, the critical aspects of the interaction of adhesives with wood are less clearly understood. General theories of bond formation need to be modified to take into account the porosity of wood and the ability of chemicals to be absorbed into the cell wall....

  18. Adhesive compositions and methods

    Science.gov (United States)

    Allen, Scott D.; Sendijarevic, Vahid; O'Connor, James

    2017-12-05

    The present invention encompasses polyurethane adhesive compositions comprising aliphatic polycarbonate chains. In one aspect, the present invention encompasses polyurethane adhesives derived from aliphatic polycarbonate polyols and polyisocyanates wherein the polyol chains contain a primary repeating unit having a structure:. In another aspect, the invention provides articles comprising the inventive polyurethane compositions as well as methods of making such compositions.

  19. Soy protein adhesives

    Science.gov (United States)

    Charles R. Frihart

    2010-01-01

    In the quest to manufacture and use building materials that are more environmentally friendly, soy adhesives can be an important component. Trees fix and store carbon dioxide in the atmosphere. After the trees are harvested, machinery converts the wood into strands, which are then bonded together with adhesives to form strandboard, used in constructing long-lasting...

  20. Durability of adhesive glass-metal connections for structural applications

    NARCIS (Netherlands)

    Van Lancker, B.; Dispersyn, J.; De Corte, W.; Belis, J.

    2016-01-01

    The use of adhesive bonds for structural glass-metal connections in the building envelope has increased in recent years. Despite the multiple advantages compared to more traditional bolted connections, long-term behaviour and durability of the adhesives have to be investigated accurately. Because,

  1. Polymer Nanocarriers for Dentin Adhesion

    Science.gov (United States)

    Osorio, R.; Osorio, E.; Medina-Castillo, A.L.; Toledano, M.

    2014-01-01

    To obtain more durable adhesion to dentin, and to protect collagen fibrils of the dentin matrix from degradation, calcium- and phosphate-releasing particles have been incorporated into the dental adhesive procedure. The aim of the present study was to incorporate zinc-loaded polymeric nanocarriers into a dental adhesive system to facilitate inhibition of matrix metalloproteinases (MMPs)-mediated collagen degradation and to provide calcium ions for mineral deposition within the resin-dentin bonded interface. PolymP-nActive nanoparticles (nanoMyP) were zinc-loaded through 30-minute ZnCl2 immersion and tested for bioactivity by means of 7 days’ immersion in simulated body fluid solution (the Kokubo test). Zinc-loading and calcium phosphate depositions were examined by scanning and transmission electron microscopy, elemental analysis, and x-ray diffraction. Nanoparticles in ethanol solution infiltrated into phosphoric-acid-etched human dentin and Single Bond (3M/ESPE) were applied to determine whether the nanoparticles interfered with bonding. Debonded sticks were analyzed by scanning electron microscopy. A metalloproteinase collagen degradation assay was also performed in resin-infiltrated dentin with and without nanoparticles, measuring C-terminal telopeptide of type I collagen (ICTP) concentration in supernatants, after 4 wk of immersion in artificial saliva. Numerical data were analyzed by analysis of variance (ANOVA) and Student-Newman-Keuls multiple comparisons tests (p calcium regardless of zinc incorporation. Nanoparticles failed to infiltrate demineralized intertubular dentin and remained on top of the hybrid layer, without altering bond strength. Calcium and phosphorus were found covering nanoparticles at the hybrid layer, after 24 h. Nanoparticle application in etched dentin also reduced MMP-mediated collagen degradation. Tested nanoparticles may be incorporated into dental adhesive systems to provide the appropriate environment in which dentin MMP

  2. Indicators for surgery in adhesive bowel obstruction.

    Science.gov (United States)

    Rajanikmanth, P V; Kate, V; Ananthakrishnan, N

    2001-01-01

    There is lack of data on risk factors, which, if present, would indicate the need for surgery in patients with adhesive bowel obstruction. A Cohort of 100 consecutive patients with adhesive obstruction was studied prospectively to compare clinical and investigative parameters between the operative and conservative group. It was found that female gender, previous obstetric or gynaecological procedures, pulse and BP on admission, nature of nasogastric aspirate, single distended loop on abdominal x-ray as also predominant ileal distension were independent factors indicating a high probability of surgical intervention. Patients with 2 or more risk factors had 12 times higher probability of surgery and in those with 3 or more the relative risk was 30 times. Patients with such risk factors should be monitored closely after admission and should be taken for surgery after an initial short trial of conservative measures.

  3. Hibernoma: MRI features in eight consecutive cases

    International Nuclear Information System (INIS)

    Lee, J.C.; Gupta, A.; Saifuddin, A.; Flanagan, A.; Skinner, J.A.; Briggs, T.W.R.; Cannon, S.R.

    2006-01-01

    Aim: To describe the preoperative magnetic resonance imaging findings of eight histologically-proven cases of hibernoma. Materials and methods: The site, size, and signal characteristics of eight consecutive hibernomas were retrospectively assessed on T1-weighted spin-echo and short T1 inversion recovery (STIR)/fat-saturated T2-weighted fast spin echo magnetic resonance images. Four patients also had gadolinium-enhanced fat-saturated T1-weighted spin echo imaging. Patient age and sex, and duration of symptoms were recorded. Results: Three female and five male patients with an average age 36 years (range 16-53 years) were included. Seven lesions occurred in the thigh, four in the anterior compartment and three in the posterior compartment. One lesion occurred superficial to the scapula. All cases demonstrated common magnetic resonance imaging findings of a well-defined, heterogeneous mass, slightly or clearly hypo-intense to subcutaneous fat on T1-weighted spin-echo images, with prominent thin low signal bands throughout the tumour. The lesions failed to fully suppress on STIR or fat-saturated T2-weighted images. Only one of the four contrast-enhanced studies demonstrated increased vascularity in the tumour. Conclusion: The MRI findings of a lesion that is diffusely slightly hypointense to surrounding subcutaneous fat, should prompt the operator to consider hibernoma in the differential diagnosis

  4. Physics of adhesion

    International Nuclear Information System (INIS)

    Gerberich, W W; Cordill, M J

    2006-01-01

    Adhesion physics was relegated to the lowest echelons of academic pursuit until the advent of three seemingly disconnected events. The first, atomic force microscopy (AFM), eventually allowed fine-scale measurement of adhesive point contacts. The second, large-scale computational materials science, now permits both hierarchical studies of a few thousand atoms from first principles or of billions of atoms with less precise interatomic potentials. The third is a microelectronics industry push towards the nanoscale which has provided the driving force for requiring a better understanding of adhesion physics. In the present contribution, an attempt is made at conjoining these separate events into an updating of how theoretical and experimental approaches are providing new understanding of adhesion physics. While all material couples are briefly considered, the emphasis is on metal/semiconductor and metal/ceramic interfaces. Here, adhesion energies typically range from 1 to 100 J m -2 where the larger value is considered a practical work of adhesion. Experimental emphasis is on thin-film de-adhesion for 10 to 1000 nm thick films. For comparison, theoretical approaches from first principles quantum mechanics to embedded atom methods used in multi-scale modelling are utilized

  5. Repeated origin and loss of adhesive toepads in geckos.

    Directory of Open Access Journals (Sweden)

    Tony Gamble

    Full Text Available Geckos are well known for their extraordinary clinging abilities and many species easily scale vertical or even inverted surfaces. This ability is enabled by a complex digital adhesive mechanism (adhesive toepads that employs van der Waals based adhesion, augmented by frictional forces. Numerous morphological traits and behaviors have evolved to facilitate deployment of the adhesive mechanism, maximize adhesive force and enable release from the substrate. The complex digital morphologies that result allow geckos to interact with their environment in a novel fashion quite differently from most other lizards. Details of toepad morphology suggest multiple gains and losses of the adhesive mechanism, but lack of a comprehensive phylogeny has hindered efforts to determine how frequently adhesive toepads have been gained and lost. Here we present a multigene phylogeny of geckos, including 107 of 118 recognized genera, and determine that adhesive toepads have been gained and lost multiple times, and remarkably, with approximately equal frequency. The most likely hypothesis suggests that adhesive toepads evolved 11 times and were lost nine times. The overall external morphology of the toepad is strikingly similar in many lineages in which it is independently derived, but lineage-specific differences are evident, particularly regarding internal anatomy, with unique morphological patterns defining each independent derivation.

  6. Repeated origin and loss of adhesive toepads in geckos.

    Science.gov (United States)

    Gamble, Tony; Greenbaum, Eli; Jackman, Todd R; Russell, Anthony P; Bauer, Aaron M

    2012-01-01

    Geckos are well known for their extraordinary clinging abilities and many species easily scale vertical or even inverted surfaces. This ability is enabled by a complex digital adhesive mechanism (adhesive toepads) that employs van der Waals based adhesion, augmented by frictional forces. Numerous morphological traits and behaviors have evolved to facilitate deployment of the adhesive mechanism, maximize adhesive force and enable release from the substrate. The complex digital morphologies that result allow geckos to interact with their environment in a novel fashion quite differently from most other lizards. Details of toepad morphology suggest multiple gains and losses of the adhesive mechanism, but lack of a comprehensive phylogeny has hindered efforts to determine how frequently adhesive toepads have been gained and lost. Here we present a multigene phylogeny of geckos, including 107 of 118 recognized genera, and determine that adhesive toepads have been gained and lost multiple times, and remarkably, with approximately equal frequency. The most likely hypothesis suggests that adhesive toepads evolved 11 times and were lost nine times. The overall external morphology of the toepad is strikingly similar in many lineages in which it is independently derived, but lineage-specific differences are evident, particularly regarding internal anatomy, with unique morphological patterns defining each independent derivation.

  7. Spatiotemporal patterns formed by deformed adhesive in peeling

    International Nuclear Information System (INIS)

    Yamazaki, Yoshihiro; Toda, Akihiko

    2007-01-01

    Dynamical properties of peeling an adhesive tape are investigated experimentally as an analogy of sliding friction. An adhesive tape is peeled by pulling an elastic spring connected to the tape. Controlling its spring constant k and pulling speed V, peel force is measured and spatiotemporal patterns formed on the peeled tape by deformed adhesive are observed. It is found that there exist two kinds of adhesive state in peeling front. The emergence of multiple states is caused by the stability of a characteristic structure (tunnel structure) formed by deformed adhesive. Tunnel structures are distributed spatiotemporally on adhesive tape after peeling. Based on the spatiotemporal distribution, a morphology-dynamical phase diagram is constructed on k-V space and is divided into the four regions: (A) uniform pattern with tunnel structure, (B) uniform pattern without tunnel structure, (C) striped pattern with oscillatory peeling, and (D) spatiotemporally coexistent pattern

  8. EB curable laminating adhesives

    International Nuclear Information System (INIS)

    Matsuyama, Asao; Kobayashi, Masahide; Gotoh, Sakiko

    1992-01-01

    New developed solvent free EB curable laminating adhesives have two liquid components, A with hydroxy and acryloyl group, B with isocyanate and acryloyl group in a molecule. These EB laminating adhesives do not need any aging process, which is a big advantage, and are very suitable for environment, safety, and health because of no heating process and solvent free formulas. And we have made basic research about the relation of peel strength or heat seal strength versus Tg of cured film, elongation at break, elastic modulus, and so on. Basic specifications of the new developed adhesives are shown. (author)

  9. Evaluation of adhesive penetration of wood fibre by nanoindentation and microscopy

    Science.gov (United States)

    Christopher G. Hunt; Joseph E. Jakes; Warren Grigsby

    2010-01-01

    Adhesives used in wood products sometimes infiltrate, or diffuse into the solid material of, wood cell walls, potentially modifying their properties. These changes in cell wall properties are likely to impact the performance of adhesive bonds. While adhesive infiltration has been observed by multiple methods, the effect on cell wall properties is not well understood....

  10. Optical adhesive property study

    Energy Technology Data Exchange (ETDEWEB)

    Sundvold, P.D.

    1996-01-01

    Tests were performed to characterize the mechanical and thermal properties of selected optical adhesives to identify the most likely candidate which could survive the operating environment of the Direct Optical Initiation (DOI) program. The DOI system consists of a high power laser and an optical module used to split the beam into a number of channels to initiate the system. The DOI requirements are for a high shock environment which current military optical systems do not operate. Five candidate adhesives were selected and evaluated using standardized test methods to determine the adhesives` physical properties. EC2216, manufactured by 3M, was selected as the baseline candidate adhesive based on the test results of the physical properties.

  11. Bioinspired pressure actuated adhesive system

    NARCIS (Netherlands)

    Paretkar, D.R.; Kamperman, M.M.G.; Schneider, A.S.; Martina, D.; Creton, C.; Arzt, E.

    2011-01-01

    We developed a dry synthetic adhesive system inspired by gecko feet adhesion that can switch reversibly from adhesion to non-adhesion with applied pressure as external stimulus. Micropatterned polydimethylsiloxane (PDMS) surfaces with pillars of 30 µm length and 10 µm diameter were fabricated using

  12. Many Roles of Wood Adhesives

    Science.gov (United States)

    Charles R. Frihart

    2014-01-01

    Although wood bonding is one of the oldest applications of adhesives, going back to early recorded history (1), some aspects of wood bonds are still not fully understood. Most books in the general area of adhesives and adhesion do not cover wood bonding. However, a clearer understanding of wood bonding and wood adhesives can lead to improved products. This is important...

  13. Cohesion and Adhesion with Proteins

    Science.gov (United States)

    Charles R. Frihart

    2016-01-01

    With increasing interest in bio-based adhesives, research on proteins has expanded because historically they have been used by both nature and humans as adhesives. A wide variety of proteins have been used as wood adhesives. Ancient Egyptians most likely used collagens tobond veneer to wood furniture, then came casein (milk), blood, fish scales, and soy adhesives, with...

  14. Dry adhesives with sensing features

    International Nuclear Information System (INIS)

    Krahn, J; Menon, C

    2013-01-01

    Geckos are capable of detecting detachment of their feet. Inspired by this basic observation, a novel functional dry adhesive is proposed, which can be used to measure the instantaneous forces and torques acting on an adhesive pad. Such a novel sensing dry adhesive could potentially be used by climbing robots to quickly realize and respond appropriately to catastrophic detachment conditions. The proposed torque and force sensing dry adhesive was fabricated by mixing Carbon Black (CB) and Polydimethylsiloxane (PDMS) to form a functionalized adhesive with mushroom caps. The addition of CB to PDMS resulted in conductive PDMS which, when under compression, tension or torque, resulted in a change in the resistance across the adhesive patch terminals. The proposed design of the functionalized dry adhesive enables distinguishing an applied torque from a compressive force in a single adhesive pad. A model based on beam theory was used to predict the change in resistance across the terminals as either a torque or compressive force was applied to the adhesive patch. Under a compressive force, the sensing dry adhesive was capable of measuring compression stresses from 0.11 Pa to 20.9 kPa. The torque measured by the adhesive patch ranged from 2.6 to 10 mN m, at which point the dry adhesives became detached. The adhesive strength was 1.75 kPa under an applied preload of 1.65 kPa for an adhesive patch with an adhesive contact area of 7.07 cm 2 . (paper)

  15. Dry adhesives with sensing features

    Science.gov (United States)

    Krahn, J.; Menon, C.

    2013-08-01

    Geckos are capable of detecting detachment of their feet. Inspired by this basic observation, a novel functional dry adhesive is proposed, which can be used to measure the instantaneous forces and torques acting on an adhesive pad. Such a novel sensing dry adhesive could potentially be used by climbing robots to quickly realize and respond appropriately to catastrophic detachment conditions. The proposed torque and force sensing dry adhesive was fabricated by mixing Carbon Black (CB) and Polydimethylsiloxane (PDMS) to form a functionalized adhesive with mushroom caps. The addition of CB to PDMS resulted in conductive PDMS which, when under compression, tension or torque, resulted in a change in the resistance across the adhesive patch terminals. The proposed design of the functionalized dry adhesive enables distinguishing an applied torque from a compressive force in a single adhesive pad. A model based on beam theory was used to predict the change in resistance across the terminals as either a torque or compressive force was applied to the adhesive patch. Under a compressive force, the sensing dry adhesive was capable of measuring compression stresses from 0.11 Pa to 20.9 kPa. The torque measured by the adhesive patch ranged from 2.6 to 10 mN m, at which point the dry adhesives became detached. The adhesive strength was 1.75 kPa under an applied preload of 1.65 kPa for an adhesive patch with an adhesive contact area of 7.07 cm2.

  16. Recurrent pregnancy loss: what is the impact of consecutive versus non-consecutive losses?

    Science.gov (United States)

    Egerup, P; Kolte, A M; Larsen, E C; Krog, M; Nielsen, H S; Christiansen, O B

    2016-11-01

    Is there a different prognostic impact for consecutive and non-consecutive early pregnancy losses in women with secondary recurrent pregnancy loss (RPL)? Only consecutive early pregnancy losses after the last birth have a statistically significant negative prognostic impact in women with secondary RPL. The risk of a new pregnancy loss increases with the number of previous pregnancy losses in patients with RPL. Second trimester losses seem to exhibit a stronger negative impact than early losses. It is unknown whether the sequence of pregnancy losses plays a role for the prognosis in patients with a prior birth. This retrospective cohort study of pregnancy outcome in patients with unexplained secondary RPL included in three previously published, Danish double-blinded placebo-controlled trials of intravenous immunoglobulin (IvIg) conducted from 1991 to 2014. No other treatments were given. Patients with documented explained pregnancy losses (ectopic pregnancies and aneuploid miscarriages) were excluded. Of the 168 patients included in the trials, 127 had secondary RPL and experienced a subsequent live birth or unexplained pregnancy loss in the first pregnancy after giving informed consent to participate in the trials (the index pregnancy). Data analyzed by multivariate analysis included the independent variables age, the number of early pregnancy losses before and after the last birth, respectively and a second trimester pregnancy loss before or after the last birth, respectively. The outcome variable was unexplained loss in the index pregnancy. In patients with secondary RPL, both a late and each early loss before the last birth did not significantly influence the risk of a new pregnancy loss in the index pregnancy: incidence rate ratio (IRR) 1.31 (95% CI 0.62-2.77) and IRR 0.88 (95% CI 0.70-1.11), respectively. In contrast, the impact on risk of pregnancy loss conferred by a late and by each early pregnancy loss occurring after the birth was significant: IRR 2

  17. Electrically Conductive Epoxy Adhesives

    Directory of Open Access Journals (Sweden)

    Lan Bai

    2011-02-01

    Full Text Available Conductive adhesives are widely used in electronic packaging applications such as die attachment and solderless interconnections, component repair, display interconnections, and heat dissipation. The effects of film thickness as functions of filler volume fraction, conductive filler size, shape, as well as uncured adhesive matrix viscosity on the electrical conduction behavior of epoxy-based adhesives are presented in this work. For this purpose, epoxy-based adhesives were prepared using conductive fillers of different size, shape, and types, including Ni powder, flakes, and filaments, Ag powder, and Cu powder. The filaments were 20 μm in diameter, and 160 or 260 μm in length. HCl and H3PO4 acid solutions were used to etch and remove the surface oxide layers from the fillers. The plane resistance of filled adhesive films was measured using the four-point method. In all cases of conductive filler addition, the planar resistivity levels for the composite adhesive films increased when the film thickness was reduced. The shape of resistivity-thickness curves was negative exponential decaying type and was modeled using a mathematical relation. The relationships between the conductive film resistivities and the filler volume fractions were also derived mathematically based on the experimental data. Thus, the effects of surface treatment of filler particles, the type, size, shape of fillers, and the uncured epoxy viscosity could be included empirically by using these mathematical relations based on the experimental data. By utilizing the relations we proposed to model thickness-dependent and volume fraction-dependent conduction behaviors separately, we were able to describe the combined and coupled volume fraction-film thickness relationship mathematically based on our experimental data.

  18. Reversible adhesion switching of porous fibrillar adhesive pads by humidity.

    Science.gov (United States)

    Xue, Longjian; Kovalev, Alexander; Dening, Kirstin; Eichler-Volf, Anna; Eickmeier, Henning; Haase, Markus; Enke, Dirk; Steinhart, Martin; Gorb, Stanislav N

    2013-01-01

    We report reversible adhesion switching on porous fibrillar polystyrene-block-poly(2-vinyl pyridine) (PS-b-P2VP) adhesive pads by humidity changes. Adhesion at a relative humidity of 90% was more than nine times higher than at a relative humidity of 2%. On nonporous fibrillar adhesive pads of the same material, adhesion increased only by a factor of ~3.3. The switching performance remained unchanged in at least 10 successive high/low humidity cycles. Main origin of enhanced adhesion at high humidity is the humidity-induced decrease in the elastic modulus of the polar component P2VP rather than capillary force. The presence of spongelike continuous internal pore systems with walls consisting of P2VP significantly leveraged this effect. Fibrillar adhesive pads on which adhesion is switchable by humidity changes may be used for preconcentration of airborne particulates, pollutants, and germs combined with triggered surface cleaning.

  19. Switchable bio-inspired adhesives

    Science.gov (United States)

    Kroner, Elmar

    2015-03-01

    Geckos have astonishing climbing abilities. They can adhere to almost any surface and can run on walls and even stick to ceilings. The extraordinary adhesion performance is caused by a combination of a complex surface pattern on their toes and the biomechanics of its movement. These biological dry adhesives have been intensely investigated during recent years because of the unique combination of adhesive properties. They provide high adhesion, allow for easy detachment, can be removed residue-free, and have self-cleaning properties. Many aspects have been successfully mimicked, leading to artificial, bio-inspired, patterned dry adhesives, and were addressed and in some aspects they even outperform the adhesion capabilities of geckos. However, designing artificial patterned adhesion systems with switchable adhesion remains a big challenge; the gecko's adhesion system is based on a complex hierarchical surface structure and on advanced biomechanics, which are both difficult to mimic. In this paper, two approaches are presented to achieve switchable adhesion. The first approach is based on a patterned polydimethylsiloxane (PDMS) polymer, where adhesion can be switched on and off by applying a low and a high compressive preload. The switch in adhesion is caused by a reversible mechanical instability of the adhesive silicone structures. The second approach is based on a composite material consisting of a Nickel- Titanium (NiTi) shape memory alloy and a patterned adhesive PDMS layer. The NiTi alloy is trained to change its surface topography as a function of temperature, which results in a change of the contact area and of alignment of the adhesive pattern towards a substrate, leading to switchable adhesion. These examples show that the unique properties of bio-inspired adhesives can be greatly improved by new concepts such as mechanical instability or by the use of active materials which react to external stimuli.

  20. Switchable Adhesion in Vacuum Using Bio-Inspired Dry Adhesives.

    Science.gov (United States)

    Purtov, Julia; Frensemeier, Mareike; Kroner, Elmar

    2015-11-04

    Suction based attachment systems for pick and place handling of fragile objects like glass plates or optical lenses are energy-consuming and noisy and fail at reduced air pressure, which is essential, e.g., in chemical and physical vapor deposition processes. Recently, an alternative approach toward reversible adhesion of sensitive objects based on bioinspired dry adhesive structures has emerged. There, the switching in adhesion is achieved by a reversible buckling of adhesive pillar structures. In this study, we demonstrate that these adhesives are capable of switching adhesion not only in ambient air conditions but also in vacuum. Our bioinspired patterned adhesive with an area of 1 cm(2) provided an adhesion force of 2.6 N ± 0.2 N in air, which was reduced to 1.9 N ± 0.2 N if measured in vacuum. Detachment was induced by buckling of the structures due to a high compressive preload and occurred, independent of air pressure, at approximately 0.9 N ± 0.1 N. The switch in adhesion was observed at a compressive preload between 5.6 and 6.0 N and was independent of air pressure. The difference between maximum adhesion force and adhesion force after buckling gives a reasonable window of operation for pick and place processes. High reversibility of the switching behavior is shown over 50 cycles in air and in vacuum, making the bioinspired switchable adhesive applicable for handling operations of fragile objects.

  1. an Adhesive Patch

    Directory of Open Access Journals (Sweden)

    S. Mojtaba Taghizadeh

    2013-01-01

    Full Text Available Drug-in-adhesive transdermal drug delivery systems  TDDSs containing stimulants, termed as energetic substances, such as caffeine and pantothenic acid, were studied. Caffeine is a white crystalline substance and a stimulant to central nervous system. In humans, caffeine acts as a central nervous system stimulant, temporarily warding off drowsiness and restoring alertness. Pantothenic acid, also recognized as vitamin B5, is a water-soluble vitamin. For many animals, pantothenic acid is an essential nutrient. Animals require pantothenic acid to synthesize and metabolize proteins, carbohydrates and fats. For this purpose caffeine and pantothenic acid were  used  as  drug  components with  6.32%  and  1.12%  loadings,  in  different functional and non-functional acrylic pressure sensitive adhesives (PSAs of 52.89%, respectively. Ethylene glycol as a chemical enhancer was used in all TDDSs with 39.67%. The effect of PSAs  type on  in vitro  release and adhesion properties  (peel strength and tack values from drug delivery devices were evaluated. It was found that TDDS containing -COOH functional PSA showed  the  lowest steady state fux. The adhesion properties of the samples were improved by addition of functional acrylic PSA in formulations.

  2. Leukocyte adhesion deficiencies

    NARCIS (Netherlands)

    van de Vijver, Edith; van den Berg, Timo K.; Kuijpers, Taco W.

    2013-01-01

    During inflammation, leukocytes play a key role in maintaining tissue homeostasis through elimination of pathogens and removal of damaged tissue. Leukocytes migrate to the site of inflammation by crawling over and through the blood vessel wall, into the tissue. Leukocyte adhesion deficiencies (ie,

  3. Adhesive tape exfoliation

    DEFF Research Database (Denmark)

    Bohr, Jakob

    2015-01-01

    Single-crystal graphite can be cleaved by the use of an adhesive tape. This was also the initial route for obtaining graphene, a one-layer thick graphite slab. In this letter a few simple and fun considerations are presented in an attempt to shed some light on why this procedure is successful...

  4. Wood Composite Adhesives

    Science.gov (United States)

    Gomez-Bueso, Jose; Haupt, Robert

    The global environment, in which phenolic resins are being used for wood composite manufacture, has changed significantly during the last decade. This chapter reviews trends that are driving the use and consumption of phenolic resins around the world. The review begins with recent data on volume usage and regional trends, followed by an analysis of factors affecting global markets. In a section on environmental factors, the impact of recent formaldehyde emission regulations is discussed. The section on economics introduces wood composite production as it relates to the available adhesive systems, with special emphasis on the technical requirement to improve phenolic reactivity. Advances in composite process technology are introduced, especially in regard to the increased demands the improvements place upon adhesive system performance. The specific requirements for the various wood composite families are considered in the context of adhesive performance needs. The results of research into current chemistries are discussed, with a review of recent findings regarding the mechanisms of phenolic condensation and acceleration. Also, the work regarding alternate natural materials, such as carbohydrates, lignins, tannins, and proteinaceous materials, is presented. Finally, new developments in alternative adhesive technologies are reported.

  5. Relationship Between Working Memory and English-Chinese Consecu-tive Interpreting

    Institute of Scientific and Technical Information of China (English)

    王磊; 陈莉; 徐晓娟

    2016-01-01

    Working memory is the system that actively holds multiple pieces of transitory information in the mind, where they can be manipulated. In interpreting, working memory is in charge of the storage and processing of immediate information, thus making an important factor in influencing interpreting quality. The role played by working memory capacity in interpreting re-mains to be a hotspot issue in the field of interpreting research.This thesis aims to investigate the relationship between working memory capacity and E-C consecutive interpreting by conducting two tests. The first test is working memory span test and the second one is E-C consecutive interpreting test. By comparing and analyzing the results of two tests, this thesis comes to the con-clusion that working memory capacity is positively correlated with E-C consecutive interpreting in terms of fluency and logic.

  6. Adhesive bonding of wood materials

    Science.gov (United States)

    Charles B. Vick

    1999-01-01

    Adhesive bonding of wood components has played an essential role in the development and growth of the forest products industry and has been a key factor in the efficient utilization of our timber resource. The largest use of adhesives is in the construction industry. By far, the largest amounts of adhesives are used to manufacture building materials, such as plywood,...

  7. Forbidden Structures for Planar Perfect Consecutively Colourable Graphs

    Directory of Open Access Journals (Sweden)

    Borowiecka-Olszewska Marta

    2017-05-01

    Full Text Available A consecutive colouring of a graph is a proper edge colouring with posi- tive integers in which the colours of edges incident with each vertex form an interval of integers. The idea of this colouring was introduced in 1987 by Asratian and Kamalian under the name of interval colouring. Sevast- janov showed that the corresponding decision problem is NP-complete even restricted to the class of bipartite graphs. We focus our attention on the class of consecutively colourable graphs whose all induced subgraphs are consecutively colourable, too. We call elements of this class perfect consecutively colourable to emphasise the conceptual similarity to perfect graphs. Obviously, the class of perfect consecutively colourable graphs is induced hereditary, so it can be characterized by the family of induced forbidden graphs. In this work we give a necessary and sufficient conditions that must be satisfied by the generalized Sevastjanov rosette to be an induced forbid- den graph for the class of perfect consecutively colourable graphs. Along the way, we show the exact values of the deficiency of all generalized Sevastjanov rosettes, which improves the earlier known estimating result. It should be mentioned that the deficiency of a graph measures its closeness to the class of consecutively colourable graphs. We motivate the investigation of graphs considered here by showing their connection to the class of planar perfect consecutively colourable graphs.

  8. The selection of adhesive systems for resin-based luting agents.

    Science.gov (United States)

    Carville, Rebecca; Quinn, Frank

    2008-01-01

    The use of resin-based luting agents is ever expanding with the development of adhesive dentistry. A multitude of different adhesive systems are used with resin-based luting agents, and new products are introduced to the market frequently. Traditional adhesives generally required a multiple step bonding procedure prior to cementing with active resin-based luting materials; however, combined agents offer a simple application procedure. Self-etching 'all-in-one' systems claim that there is no need for the use of a separate adhesive process. The following review addresses the advantages and disadvantages of the available adhesive systems used with resin-based luting agents.

  9. Syndecans and cell adhesion

    DEFF Research Database (Denmark)

    Couchman, J R; Chen, L; Woods, A

    2001-01-01

    Now that transmembrane signaling through primary cell-matrix receptors, integrins, is being elucidated, attention is turning to how integrin-ligand interactions can be modulated. Syndecans are transmembrane proteoglycans implicated as coreceptors in a variety of physiological processes, including...... cell adhesion, migration, response to growth factors, development, and tumorigenesis. This review will describe this family of proteoglycans in terms of their structures and functions and their signaling in conjunction with integrins, and indicate areas for future research....

  10. The preventive effect of Rofecoxib in postoperative intraperitoneal adhesions.

    Science.gov (United States)

    Aldemir, M; Oztürk, H; Erten, C; Büyükbayram, H

    2004-02-01

    Previous studies showed that nonsteroidal anti-inflammatory (NSAI) drugs suppressed prostaglandin synthesis and were able to prevent adhesion formation following surgical trauma to the peritoneum. The selective suppression inflammatory cascade may prevent adhesion formation. Therefore, we planned this study to experimentally evaluate the effects of Rofecoxib, the selective cyclo-oxygenase-2 inhibitor, in postoperative intraperitoneal adhesions in an animal model. Male Sprague-Dawley rats were divided into three groups of 10. All rats underwent midline laparotomy under ketamine anaesthesia (25 mg/kg im). In group 1 (n = 10), the sham operation group (SG); abdominal walls were closed without any process after 2 minutes. In Group 2 (n = 10), the control group (CG); standard serosal damage was constituted and the abdominal wall was closed. In group 3 (n = 10), the COX-2 group (COXG), after serosal damage, the abdominal wall was closed. A 12 mg/kg/day dose of was given orally to the rats during one week. On the 7th postoperative day, all rats were sacrificed and intra-abdominal adhesions were evaluated both macroscopically and microscopically. Macroscopically, no serious adhesion formations were seen in the SG. Multiple adhesion formations of the CG were significantly more than those of the SG (p < 0.0001). It was determined that adhesions of the COXG diminished (p < 0.0001) when macromorphological adhesion scale results of the COXG were compared with those of the CG. The adhesion scores of the CG were compared microscopically with those of the COXG and granulation tissue formation and fibrosis in the COXG were found to be significantly less than those of the CG (respectively p = 0.002, p < 0.0001). We were of the opinion that Rofecoxib, the selective cyclo-oxygenase inhibitor, was effective in the prevention of postoperative peritoneal adhesions.

  11. Impact of x-Linkable Polymer Blends on Phase Morphology and Adhesion

    Science.gov (United States)

    Liu, Chun; Wan, Grace; Keene, Ellen; Harris, Joseph; Zhang, Sipei; Anderson, Stephanie; Li Pi Shan, Colin

    Adhesion to dissimilar substrate is highly important to multiple industrial applications such as automotive adhesives, food packaging, transportation etc. Adhesive design has to include components that are affinity to both substrates, e.g. high surface energy polar and low surface non-polar substrates. Typically, these adhesive components are thermodynamically incompatible with each other, leading to macrophase separation and thus adhesive failure. By using functional adhesive components plus some additives, the adhesive can be in-situ cross-linked to prevent the macrophase separation with controlled phase morphology. Herein, we present the study on a cross-linkable adhesive formulation consisting of acrylic emulsion and polyolefin aqueous dispersion with additives for enhancing cross-linking and controlled phase morphologies. Contact angle measurement and ATR-IR spectroscopy are used to characterize the properties of adhesive surface. DMA is used to study the mechanical property of adhesive before and after cross-linking. The detailed phase morphologies are revealed by AFM, SEM and TEM. The resulting adhesive morphologies are correlated with the adhesive performance to establish structure-property relationship.

  12. Consecutive Acupuncture Stimulations Lead to Significantly Decreased Neural Responses

    NARCIS (Netherlands)

    Yeo, S.; Choe, I.H.; Noort, M.W.M.L. van den; Bosch, M.P.C.; Lim, S.

    2010-01-01

    Objective: Functional magnetic resonance imaging (fMRI), in combination with block design paradigms with consecutive acupuncture stimulations, has often been used to investigate the neural responses to acupuncture. In this study, we investigated whether previous acupuncture stimulations can affect

  13. Etiology of azoospermia in 100 consecutive nonvasectomized men

    DEFF Research Database (Denmark)

    Fedder, Jens; Crüger, Dorthe; Oestergaard, Birthe

    2004-01-01

    History was taken systematically for 100 azoospermic, nonvasectomized men referred consecutively to a Danish fertility clinic. The men were examined by ultrasound, and their blood samples were analyzed for karyotype, Y microdeletions, and cystic fibrosis transmembrane conductance regulator gene...

  14. Assessment of Risk Factors of Intrauterine Adhesions in Patients With Induced Abortion and the Curative Effect of Hysteroscopic Surgery.

    Science.gov (United States)

    Mo, Xiaoliang; Qin, Guirong; Zhou, Zhoulin; Jiang, Xiaoli

    2017-10-03

    To explore the risk factors for intrauterine adhesions in patients with artificial abortion and clinical efficacy of hysteroscopic dissection. 1500 patients undergoing artificial abortion between January 2014 and June 2015 were enrolled into this study. The patients were divided into two groups with or without intrauterine adhesions. Univariate and Multiple logistic regression were conducted to assess the effects of multiple factors on the development of intrauterine adhesions following induced abortion. The incidence rate for intrauterine adhesions following induced abortion is 17.0%. Univariate showed that preoperative inflammation, multiple pregnancies and suction evacuation time are the influence risk factors of intrauterine adhesions. Multiple logistic regression demonstrates that multiple pregnancies, high intrauterine negative pressure, and long suction evacuation time are independent risk factors for the development of intrauterine adhesions following induced abortion. Additionally, intrauterine adhesions were observed in 105 mild, 80 moderate, and 70 severe cases. The cure rates for these three categories of intrauterine adhesions by hysteroscopic surgery were 100.0%, 93.8%, and 85.7%, respectively. Multiple pregnancies, high negative pressure suction evacuation and long suction evacuation time are independent risk factors for the development of intrauterine adhesions following induced abortions. Hysteroscopic surgery substantially improves the clinical outcomes of intrauterine adhesions.

  15. Gecko Adhesion on Wet and Dry Patterned Substrates.

    Directory of Open Access Journals (Sweden)

    Alyssa Y Stark

    Full Text Available Perhaps one of the most astounding characteristics of the gecko adhesive system is its versatility. Geckos can locomote across complex substrates in a variety of conditions with apparent ease. In contrast, many of our synthetic pressure sensitive adhesives fail on substrates that are dirty, wet or rough. Although many studies have investigated the effect of environmental challenges on performance, the interaction of multiple, potentially compromising variables is studied less often. Here we focus on substrate structure and surface water, both of which are highly relevant to the biological system and to synthetic design. To do this we utilized a highly controlled, patterned substrate (Sharklet®, by Sharklet® Technologies Inc.. This allowed us to test independently and jointly the effects of reduced surface area substrates, with a defined pattern, on adhesion in both air and water. Our results show that adhesion is not significantly impaired in air, whereas surface area and pattern significantly affect adhesion in water. These findings highlight the need to study multiple parameters that are relevant to the gecko adhesive system to further improve our understanding of the biological system and to design better, more versatile synthetics.

  16. Syndecan proteoglycans and cell adhesion

    DEFF Research Database (Denmark)

    Woods, A; Oh, E S; Couchman, J R

    1998-01-01

    It is now becoming clear that a family of transmembrane proteoglycans, the syndecans, have important roles in cell adhesion. They participate through binding of matrix ligand to their glycosaminoglycan chains, clustering, and the induction of signaling cascades to modify the internal microfilament...... organization. Syndecans can modulate the type of adhesive responses induced by other matrix ligand-receptor interactions, such as those involving the integrins, and so contribute to the control of cell morphology, adhesion and migration....

  17. The neural cell adhesion molecule

    DEFF Research Database (Denmark)

    Berezin, V; Bock, E; Poulsen, F M

    2000-01-01

    During the past year, the understanding of the structure and function of neural cell adhesion has advanced considerably. The three-dimensional structures of several of the individual modules of the neural cell adhesion molecule (NCAM) have been determined, as well as the structure of the complex...... between two identical fragments of the NCAM. Also during the past year, a link between homophilic cell adhesion and several signal transduction pathways has been proposed, connecting the event of cell surface adhesion to cellular responses such as neurite outgrowth. Finally, the stimulation of neurite...

  18. A mucus adhesion promoting protein, MapA, mediates the adhesion of Lactobacillus reuteri to Caco-2 human intestinal epithelial cells.

    Science.gov (United States)

    Miyoshi, Yukihiro; Okada, Sanae; Uchimura, Tai; Satoh, Eiichi

    2006-07-01

    Lactobacillus reuteri is one of the dominant lactobacilli found in the gastrointestinal tract of various animals. A surface protein of L. reuteri 104R, mucus adhesion promoting protein (MapA), is considered to be an adhesion factor of this strain. We investigated the relation between MapA and adhesion of L. reuteri to human intestinal (Caco-2) cells. Quantitative analysis of the adhesion of L. reuteri strains to Caco-2 cells showed that various L. reuteri strains bind not only to mucus but also to intestinal epithelial cells. In addition, purified MapA bound to Caco-2 cells, and this binding inhibited the adhesion of L. reuteri in a concentration-dependent manner. Based on these observations, the adhesion of L. reuteri appears due to the binding of MapA to receptor-like molecules on Caco-2 cells. Further, far-western analysis indicated the existence of multiple receptor-like molecules in Caco-2 cells.

  19. Adhesive sealing of dentin surfaces in vitro: A review

    Science.gov (United States)

    Abu-Nawareg, Manar M; Zidan, Ahmed Z; Zhou, Jianfeng; Agee, Kelli; Chiba, Ayaka; Tagami, Jungi; Pashley, David H

    2016-01-01

    Purpose The purpose of this review is to describe the evolution of the use of dental adhesives to form a tight seal of freshly prepared dentin to protect the pulp from bacterial products, during the time between crown preparation and final cementum of full crowns. The evolution of these “immediate dentin sealants” follows the evolution of dental adhesives, in general. That is, they began with multiple-step, etch-and-rinse adhesives, and then switched to the use of simplified adhesives. Methods Literature was reviewed for evidence that bacteria or bacterial products diffusing across dentin can irritate pulpal tissues before and after smear layer removal. Smear layers can be solubilized by plaque organisms within 7–10 days if they are directly exposed to oral fluids. It is likely that smear layers covered by temporary restorations may last more than one month. As long as smear layers remain in place, they can partially seal dentin. Thus, many in vitro studies evaluating the sealing ability of adhesive resins use smear layer-covered dentin as a reference condition. Surprisingly, many adhesives do not seal dentin as well as do smear layers. Results Both in vitro and in vivo studies show that resin-covered dentin allows dentinal fluid to cross polymerized resins. The use of simplified single bottle adhesives to seal dentin was a step backwards. Currently, most authorities use either 3-step adhesives such as Scotchbond Multi-Purposea or OptiBond FLb or two-step self-etching primer adhesives, such as Clearfil SEc, Unifil Bondd or AdheSEe, respectfully. PMID:26846037

  20. Improved Adhesion and Compliancy of Hierarchical Fibrillar Adhesives.

    Science.gov (United States)

    Li, Yasong; Gates, Byron D; Menon, Carlo

    2015-08-05

    The gecko relies on van der Waals forces to cling onto surfaces with a variety of topography and composition. The hierarchical fibrillar structures on their climbing feet, ranging from mesoscale to nanoscale, are hypothesized to be key elements for the animal to conquer both smooth and rough surfaces. An epoxy-based artificial hierarchical fibrillar adhesive was prepared to study the influence of the hierarchical structures on the properties of a dry adhesive. The presented experiments highlight the advantages of a hierarchical structure despite a reduction of overall density and aspect ratio of nanofibrils. In contrast to an adhesive containing only nanometer-size fibrils, the hierarchical fibrillar adhesives exhibited a higher adhesion force and better compliancy when tested on an identical substrate.

  1. Stretchable, Adhesion-Tunable Dry Adhesive by Surface Wrinkling

    KAUST Repository

    Jeong, Hoon Eui

    2010-02-16

    We introduce a simple yet robust method of fabricating a stretchable, adhesion-tunable dry adhesive by combining replica molding and surface wrinkling. By utilizing a thin, wrinkled polydimethyl siloxane (PDMS) sheet with a thickness of 1 mm with built-in micropillars, active, dynamic control of normal and shear adhesion was achieved. Relatively strong normal (∼10.8 N/cm2) and shear adhesion (∼14.7 N/cm2) forces could be obtained for a fully extended (strained) PDMS sheet (prestrain of∼3%), whereas the forces could be rapidly reduced to nearly zero once the prestrain was released (prestrain of ∼0.5%). Moreover, durability tests demonstrated that the adhesion strength in both the normal and shear directions was maintained over more than 100 cycles of attachment and detachment. © 2010 American Chemical Society.

  2. Effect of adhesive thickness on adhesively bonded T-joint

    International Nuclear Information System (INIS)

    Abdullah, A R; Afendi, Mohd; Majid, M S Abdul

    2013-01-01

    The aim of this work is to analyze the effect of adhesive thickness on tensile strength of adhesively bonded stainless steel T-joint. Specimens were made from SUS 304 Stainless Steel plate and SUS 304 Stainless Steel perforated plate. Four T-joint specimens with different adhesive thicknesses (0.5, 1.0, 1.5 and 2.0 mm) were made. Experiment result shows T-joint specimen with adhesive thickness of 1.0 mm yield highest maximum load. Identical T-joint specimen jointed by spot welding was also tested. Tensile test shows welded T-Joint had eight times higher tensile load than adhesively bonded T-joint. However, in low pressure application such as urea granulator chamber, high tensile strength is not mandatory. This work is useful for designer in fertilizer industry and others who are searching for alternative to spot welding

  3. Stretchable, Adhesion-Tunable Dry Adhesive by Surface Wrinkling

    KAUST Repository

    Jeong, Hoon Eui; Kwak, Moon Kyu; Suh, Kahp Y.

    2010-01-01

    We introduce a simple yet robust method of fabricating a stretchable, adhesion-tunable dry adhesive by combining replica molding and surface wrinkling. By utilizing a thin, wrinkled polydimethyl siloxane (PDMS) sheet with a thickness of 1 mm with built-in micropillars, active, dynamic control of normal and shear adhesion was achieved. Relatively strong normal (∼10.8 N/cm2) and shear adhesion (∼14.7 N/cm2) forces could be obtained for a fully extended (strained) PDMS sheet (prestrain of∼3%), whereas the forces could be rapidly reduced to nearly zero once the prestrain was released (prestrain of ∼0.5%). Moreover, durability tests demonstrated that the adhesion strength in both the normal and shear directions was maintained over more than 100 cycles of attachment and detachment. © 2010 American Chemical Society.

  4. Syndecans, signaling, and cell adhesion

    DEFF Research Database (Denmark)

    Couchman, J R; Woods, A

    1996-01-01

    structures within the heparan sulfate chains, leaving the roles of chondroitin sulfate chains and extracellular portion of the core proteins to be elucidated. Evidence that syndecans are a class of receptor involved in cell adhesion is mounting, and their small cytoplasmic domains may link...... transmembrane signaling from matrix to cytoskeleton, as proposed for other classes of adhesion receptors....

  5. Controlling adhesive behavior during recycling

    Science.gov (United States)

    Carl Houtman; Karen Scallon; Jihui Guo; XinPing Wang; Steve Severtson; Mark Kroll; Mike Nowak

    2004-01-01

    Adhesives can be formulated to facilitate their removal by typical paper recycling unit operations. The investigations described in this paper are focused on determining fundamental properties that control particle size during pulping. While pressure-sensitive adhesives (PSAs) with high elastic moduli tend to survive pulping with larger particles, facestock and...

  6. Two consecutive levels of unilateral cervical spondylolysis on opposite sides

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Kyeong Hwa; Kim, Seon Jeong; KIm Ok Hwa; Kim, Seung Ho; Lee, Kwang Hwi; Beak, Hye Jin; Lee, Ye Daun [Dept. of Radiology, Inje University College of Medicine, Haeundae Paik Hospital, Busan (Korea, Republic of); Cha, Yoon Ki [Dept. of Radiology, Dongguk University College of Medicine, Ilsan Hospital, Goyang (Korea, Republic of)

    2015-09-15

    Cervical spondylolysis, with or without spondylolisthesis, is a rare condition defined as a corticated cleft between the superior and inferior articular facets of the articular pillar. The defect occurs predominantly at C6, and is usually bilateral in up to two-thirds of cases. Multilevel involvement is uncommon, however, to date, no case of two consecutive levels of unilateral cervical spondylolysis on opposite sides has been reported. Here, we report a rare case of a patient affected by two consecutive levels of unilateral cervical spondylolysis at C5 and C6 on opposite sides in a 19-year-old male complaining of neck pain.

  7. Two consecutive levels of unilateral cervical spondylolysis on opposite sides

    International Nuclear Information System (INIS)

    Ryu, Kyeong Hwa; Kim, Seon Jeong; KIm Ok Hwa; Kim, Seung Ho; Lee, Kwang Hwi; Beak, Hye Jin; Lee, Ye Daun; Cha, Yoon Ki

    2015-01-01

    Cervical spondylolysis, with or without spondylolisthesis, is a rare condition defined as a corticated cleft between the superior and inferior articular facets of the articular pillar. The defect occurs predominantly at C6, and is usually bilateral in up to two-thirds of cases. Multilevel involvement is uncommon, however, to date, no case of two consecutive levels of unilateral cervical spondylolysis on opposite sides has been reported. Here, we report a rare case of a patient affected by two consecutive levels of unilateral cervical spondylolysis at C5 and C6 on opposite sides in a 19-year-old male complaining of neck pain

  8. Regulative mechanisms of chondrocyte adhesion

    DEFF Research Database (Denmark)

    Schmal, Hagen; Mehlhorn, Alexander T; Fehrenbach, Miriam

    2006-01-01

    Interaction between chondrocytes and extracellular matrix is considered a key factor in the generation of grafts for matrix-associated chondrocyte transplantation. Therefore, our objective was to study the influence of differentiation status on cellular attachment. Adhesion of chondrocytes...... to collagen type II increased after removal from native cartilage up to the third day in monolayer in a dose-dependent manner. Following dedifferentiation after the second passage, adhesion to collagen types I (-84%) and II (-46%) decreased, whereas adhesion to fibrinogen (+59%) and fibronectin (+43......%) increased. A cartilage construct was developed based on a clinically established collagen type I scaffold. In this matrix, more than 80% of the cells could be immobilized by mechanisms of adhesion, filtration, and cell entrapment. Confocal laser microscopy revealed focal adhesion sites as points of cell...

  9. Universal adhesives: the next evolution in adhesive dentistry?

    Science.gov (United States)

    Alex, Gary

    2015-01-01

    Every so often a new material, technique, or technological breakthrough spurs a paradigm shift in the way dentistry is practiced. The development and evolution of reliable enamel and dentin bonding agents is one such example. Indeed, the so-called "cosmetic revolution" in dentistry blossomed in large part due to dramatic advances in adhesive technology. It is the ability to bond various materials in a reasonably predictable fashion to both enamel and dentin substrates that enables dentists to routinely place porcelain veneers, direct and indirect composites, and a plethora of other restorative and esthetic materials. In fact, the longevity and predictability of many (if not most) current restorative procedures is wholly predicated on the dentist's ability to bond various materials to tooth tissues. Adhesive systems have progressed from the largely ineffective systems of the 1970s and early 1980s to the relatively successful total- and self-etching systems of today. The latest players in the adhesive marketplace are the so-called "universal adhesives." In theory, these systems have the potential to significantly simplify and expedite adhesive protocols and may indeed represent the next evolution in adhesive dentistry. But what defines a universal system, and are all these new systems truly "universal" and everything they are claimed to be? This article will examine the origin, chemistry, strengths, weaknesses, and clinical relevance of this new genre of dental adhesives.

  10. Asymptotics of Multivariate Regression with Consecutively Added Dependent Varibles

    NARCIS (Netherlands)

    Raats, V.M.; van der Genugten, B.B.; Moors, J.J.A.

    2004-01-01

    We consider multivariate regression where new dependent variables are consecutively added during the experiment (or in time).So, viewed at the end of the experiment, the number of observations decreases with each added variable. The explanatory variables are observed throughout.In a previous paper

  11. Confabulations after Bilateral Consecutive Strokes of the Lenticulostriate Arteries

    Directory of Open Access Journals (Sweden)

    Antonio Carota

    2012-03-01

    Full Text Available We describe the case of a 75-year-old woman who manifested persistent confabulations after two consecutive strokes encompassing the area of the lenticulostriate arteries territory on both hemispheres. Findings reported on this rare clinical syndrome suggest that fantastic confabulations and delusional thoughts may arise after bilateral damage of subcortical nonthalamic structures.

  12. Erectile Dysfunction in 101 Consecutive Hypertensive Patients and ...

    African Journals Online (AJOL)

    In a 6 month prospective questionnaire study of 101 consecutive newly referred hypertensive patients and 86 normotensive volunteers, the relationship of erectile dysfunction and hypertension in these patients was studied using a modified international index of erectile function (IIEF). The mean age of the hypertensive ...

  13. Surface control of blastospore attachment and ligand-mediated hyphae adhesion of Candida albicans.

    Science.gov (United States)

    Varghese, Nisha; Yang, Sijie; Sejwal, Preeti; Luk, Yan-Yeung

    2013-11-14

    Adhesion on a surface via nonspecific attachment or multiple ligand-receptor interactions is a critical event for fungal infection by Candida albicans. Here, we find that the tri(ethylene glycol)- and d-mannitol-terminated monolayers do not resist the blastospore attachment, but prevent the hyphae adhesion of C. albicans. The hyphae adhesion can be facilitated by tripeptide sequences of arginine-glycine-aspartic acid (RGD) covalently decorated on a background of tri(ethylene glycol)-terminated monolayers. This adhesion mediated by selected ligands is sensitive to the scrambling of peptide sequences, and is inhibited by the presence of cyclic RGD peptides in the solution.

  14. Clinico-hysteroscopic analysis of severe intrauterine adhesions ...

    African Journals Online (AJOL)

    Secondary dysmenorrhea and cyclical abdominal pain were found in 10.8% and 31.6% of the women respectively. The main aetiological events were complicated caesarean section (42.1%) and abdominal myomectomy (26.3%). The adhesions were mainly dense (52.6%) and multiple (94.7%) with complete involvement of ...

  15. Adhesion and multi-materials

    International Nuclear Information System (INIS)

    Schultz, J.

    1997-01-01

    Adhesion is a multidisciplinary science relevant to many practical fields. The main application of adhesion is bonding by adhesives. This technique is widely used in the industrial world and more specifically in the advanced technical domains. Adhesion is also involved in multi-component materials such as coatings, multilayer materials, polymer blends, composite materials... The multidisciplinary aspect of adhesion is well demonstrated by considering the wide variety of concepts, models and theories proposed for its description. An example of the adhesion between a fiber and a matrix in a composite material will lead to a general model relating the molecular properties of the interface to its capacity of stress transfer and hence to the macroscopic mechanical properties of the composite. This relationship is valid whatever the fiber (glass, carbon, polymeric) or the polymer matrix (thermoplastics, thermosetting). Any deviation from this model can be attributed to the existence of an interfacial zone or interphase exhibiting properties, mainly mechanical properties, different from the bulk matrix. Two examples are examined: the first one deals with the creation of a trans crystalline interphase in a semi-crystalline thermoplastic matrix and the second one is concerned with the formation of a pseudo glassy interphase in an elastomer matrix. These examples stress the need for complementary approaches in the understanding of adhesion phenomena at different levels of knowledge, from molecular to macroscopic. They also show how important it is to understand the mechanisms of formation of inter phases in order to be able to master the performance of multicomponent materials. (Author)

  16. TANNIN ADHESIVES AS AN ALTENATIVE TO THE SYNTHETIC PHENOLIC ADHESIVES

    Directory of Open Access Journals (Sweden)

    Semra Çolak

    2003-04-01

    Full Text Available Recently, increasing attention has been paid industrially to the use of tannin formaldehyde adhesives in production of wood based panel products such as particleboard, fiber board and plywood. The researches on the use of tannin extracts as a wood adhesive started in 1950, however, they proceeded very slowly since the problems associated with the application of them. The idea which tannin extract can be used replace the oil-based phenolic adhesive was the base of several studies after the oil crisis of the 1970s. In the past, the economical aspects were important in the researches on the tannin-based adhesives. Nowadays, however, both economical and ecological factors should have taken into consideration in wood bonding.

  17. Photovoltaic module with adhesion promoter

    Science.gov (United States)

    Xavier, Grace

    2013-10-08

    Photovoltaic modules with adhesion promoters and methods for fabricating photovoltaic modules with adhesion promoters are described. A photovoltaic module includes a solar cell including a first surface and a second surface, the second surface including a plurality of interspaced back-side contacts. A first glass layer is coupled to the first surface by a first encapsulating layer. A second glass layer is coupled to the second surface by a second encapsulating layer. At least a portion of the second encapsulating layer is bonded directly to the plurality of interspaced back-side contacts by an adhesion promoter.

  18. Adhesives from modified soy protein

    Science.gov (United States)

    Sun, Susan [Manhattan, KS; Wang, Donghai [Manhattan, KS; Zhong, Zhikai [Manhattan, KS; Yang, Guang [Shanghai, CN

    2008-08-26

    The present invention provides useful adhesive compositions having similar adhesive properties to conventional UF and PPF resins. The compositions generally include a protein portion and modifying ingredient portion selected from the group consisting of carboxyl-containing compounds, aldehyde-containing compounds, epoxy group-containing compounds, and mixtures thereof. The composition is preferably prepared at a pH level at or near the isoelectric point of the protein. In other preferred forms, the adhesive composition includes a protein portion and a carboxyl-containing group portion.

  19. Structural adhesives directory and databook

    CERN Document Server

    Wilson, Jo

    1996-01-01

    A worldwide directory of commercially available adhesive products for use in a wide range of engineering disciplines. Along with product names and suppliers, basic property data are tabulated and cross-referenced. The book is subdivided according to class of adhesive, with introductions to each class followed by comparison tables and datasheets for each adhesive. The datasheets contain detailed information, from product codes to environmental properties and are therefore of interest across a broad readership. Standardized data will aid the user in cross-comparison between different manufacturers and in easily identifying the required information.

  20. Comparing Soy Flour Wood Adhesives to Purified Soy Protein Adhesives

    Science.gov (United States)

    Charles R. Frihart; Linda F. Lorenz

    2013-01-01

    While economics dictate that soy-based wood adhesives be made with soy flour, much of the recent literature on soy-based wood adhesives has involved using soy protein isolate. The obvious assumption is that the additional carbohydrates in the flour but not in the isolate only serve as inert diluents. Our studies have shown that the isolate can provide 10 times the wet...

  1. Bacterial endotoxin adhesion to different types of orthodontic adhesives

    Directory of Open Access Journals (Sweden)

    Priscilla Coutinho ROMUALDO

    Full Text Available Abstract Bacterial endotoxin (LPS adhesion to orthodontic brackets is a known contributing factor to inflammation of the adjacent gingival tissues. Objective The aim of this study was to assess whether LPS adheres to orthodontic adhesive systems, comparing two commercial brands. Material and Methods Forty specimens were fabricated from Transbond XT and Light Bond composite and bonding agent components (n=10/component, then contaminated by immersion in a bacterial endotoxin solution. Contaminated and non-contaminated acrylic resin samples were used as positive and negative control groups, respectively. LPS quantification was performed by the Limulus Amebocyte Lysate QCL-1000™ test. Data obtained were scored and subjected to the Chi-square test using a significance level of 5%. Results There was endotoxin adhesion to all materials (p0.05. There was no significant difference (p>0.05 among commercial brands. Affinity of endotoxin was significantly greater for the bonding agents (p=0.0025. Conclusions LPS adhered to both orthodontic adhesive systems. Regardless of the brand, the endotoxin had higher affinity for the bonding agents than for the composites. There is no previous study assessing the affinity of LPS for orthodontic adhesive systems. This study revealed that LPS adheres to orthodontic adhesive systems. Therefore, additional care is recommended to orthodontic applications of these materials.

  2. Yield of two consecutive sputum specimens for the effective diagnosis of pulmonary tuberculosis.

    Directory of Open Access Journals (Sweden)

    Mohammad R Islam

    Full Text Available BACKGROUND: From long instances, it is debatable whether three sputum specimens are required for the diagnosis of pulmonary tuberculosis (TB or TB can be diagnosed effectively using two consecutive sputum specimens. This study was set out to evaluate the significance of examining multiple sputum specimens in diagnosis of TB. METHODS: We retrospectively reviewed the acid-fast bacillus (AFB smear and culture results of three consecutive days' sputum specimens from 413 confirmed TB patients which were detected as part of a larger active case finding study in Dhaka Central Jail, the largest correctional facility in Bangladesh. RESULTS: AFB was detected from 81% (n = 334 patients, of which 89% (n = 297 were diagnosed from the first and additional 9% (n = 30 were from the second sputum specimen. M. tuberculosis growth was observed for 406 patients and 85% (n = 343 were obtained from the first sputum and additional 10% (n = 42 were from the second one. The third specimen didn't show significant additional diagnostic value for the detection of AFB by microscopy or growth of the M. tuberculosis. CONCLUSIONS: We concluded from our study results that examining two consecutive sputum specimens is sufficient enough for the effective diagnosis of TB. It can also decrease the laboratory workload and hence improve the quality of work in settings with high TB burden like Bangladesh.

  3. Yield of two consecutive sputum specimens for the effective diagnosis of pulmonary tuberculosis.

    Science.gov (United States)

    Islam, Mohammad R; Khatun, Razia; Uddin, Mohammad Khaja Mafij; Khan, Md Siddiqur Rahman; Rahman, Md Toufiq; Ahmed, Tahmeed; Banu, Sayera

    2013-01-01

    From long instances, it is debatable whether three sputum specimens are required for the diagnosis of pulmonary tuberculosis (TB) or TB can be diagnosed effectively using two consecutive sputum specimens. This study was set out to evaluate the significance of examining multiple sputum specimens in diagnosis of TB. We retrospectively reviewed the acid-fast bacillus (AFB) smear and culture results of three consecutive days' sputum specimens from 413 confirmed TB patients which were detected as part of a larger active case finding study in Dhaka Central Jail, the largest correctional facility in Bangladesh. AFB was detected from 81% (n = 334) patients, of which 89% (n = 297) were diagnosed from the first and additional 9% (n = 30) were from the second sputum specimen. M. tuberculosis growth was observed for 406 patients and 85% (n = 343) were obtained from the first sputum and additional 10% (n = 42) were from the second one. The third specimen didn't show significant additional diagnostic value for the detection of AFB by microscopy or growth of the M. tuberculosis. We concluded from our study results that examining two consecutive sputum specimens is sufficient enough for the effective diagnosis of TB. It can also decrease the laboratory workload and hence improve the quality of work in settings with high TB burden like Bangladesh.

  4. Ciclon: A neutronic fuel management program for PWR's consecutive cycles

    International Nuclear Information System (INIS)

    Aragones, J.M.

    1977-01-01

    The program description and user's manual of a new computer code is given. Ciclon performs the neutronic calculation of consecutive reload cycles for PWR's fuel management optimization. Fuel characteristics and burnup data, region or batch sizes, loading schemes and state of previously irradiated fuel are input to the code. Cycle lengths or feed enrichments and burnup sharing for each region or batch are calculate using different core neutronic models and printed or punched in standard fuel management format. (author) [es

  5. Underwater adhesion: The barnacle way

    Digital Repository Service at National Institute of Oceanography (India)

    Khandeparker, L.; Anil, A.C.

    . Understanding of the molecular mechanisms of adhesion, that is bioadhesive bond formation and curing, is essential to develop a more rational approach in designing fouling- release coatings. Silicone biofouling release coatings have been shown...

  6. Mechanisms of adhesion in geckos.

    Science.gov (United States)

    Autumn, Kellar; Peattie, Anne M

    2002-12-01

    The extraordinary adhesive capabilities of geckos have challenged explanation for millennia, since Aristotle first recorded his observations. We have discovered many of the secrets of gecko adhesion, yet the millions of dry, adhesive setae on the toes of geckos continue to generate puzzling new questions and valuable answers. Each epidermally-derived, keratinous seta ends in hundreds of 200 nm spatular tips, permitting intimate contact with rough and smooth surfaces alike. Prior studies suggested that adhesive force in gecko setae was directly proportional to the water droplet contact angle (θ) , an indicator of the free surface energy of a substrate. In contrast, new theory suggests that adhesion energy between a gecko seta and a surface (W(GS)) is in fact proportional to (1 + cosθ), and only for θ > 60°. A reanalysis of prior data, in combination with our recent study, support the van der Waals hypothesis of gecko adhesion, and contradict surface hydrophobicity as a predictor of adhesion force. Previously, we and our collaborators measured the force production of a single seta. Initial efforts to attach a seta failed because of improper 3D orientation. However, by simulating the dynamics of gecko limbs during climbing (based on force plate data) we discovered that, in single setae, a small normal preload, combined with a 5 μm displacement yielded a very large adhesive force of 200 microNewton (μN), 10 times that predicted by whole-animal measurements. 6.5 million setae of a single tokay gecko attached maximally could generate 130 kg force. This raises the question of how geckos manage to detach their feet in just 15 ms. We discovered that simply increasing the angle that the setal shaft makes with the substrate to 30° causes detachment. Understanding how simultaneous attachment and release of millions of setae are controlled will require an approach that integrates levels ranging from molecules to lizards.

  7. Bio-Inspired Controllable Adhesive

    Science.gov (United States)

    2008-12-01

    pad of the tarsus – which act as a sort of hydraulic suspension. The lamellae contain rows of thin slender fibers , called setae, approximately 130 µm...in length and 20 µm in diameter (Hildebrand, 1988), Fig.1. The terminus of each seta branches into thousands of smaller fibers , or spatular stalks...ADHESION TESTING The structures were characterized (Northen et al., 2008) using a home-built adhesion test apparatus ( Basalt - II) with C. Greiner

  8. Analysis of Dietary Intake during Consecutive-Day Chemotherapy for Bone and Soft-Tissue Sarcomas

    Directory of Open Access Journals (Sweden)

    Yuta Hori

    2018-01-01

    Full Text Available BackgroundBone and soft tissue sarcomas are commonly treated with consecutive-day chemotherapy regimens consisting of multiple anticancer agents. Chemotherapy-induced nausea and vomiting (CINV is a serious adverse effect of these regimens and may result in decreased energy intake during chemotherapy. Decreased energy intake may lead to undernutrition and may cause adverse effects on patient quality of life and survival.MethodsPatients with bone and soft tissue sarcomas who received consecutive-day chemotherapy were retrospectively evaluated. CINV and dietary energy intake were assessed, as well as the occurrences of hiccups and constipation during chemotherapy.ResultsA total of 13 patients, 10 males and 3 females, with a total 16 chemotherapy courses were included in the study. All patients received antiemetic prophylaxis. The CINV control rate, defined as no emesis and no rescue therapy, gradually decreased from chemotherapy day 1 (94% to day 5 (75%. Four patients experienced emesis, two of whom had been treated with a cisplatin-containing regimen. Decreased dietary energy intake was possibly associated with CINV during chemotherapy. Anorexia was grade 2 except for one case of grade 3. The incidences of hiccups and constipation were high on days 3–5.ConclusionAntiemetic prophylaxis treatment did not prevent emesis due to consecutive-day chemotherapy, especially with cisplatin-containing regimens, in patients with bone and soft-tissue tumors. Dietary energy intake decreased during chemotherapy, and this appeared to be associated with CINV. In addition, the incidence of hiccups and constipation increased during the course of consecutive-day chemotherapy regimens. Although these results are based on a small number of patients, it may be important to observe nutritional status during chemotherapy, as this may reflect a patient’s general condition. Nutritional counseling might be useful in supporting nutritional status in patients undergoing

  9. Fibrillar Adhesive for Climbing Robots

    Science.gov (United States)

    Pamess, Aaron; White, Victor E.

    2013-01-01

    A climbing robot needs to use its adhesive patches over and over again as it scales a slope. Replacing the adhesive at each step is generally impractical. If the adhesive or attachment mechanism cannot be used repeatedly, then the robot must carry an extra load of this adhesive to apply a fresh layer with each move. Common failure modes include tearing, contamination by dirt, plastic deformation of fibers, and damage from loading/ unloading. A gecko-like fibrillar adhesive has been developed that has been shown useful for climbing robots, and may later prove useful for grasping, anchoring, and medical applications. The material consists of a hierarchical fibrillar structure that currently contains two levels, but may be extended to three or four levels in continuing work. The contacting level has tens of thousands of microscopic fibers made from a rubberlike material that bend over and create intimate contact with a surface to achieve maximum van der Waals forces. By maximizing the real area of contact that these fibers make and minimizing the bending energy necessary to achieve that contact, the net amount of adhesion has been improved dramatically.

  10. Proteomic dataset of the sea urchin Paracentrotus lividus adhesive organs and secreted adhesive

    NARCIS (Netherlands)

    Lebesgue, Nicolas; da Costa, Gonçalo; Ribeiro, Raquel Mesquita; Ribeiro-Silva, Cristina; Martins, Gabriel G; Matranga, Valeria; Scholten, Arjen; Cordeiro, Carlos; Heck, Albert J R; Santos, Romana

    Sea urchins have specialized adhesive organs called tube feet, which mediate strong but reversible adhesion. Tube feet are composed by a disc, producing adhesive and de-adhesive secretions for substratum attachment, and a stem for movement. After detachment the secreted adhesive remains bound to the

  11. Reliability evaluation of linear multi-state consecutively-connected systems constrained by m consecutive and n total gaps

    International Nuclear Information System (INIS)

    Yu, Huan; Yang, Jun; Peng, Rui; Zhao, Yu

    2016-01-01

    This paper extends the linear multi-state consecutively-connected system (LMCCS) to the case of LMCCS-MN, where MN denotes the dual constraints of m consecutive gaps and n total gaps. All the nodes are distributed along a line and form a sequence. The distances between the adjacent nodes are usually non-uniform. The nodes except the last one can contain statistically independent multi-state connection elements (MCEs). Each MCE can provide a connection between the node at which it is located and the next nodes along the sequence. The LMCCS-MN fails if it meets either of the two constraints. The universal generating function technique is adopted to evaluate the system reliability. The optimal allocations of LMCCS-MN with two different types of failures are solved by genetic algorithm. Finally, two examples are given for the demonstration of the proposed model. - Highlights: • A new model of multi-state consecutively-connected system (LMCCS-MN) is proposed. • The non-uniform distributed nodes are involved in the proposed LMCCS-MN model. • An algorithm for system reliability evaluation is provided by the UGF method. • The computational complexity of the proposed algorithm is discussed in detail. • Optimal element allocation problem is formulated and solved.

  12. Management approach for recurrent spontaneous pneumothorax in consecutive pregnancies based on clinical and radiographic findings

    Directory of Open Access Journals (Sweden)

    Dixson George R

    2006-10-01

    Full Text Available Abstract Objective To describe management and clinical features observed in a patient's seven spontaneous pneumothoraces that developed during two consecutive pregnancies involving both hemithoraces. Materials and methods A 21 year old former smoker developed three spontaneous left pneumothoraces in the index pregnancy, having already experienced four right pneumothorax events in a prior pregnancy at age 19. Results Chest tubes were required in several (but not all hospitalizations during these two pregnancies. Following her fourth right pneumothorax, thoracoscopic excision of right apical lung blebs and mechanical pleurodesis was performed. The series of left pneumothoraces culminated in mini-thoracotomy and thoracoscopically directed mechanical pleurodesis. For both pregnancies unassisted vaginal delivery was performed with no adverse perinatal sequelae. With the exception of multiple pneumothoraces, there were no additional pregnancy complications. Conclusion Spontaneous pneumothorax in pregnancy is believed to be a rare phenomenon, yet the exact incidence is unknown. Here we present the first known case of multiple spontaneous pneumothoraces in two consecutive pregnancies involving both hemithoraces. Clinical management coordinated with obstetrics and surgical teams facilitated a satisfactory outcome for both pregnancies. The diagnosis of pneumothorax should be contemplated in any pregnant patient with dyspnea and chest pain, followed by radiographic confirmation.

  13. Denture adhesives: a systematic review.

    Science.gov (United States)

    Papadiochou, Sofia; Emmanouil, Ioannis; Papadiochos, Ioannis

    2015-05-01

    Denture adhesives have been the objective of scientific research for over half a century. Although they are used by denture wearers worldwide, investigations of their effectiveness and biocompatibility have led to controversial conclusions. The purpose of this study was to review the literature data with regard to the effectiveness and biocompatibility of denture adhesives as well as the attitudes of both patients and dental professionals toward these materials. An electronic search of English peer-reviewed dental literature in the Medline database was conducted to evaluate the effectiveness and biocompatibility of denture adhesives. There was no limitation in publication year, so the search included all the available scientific evidence included in that particular database until March 2014. Specific inclusion criteria were used for the selection of the appropriate articles. A manual search of the citations of the obtained articles followed to extend the electronic search. A full text review was carried out for only 32 articles. Of the 32 articles, 21 examined the efficacy of denture adhesives in terms of retention and stability and masticatory performance, 6 evaluated the issue of the biocompatibility of denture adhesives, and 5 presented the attitudes of either professionals or patients toward these materials. The majority of clinical studies supported the fact that denture adhesives enhance the retention, stability, and masticatory performance of a removable prosthesis. In terms of biocompatibility, long-term in vivo studies to investigate potential harmful effects were lacking. Patients are satisfied with denture adhesives that meet their needs. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  14. Efficiency of Medial Rectus Advancement Surgery in Consecutive Exotropia

    Directory of Open Access Journals (Sweden)

    Kemal Yar

    2015-12-01

    Full Text Available Purpose: To evaluate the efficiency of medial rectus advancement surgery in consecutive exotropia. Material and Methods: The study group consisted of 20 cases, 10 male, 10 female, who were diagnosed as consecutive exotropia and underwent surgery between 2008-2013 at Cukurova University Medical Faculty Ophthalmology Department. Records of the patients were investigated retrospectively. We evaluated best corrected visual acuity, existence of ambliopia, postoperative duration following the first surgery and applied surgical procedures. Postoperative deviation lower than 10 PD were assesed as successful. Mean follow up period was 29,8 +/- 21,36 (8-80 months, patients with inadequate follow up period were dismissed from the study group. Results: We only applied bilateral medial rectus advancement surgery to 6 and unilateral medial rectus advancement surgery to 5 patients and obtained intended surgical result in these 11 cases. The other patients underwent lateral rectus recession or/and medial rectus resection operations inorder to reach projected deviation degrees. Deviation was found to be 46,4+/-9,24 (40-70 PD in cases who only underwent advancement surgery and was 65,56 +/- 18,78 (40-90 PD in cases who underwent additional surgical procedure. 16 (%80 of the cases had hypermetropi various dioptries and 7 (%35 had ambliopia. Discussion: Consecutive exotropia can appear years after surgery and is an important late period complication. In this study achievement of %55 success with medial rectus advancement surgery indicates that this is a preferable procedure. But in wide angle deviations additional lateral rectus recession or/and medial rectus resection operations can be applied inorder to reach intended adjustment. Accurrate prediction of the propotion of advancement surgery and adjustment is not always possible because of intensive fybrosis in operated muscles and enviroment tissue. [Cukurova Med J 2015; 40(4.000: 707-713

  15. Caffeine and performance over consecutive days of simulated competition.

    Science.gov (United States)

    Stadheim, Hans Kristian; Spencer, Matthew; Olsen, Raymond; Jensen, Jørgen

    2014-09-01

    Performance improvements after caffeine (CAF) ingestion are well documented when using a 1-d protocol. In numerous competitions such as the Tour de France, Tour de Ski, world championships, and National College Athletic Association championships, athletes compete for several days in a row. To date, no studies have investigated the effects of CAF when competing for consecutive days in a row. This study aimed to investigate the effects of placebo (PLA) and two different CAF doses (3 and 4.5 mg·kg body mass) on performance in a 10-min all-out, cross-country, double poling ergometer test (C-PT) 2 d in a row. Eight highly trained male cross-country skiers (V˙O2max-run, 78.5 ± 1.6 mL·kg·min) participated in the study, which was a randomized, double-blind, PLA-controlled, crossover design. Performance was assessed as distance covered during a 10-min all-out C-PT. Oral ingestion of CAF or PLA was consumed 75 min before the all-out C-PT. Poling distance was improved after CAF ingestions compared with that after PLA on both days. The improvements on day 1 were 4.0% (90% confidence limits, ±3.3) and 4.0% ± 2.9% for both CAF doses, respectively (P performance was associated with increased HR, adrenaline concentration, blood lactate concentration, and V˙O2 consumption after CAF ingestion. Furthermore, performance was elevated despite higher creatine kinase concentration and muscular pain at arrival on day 2 for both CAF doses. Both CAF doses improved performance in the 10-min all-out C-PT compared with PLA over two consecutive days. Therefore, CAF seems useful for athletes competing over consecutive days despite higher muscle damage occurring after enhanced performance on the first day.

  16. Innovative Electrostatic Adhesion Technologies

    Science.gov (United States)

    Bryan, Tom; Macleod, Todd; Gagliano, Larry; Williams, Scott; McCoy, Brian

    2015-01-01

    Developing specialized Electro-Static grippers (commercially used in Semiconductor Manufacturing and in package handling) will allow gentle and secure Capture, Soft Docking, and Handling of a wide variety of materials and shapes (such as upper-stages, satellites, arrays, and possibly asteroids) without requiring physical features or cavities for a pincher or probe or using harpoons or nets. Combined with new rigid boom mechanisms or small agile chaser vehicles, flexible, high speed Electro-Static Grippers can enable compliant capture of spinning objects starting from a safe stand-off distance. Electroadhesion (EA) can enable lightweight, ultra-low-power, compliant attachment in space by using an electrostatic force to adhere similar and dissimilar surfaces. A typical EA enabled device is composed of compliant space-rated materials, such as copper-clad polyimide encapsulated by polymers. Attachment is induced by strong electrostatic forces between any substrate material, such as an exterior satellite panel and a compliant EA gripper pad surface. When alternate positive and negative charges are induced in adjacent planar electrodes in an EA surface, the electric fields set up opposite charges on the substrate and cause an electrostatic adhesion between the electrodes and the induced charges on the substrate. Since the electrodes and the polymer are compliant and can conform to uneven or rough surfaces, the electrodes can remain intimately close to the entire surface, enabling high clamping pressures. Clamping pressures of more than 3 N/cm2 in shear can be achieved on a variety of substrates with ultra-low holding power consumption (measured values are less than 20 microW/Newton weight held). A single EA surface geometry can be used to clamp both dielectric and conductive substrates, with slightly different physical mechanisms. Furthermore EA clamping requires no normal force be placed on the substrate, as conventional docking requires. Internally funded research and

  17. The structure of cell-matrix adhesions: the new frontier.

    Science.gov (United States)

    Hanein, Dorit; Horwitz, Alan Rick

    2012-02-01

    Adhesions between the cell and the extracellular matrix (ECM) are mechanosensitive multi-protein assemblies that transmit force across the cell membrane and regulate biochemical signals in response to the chemical and mechanical environment. These combined functions in force transduction, signaling and mechanosensing contribute to cellular phenotypes that span development, homeostasis and disease. These adhesions form, mature and disassemble in response to actin organization and physical forces that originate from endogenous myosin activity or external forces by the extracellular matrix. Despite advances in our understanding of the protein composition, interactions and regulation, our understanding of matrix adhesion structure and organization, how forces affect this organization, and how these changes dictate specific signaling events is limited. Insights across multiple structural levels are acutely needed to elucidate adhesion structure and ultimately the molecular basis of signaling and mechanotransduction. Here we describe the challenges and recent advances and prospects for unraveling the structure of cell-matrix adhesions and their response to force. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Polyurethane adhesives in flat roofs

    Directory of Open Access Journals (Sweden)

    Bogárová Markéta

    2017-01-01

    Full Text Available It is necessary to stabilize individual layers of flat roofs, mainly because of wind suction. Apart from anchoring and surcharge, these layers can be secured by bonding. At present gluing is an indispensable and widely used stabilization method. On our market we can found many types of adhesives, most widely used are based on polyurethane. This paper focuses on problematic about stabilization thermal insulation from expanded polystyrene to vapor barrier from bitumen. One of the main issues is to calculate the exact amount of adhesive, which is required to guarantee the resistance against wind suction. In this problematic we can not find help neither in technical data sheets provided by the manufactures. Some of these data sheets contain at least information about amount of adhesive depending on location in roof plane and building height, but they do not specify the strength of such connection. It was therefore resorted to select several representatives polyurethane adhesives and their subsequent testing on specimens simulating the flat roof segment. The paper described the test methodology and results for two types of polyurethane adhesives.

  19. Theoretical analysis of consecutive reactions in adiabatic stirred tank reactors

    International Nuclear Information System (INIS)

    Jo, Byung Wook; Kim, Sun Il; Hong, Won Hae; Cha, Wol Suk; Kim, Soong Pyung; Kim, Jung Gyu

    1990-01-01

    By mathematical model for the case of the consecutive first-order exothermic reaction in an adiabatic CSTR, the effects of the system parameter i. e. relative residence time, heat of reaction and thermal sensitivity of reaction rate constant, on the concentration profile of the intermediate product of a consecutive reaction were obtained as follows. For fixed values of the ratio of the reaction rate constants t 1 / t 2 , the ratio of the correponding system parameter α where α>1 and the sensitivities of the reaction rate constants S1 and S2, the maximum value of the intermediate production dimensionless concentration increases with increase in the values of the relative energy parameter E1 and E2 and it decreases with a decrease in E1 and E2. For fixed values of the ratio of the reaction rate constants t 1 / t 2 , the ratio of the corresponding system parameter α where α 1 and t 2 and it increases with a decrease in S1 and S2. For fixed values of the ratio of the reaction rate constants t 1 / t 2 , the ratio of the corresponding system parameters α where α=1 and the relative energy parameters E1 and E2, the maximum value of the intermediate product dimensionless is constant with either increase or decrease in the sensitivities of the reaction rate constants S1 and S2. (Author)

  20. The consecutive dry days to trigger rainfall over West Africa

    Science.gov (United States)

    Lee, J. H.

    2018-01-01

    In order to resolve contradictions in addressing a soil moisture-precipitation feedback mechanism over West Africa and to clarify the impact of antecedent soil moisture on subsequent rainfall evolution, we first validated various data sets (SMOS satellite soil moisture observations, NOAH land surface model, TRMM rainfall, CMORPH rainfall and HadGEM climate models) with the Analyses Multidisciplinaires de la Mousson Africaine (AMMA) field campaign data. Based on this analysis, it was suggested that biases of data sets might cause contradictions in studying mechanisms. Thus, by taking into account uncertainties in data, it was found that the approach of consecutive dry days (i.e. a relative comparison of time-series) showed consistency across various data sets, while the direct comparison approach for soil moisture state and rainfall did not. Thus, it was discussed that it may be difficult to directly relate rain with soil moisture as the absolute value, however, it may be reasonable to compare a temporal progress of the variables. Based upon the results consistently showing a positive relationship between the consecutive dry days and rainfall, this study supports a negative feedback often neglected by climate model structure. This approach is less sensitive to interpretation errors arising from systematic errors in data sets, as this measures a temporal gradient of soil moisture state.

  1. Lignin-Furfural Based Adhesives

    Directory of Open Access Journals (Sweden)

    Prajakta Dongre

    2015-07-01

    Full Text Available Lignin recovered from the hot-water extract of sugar maple (Acer saccharum is used in this study to synthesize adhesive blends to replace phenol-formaldehyde (PF resin. Untreated lignin is characterized by lignin content and nuclear magnetic resonance (NMR analysis. The molecular weight distribution of the lignin and the blends are characterized by size exclusion chromatography (SEC. The effect of pH (0.3, 0.65 and 1, ex situ furfural, and curing conditions on the tensile properties of adhesive reinforced glass fibers is determined and compared to the reinforcement level of commercially available PF resin. The adhesive blend prepared at pH = 0.65 with no added furfural exhibits the highest tensile properties and meets 90% of the PF tensile strength.

  2. Adhesive capsulitis: role of MR imaging in differential diagnosis

    International Nuclear Information System (INIS)

    Connell, David; Padmanabhan, Ravi; Buchbinder, Rachelle

    2002-01-01

    The purpose of this study was to describe and characterize the MR imaging findings in a group of patients who underwent surgery for adhesive capsulitis. Twenty-four MR imaging studies in 24 consecutive patients with clinical evidence of adhesive capsulitis were performed prior to arthroscopic capsulotomy. There were 17 women and 7 men with a mean age of 53.5 years. Images were scrutinised for changes in the synovium particularly in the rotator interval, around the biceps anchor and axillary pouch. Intravenous gadolinium was given routinely. We also examined a control group of 22 patients who underwent the same MR imaging protocol after referral for rotator cuff pathology. Soft tissue density showing variable enhancement after gadolinium administration was visible in the rotator interval in 22 of 24 studies on MR imaging. Seventeen patients showed soft tissue density partially encasing the biceps anchor. Ten patients showed thickening and gadolinium enhancement of the axillary pouch. Three patients from the study cohort had partial tears of the supraspinatus tendon. All the patients subsequently had surgery which confirmed fibrovascular scar tissue in the rotator interval, around the biceps anchor and a variable degree of synovial inflammation of the glenohumeral capsule. Two patients from a control group with suspected rotator cuff pathology showed abnormal intensity in the rotator interval on MR imaging. Magnetic resonance imaging can identify changes in the shoulder joint that correspond to abnormalities seen at surgery. This may be useful for discriminating adhesive capsulitis from other causes of shoulder pain. (orig.)

  3. Androgen excess in women: experience with over 1000 consecutive patients.

    Science.gov (United States)

    Azziz, R; Sanchez, L A; Knochenhauer, E S; Moran, C; Lazenby, J; Stephens, K C; Taylor, K; Boots, L R

    2004-02-01

    The objective of the present study was to estimate the prevalence of the different pathological conditions causing clinically evident androgen excess and to document the degree of long-term success of suppressive and/or antiandrogen hormonal therapy in a large consecutive population of patients. All patients presenting for evaluation of symptoms potentially related to androgen excess between October 1987 and June 2002 were evaluated, and the data were maintained prospectively in a computerized database. For the assessment of therapeutic response, a retrospective review of the medical chart was performed, after the exclusion of those patients seeking fertility therapy only, or with inadequate follow-up or poor compliance. A total of 1281 consecutive patients were seen during the study period. Excluded from analysis were 408 patients in whom we were unable to evaluate hormonal status, determine ovulatory status, or find any evidence of androgen excess. In the remaining population of 873 patients, the unbiased prevalence of androgen-secreting neoplasms was 0.2%, 21-hydroxylase-deficient classic adrenal hyperplasia (CAH) was 0.6%, 21-hydroxylase-deficient nonclassic adrenal hyperplasia (NCAH) was 1.6%, hyperandrogenic insulin-resistant acanthosis nigricans (HAIRAN) syndrome was 3.1%, idiopathic hirsutism was 4.7%, and polycystic ovary syndrome (PCOS) was 82.0%. Fifty-nine (6.75%) patients had elevated androgen levels and hirsutism but normal ovulation. A total of 257 patients were included in the assessment of the response to hormonal therapy. The mean duration of follow-up was 33.5 months (range, 6-155). Hirsutism improved in 86%, menstrual dysfunction in 80%, acne in 81%, and hair loss in 33% of patients. The major side effects noted were irregular vaginal bleeding (16.1%), nausea (13.0%), and headaches (12.6%); only 36.6% of patients never complained of side effects. In this large study of consecutive patients presenting with clinically evident androgen excess

  4. Effect of rate on adhesion and static friction of a film-terminated fibrillar interface.

    Science.gov (United States)

    Vajpayee, Shilpi; Long, Rong; Shen, Lulin; Jagota, Anand; Hui, Chung-Yuen

    2009-03-03

    A film-terminated fibrillar interface has been shown to result in significant enhancement of adhesion and static friction compared to a flat control. This enhancement increases with interfibril spacing. In this, the first of a two-part study, by studying the effect of rate on adhesion and static friction, we show that both adhesion and static friction enhancement are due to a crack-trapping mechanism. For adhesion, as measured by an indentation experiment, an analytical model is used to relate the applied indenter displacement rate and measured forces to contact line velocity and energy release rate, respectively. The two mechanisms for adhesion enhancement--varying rate and crack-trapping--are found to be coupled multiplicatively.

  5. Spectrum of histological lesions in 185 consecutive prostatic specimens.

    Directory of Open Access Journals (Sweden)

    Mittal B

    1989-07-01

    Full Text Available One hundred and eighty five consecutive prostate specimens were studied. The predominant lesion noted was benign prostatic hyperplasia (B.P.H. (92.97%. The incidence of carcinoma was low, (7.02%. Conditions which can mimic and should be considered in the differential diagnosis of carcinoma, like basal cell hyperplasia, atypical hyperplasia and atrophy associated hyperplasia were noted in 10, 4 and 3 cases of B.P.H. respectively. None of these cases showed evidence of carcinoma. Corpora amylacea were noted in 38.91% of the cases of B.P.H. and were conspicuously absent in cases of carcinoma. Chronic prostatitis was frequently encountered (58% and metaplastic changes were seen in 11% of the cases.

  6. Attitudes and usage of denture adhesives by complete denture wearers: a survey in Greece and the Netherlands.

    Science.gov (United States)

    Polyzois, Gregory L; de Baat, Cees

    2012-06-01

    To explore whether there are differences in usage of and attitudes towards denture adhesives among patients in two countries. There are no multi-country surveys concerning usage of and attitudes towards denture adhesives from complete denture wearers. The survey took place in Greece and the Netherlands with a sample of 284 and 165 consecutive complete denture wearers, respectively, by using a 9-item prepared questionnaire. Statistical analysis relied on chi-square test at α = 0.05. In this survey, 26 and 20% of Greek and Dutch patients, respectively, had tried denture adhesive, but only 27% of them in Greece as well as in the Netherlands currently used it; 49% of the Greek and 45% of the Dutch participants rated the overall performance of adhesives as good. Between the two populations, no differences were identified in a majority of the research variables, except where 27% of Greeks answered that they did not know the existence of denture adhesives compared to none of the Dutch patients and when 90% of the Dutch contrary to 70% of Greeks reported that they did not need denture adhesives as they could manage their dentures well. The usage of and attitudes towards denture adhesives between the Greek and Dutch sample were similar with only two exceptions concerning the knowledge of existence and the need of using denture adhesives. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

  7. Hysteroscopic Management Of Intrauterin Adhesion

    Directory of Open Access Journals (Sweden)

    Ayşegül Dikmen

    2013-03-01

    Full Text Available Objective: Assessment of preoperative and postoperative outcomes of patients that were performed hysterescopic intrauterine adhesiolysis. Material and method: We reviewed 24 patients that underwent hysterescopy with the complaints of amenorrhea, hypomenorrhea, recurrent pregnancy loss between 2004-2008. The most complaints of patients were infertilty amenorrhea. Results: Adhesions occurs mainly as a result of trauma to the gravid uterine cavity in 14 patients. When classifying patients with their intrauterine adhesions, Grade 3 was the most frequently seen. Adhesiolisis was performed with hysteresopic scissors in all patients. In postoperative period following synechiolysis, 10 patients were treated with estrogen and progestogen, 11 of them used intrauterine device with estrogen and progestogen therapy, foley catheter was used in 3 patients. Hysterescopy was performed in 5 patients for second time because of adhesion suspicions. The re-adhesiolysis performed to 3 patients because of determined to mild adhesion. Conclusion: After hysterescopic adhesiolysis, all patients with the complaint of amenorrhea had regular menstruation. Pregnancy after treatment occured in 4 patients but live birth rate was 75%.

  8. Candida biofilms: is adhesion sexy?

    Science.gov (United States)

    Soll, David R

    2008-08-26

    The development of Candida albicans biofilms requires two types of adhesion molecule - the Als proteins and Hwp1. Mutational analyses have recently revealed that these molecules play complementary roles, and their characteristics suggest that they may have evolved from primitive mating agglutinins.

  9. Focal adhesions and cell-matrix interactions

    DEFF Research Database (Denmark)

    Woods, A; Couchman, J R

    1988-01-01

    Focal adhesions are areas of cell surfaces where specializations of cytoskeletal, membrane and extracellular components combine to produce stable cell-matrix interactions. The morphology of these adhesions and the components identified in them are discussed together with possible mechanisms...

  10. Bio-inspired reversible underwater adhesive.

    Science.gov (United States)

    Zhao, Yanhua; Wu, Yang; Wang, Liang; Zhang, Manman; Chen, Xuan; Liu, Minjie; Fan, Jun; Liu, Junqiu; Zhou, Feng; Wang, Zuankai

    2017-12-20

    The design of smart surfaces with switchable adhesive properties in a wet environment has remained a challenge in adhesion science and materials engineering. Despite intense demands in various industrial applications and exciting progress in mimicking the remarkable wet adhesion through the delicate control of catechol chemistry, polyelectrolyte complex, and supramolecular architectures, the full recapitulation of nature's dynamic function is limited. Here, we show a facile approach to synthesize bioinspired adhesive, which entails the reversible, tunable, and fast regulation of the wet adhesion on diverse surfaces. The smart wet adhesive takes advantage of the host-guest molecular interaction and the adhesive nature of catechol chemistry, as well as the responsive polymer, allowing for screening and activation of the interfacial interaction simply by a local temperature trigger in an on-demand manner. Our work opens up an avenue for the rational design of bioinspired adhesives with performances even beyond nature.

  11. Influence of Blood Contamination During Multimode Adhesive ...

    African Journals Online (AJOL)

    2018-01-30

    Jan 30, 2018 ... (μTBS) of multimode adhesives to dentin when using the self‑etch approach. Materials and Methods: ... adhesion, the collagen fibers collapse during the. Introduction ..... The failure mode was determined using an optical.

  12. Relationship between consecutive deterioration of mean deviation value and progression of visual field defect in open-angle glaucoma.

    Science.gov (United States)

    Naito, Tomoko; Yoshikawa, Keiji; Mizoue, Shiro; Nanno, Mami; Kimura, Tairo; Suzumura, Hirotaka; Takeda, Ryuji; Shiraga, Fumio

    2015-01-01

    To analyze the relationship between consecutive deterioration of mean deviation (MD) value and glaucomatous visual field (VF) progression in open-angle glaucoma (OAG), including primary OAG and normal tension glaucoma. The subjects of the study were patients undergoing treatment for OAG who had performed VF tests at least 10 times with a Humphrey field analyzer (SITA standard, C30-2 program). The VF progression was defined by a significantly negative MD slope (MD slope worsening) at the final VF test during the follow-up period. The relationship between the MD slope worsening and the consecutive deterioration of MD value were retrospectively analyzed. A total of 165 eyes of 165 patients were included in the analysis. Significant progression of VF defects was observed in 72 eyes of 72 patients (43.6%), while no significant progression was evident in 93 eyes of 93 patients (56.4%). There was significant relationship between the frequency of consecutive deterioration of MD value and MD slope worsening (P<0.0001, Cochran-Armitage trend test). A significant association was observed for MD slope worsening in the eyes with three (odds ratio: 2.1, P=0.0224) and four (odds ratio: 3.6, P=0.0008) consecutive deterioration of MD value in multiple logistic regression analysis, but no significant association in the eyes with two consecutive deterioration (odds ratio: 1.1, P=0.8282). The eyes with VF progression had significantly lower intraocular pressure reduction rate (P<0.01). This retrospective study has shown that three or more consecutive deterioration of MD value might be a predictor to future significant MD slope worsening in OAG.

  13. Multiple linear regression analysis of bacterial deposition to polyurethane coatings after conditioning film formation in the marine environment

    NARCIS (Netherlands)

    Bakker, D.P.; Busscher, H.J.; Zanten, J. van; Vries, J. de; Klijnstra, J.W.; Mei, H.C. van der

    2004-01-01

    Many studies have shown relationships of substratum hydrophobicity, charge or roughness with bacterial adhesion, although bacterial adhesion is governed by interplay of different physico-chemical properties and multiple regression analysis would be more suitable to reveal mechanisms of bacterial

  14. Multiple linear regression analysis of bacterial deposition to polyurethane coating after conditioning film formation in the marine environment

    NARCIS (Netherlands)

    Bakker, Dewi P; Busscher, Henk J; van Zanten, Joyce; de Vries, Jacob; Klijnstra, Job W; van der Mei, Henny C

    Many studies have shown relationships of substratum hydrophobicity, charge or roughness with bacterial adhesion, although bacterial adhesion is governed by interplay of different physico-chemical properties and multiple regression analysis would be more suitable to reveal mechanisms of bacterial

  15. Aspirin augments hyaluronidase induced adhesion inhibition ...

    African Journals Online (AJOL)

    Postoperative adhesions occur after virtually all abdomino-pelvic surgery and are the leading cause of intestinal obstruction and other gynaecologic problems. We used an animal model to test the efficacy of combined administration of aspirin and hyaluronidase on adhesion formation. Adhesions were induced using ...

  16. Potential for Biobased Adhesives in Wood Bonding

    Science.gov (United States)

    Charles R. Frihart

    2016-01-01

    There has been a resurgence of interest and research on using bio-based materials as wood adhesives; however, they have achieved only limited market acceptance. To better understand this low level of replacement, it is important to understand why adhesives work or fail in moisture durability tests. A holistic model for wood adhesives has been developed that clarifies...

  17. Current dental adhesives systems. A narrative review.

    Science.gov (United States)

    Milia, Egle; Cumbo, Enzo; Cardoso, Rielson Jose A; Gallina, Giuseppe

    2012-01-01

    Adhesive dentistry is based on the development of materials which establish an effective bond with the tooth tissues. In this context, adhesive systems have attracted considerable research interest in recent years. Successful adhesive bonding depends on the chemistry of the adhesive, on appropriate clinical handling of the material as well as on the knowledge of the morphological changes caused on dental tissue by different bonding procedures. This paper outlines the status of contemporary adhesive systems, with particular emphasis on chemical characteristics and mode of interaction of the adhesives with enamel and dentinal tissues. Dental adhesives are used for several clinical applications and they can be classified based on the clinical regimen in "etch-and-rinse adhesives" and "self-etch adhesives". Other important considerations concern the different anatomical characteristics of enamel and dentine which are involved in the bonding procedures that have also implications for the technique used as well as for the quality of the bond. Etch-and-rinse adhesive systems generally perform better on enamel than self-etching systems which may be more suitable for bonding to dentine. In order to avoid a possible loss of the restoration, secondary caries or pulp damage due to bacteria penetration or due to cytotoxicity effects of eluted adhesive components, careful consideration of several factors is essential in selecting the suitable bonding procedure and adhesive system for the individual patient situation.

  18. Influence of substrate modulus on gecko adhesion

    Science.gov (United States)

    Klittich, Mena R.; Wilson, Michael C.; Bernard, Craig; Rodrigo, Rochelle M.; Keith, Austin J.; Niewiarowski, Peter H.; Dhinojwala, Ali

    2017-03-01

    The gecko adhesion system fascinates biologists and materials scientists alike for its strong, reversible, glue-free, dry adhesion. Understanding the adhesion system’s performance on various surfaces can give clues as to gecko behaviour, as well as towards designing synthetic adhesive mimics. Geckos encounter a variety of surfaces in their natural habitats; tropical geckos, such as Gekko gecko, encounter hard, rough tree trunks as well as soft, flexible leaves. While gecko adhesion on hard surfaces has been extensively studied, little work has been done on soft surfaces. Here, we investigate for the first time the influence of macroscale and nanoscale substrate modulus on whole animal adhesion on two different substrates (cellulose acetate and polydimethylsiloxane) in air and find that across 5 orders of magnitude in macroscale modulus, there is no change in adhesion. On the nanoscale, however, gecko adhesion is shown to depend on substrate modulus. This suggests that low surface-layer modulus may inhibit the gecko adhesion system, independent of other influencing factors such as macroscale composite modulus and surface energy. Understanding the limits of gecko adhesion is vital for clarifying adhesive mechanisms and in the design of synthetic adhesives for soft substrates (including for biomedical applications and wearable electronics).

  19. Tailored Poly(2-oxazoline) Polymer Brushes to Control Protein Adsorption and Cell Adhesion

    KAUST Repository

    Zhang, Ning; Pompe, Tilo; Amin, Ihsan; Luxenhofer, Robert; Werner, Carsten; Jordan, Rainer

    2012-01-01

    POx bottle-brush brushes (BBBs) are synthesized by SIPGP of 2-isopropenyl-2-oxazoline and consecutive LCROP of 2-oxazolines on 3-aminopropyltrimethoxysilane-modified silicon substrates. The side chain hydrophilicity and polarity are varied. The impact of the chemical composition and architecture of the BBB upon protein (fibronectin) adsorption and endothelial cell adhesion are investigated and prove extremely low protein adsorption and cell adhesion on BBBs with hydrophilic side chains such as poly(2-methyl-2-oxazoline) and poly(2-ethyl-2-oxazoline). The influence of the POx side chain terminal function upon adsorption and adhesion is minor but the side chain length has a significant effect on bioadsorption. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Tailored Poly(2-oxazoline) Polymer Brushes to Control Protein Adsorption and Cell Adhesion

    KAUST Repository

    Zhang, Ning

    2012-05-18

    POx bottle-brush brushes (BBBs) are synthesized by SIPGP of 2-isopropenyl-2-oxazoline and consecutive LCROP of 2-oxazolines on 3-aminopropyltrimethoxysilane-modified silicon substrates. The side chain hydrophilicity and polarity are varied. The impact of the chemical composition and architecture of the BBB upon protein (fibronectin) adsorption and endothelial cell adhesion are investigated and prove extremely low protein adsorption and cell adhesion on BBBs with hydrophilic side chains such as poly(2-methyl-2-oxazoline) and poly(2-ethyl-2-oxazoline). The influence of the POx side chain terminal function upon adsorption and adhesion is minor but the side chain length has a significant effect on bioadsorption. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Predictive variables for postoperative pain after 520 consecutive dental extraction surgeries.

    Science.gov (United States)

    Bortoluzzi, Marcelo Carlos; Manfro, Aline Rosler Grings; Nodari, Rudy Jose; Presta, Andreia Antoniuk

    2012-01-01

    The aim of this study was to evaluate postoperative pain in patients who had a single tooth or multiple erupted teeth extracted. This research evaluated 520 consecutive dental extraction surgeries in which 680 teeth were removed. Data collection was obtained through a questionnaire of patients and of the undergraduate students who performed all procedures. Pain was evaluated through qualitative self-reported scores at seven days postsurgery. An increased pain level was statistically associated with ostectomy, postoperative complications, and tobacco consumption. Pain that persisted for more than two days was statistically associated with the amount of anesthetic solution used, with a notable increase in surgical time and development of postoperative complications. Periods of pain lasting more than two days could be expected for traumatic surgeries lasting more than 30 minutes. Both severe and prolonged pain were signs of development of postoperative complications, such as alveolar osteitis and alveolar infection.

  2. Strong composition dependence of adhesive properties of ultraviolet curing adhesives with modified acrylates

    Science.gov (United States)

    Feng, Yefeng; Li, Yandong; Wang, Fupeng; Peng, Cheng; Xu, Zhichao; Hu, Jianbing

    2018-05-01

    Ultraviolet (UV) curable adhesives have been widely researched in fields of health care and electronic components. UV curing systems with modified acrylic ester prepolymers have been frequently employed. In order to clarify composition dependence of adhesive properties of adhesives containing modified acrylates, in this work, several UV curing adhesives bearing urethane and epoxy acrylates were designed and fabricated. The effects of prepolymer, diluent, feed ratio, initiator and assistant on adhesive performances were investigated. This work might offer a facile route to gain promising high-performance UV curable adhesives with desired adhesive traits through regulating their compositions.

  3. Aspiration-related deaths in 57 consecutive patients: autopsy study.

    Directory of Open Access Journals (Sweden)

    Xiaowen Hu

    Full Text Available Aspiration can cause a diverse spectrum of pulmonary disorders some of which can lead to death but can be difficult to diagnose.The medical records and autopsy findings of 57 consecutive patients in whom aspiration was the immediate cause of death at Mayo Clinic (Rochester, MN, USA over a 9-yr period, from January 1 2004 to December 31 2012 were analyzed.The median age at death was 72 years (range, 13-95 years and included 39 (68% males. The most common symptom before death was dyspnea (63% and chest radiography revealed bilateral infiltrates in the majority (81%. Most common precipitating factors for aspiration were depressed consciousness (46% and dysphagia (44%. Aspiration-related syndromes leading to death were aspiration pneumonia in 26 (46%, aspiration pneumonitis in 25 (44%, and large airway obstruction in 6 patients (11%. Aspiration was clinically unsuspected in 19 (33% patients. Antimicrobial therapy had been empirically administered to most patients (90% with aspiration pneumonia and aspiration pneumonitis.We conclude aspiration-related deaths occur most commonly in the elderly with identifiable risks and presenting bilateral pulmonary infiltrates. One-third of these aspiration-related pulmonary syndromes were clinically unsuspected at the time of death.

  4. Hepatotoxicity in hyperthyroid patient after consecutive methimazole and propylthiouracil therapies

    Directory of Open Access Journals (Sweden)

    Fernando Gomez-Peralta

    2018-01-01

    Full Text Available Methimazole (MMI and propylthiouracil (PTU are widely used antithyroid drugs (ATD that have been approved for the treatment of hyperthyroidism. Hepatotoxicity may be induced by these drugs, though they exert dissimilar incidence rates of hepatotoxicity and, possibly, with different underlying pathogenic mechanisms. We report the case of a 55-year-old woman with no relevant medical history diagnosed with hyperthyroidism due to Graves’ disease, who developed two episodes of acute hepatitis concurrent with the consecutive administration of two different ATDs, first MMI and then PTU. Given the impossibility of administering ATDs, it was decided to perform a total thyroidectomy because the patient was found to be euthyroid at that point. Pathological anatomy showed diffuse hyperplasia and a papillary thyroid microcarcinoma of 2 mm in diameter. Subsequent clinical check-ups were normal. This case suggests the importance of regular monitoring of liver function for hyperthyroid patients. Due to the potential severity of this side effect, it is recommended to determine baseline liver function prior to initiation of treatment.

  5. Adhesives for fixed orthodontic bands.

    Science.gov (United States)

    Millett, Declan T; Glenny, Anne-Marie; Mattick, Rye Cr; Hickman, Joy; Mandall, Nicky A

    2016-10-25

    Orthodontic treatment involves using fixed or removable appliances (dental braces) to correct the positions of teeth. It has been shown that the quality of treatment result obtained with fixed appliances is much better than with removable appliances. Fixed appliances are, therefore, favoured by most orthodontists for treatment. The success of a fixed orthodontic appliance depends on the metal attachments (brackets and bands) being attached securely to the teeth so that they do not become loose during treatment. Brackets are usually attached to the front and side teeth, whereas bands (metal rings that go round the teeth) are more commonly used on the back teeth (molars). A number of adhesives are available to attach bands to teeth and it is important to understand which group of adhesives bond most reliably, as well as reducing or preventing dental decay during the treatment period. To evaluate the effectiveness of the adhesives used to attach bands to teeth during fixed appliance treatment, in terms of:(1) how often the bands come off during treatment; and(2) whether they protect the banded teeth against decay during fixed appliance treatment. The following electronic databases were searched: Cochrane Oral Health's Trials Register (searched 2 June 2016), Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 5) in the Cochrane Library (searched 2 June 2016), MEDLINE Ovid (1946 to 2 June 2016) and EMBASE Ovid (1980 to 2 June 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. Randomised and controlled clinical trials (RCTs and CCTs) (including split-mouth studies) of adhesives used to attach orthodontic bands to molar teeth were selected. Patients with full arch fixed orthodontic appliance(s) who had bands attached to molars were included. All review authors

  6. Differential and Cooperative Cell Adhesion Regulates Cellular Pattern in Sensory Epithelia.

    Science.gov (United States)

    Togashi, Hideru

    2016-01-01

    Animal tissues are composed of multiple cell types arranged in complex and elaborate patterns. In sensory epithelia, including the auditory epithelium and olfactory epithelium, different types of cells are arranged in unique mosaic patterns. These mosaic patterns are evolutionarily conserved, and are thought to be important for hearing and olfaction. Recent progress has provided accumulating evidence that the cellular pattern formation in epithelia involves cell rearrangements, movements, and shape changes. These morphogenetic processes are largely mediated by intercellular adhesion systems. Differential adhesion and cortical tension have been proposed to promote cell rearrangements. Many different types of cells in tissues express various types of cell adhesion molecules. Although cooperative mechanisms between multiple adhesive systems are likely to contribute to the production of complex cell patterns, our current understanding of the cooperative roles between multiple adhesion systems is insufficient to entirely explain the complex mechanisms underlying cellular patterning. Recent studies have revealed that nectins, in cooperation with cadherins, are crucial for the mosaic cellular patterning in sensory organs. The nectin and cadherin systems are interacted with one another, and these interactions provide cells with differential adhesive affinities for complex cellular pattern formations in sensory epithelia, which cannot be achieved by a single mechanism.

  7. Opto-acoustic microscopy reveals adhesion mechanics of single cells

    Science.gov (United States)

    Abi Ghanem, Maroun; Dehoux, Thomas; Liu, Liwang; Le Saux, Guillaume; Plawinski, Laurent; Durrieu, Marie-Christine; Audoin, Bertrand

    2018-01-01

    Laser-generated GHz-ultrasonic-based technologies have shown the ability to image single cell adhesion and stiffness simultaneously. Using this new modality, we here demonstrate quantitative indicators to investigate contact mechanics and adhesion processes of the cell. We cultured human cells on a rigid substrate, and we used an inverted pulsed opto-acoustic microscope to generate acoustic pulses containing frequencies up to 100 GHz in the substrate. We map the reflection of the acoustic pulses at the cell-substrate interface to obtain images of the acoustic impedance of the cell, Zc, as well as of the stiffness of the interface, K, with 1 μm lateral resolution. Our results show that the standard deviation ΔZc reveals differences between different cell types arising from the multiplicity of local conformations within the nucleus. From the distribution of K-values within the nuclear region, we extract a mean interfacial stiffness, Km, that quantifies the average contact force in areas of the cell displaying weak bonding. By analogy with classical contact mechanics, we also define the ratio of the real to nominal contact areas, Sr/St. We show that Km can be interpreted as a quantitative indicator of passive contact at metal-cell interfaces, while Sr/St is sensitive to active adhesive processes in the nuclear region. The ability to separate the contributions of passive and active adhesion processes should allow gaining insight into cell-substrate interactions, with important applications in tissue engineering.

  8. Gecko adhesion pad: a smart surface?

    Science.gov (United States)

    Pesika, Noshir S.; Zeng, Hongbo; Kristiansen, Kai; Zhao, Boxin; Tian, Yu; Autumn, Kellar; Israelachvili, Jacob

    2009-11-01

    Recently, it has been shown that humidity can increase the adhesion of the spatula pads that form the outermost (adhesive) surface of the tokay gecko feet by 50% relative to the main adhesion mechanism (i.e. van der Waals adhesive forces), although the mechanism by which the enhancement is realized is still not well understood. A change in the surface hydrophobicity of a gecko setal array is observed when the array, which supports the spatulae, is exposed to a water drop for more than 20 min, suggesting a change in the hydrophilic-lyophilic balance (HLB), and therefore of the conformation of the surface proteins. A surface force apparatus (SFA) was used to quantify these changes, i.e. in the adhesion and friction forces, while shearing the setal array against a silica surface under (i) dry conditions, (ii) 100% humidity and (iii) when fully immersed in water. The adhesion increased in the humid environment but greatly diminished in water. Although the adhesion forces changed significantly, the friction forces remained unaffected, indicating that the friction between these highly textured surfaces is 'load-controlled' rather than 'adhesion-controlled'. These results demonstrate that the gecko adhesive pads have the ability to exploit environmental conditions to maximize their adhesion and stabilize their friction forces. Future designs of synthetic dry adhesives inspired by the gecko can potentially include similar 'smart' surfaces that adapt to their environment.

  9. Gecko adhesion pad: a smart surface?

    Energy Technology Data Exchange (ETDEWEB)

    Pesika, Noshir S [Chemical and Biomolecular Engineering Department, Tulane University, New Orleans, LA 70118 (United States); Zeng Hongbo [Chemical and Materials Engineering Department, University of Alberta, Edmonton, AB, T6G 2V4 (Canada); Kristiansen, Kai; Israelachvili, Jacob [Chemical Engineering Department, University of California, Santa Barbara, CA 93117 (United States); Zhao, Boxin [Chemical Engineering Department and Waterloo Institute of Nanotechnology, University of Waterloo, Ontario, N2L 3G1 (Canada); Tian Yu [State Key Laboratory of Tribology, Department of Precision Instruments, Tsinghua University, Beijing 100084 (China); Autumn, Kellar, E-mail: npesika@tulane.ed [Department of Biology, Lewis and Clark College, Portland, OR 97219 (United States)

    2009-11-18

    Recently, it has been shown that humidity can increase the adhesion of the spatula pads that form the outermost (adhesive) surface of the tokay gecko feet by 50% relative to the main adhesion mechanism (i.e. van der Waals adhesive forces), although the mechanism by which the enhancement is realized is still not well understood. A change in the surface hydrophobicity of a gecko setal array is observed when the array, which supports the spatulae, is exposed to a water drop for more than 20 min, suggesting a change in the hydrophilic-lyophilic balance (HLB), and therefore of the conformation of the surface proteins. A surface force apparatus (SFA) was used to quantify these changes, i.e. in the adhesion and friction forces, while shearing the setal array against a silica surface under (i) dry conditions, (ii) 100% humidity and (iii) when fully immersed in water. The adhesion increased in the humid environment but greatly diminished in water. Although the adhesion forces changed significantly, the friction forces remained unaffected, indicating that the friction between these highly textured surfaces is 'load-controlled' rather than 'adhesion-controlled'. These results demonstrate that the gecko adhesive pads have the ability to exploit environmental conditions to maximize their adhesion and stabilize their friction forces. Future designs of synthetic dry adhesives inspired by the gecko can potentially include similar 'smart' surfaces that adapt to their environment.

  10. Gecko adhesion pad: a smart surface?

    International Nuclear Information System (INIS)

    Pesika, Noshir S; Zeng Hongbo; Kristiansen, Kai; Israelachvili, Jacob; Zhao, Boxin; Tian Yu; Autumn, Kellar

    2009-01-01

    Recently, it has been shown that humidity can increase the adhesion of the spatula pads that form the outermost (adhesive) surface of the tokay gecko feet by 50% relative to the main adhesion mechanism (i.e. van der Waals adhesive forces), although the mechanism by which the enhancement is realized is still not well understood. A change in the surface hydrophobicity of a gecko setal array is observed when the array, which supports the spatulae, is exposed to a water drop for more than 20 min, suggesting a change in the hydrophilic-lyophilic balance (HLB), and therefore of the conformation of the surface proteins. A surface force apparatus (SFA) was used to quantify these changes, i.e. in the adhesion and friction forces, while shearing the setal array against a silica surface under (i) dry conditions, (ii) 100% humidity and (iii) when fully immersed in water. The adhesion increased in the humid environment but greatly diminished in water. Although the adhesion forces changed significantly, the friction forces remained unaffected, indicating that the friction between these highly textured surfaces is 'load-controlled' rather than 'adhesion-controlled'. These results demonstrate that the gecko adhesive pads have the ability to exploit environmental conditions to maximize their adhesion and stabilize their friction forces. Future designs of synthetic dry adhesives inspired by the gecko can potentially include similar 'smart' surfaces that adapt to their environment.

  11. The adhesive bonding of beryllium structural components

    International Nuclear Information System (INIS)

    Fullerton-Batten, R.C.

    1977-01-01

    Where service conditions permit, adhesive bonding is a highly recommendable, reliable means of joining beryllium structural parts. Several important programs have successfully used adhesive bonding for joining structural and non-structural beryllium components. Adhesive bonding minimizes stress concentrations associated with other joining techniques and considerably improves fatigue resistance. In addition, no degradation of base metal properties occur. In many instances, structural joints can be fabricated more cheaply by adhesive bonding or in combination with adhesive bonding than by any other method used alone. An evaluation program on structural adhesive bonding of beryllium sheet components is described. A suitable surface pretreatment for beryllium adherends prior to bonding is given. Tensile shear strength and fatigue properties of FM 1000 and FM 123-5 adhesive bonded joints are reviewed and compared with data obtained from riveted joints of similar geometry. (author)

  12. Polyurethane adhesives in flat roofs

    OpenAIRE

    Bogárová Markéta; Stodůlka Jindřich; Šuhajda Karel

    2017-01-01

    It is necessary to stabilize individual layers of flat roofs, mainly because of wind suction. Apart from anchoring and surcharge, these layers can be secured by bonding. At present gluing is an indispensable and widely used stabilization method. On our market we can found many types of adhesives, most widely used are based on polyurethane. This paper focuses on problematic about stabilization thermal insulation from expanded polystyrene to vapor barrier from bitumen. One of the main issues is...

  13. Adhesives for fixed orthodontic brackets.

    Science.gov (United States)

    Mandall, N A; Millett, D T; Mattick, C R; Hickman, J; Macfarlane, T V; Worthington, H V

    2003-01-01

    Bonding of orthodontic brackets to teeth is important to enable effective and efficient treatment with fixed appliances. The problem is bracket failure during treatment which increases operator chairside time and lengthens treatment time. A prolonged treatment is likely to increase the oral health risks of orthodontic treatment with fixed appliances one of which is irreversible enamel decalcification. To evaluate the effectiveness of different orthodontic adhesives for bonding. Electronic databases: the Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE. Date of most recent searches: August 2002 (CENTRAL) (The Cochrane Library Issue 2, 2002). Trials were selected if they met the following criteria: randomised controlled trials (RCTs) and controlled clinical trials (CCTs) comparing two different adhesive groups. Participants were patients with fixed orthodontic appliances. The interventions were adhesives that bonded stainless steel brackets to all teeth except the molars. The primary outcome was debond or bracket failure. Data were recorded on decalcification as a secondary outcome, if present. Information regarding methods, participants, interventions, outcome measures and results were extracted in duplicate by pairs of reviewers (Nicky Mandall (NM) and Rye Mattick (CRM); Declan Millett (DTM) and Joy Hickman (JH2)). Since the data were not presented in a form that was amenable to meta-analysis, the results of the review are presented in narrative form only. Three trials satisfied the inclusion criteria. A chemical cured composite was compared with a light cure composite (one trial), a conventional glass ionomer cement (one trial) and a polyacid-modified resin composite (compomer) (one trial). The quality of the trial reports was generally poor. It is difficult to draw any conclusions from this review, however, suggestions are made for methods of improving future research involving

  14. Culinary Medicine-Jalebi Adhesions.

    Science.gov (United States)

    Kapoor, Vinay K

    2016-02-01

    Culinary terms have been used to describe anatomy (bean-shaped kidneys), pathology (strawberry gall bladder), clinical signs (café-au-lait spots), radiological images (sausage-shaped pancreas), etc. While Indian cuisine is popular all over the world, no Indian dish finds mention in medical terminology. In intra-abdominal adhesions, sometimes, the intestinal loops are so densely adherent that it is difficult to make out proximal from distal and it is impossible to separate them without injuring the bowel resulting in spill of contents-resection is the only option (Fig. 1). Jalebi, an Indian dessert, has a single long tubular strip of fried batter filled with sugary syrup so intertwined that it is impossible to discern its ends; if broken, the syrup spills out-the best way to relish it is to chew the whole piece (Fig. 2). Because of these similarities between them, I propose to name dense intra-abdominal adhesions as 'jalebi adhesions.'

  15. Modeling of Sylgard Adhesive Strength

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, Ralph Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-03

    Sylgard is the name of a silicone elastomeric potting material manufactured by Dow Corning Corporation.1 Although the manufacturer cites its low adhesive strength as a feature of this product, thin layers of Sylgard do in fact have a non-negligible strength, which has been measured in recent tensile and shear debonding tests. The adhesive strength of thin layers of Sylgard potting material can be important in applications in which components having signi cantly di erent thermal expansion properties are potted together, and the potted assembly is subjected to temperature changes. The tensile and shear tractions developed on the potted surfaces of the components can cause signi cant internal stresses, particularly for components made of low-strength materials with a high area-to-volume ratio. This report is organized as follows: recent Sylgard debonding tests are rst brie y summarized, with particular attention to the adhesion between Sylgard and PBX 9501, and also between Sylgard and aluminum. Next, the type of numerical model that will be used to simulate the debonding behavior exhibited in these tests is described. Then the calibration of the debonding model will be illustrated. Finally, the method by which the model parameters are adjusted (scaled) to be applicable to other, non- tested bond thicknesses is summarized, and all parameters of the model (scaled and unscaled) are presented so that other investigators can reproduce all of the simulations described in this report as well as simulations of the application of interest.

  16. Laparoscopic repair of hiatal hernias: Experience after 200 consecutive cases

    Directory of Open Access Journals (Sweden)

    Bjelović Miloš

    2014-01-01

    Full Text Available Introduction. Repair of hiatal hernias has been performed traditionally via open laparotomy or thoracotomy. Since first laparoscopic hiatal hernia repair in 1992, this method had a growing popularity and today it is the standard approach in experienced centers specialized for minimally invasive surgery. Objective. In the current study we present our experience after 200 consecutive laparoscopic hiatal hernia repairs. Methods. A retrospective cohort study included 200 patients who underwent elective laparoscopic hiatal hernia repair at the Department for Minimally Invasive Upper Digestive Surgery, Clinic for Digestive Surgery, Clinical Center of Serbia in Belgrade from April 2004 to December 2013. Results. Hiatal hernia types included 108 (54% patients with type I, 30 (15% with type III, 62 (31% with giant paraesophageal hernia, while 27 (13.5% patients presented with a chronic gastric volvulus. There were a total of 154 (77% Nissen fundoplications. In 26 (13% cases Nissen procedure was combined with esophageal lengthening procedure (Collis-Nissen, and in 17 (8.5% Toupet fundoplications was performed. Primary retroesophageal crural repair was performed in 164 (82% cases, Cleveland Clinic Foundation suture modification in 27 (13.5%, 4 (2% patients underwent synthetic mesh hiatoplasty, 1 (0.5% primary repair reinforced with pledgets, and 4 (2% autologous fascia lata graft reinforcement. Poor result with anatomic and symptomatic recurrence (indication for revisional surgery was detected in 5 patients (2.7%. Conclusion. Based on the result analysis, we found that laparoscopic hiatal hernia repair was a technically challenging but feasible technique, associated with good to excellent postoperative outcomes comparable to the best open surgery series.

  17. Pathologic audit of 164 consecutive cases of vulvar intraepithelial neoplasia.

    Science.gov (United States)

    Scurry, James; Campion, Michael; Scurry, Bonnie; Kim, Soo Nyung; Hacker, Neville

    2006-04-01

    There are 2 types of vulvar intraepithelial neoplasia (VIN): warty-basaloid and differentiated. Differentiated VIN is uncommon and seldom diagnosed prior to carcinoma and, traditionally, is not graded. There are currently 3 grading systems for warty-basaloid VIN: the World Health Organization (WHO) 3 grade system of VIN 1-3, a 2 grade system of low and high grade vulvar intraepithelial lesions, and the revised International Society for the Study of Vulvovaginal Disease (ISSVD) classification which has no grading of VIN. According to the ISSVD, VIN 1 should be abolished and VIN 2 and 3 combined into a single category, simply termed warty-basaloid VIN. To determine the best system for grading warty-basaloid VIN and learn more about differentiated VIN, we reviewed the pathology of 164 consecutive women with VIN. Of these, 134 (82.3%) had warty-basaloid VIN, 29 (18.2%) had differentiated VIN, and 1 had both. Of warty-basaloid VIN cases, 4 had VIN 1, 13 VIN 2, and 118 VIN 3 when graded according to the WHO. All VIN 1 occurred in condylomata acuminata. VIN 2 and 3 were distinguished only by degree of abnormality. Differentiated VIN was diagnosed before SCC in only 7 cases (26.7%). Because the only VIN 1 cases seen were in condylomata acuminata and because VIN 2 and 3 were difficult to distinguish and there appears little clinical reason to do so, our study supports the ISSVD proposal that VIN 1 be abolished and VIN 2 and 3 be combined. There needs to be more clinical awareness of vulvar conditions, so that differentiated VIN is biopsied before cancer has supervened.

  18. Reconstruction of alveolar defects in patients with cleft lip and palate - 111 consecutive patients

    DEFF Research Database (Denmark)

    Andersen, Kristian

    2012-01-01

    Reconstruction of alveolar defects in patients with cleft lip and palate - 111 consecutive patients......Reconstruction of alveolar defects in patients with cleft lip and palate - 111 consecutive patients...

  19. Disorders of adhesions or adhesion-related disorder: monolithic entities or part of something bigger--CAPPS?

    Science.gov (United States)

    Wiseman, David M

    2008-07-01

    The purpose of this article is to review progress in the field of abdominopelvic adhesions and the validity of its two underlying assumptions: (1) The formation of adhesions results in infertility, bowel obstruction, or other complications. Reducing or avoiding adhesions will curb these sequelae. (2) "Adhesions" is a monolithic entity to be tackled without regard to any other condition. Evidence is discussed to validate the first assumption. We reviewed progress in the field by examining hospital data. We found a growing trend in the number and cost of discharges for just two adhesion-related diagnoses, and the low usage of adhesion barriers appears in at most 5% of appropriate procedures. Data from an Internet-based survey suggested that the problem may be partly due to ignorance among patients and physicians about adhesions and their prevention. Two other surveys of patients visiting the adhesions.org Web site defined more fully adhesion-related disorder (ARD). The first survey ( N = 466) described a patient with chronic pain, gastrointestinal disturbances, an average of nine bowel obstructions, and an inability to work or maintain family or social relationships. The second survey (687 U.S. women) found a high (co-) prevalence of abdominal or pelvic adhesions (85%), chronic abdominal or pelvic pain (69%), irritable bowel syndrome (55%), recurrent bowel obstruction (44%), endometriosis (40%), and interstitial cystitis (29%). This pattern suggests that although "adhesions" may start out as a monolithic entity, an adhesions patient may develop related conditions (ARD) until they merge into an independent entity where they are practically indistinguishable from patients with multiple symptoms originating from other abdominopelvic conditions such as pelvic or bladder pain. Rather than use terms that constrain the required multidisciplinary, biopsychosocial approach to these patients by the paradigms of the specialty related to the patient's initial symptom set, the

  20. TRIM15 is a focal adhesion protein that regulates focal adhesion disassembly

    Science.gov (United States)

    Uchil, Pradeep D.; Pawliczek, Tobias; Reynolds, Tracy D.; Ding, Siyuan; Hinz, Angelika; Munro, James B.; Huang, Fang; Floyd, Robert W.; Yang, Haitao; Hamilton, William L.; Bewersdorf, Joerg; Xiong, Yong; Calderwood, David A.; Mothes, Walther

    2014-01-01

    ABSTRACT Focal adhesions are macromolecular complexes that connect the actin cytoskeleton to the extracellular matrix. Dynamic turnover of focal adhesions is crucial for cell migration. Paxillin is a multi-adaptor protein that plays an important role in regulating focal adhesion dynamics. Here, we identify TRIM15, a member of the tripartite motif protein family, as a paxillin-interacting factor and a component of focal adhesions. TRIM15 localizes to focal contacts in a myosin-II-independent manner by an interaction between its coiled-coil domain and the LD2 motif of paxillin. Unlike other focal adhesion proteins, TRIM15 is a stable focal adhesion component with restricted mobility due to its ability to form oligomers. TRIM15-depleted cells display impaired cell migration and reduced focal adhesion disassembly rates, in addition to enlarged focal adhesions. Thus, our studies demonstrate a cellular function for TRIM15 as a regulatory component of focal adhesion turnover and cell migration. PMID:25015296

  1. Shear bond strength of hydrophilic adhesive systems to enamel.

    Science.gov (United States)

    Hara, A T; Amaral, C M; Pimenta, L A; Sinhoreti, M A

    1999-08-01

    To compare the enamel shear bond strength of four hydrophilic adhesive systems: one multiple-bottle (Scotchbond Multi-Purpose Plus), two one-bottle (Stae, Single Bond) and one self-etching (Etch & Prime). 120 bovine incisor teeth were obtained, embedded in polyester resin, polished to 600 grit to form standardized enamel surfaces, and randomly assigned to four groups (n = 30). Each adhesive system was used on enamel according to the manufacturer's instructions, and resin-based composite (Z100) cylinders with 3 mm diameter and 5 mm height were bonded. Specimens were stored in humid environment for 1 week, and bond strength was determined using a universal testing machine, at a crosshead speed of 0.5 mm/minute. The mean shear bond strength values (MPa +/- SD) were: Single Bond: 24.28 +/- 5.27 (a); Scotchbond Multi-Purpose Plus: 21.18 +/- 4.35 (ab); Stae: 19.56 +/- 4.71 (b); Etch & Prime 3.0: 15.13 +/- 4.92 (c). ANOVA revealed significant difference in means (P < 0.01) and Tukey's test showed the statistical differences that are expressed by different letters for each group. It could be concluded that the self-etching adhesive system did not provide as good a bond to enamel surface, as did the one- and multiple-bottle systems.

  2. Focal adhesive arachnoiditis of the spinal cord: Imaging diagnosis and surgical resolution

    Directory of Open Access Journals (Sweden)

    Hiroki Morisako

    2010-01-01

    Full Text Available Background: Although adhesive arachnoiditis of the spinal cord can cause progressive symptoms associated with syringomyelia or myelomalacia, its surgical resolution based on the imaging diagnosis is not well characterized. This study aims to describe the use of imaging for the diagnosis of focal adhesive arachnoiditis of the spinal cord and its surgical resolution using microsurgical arachnoidolysis. Materials and Methods: Four consecutive patients with symptomatic syringomyelia or myelomalacia caused by focal adhesive arachnoiditis underwent microsurgical arachnoidolysis. Comprehensive imaging evaluation using constructive interference in steady-state (CISS magnetic resonance imaging (MRI or myelographic MR imaging using true fast imaging with steady-state precession (TrueFISP sequences was included before surgery to determine the surgical indication. Results: In all four patients a focal adhesion was identified at the cervical or thoracic level of the spinal cord, a consequence of infection or trauma. Three patients showed modest or minor improvement in neurological function, and one patient was unchanged after surgery. The syringomyelia or myelomalacia resolved after surgery and no recurrence was noted within the follow-up period, which ranged from 5 months to 30 months. Conclusions: MRI diagnosis of focal adhesive arachnoiditis is critical to determine the surgical indication. Microsurgical arachnoidolysis appears to be a straightforward method for stabilizing the progressive symptoms, though the procedure is technically demanding.

  3. Complications of laparoscopic cholecystectomy: an analysis of 400 consecutive cases

    International Nuclear Information System (INIS)

    Afzal, M.; Butt, M.Q.

    2014-01-01

    To analyze the complications of first 400 laparoscopic cholecystectomies (LC) for patients with symptomatic gall stone disease at a tertiary care hospital. Study Design: Quasi-experimental study. Place and Duration of Study: PNS Shifa Karachi and CMH Lahore, Pakistan from Nov 2009 to Jan 2013. Patients and Methods: A prospective analysis of complications occurring in first 400 consecutive laparoscopic cholecystectomies by a single consultant/unit at a tertiary care hospital was made. Out of total 421 patients presenting with symptomatic gall stone disease in a single unit, 21 cases that underwent open cholecystectomy were excluded from the study. Laparoscopic cholecystectomies were performed using three port and four port technique and data including age, sex, diagnosis, number of trocar placements, conversion to open surgery and its reasons, operative time, post-operative hospital stay and complications was collected on personal computer and analyzed using Statistical package for social sciences (SPSS) version 13. Results: Total 400 patients were included in study with median age of 44 years. Female to male ratio was 5.3: 1. Depending upon the preoperative diagnosis and laparoscopic findings, patients had diagnosis of Chronic cholecystitis / biliary colic 68.25%, acute cholecystitis 23.75%, empyema gall bladder 7.25%, gallstone pancreatitis 0.5% and mucocele gallbladder 0.25%. Median operating time was 30min. Median hospital stay was 1 days (range 1 -20 days). Conversion rate was 1.25%. Postoperative complications included bleeding 0.5%, biliaryperitonitis due to cystic duct leak 0.25%, biloma 0.25%, sub hepaticabscess 0.25%, subcutaneous fat necrosis right flank at drain site 0.25%, umbilical trocarsite infection 2%, keloid at umbilical port site 0.25% and incisional hernia at umbilicus 0.25%. There was one hospital death due to myocardial infarction on 2nd post-operative day. Conclusion: Laparoscopic Cholecystectomy is associated with some serious complications

  4. Adhesion enhancement of biomimetic dry adhesives by nanoparticle in situ synthesis

    International Nuclear Information System (INIS)

    Díaz Téllez, J P; Harirchian-Saei, S; Li, Y; Menon, C

    2013-01-01

    A novel method to increase the adhesion strength of a gecko-inspired dry adhesive is presented. Gold nanoparticles are synthesized on the tips of the microfibrils of a polymeric dry adhesive to increase its Hamaker constant. Formation of the gold nanoparticles is qualitatively studied through a colour change in the originally transparent substance and quantitatively analysed using ultraviolet–visible spectrophotometry. A pull-off force test is employed to quantify the adhesion enhancement. Specifically, adhesion forces of samples with and without embedded gold nanoparticles are measured and compared. The experimental results indicate that an adhesion improvement of 135% can be achieved. (paper)

  5. Bond strength of adhesive resin cement with different adhesive systems

    OpenAIRE

    Lorenzoni e Silva, Fabrizio; Pamato, Saulo; Kuga, Milton-Carlos; S?, Marcus-Vinicius-Reis; Pereira, Jefferson-Ricardo

    2017-01-01

    Background To assess the immediate bond strength of a dual-cure adhesive resin cement to the hybridized dentin with different bonding systems. Material and Methods Fifty-six healthy human molars were randomly divided into 7 groups (n=8). After 3 longitudinal sections, the central cuts were included in PVC matrix and were submitted to dentin hybridization according to the groups: G1 - etch & rinse system with 3-step (Apder? Scotchbond? Multi-Purpose, 3M ESPE), G2 - etch & rinse system with 3-s...

  6. Relationship between consecutive deterioration of mean deviation value and progression of visual field defect in open-angle glaucoma

    Directory of Open Access Journals (Sweden)

    Naito T

    2015-11-01

    Full Text Available Tomoko Naito,1 Keiji Yoshikawa,2 Shiro Mizoue,3 Mami Nanno,4 Tairo Kimura,5 Hirotaka Suzumura,6 Ryuji Takeda,7 Fumio Shiraga1 1Department of Ophthalmology, Okayama University Graduate School of Medicine, Okayama, 2Yoshikawa Eye Clinic, Tokyo, 3Department of Ophthalmology, Ehime University Graduate School of Medicine, Ehime, 4Kagurazaka Minamino Eye Clinic, 5Ueno Eye Clinic, 6Suzumura Eye Clinic, Tokyo, 7Department of Agriculture, Kinki University, Nara, Japan Purpose: To analyze the relationship between consecutive deterioration of mean deviation (MD value and glaucomatous visual field (VF progression in open-angle glaucoma (OAG, including primary OAG and normal tension glaucoma.Patients and methods: The subjects of the study were patients undergoing treatment for OAG who had performed VF tests at least 10 times with a Humphrey field analyzer (SITA standard, C30-2 program. The VF progression was defined by a significantly negative MD slope (MD slope worsening at the final VF test during the follow-up period. The relationship between the MD slope worsening and the consecutive deterioration of MD value were retrospectively analyzed.Results: A total of 165 eyes of 165 patients were included in the analysis. Significant progression of VF defects was observed in 72 eyes of 72 patients (43.6%, while no significant progression was evident in 93 eyes of 93 patients (56.4%. There was significant relationship between the frequency of consecutive deterioration of MD value and MD slope worsening (P<0.0001, Cochran–Armitage trend test. A significant association was observed for MD slope worsening in the eyes with three (odds ratio: 2.1, P=0.0224 and four (odds ratio: 3.6, P=0.0008 consecutive deterioration of MD value in multiple logistic regression analysis, but no significant association in the eyes with two consecutive deterioration (odds ratio: 1.1, P=0.8282. The eyes with VF progression had significantly lower intraocular pressure reduction rate (P<0

  7. Human climbing with efficiently scaled gecko-inspired dry adhesives

    OpenAIRE

    Hawkes, Elliot W.; Eason, Eric V.; Christensen, David L.; Cutkosky, Mark R.

    2015-01-01

    Since the discovery of the mechanism of adhesion in geckos, many synthetic dry adhesives have been developed with desirable gecko-like properties such as reusability, directionality, self-cleaning ability, rough surface adhesion and high adhesive stress. However, fully exploiting these adhesives in practical applications at different length scales requires efficient scaling (i.e. with little loss in adhesion as area grows). Just as natural gecko adhesives have been used as a benchmark for syn...

  8. Competitive endothelial adhesion between Plasmodium falciparum isolates under physiological flow conditions

    Directory of Open Access Journals (Sweden)

    Molyneux Malcolm

    2009-09-01

    Full Text Available Abstract Background Sequestration of parasitized red blood cells in the microvasculature of major organs involves a sequence of events that is believed to contribute to the pathogenesis of severe falciparum malaria. Plasmodium falciparum infections are commonly composed of multiple subpopulations of parasites with varied adhesive properties. A key question is: do these subpopulations compete for adhesion to endothelium? This study investigated whether, in a laboratory model of cytoadherence, there is competition in binding to endothelium between pRBC infected with P. falciparum of variant adhesive phenotypes, particularly under flow conditions. Methods Four different P. falciparum isolates, of known adherence phenotypes, were matched in pairs, mixed in different proportions and allowed to bind to cultured human endothelium. Using in vitro competitive static and flow-based adhesion assays, that allow simultaneous testing of the adhesive properties of two different parasite lines, adherence levels of paired P. falciparum isolates were quantified and analysed using either non-parametric Wilcoxon's paired signed rank test or Student paired test. Results Study findings show that P. falciparum parasite lines show marked differences in the efficiency of adhesion to endothelium. Conclusion Plasmodium falciparum variants will compete for adhesion to endothelia and variants can be ranked by their efficiency of binding. These findings suggest that variants from a mixed infection will not show uniform cytoadherence and so may vary in their ability to cause disease.

  9. Potential risk of port-site adhesions in patients after laparoscopic myomectomy using radially expanding trocars.

    Science.gov (United States)

    Kumakiri, Jun; Kikuchi, Iwaho; Kitade, Mari; Jinushi, Makoto; Shinjyo, Azusa; Takeda, Satoru

    2015-01-01

    To investigate the incidence of port-site adhesions following use of radially expanding trocars (RETs) at laparoscopic myomectomy by observation via second-look laparoscopy (SLL). In a retrospective study, data from patients who underwent SLL after laparoscopic myomectomy between January 2007 and June 2012 at Juntendo University Hospital, Tokyo, were assessed for the incidence of port-site adhesions forming below RET incisional scars when fascial and peritoneal defects had not been closed. During the study period, 554 patients underwent SLL, and 2176 incisional scars were examined. Adhesions were detected in 15 patients (2.8%); thus, the incidence of port-site adhesions under scars was 0.7% (15/2176). Among these 15 patients, the wounds with adhesions were located as follows: 6 (1.1%) under the umbilical scar, 5 (0.9%) under the right lower abdominal scar, 2 (0.4%) under the left upper abdominal scar, and 2 (0.4%) under the left lower abdominal scar. According to multiple regression analysis, the duration of laparoscopic myomectomy was positively associated with port-site adhesions (odds ratio, 1.79; 95% confidence interval, 1.09-2.94; P=0.02). The present data suggest that the incidence of port-site hernias and adhesions under RET incisional scars is low despite the non-closure of fascial and peritoneal defects. Copyright © 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  10. Structural Insights into Ail-Mediated Adhesion in Yersinia pestis

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, Satoshi; Lukacik, Petra; Barnard, Travis J.; Noinaj, Nicholas; Felek, Suleyman; Tsang, Tiffany M.; Krukonis, Eric S.; Hinnebusch, B. Joseph; Buchanan, Susan K. (Michigan); (NIH); (Michigan-Med)

    2012-01-30

    Ail is an outer membrane protein from Yersinia pestis that is highly expressed in a rodent model of bubonic plague, making it a good candidate for vaccine development. Ail is important for attaching to host cells and evading host immune responses, facilitating rapid progression of a plague infection. Binding to host cells is important for injection of cytotoxic Yersinia outer proteins. To learn more about how Ail mediates adhesion, we solved two high-resolution crystal structures of Ail, with no ligand bound and in complex with a heparin analog called sucrose octasulfate. We identified multiple adhesion targets, including laminin and heparin, and showed that a 40 kDa domain of laminin called LG4-5 specifically binds to Ail. We also evaluated the contribution of laminin to delivery of Yops to HEp-2 cells. This work constitutes a structural description of how a bacterial outer membrane protein uses a multivalent approach to bind host cells.

  11. Proteomic dataset of the sea urchin Paracentrotus lividus adhesive organs and secreted adhesive.

    Science.gov (United States)

    Lebesgue, Nicolas; da Costa, Gonçalo; Ribeiro, Raquel Mesquita; Ribeiro-Silva, Cristina; Martins, Gabriel G; Matranga, Valeria; Scholten, Arjen; Cordeiro, Carlos; Heck, Albert J R; Santos, Romana

    2016-06-01

    Sea urchins have specialized adhesive organs called tube feet, which mediate strong but reversible adhesion. Tube feet are composed by a disc, producing adhesive and de-adhesive secretions for substratum attachment, and a stem for movement. After detachment the secreted adhesive remains bound to the substratum as a footprint. Recently, a label-free quantitative proteomic approach coupled with the latest mass-spectrometry technology was used to analyze the differential proteome of Paracentrotus lividus adhesive organ, comparing protein expression levels in the tube feet adhesive part (the disc) versus the non-adhesive part (the stem), and also to profile the proteome of the secreted adhesive (glue). This data article contains complementary figures and results related to the research article "Deciphering the molecular mechanisms underlying sea urchin reversible adhesion: a quantitative proteomics approach" (Lebesgue et al., 2016) [1]. Here we provide a dataset of 1384 non-redundant proteins, their fragmented peptides and expression levels, resultant from the analysis of the tube feet differential proteome. Of these, 163 highly over-expressed tube feet disc proteins (>3-fold), likely representing the most relevant proteins for sea urchin reversible adhesion, were further annotated in order to determine the potential functions. In addition, we provide a dataset of 611 non-redundant proteins identified in the secreted adhesive proteome, as well as their functional annotation and grouping in 5 major protein groups related with adhesive exocytosis, and microbial protection. This list was further analyzed to identify the most abundant protein groups and pinpoint putative adhesive proteins, such as Nectin, the most abundant adhesive protein in sea urchin glue. The obtained data uncover the key proteins involved in sea urchins reversible adhesion, representing a step forward to the development of new wet-effective bio-inspired adhesives.

  12. Proteomic dataset of the sea urchin Paracentrotus lividus adhesive organs and secreted adhesive

    Directory of Open Access Journals (Sweden)

    Nicolas Lebesgue

    2016-06-01

    Full Text Available Sea urchins have specialized adhesive organs called tube feet, which mediate strong but reversible adhesion. Tube feet are composed by a disc, producing adhesive and de-adhesive secretions for substratum attachment, and a stem for movement. After detachment the secreted adhesive remains bound to the substratum as a footprint. Recently, a label-free quantitative proteomic approach coupled with the latest mass-spectrometry technology was used to analyze the differential proteome of Paracentrotus lividus adhesive organ, comparing protein expression levels in the tube feet adhesive part (the disc versus the non-adhesive part (the stem, and also to profile the proteome of the secreted adhesive (glue. This data article contains complementary figures and results related to the research article “Deciphering the molecular mechanisms underlying sea urchin reversible adhesion: a quantitative proteomics approach” (Lebesgue et al., 2016 [1]. Here we provide a dataset of 1384 non-redundant proteins, their fragmented peptides and expression levels, resultant from the analysis of the tube feet differential proteome. Of these, 163 highly over-expressed tube feet disc proteins (>3-fold, likely representing the most relevant proteins for sea urchin reversible adhesion, were further annotated in order to determine the potential functions. In addition, we provide a dataset of 611 non-redundant proteins identified in the secreted adhesive proteome, as well as their functional annotation and grouping in 5 major protein groups related with adhesive exocytosis, and microbial protection. This list was further analyzed to identify the most abundant protein groups and pinpoint putative adhesive proteins, such as Nectin, the most abundant adhesive protein in sea urchin glue. The obtained data uncover the key proteins involved in sea urchins reversible adhesion, representing a step forward to the development of new wet-effective bio-inspired adhesives.

  13. Measuring Rock-Fluid Adhesion Directly

    Science.gov (United States)

    Tadmor, R.

    2017-12-01

    We show how to measure directly solid-liquid adhesion. We consider the normal adhesion, the work adhesion, and the lateral adhesion. The technique at the center of the method is Centrifugal Adhesion Balance (CAB) which allows coordinated manipulation of normal and lateral forces. For example: 1. It allows to induce an increase in the normal force which pulls on a liquid drop while keeping zero lateral force. This method mimics a drop that is subjected to a gravitational force that is gradually increasing. 2. It allows to increase the lateral force at zero normal force, mimicking zero gravity. From this one can obtain additional solid-liquid interaction parameters. When performing work of adhesion measurements, the values obtained are independent of drop size and are in agreement with theoretical predictions.

  14. Functionally Graded Adhesives for Composite Joints

    Science.gov (United States)

    Stapleton, Scott E.; Waas, Anthony M.; Arnold, Steven M.

    2012-01-01

    Adhesives with functionally graded material properties are being considered for use in adhesively bonded joints to reduce the peel stress concentrations located near adherend discontinuities. Several practical concerns impede the actual use of such adhesives. These include increased manufacturing complications, alterations to the grading due to adhesive flow during manufacturing, and whether changing the loading conditions significantly impact the effectiveness of the grading. An analytical study is conducted to address these three concerns. An enhanced joint finite element, which uses an analytical formulation to obtain exact shape functions, is used to model the joint. Furthermore, proof of concept testing is conducted to show the potential advantages of functionally graded adhesives. In this study, grading is achieved by strategically placing glass beads within the adhesive layer at different densities along the joint.

  15. Adhesive Joints in Wind Turbine Blades

    DEFF Research Database (Denmark)

    Jørgensen, Jeppe Bjørn

    to be determined in several different ways. The accuracy of different ways of measuring residual stresses in the adhesive was tested by applying five different methods on a single sandwich test specimen (laminate/adhesive/laminate) that was instrumented with strain gauges and fiber Bragg gratings. Quasi...... of the project is to develop new- and to improve the existing design rules for adhesive joints in wind turbine blades. The first scientific studies of adhesive joints were based on stress analysis, which requires that the bond-line is free of defects, but this is rarely the case for a wind turbine blade. Instead...... curing and test temperatures) on the formation of transverse cracks in the adhesive were tested experimentally. It was assumed that the transverse cracks evolved due to a combination of mechanical- and residual stresses in the adhesive. A new approach was developed that allows the residual stress...

  16. IMMEDIATE COMPLICATIONS AFTER 88 HEPATECTOMIES - BRAZILIAN CONSECUTIVE SERIES.

    Science.gov (United States)

    Amico, Enio Campos; Alves, José Roberto; João, Samir Assi; Guimarães, Priscila Luana Franco Costa; Medeiros, Joafran Alexandre Costa de; Barreto, Élio José Silveira da Silva

    2016-01-01

    Hepatectomies have been increasingly recommended and performed in Brazil; they present great differences related to immediate complications. Assessing the immediate postoperative complications in a series of 88 open liver resections. Prospective database of patients subjected to consecutive hepatectomies over nine years. The post-hepatectomy complications were categorized according to the Clavien-Dindo classification; complications presenting grade equal to or greater than 3 were considered major complications. Hepatic resections involving three or more resected liver segments were considered major hepatectomies. Eighty-four patients were subjected to 88 hepatectomies, mostly were minor liver resections (50 cases, 56.8%). Most patients had malignant diseases (63 cases; 71.6%). The mean hospitalization time was 10.9 days (4-43). Overall morbidity and mortality rates were 37.5% and 6.8%, respectively. The two most common immediate general complications were intra-peritoneal collections (12.5%) and pleural effusion (12.5%). Bleeding, biliary fistula and liver failure were identified in 6.8%, 4.5% and 1.1% of the cases, respectively, among the hepatectomy-specific complications. The patients operated in the second half of the series showed better results, which were apparently influenced by the increased surgical expertise, by the modification of the hepatic parenchyma section method and by the increased organ preservation. No Brasil as hepatectomias têm sido cada vez mais indicadas e realizadas, apresentando grandes diferenças relacionadas às complicações imediatas. Avaliar as complicações pós-operatórias imediatas em uma série de 88 ressecções hepáticas abertas. Foi utilizada uma base de dados prospectiva de pacientes submetidos à hepatectomias consecutivas em nove anos. As complicações pós-hepatectomia seguiram a Classificação de Clavien-Dindo, sendo consideradas complicações maiores aquelas as quais apresentaram grau igual ou maior que 3. Foram

  17. Lignin-Furfural Based Adhesives

    OpenAIRE

    Dongre, Prajakta; Driscoll, Mark; Amidon, Thomas; Bujanovic, Biljana

    2015-01-01

    Lignin recovered from the hot-water extract of sugar maple ( Acer saccharum ) is used in this study to synthesize adhesive blends to replace phenol-formaldehyde (PF) resin. Untreated lignin is characterized by lignin content and nuclear magnetic resonance (NMR) analysis. The molecular weight distribution of the lignin and the blends are characterized by size exclusion chromatography (SEC). The effect of pH (0.3, 0.65 and 1), ex situ furfural, and curing conditions on the tensile properties of...

  18. Adhesives for fixed orthodontic brackets.

    Science.gov (United States)

    Mandall, Nicky A; Hickman, Joy; Macfarlane, Tatiana V; Mattick, Rye Cr; Millett, Declan T; Worthington, Helen V

    2018-04-09

    Bonding of orthodontic brackets to teeth is important to enable effective and efficient treatment with fixed appliances. The problem is bracket failure during treatment which increases operator chairside time and lengthens treatment time. A prolonged treatment is likely to increase the oral health risks of orthodontic treatment with fixed appliances one of which is irreversible enamel decalcification. This is an update of the Cochrane Review first published in 2003. A new full search was conducted on 26 September 2017 but no new studies were identified. We have only updated the search methods section in this new version. The conclusions of this Cochrane Review remain the same. To evaluate the effects of different orthodontic adhesives for bonding. Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 26 September 2017), the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 8) in the Cochrane Library (searched 26 September 2017), MEDLINE Ovid (1946 to 26 September 2017), and Embase Ovid (1980 to 26 September 2017). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. Trials were selected if they met the following criteria: randomised controlled trials (RCTs) and controlled clinical trials (CCTs) comparing two different adhesive groups. Participants were patients with fixed orthodontic appliances. The interventions were adhesives that bonded stainless steel brackets to all teeth except the molars. The primary outcome was debond or bracket failure. Data were recorded on decalcification as a secondary outcome, if present. Information regarding methods, participants, interventions, outcome measures and results were extracted in

  19. Factors influencing bacterial adhesion to contact lenses

    OpenAIRE

    Dutta, Debarun; Cole, Nerida; Willcox, Mark

    2012-01-01

    The process of any contact lens related keratitis generally starts with the adhesion of opportunistic pathogens to contact lens surface. This article focuses on identifying the factors which have been reported to affect bacterial adhesion to contact lenses. Adhesion to lenses differs between various genera/species/strains of bacteria. Pseudomonas aeruginosa, which is the predominant causative organism, adheres in the highest numbers to both hydrogel and silicone hydrogel lenses in vitro. The ...

  20. Syndecan-4 and focal adhesion function

    DEFF Research Database (Denmark)

    Woods, A; Couchman, J R

    2001-01-01

    Two groups have now reported the viability of mice that lack syndecan-4. These mice have wound healing/angiogenesis problems, and fibroblasts from these animals differ in adhesion and migration from normal. This is consistent with recent in vitro data indicating a need for signaling via syndecan-4...... for focal adhesion formation, and reports that overexpression of proteins that bind syndecan-4 can modify cell adhesion and migration....

  1. Photoactivatable Mussel-Based Underwater Adhesive Proteins by an Expanded Genetic Code.

    Science.gov (United States)

    Hauf, Matthias; Richter, Florian; Schneider, Tobias; Faidt, Thomas; Martins, Berta M; Baumann, Tobias; Durkin, Patrick; Dobbek, Holger; Jacobs, Karin; Möglich, Andreas; Budisa, Nediljko

    2017-09-19

    Marine mussels exhibit potent underwater adhesion abilities under hostile conditions by employing 3,4-dihydroxyphenylalanine (DOPA)-rich mussel adhesive proteins (MAPs). However, their recombinant production is a major biotechnological challenge. Herein, a novel strategy based on genetic code expansion has been developed by engineering efficient aminoacyl-transfer RNA synthetases (aaRSs) for the photocaged noncanonical amino acid ortho-nitrobenzyl DOPA (ONB-DOPA). The engineered ONB-DOPARS enables in vivo production of MAP type 5 site-specifically equipped with multiple instances of ONB-DOPA to yield photocaged, spatiotemporally controlled underwater adhesives. Upon exposure to UV light, these proteins feature elevated wet adhesion properties. This concept offers new perspectives for the production of recombinant bioadhesives. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. CD147-targeting siRNA inhibits cell-matrix adhesion of human malignant melanoma cells by phosphorylating focal adhesion kinase.

    Science.gov (United States)

    Nishibaba, Rie; Higashi, Yuko; Su, Juan; Furukawa, Tatsuhiko; Kawai, Kazuhiro; Kanekura, Takuro

    2012-01-01

    CD147/basigin, highly expressed on the surface of malignant tumor cells including malignant melanoma (MM) cells, plays a critical role in the invasiveness and metastasis of MM. Metastasis is an orchestrated process comprised of multiple steps including adhesion and invasion. Integrin, a major adhesion molecule, co-localizes with CD147/basigin on the cell surface. Using the human MM cell line A375 that highly expresses CD147/basigin, we investigated whether CD147/basigin is involved in adhesion in association with integrin. CD147/basigin was knocked-down using siRNA targeting CD147 to elucidate the role of CD147/basigin. Cell adhesion was evaluated by adhesion assay on matrix-coated plates. The localization of integrin was inspected under a confocal microscope and the expression and phosphorylation of focal adhesion kinase (FAK), a downstream kinase of integrin, were examined by western blot analysis. Silencing of CD147/basigin in A375 cells by siRNA induced the phosphorylation of FAK at Y397. Integrin identified on the surface of parental cells was distributed in a speckled fashion in the cytoplasm of CD147 knockdown cells, resulting in morphological changes from a round to a polygonal shape with pseudopodial protrusions. Silencing of CD147/basigin in A375 cells clearly weakened their adhesiveness to collagen I and IV. Our results suggest that CD147/basigin regulates the adhesion of MM cells to extracellular matrices and of integrin β1 signaling via the phosphorylation of FAK. © 2011 Japanese Dermatological Association.

  3. Adhesive Strength of dry Adhesive Structures Depending on the Thickness of Metal Coating

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Gyu Hye; Kwon, Da Som; Kim, Mi Jung; Kim, Su Hee; Yoon, Ji Won; An, Tea Chang; Hwang, Hui Yun [Andong National Univ., Andong (Korea, Republic of)

    2016-07-15

    Recently, engineering applications have started to adopt solutions inspired by nature. The peculiar adhesive properties of gecko skin are an example, as they allow the animal to move freely on vertical walls and even on ceilings. The high adhesive forces between gecko feet and walls are due to the hierarchical microscopical structure of the skin. In this study, the effect of metal coatings on the adhesive strength of synthetic, hierarchically structured, dry adhesives was investigated. Synthetic dry adhesives were fabricated using PDMS micro-molds prepared by photolithography. Metal coatings on synthetic dry adhesives were formed by plasma sputtering. Adhesive strength was measured by pure shear tests. The highest adhesion strengths were found with coatings composed of 4 nm thick layers of Indium, 8 nm thick layers of Zinc and 6 nm thick layers of Gold, respectively.

  4. Adhesive Strength of dry Adhesive Structures Depending on the Thickness of Metal Coating

    International Nuclear Information System (INIS)

    Kim, Gyu Hye; Kwon, Da Som; Kim, Mi Jung; Kim, Su Hee; Yoon, Ji Won; An, Tea Chang; Hwang, Hui Yun

    2016-01-01

    Recently, engineering applications have started to adopt solutions inspired by nature. The peculiar adhesive properties of gecko skin are an example, as they allow the animal to move freely on vertical walls and even on ceilings. The high adhesive forces between gecko feet and walls are due to the hierarchical microscopical structure of the skin. In this study, the effect of metal coatings on the adhesive strength of synthetic, hierarchically structured, dry adhesives was investigated. Synthetic dry adhesives were fabricated using PDMS micro-molds prepared by photolithography. Metal coatings on synthetic dry adhesives were formed by plasma sputtering. Adhesive strength was measured by pure shear tests. The highest adhesion strengths were found with coatings composed of 4 nm thick layers of Indium, 8 nm thick layers of Zinc and 6 nm thick layers of Gold, respectively

  5. Adhesion of rhodium films on metallic substrates

    International Nuclear Information System (INIS)

    Marot, L.; Covarel, G.; Tuilier, M.-H.; Steiner, R.; Oelhafen, P.

    2008-01-01

    Rhodium coated metallic films were prepared by magnetron sputtering on metallic substrates. All films were elaborated in same conditions on copper, molybdenum and stainless steel. Adhesion strength tests were carried out by scratch test. The results reveal that the adhesion strength between the film and the substrate is influenced by the hardness of the substrate. Increase of deposition temperature improves the adhesion of the coating. In addition, pre-treatment of substrates by a filtered cathodic vacuum arc and the layer thickness have has some effects on the final adhesion strength

  6. Adhesion of rhodium films on metallic substrates

    Energy Technology Data Exchange (ETDEWEB)

    Marot, L. [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland)], E-mail: laurent.marot@unibas.ch; Covarel, G.; Tuilier, M.-H. [Laboratoire Mecanique, Materiaux et Procedes de Fabrication, Pole STIC-SPI-Math 61 rue Albert Camus, Universite de Haute-Alsace, F-68093 - Mulhouse Cedex (France); Steiner, R.; Oelhafen, P. [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland)

    2008-09-01

    Rhodium coated metallic films were prepared by magnetron sputtering on metallic substrates. All films were elaborated in same conditions on copper, molybdenum and stainless steel. Adhesion strength tests were carried out by scratch test. The results reveal that the adhesion strength between the film and the substrate is influenced by the hardness of the substrate. Increase of deposition temperature improves the adhesion of the coating. In addition, pre-treatment of substrates by a filtered cathodic vacuum arc and the layer thickness have has some effects on the final adhesion strength.

  7. Structural adhesives for missile external protection material

    Science.gov (United States)

    Banta, F. L.; Garzolini, J. A.

    1981-07-01

    Two basic rubber materials are examined as possible external substrate protection materials (EPM) for missiles. The analysis provided a data base for selection of the optimum adhesives which are compatible with the substrate, loads applied and predicted bondline temperatures. Under the test conditions, EA934/NA was found to be the optimum adhesive to bond VAMAC 2273 and/or NBR/EPDM 9969A to aluminum substrate. The optimum adhesive for composite structures was EA956. Both of these adhesives are two-part epoxy systems with a pot life of approximately two hours. Further research is suggested on field repair criteria, nuclear hardness and survivability effects on bondline, and ageing effects.

  8. Nucleation and growth of cadherin adhesions

    International Nuclear Information System (INIS)

    Lambert, Mireille; Thoumine, Olivier; Brevier, Julien; Choquet, Daniel; Riveline, Daniel; Mege, Rene-Marc

    2007-01-01

    Cell-cell contact formation relies on the recruitment of cadherin molecules and their anchoring to actin. However, the precise chronology of events from initial cadherin trans-interactions to adhesion strengthening is unclear, in part due to the lack of access to the distribution of cadherins within adhesion zones. Using N-cadherin expressing cells interacting with N-cadherin coated surfaces, we characterized the formation of cadherin adhesions at the ventral cell surface. TIRF and RIC microscopies revealed streak-like accumulations of cadherin along actin fibers. FRAP analysis indicated that engaged cadherins display a slow turnover at equilibrium, compatible with a continuous addition and removal of cadherin molecules within the adhesive contact. Association of cadherin cytoplasmic tail to actin as well as actin cables and myosin II activity are required for the formation and maintenance of cadherin adhesions. Using time lapse microscopy we deciphered how cadherin adhesions form and grow. As lamellipodia protrude, cadherin foci stochastically formed a few microns away from the cell margin. Neo-formed foci coalesced aligned and coalesced with preformed foci either by rearward sliding or gap filling to form cadherin adhesions. Foci experienced collapse at the rear of cadherin adhesions. Based on these results, we present a model for the nucleation, directional growth and shrinkage of cadherin adhesions

  9. Denture Adhesives in Prosthodontics: An Overview.

    Science.gov (United States)

    Kumar, P Ranjith; Shajahan, P A; Mathew, Jyothis; Koruthu, Anil; Aravind, Prasad; Ahammed, M Fazeel

    2015-01-01

    The use of denture adhesives is common among denture wearers, and it is also prescribed by many dentists. Prescribing denture adhesives has been viewed by many prosthodontists as a means of compensating for any defects in the fabrication procedures. Denture adhesives add to the retention and thereby improve chewing ability, reduce any instability, provide comfort and eliminate the accumulation of food debris beneath the dentures. Consequently, they increase the patient's sense of security and satisfaction. However, obtaining the advice of the dental practitioner prior to the use of adhesives is a must.

  10. The Effect of Phospholipids (Surfactant on Adhesion and Biomechanical Properties of Tendon: A Rat Achilles Tendon Repair Model

    Directory of Open Access Journals (Sweden)

    T. Kursat Dabak

    2015-01-01

    Full Text Available Adhesion of the tendon is a major challenge for the orthopedic surgeon during tendon repair. Manipulation of biological environment is one of the concepts to prevent adhesion. Lots of biochemicals have been studied for this purpose. We aimed to determine the effect of phospholipids on adhesion and biomechanical properties of tendon in an animal tendon repair model. Seventy-two Wistar rats were divided into 4 groups. Achilles tendons of rats were cut and repaired. Phospholipids were applied at two different dosages. Tendon adhesion was determined histopathologically and biomechanical test was performed. At macroscopic evaluation of adhesion, there are statistically significant differences between multiple-dose phospholipid injection group and Control group and also hyaluronic acid group and Control group (p0.008. Ultimate strength was highest at hyaluronic acid injection group and lowest at multiple-dose phospholipid injection group. Single-dose phospholipids (surfactant application may have a beneficial effect on the tendon adhesion. Although multiple applications of phospholipids seem the most effective regime to reduce the tendon adhesion among groups, it deteriorated the biomechanical properties of tendon.

  11. Importance of loading and unloading procedures for gecko-inspired controllable adhesives.

    Science.gov (United States)

    Tamelier, John; Chary, Sathya; Turner, Kimberly L

    2013-08-27

    The importance of loading and unloading procedures has been shown in a variety of different methods for biological dry adhesives, such as the fibers on the feet of the Tokay gecko, but biomimetic dry adhesives have yet to be explored in a similar manner. To date, little work has systematically varied multiple parameters to discern the influence of the testing procedure, and the effect of the approach angle remains uncertain. In this study, a synthetic adhesive is moved in 13 individual approach and retraction angles relative to a flat substrate as well as 9 different shear lengths to discern how loading and unloading procedures influence the preload, adhesion, and shear/friction forces supported. The synthetic adhesive, composed of vertical 10 μm diameter semicircular poly(dimethylsiloxane) fibers, is tested against a 4 mm diameter flat glass puck on a home-built microtribometer using both vertical approach and retraction tests and angled approach and retraction tests. The results show that near maximum adhesion and friction can be obtained for most approach and retraction angles, provided that a sufficient shear length is performed. The results also show that the reaction forces during adhesive placement can be significantly reduced by using specific approach angles, resulting for the vertical fibers in a 38-fold increase in the ratio of adhesion force to preload force, μ', when compared to that when using a vertical approach. These results can be of use to those currently researching gecko-inspired adhesives when designing their testing procedures and control algorithms for climbing and perching robots.

  12. Identifying the rules of engagement enabling leukocyte rolling, activation, and adhesion.

    Directory of Open Access Journals (Sweden)

    Jonathan Tang

    2010-02-01

    Full Text Available The LFA-1 integrin plays a pivotal role in sustained leukocyte adhesion to the endothelial surface, which is a precondition for leukocyte recruitment into inflammation sites. Strong correlative evidence implicates LFA-1 clustering as being essential for sustained adhesion, and it may also facilitate rebinding events with its ligand ICAM-1. We cannot challenge those hypotheses directly because it is infeasible to measure either process during leukocyte adhesion following rolling. The alternative approach undertaken was to challenge the hypothesized mechanisms by experimenting on validated, working counterparts: simulations in which diffusible, LFA1 objects on the surfaces of quasi-autonomous leukocytes interact with simulated, diffusible, ICAM1 objects on endothelial surfaces during simulated adhesion following rolling. We used object-oriented, agent-based methods to build and execute multi-level, multi-attribute analogues of leukocytes and endothelial surfaces. Validation was achieved across different experimental conditions, in vitro, ex vivo, and in vivo, at both the individual cell and population levels. Because those mechanisms exhibit all of the characteristics of biological mechanisms, they can stand as a concrete, working theory about detailed events occurring at the leukocyte-surface interface during leukocyte rolling and adhesion experiments. We challenged mechanistic hypotheses by conducting experiments in which the consequences of multiple mechanistic events were tracked. We quantified rebinding events between individual components under different conditions, and the role of LFA1 clustering in sustaining leukocyte-surface adhesion and in improving adhesion efficiency. Early during simulations ICAM1 rebinding (to LFA1 but not LFA1 rebinding (to ICAM1 was enhanced by clustering. Later, clustering caused both types of rebinding events to increase. We discovered that clustering was not necessary to achieve adhesion as long as LFA1 and

  13. Histological Analysis of Intra-Abdominal Adhesions Treated with Sodium Hyaluronate and Carboxymethylcellulose Gel.

    Science.gov (United States)

    Montalvo-Javé, Eduardo Esteban; Mendoza-Barrera, German Eduardo; García-Pineda, Manuel Alejandro; Jaime Limón, Álvaro Rodrigo; Montalvo-Arenas, César; Castell Rodríguez, Andrés Eliú; Tapia Jurado, Jesús

    2016-01-01

    To evaluate macro and microscopically the adhesions developed after using the anti-adherence compound sodium hyaluronate and carboxymethylcellulose (SH-CBMC) gel and to determine the volume of the adhesions using a stereological estimation. The study was experimental, random, comparative, and prospective. The subjects of the study were male Wistar rats divided in three groups (n = 10). Group I (control) included rats with no peritoneal injury. Group II rats had a 2 cm diameter injury created bilaterally in the parietal peritoneum at 3 cm from the abdominal midline with electrocautery coated with physiological solution. Group III rats were given the same injuries and coated with SH-CBMC gel. All groups were followed up postoperatively for 30 days, after which a laparotomy was performed to macroscopically determine the presence and type of adhesions. Experimental models were euthanized with anesthetic overdose and biopsies were taken for histopathological examination and stereological estimate of the volume of adhesions. Macroscopic adhesions were 20% less prevalent in Group III compared to Group II, which presented 40% more multiple and firm adhesions, unlike in Group III, in which they were unique and lax. There was a statistically significant decrease in the presence and number of adhesions in rats treated with SH-CBMC gel. Inflammatory infiltrate was significantly lower in rats treated with SH-CBMC gel, but there were no differences in connective tissue, fibrosis, and angiogenesis among groups. There was no statistical difference in the overall volume of adhesions among the treatment groups. SH-CBMC gel reduces macroscopic presence and number of adhesions and the severity of the inflammatory infiltrate.

  14. Effect of inorganic fillers in paper on the adhesion of pressure-sensitive adhesives

    Science.gov (United States)

    Weixu Chen; Xiaoyan Tang; John Considine; Kevin T. Turner

    2011-01-01

    Inorganic fillers are inexpensive materials used to increase the density, smoothness and other properties of paper that are important for printing. In the current study, the adhesion of pressure-sensitive adhesives (PSAs), a common type of adhesive used in labels and tapes, to papers containing varying amounts and types of fillers is investigated. Papers with three...

  15. Adhesive Bonding and Corrosion Performance Investigated as a Function of Aluminum Oxide Chemistry and Adhesives

    NARCIS (Netherlands)

    Abrahami, S.T.; Hauffman, T.; de Kok, John M.M.; Terryn, H.A.; Mol, J.M.C.

    2017-01-01

    The long-term strength and durability of an adhesive bond is dependent on the stability of the oxide-adhesive interface. As such, changes in the chemistry of the oxide and/or the adhesive are expected to modify the interfacial properties and affect the joint performance in practice. The upcoming

  16. Design and fabrication of polymer based dry adhesives inspired by the gecko adhesive system

    Science.gov (United States)

    Jin, Kejia

    There has been significant interest in developing dry adhesives mimicking the gecko adhesive system, which offers several advantages compared to conventional pressure sensitive adhesives. Specifically, gecko adhesive pads have anisotropic adhesion properties: the adhesive pads (spatulae) stick strongly when sheared in one direction but are non-adherent when sheared in the opposite direction. This anisotropy property is attributed to the complex topography of the array of fine tilted and curved columnar structures (setae) that bear the spatulae. In this thesis, easy, scalable methods, relying on conventional and unconventional techniques are presented to incorporate tilt in the fabrication of synthetic polymer-based dry adhesives mimicking the gecko adhesive system, which provide anisotropic adhesion properties. In the first part of the study, the anisotropic adhesion and friction properties of samples with various tilt angles to test the validity of a nanoscale tape-peeling model of spatular function are measured. Consistent with the Peel Zone model, samples with lower tilt angles yielded larger adhesion forces. Contact mechanics of the synthetic array were highly anisotropic, consistent with the frictional adhesion model and gecko-like. Based on the original design, a new design of gecko-like dry adhesives was developed which showed superior tribological properties and furthermore showed anisotropic adhesive properties without the need for tilt in the structures. These adhesives can be used to reversibly suspend weights from vertical surfaces (e.g., walls) and, for the first time to our knowledge, horizontal surfaces (e.g., ceilings) by simultaneously and judiciously activating anisotropic friction and adhesion forces. Furthermore, adhesion properties between artificial gecko-inspired dry adhesives and rough substrates with varying roughness are studied. The results suggest that both adhesion and friction forces on a rough substrate depends significantly on the

  17. AN ANALYTICAL STUDY IN ADHESIVE BOWEL OBSTRUCTION

    Directory of Open Access Journals (Sweden)

    Gerald Anand Raja

    2017-04-01

    Full Text Available BACKGROUND Peritoneal adhesions can be defined as abnormal fibrous bands between organs or tissues or both in the abdominal cavity that are normally separated. Adhesions may be acquired or congenital; however, most are acquired as a result of peritoneal injury, the most common cause of which is abdominopelvic surgery. Less commonly, adhesions may form as the result of inflammatory conditions, intraperitoneal infection or abdominal trauma. The extent of adhesion formation varies from one patient to another and is most dependent on the type and magnitude of surgery performed as well as whether any postoperative complications develop. Fortunately, most patients with adhesions do not experience any overt clinical symptoms. For others, adhesions may lead to any one of a host of problems and can be the cause of significant morbidity and mortality. MATERIALS AND METHODS This is a retrospective study of 50 patients admitted in Government Royapettah Hospital with adhesive bowel obstruction between September 2008 to September 2010. All patients were admitted and managed either conservatively or surgically. RESULTS 1. Adhesive bowel disease is the most common cause for bowel obstruction followed by hernias. 2. Increased incidence is noted in females. 3. Increased incidence of adhesions was documented in gynaecological and colorectal surgeries. 4. Below umbilical incisions have higher propensity for adhesion formation. 5. Laparotomies done for infective aetiology have higher adhesion risks. 6. Most of adhesive obstructions can be managed conservatively. 7. Adhesiolysis preferably laparoscopic can be done. For gangrenous bowel resection and anastomosis or ostomy done. 8. Given the above risk factors, adhesive bowel disease can be prevented to a certain extent. CONCLUSION The formation of peritoneal adhesions continues to plague patients, surgeons and society. Although, research in this area is ongoing, there is currently no method that is 100% effective in

  18. Influence of Blood Contamination During Multimode Adhesive ...

    African Journals Online (AJOL)

    Objectives: The present study evaluated the effects of blood contamination performed at different steps of bonding on the microtensile bond strength (μTBS) of multimode adhesives to dentin when using the self-etch approach. Materials and Methods: Seventy-five molars were randomly assigned to three adhesive groups ...

  19. Is nonoperative management of adhesive intestinal obstruction ...

    African Journals Online (AJOL)

    Background: Nonoperative management of adhesive intestinal obstruction gives good results in adults but there are scant studies on its outcome in children. This study reports outcomes and experiences with nonoperative and operative management of adhesive intestinal obstruction in children in a resource-poor country.

  20. Tuneable adhesion through novel binder technologies

    NARCIS (Netherlands)

    Wouters, M.E.L.; Burghoorn, M.M.A.; Ingenhut, B.; Timmer, K.; Rentrop, C.H.A.; Bots, T.L.; Oosterhuis, G.; Fischer, H.R.

    2011-01-01

    A reversible crosslinking mechanism enabling bonding and debonding of adhesives and coatings based on Diels-Alder chemistry is described. The Diels-Alder compounds form a covalently crosslinked network at low temperatures that break at elevated temperatures. As a result, the adhesive exhibits good

  1. Tensile and shear strength of adhesives

    Science.gov (United States)

    Stibolt, Kenneth A.

    1990-01-01

    This experiment is conducted in a freshman-level course: Introduction to Engineering Materials. There are no prerequisites for the course although students should have some knowledge of basic algebra. The objectives are to tension and shear test adhesives and to determine the tensile and shear properties of adhesives. Details of equipment of procedure are given.

  2. A CLINICAL STUDY OF ADHESIVE INTESTINAL OBSTRUCTION

    OpenAIRE

    Haricharan; Murali Krishna; Koti Reddy; Nara Hari

    2015-01-01

    INTRODUCTION: Adhesive intestinal obstruction is an inevitable complication of abdominal surgeries. It has high morbidity with associated poor quality of life and predisposition to repeated hospitalization. Commonest cause of bowel obstruction in developed countries is postoperative adhesions with extrinsic compression of the intestine. Most of them can be managed conservatively. METHODS: A retrospective study of 30 patients admit...

  3. Predicting Failure Initiation in Structural Adhesive Joints

    Science.gov (United States)

    2012-08-15

    Elastoplástico de Adhesivos – Modeling, characterization and simulation of the elastoplastic behavior of adhesives. Maestría en Ciencia de Materiales...adhesive and a 1018 steel”. Maestría en Ciencia de Materiales. Centro de Investigación en Materiales Avanzados S.C. May 2012.  Abstract: In the

  4. Chapter 16: Soy Proteins as Wood Adhesives

    Science.gov (United States)

    Charles R. Frihart; Christopher G. Hunt; Michael J. Birkeland

    2014-01-01

    Protein adhesives allowed the development of bonded wood products such as plywood and glulam in the early 20th century. Petrochemical-based adhesives replaced proteins in most wood bonding applications because of lower cost, improved production efficiencies, and enhanced durability. However, several technological and environmental factors have led to a resurgence of...

  5. Degradable Adhesives for Surgery and Tissue Engineering.

    Science.gov (United States)

    Bhagat, Vrushali; Becker, Matthew L

    2017-10-09

    This review highlights the research on degradable polymeric tissue adhesives for surgery and tissue engineering. Included are a comprehensive listing of specific uses, advantages, and disadvantages of different adhesive groups. A critical evaluation of challenges affecting the development of next generation materials is also discussed, and insights into the outlook of the field are explored.

  6. Functional Group Imaging by Adhesion AFM

    NARCIS (Netherlands)

    Berger, C.E.H.; Berger, C.E.H.; van der Werf, Kees; Kooyman, R.P.H.; de Grooth, B.G.; Greve, Jan

    1995-01-01

    Recently developed adhesion atomic force microscopy was used as a technique to map the spatial arrangement of chemical functional groups at a surface with a lateral resolution of 20 nm. The ratio of the adhesion forces for different functional groups can be compared with values determined from the

  7. Age Increases Monocyte Adhesion on Collagen

    Science.gov (United States)

    Khalaji, Samira; Zondler, Lisa; Kleinjan, Fenneke; Nolte, Ulla; Mulaw, Medhanie A.; Danzer, Karin M.; Weishaupt, Jochen H.; Gottschalk, Kay-E.

    2017-05-01

    Adhesion of monocytes to micro-injuries on arterial walls is an important early step in the occurrence and development of degenerative atherosclerotic lesions. At these injuries, collagen is exposed to the blood stream. We are interested whether age influences monocyte adhesion to collagen under flow, and hence influences the susceptibility to arteriosclerotic lesions. Therefore, we studied adhesion and rolling of human peripheral blood monocytes from old and young individuals on collagen type I coated surface under shear flow. We find that firm adhesion of monocytes to collagen type I is elevated in old individuals. Pre-stimulation by lipopolysaccharide increases the firm adhesion of monocytes homogeneously in older individuals, but heterogeneously in young individuals. Blocking integrin αx showed that adhesion of monocytes to collagen type I is specific to the main collagen binding integrin αxβ2. Surprisingly, we find no significant age-dependent difference in gene expression of integrin αx or integrin β2. However, if all integrins are activated from the outside, no differences exist between the age groups. Altered integrin activation therefore causes the increased adhesion. Our results show that the basal increase in integrin activation in monocytes from old individuals increases monocyte adhesion to collagen and therefore the risk for arteriosclerotic plaques.

  8. Adhesion of Zinc Hot-dip Coatings

    Directory of Open Access Journals (Sweden)

    Michal Černý

    2014-01-01

    Full Text Available The work is focused on verification of quality adhesion of zinc coating. It describes elements which affect quality and adhesive solidity within the coating. For assessment itself it will be neccessary to get know the basic elements which can affect adhesion of hot-dip coating which will be essential for choosing suitable samples for verification itself. These elements characterise acoustic responses during delamination coating. They affect elements influencing progress of signal. In research there is also a summary of existing methods for testing adhesion of coatings. As a result a new proposal of a new method comes out for purpose of quality testing of adhesion zinc hot-dip coating. The results of verification of this method are put to scientific analysis and findings lead to assessment of proposed method and its application in technical practise.The goal of this contribution is also include to proposed methodology testing adhesion zinc coating by nondestructive diagnostic method of acoustic emission (AE, which would monitor characterise progress of coating delamination of hot-dip zinc from basic material in way to adhesion tests would be practicable in situ. It can be enabled by analysis and assessment of results acquired by method AE and its application within verification of new method of adhesion anti-corrosive zinc coating.

  9. Switchable adhesion by chemical functionality and topography

    NARCIS (Netherlands)

    Kamperman, M.M.G.; Synytska, A.

    2012-01-01

    Progress in adhesion technology over the last few decades has led to widespread replacement of mechanical fasteners with adhesive bonds. Despite the advances, it remains challenging to produce materials that are sticky on demand. In this feature article we highlight recent efforts to develop

  10. Syndecans: synergistic activators of cell adhesion

    DEFF Research Database (Denmark)

    Woods, A; Couchman, J R

    1998-01-01

    Cell-surface proteoglycans participate in cell adhesion, growth-factor signalling, lipase activity and anticoagulation. Until recently, only the roles of the glycosaminoglycan chains were investigated. Now, with molecular characterization of several core proteins, the roles of each individual...... molecules modulating integrin-based adhesion....

  11. Biobased adhesives and non-conventional bonding

    Science.gov (United States)

    Charles Frihart

    2010-01-01

    Biobased adhesives fall into several major classes based upon their chemical structures. Starches are used in large volume, especially in the paper products industries, but cellulosics generally do not have the strength and water resistance needed for most wood products. Several authors have covered cellulosics adhesives (Baumann and Conner 2002, Pizzi 2006). However...

  12. Adhesion studies by instrumental indentation testing

    NARCIS (Netherlands)

    Hangen, U.D.; Downs, S.; Kranenburg, J.M.; Hoogenboom, R.; Schubert, U.S.

    2006-01-01

    The miniaturization of devices and the advances in nanotechnol.-enabled products has led to the requirement of an increased understanding of the various interactions present in nanoscale contacts - including adhesion and surface tension. It is well known that adhesion plays an important role in the

  13. Microparticle adhesion studies by atomic force microscopy

    NARCIS (Netherlands)

    Segeren, L.H.G.J.; Siebum, B.; Karssenberg, F.G.; Berg, van den J.W.A.; Vancso, G.J.

    2002-01-01

    Atomic force microscopy (AFM) is one of the most flexible and simple techniques for probing surface interactions. This article reviews AFM studies on particle adhesion. Special attention is paid to the characterization of roughness and its effect on adhesion. This is of importance when comparing the

  14. Scaling Principles for Understanding and Exploiting Adhesion

    Science.gov (United States)

    Crosby, Alfred

    A grand challenge in the science of adhesion is the development of a general design paradigm for adhesive materials that can sustain large forces across an interface yet be detached with minimal force upon command. Essential to this challenge is the generality of achieving this performance under a wide set of external conditions and across an extensive range of forces. Nature has provided some guidance through various examples, e.g. geckos, for how to meet this challenge; however, a single solution is not evident upon initial investigation. To help provide insight into nature's ability to scale reversible adhesion and adapt to different external constraints, we have developed a general scaling theory that describes the force capacity of an adhesive interface in the context of biological locomotion. We have demonstrated that this scaling theory can be used to understand the relative performance of a wide range of organisms, including numerous gecko species and insects, as well as an extensive library of synthetic adhesive materials. We will present the development and testing of this scaling theory, and how this understanding has helped guide the development of new composite materials for high capacity adhesives. We will also demonstrate how this scaling theory has led to the development of new strategies for transfer printing and adhesive applications in manufacturing processes. Overall, the developed scaling principles provide a framework for guiding the design of adhesives.

  15. Noninvasive detection and mapping of intraabdominal adhesions

    DEFF Research Database (Denmark)

    Zinther, Nellie Bering; Fedder, Jens; Friis-Andersen, Hans

    2010-01-01

    BACKGROUND: Adhesions are a well-known and very common complication to surgery. Their extent and severity varies according to type and number of surgeries, use of intraabdominal mesh, and presence of peritonitis. Adhesions cause increased morbidity and mortality, with subsequent socioeconomic con...

  16. Adhesion mechanism of a gecko-inspired oblique structure with an adhesive tip for asymmetric detachment

    International Nuclear Information System (INIS)

    Sekiguchi, Yu; Sato, Chiaki; Takahashi, Kunio

    2015-01-01

    An adhesion model of an oblique structure with an adhesive tip is proposed by considering a limiting stress for adhesion to describe the detachment mechanism of gecko foot hairs. When a force is applied to the root of the oblique structure, normal and shear stresses are generated at contact and the adhesive tip is detached from the surface when reaching the limiting stress. An adhesion criterion that considers both the normal and shear stresses is introduced, and the asymmetric detachment of the oblique structure is theoretically investigated. In addition, oblique beam array structures are manufactured, and an inclination effect of the structure on the asymmetric detachment is experimentally verified. (paper)

  17. Chemical screening identifies filastatin, a small molecule inhibitor of Candida albicans adhesion, morphogenesis, and pathogenesis.

    Science.gov (United States)

    Fazly, Ahmed; Jain, Charu; Dehner, Amie C; Issi, Luca; Lilly, Elizabeth A; Ali, Akbar; Cao, Hong; Fidel, Paul L; Rao, Reeta P; Kaufman, Paul D

    2013-08-13

    Infection by pathogenic fungi, such as Candida albicans, begins with adhesion to host cells or implanted medical devices followed by biofilm formation. By high-throughput phenotypic screening of small molecules, we identified compounds that inhibit adhesion of C. albicans to polystyrene. Our lead candidate compound also inhibits binding of C. albicans to cultured human epithelial cells, the yeast-to-hyphal morphological transition, induction of the hyphal-specific HWP1 promoter, biofilm formation on silicone elastomers, and pathogenesis in a nematode infection model as well as alters fungal morphology in a mouse mucosal infection assay. We term this compound filastatin based on its strong inhibition of filamentation, and we use chemical genetic experiments to show that it acts downstream of multiple signaling pathways. These studies show that high-throughput functional assays targeting fungal adhesion can provide chemical probes for study of multiple aspects of fungal pathogenesis.

  18. Do uniform tangential interfacial stresses enhance adhesion?

    Science.gov (United States)

    Menga, Nicola; Carbone, Giuseppe; Dini, Daniele

    2018-03-01

    We present theoretical arguments, based on linear elasticity and thermodynamics, to show that interfacial tangential stresses in sliding adhesive soft contacts may lead to a significant increase of the effective energy of adhesion. A sizable expansion of the contact area is predicted in conditions corresponding to such scenario. These results are easily explained and are valid under the assumptions that: (i) sliding at the interface does not lead to any loss of adhesive interaction and (ii) spatial fluctuations of frictional stresses can be considered negligible. Our results are seemingly supported by existing experiments, and show that frictional stresses may lead to an increase of the effective energy of adhesion depending on which conditions are established at the interface of contacting bodies in the presence of adhesive forces.

  19. Designing Hydrogel Adhesives for Corneal Wound Repair

    Science.gov (United States)

    Grinstaff, Mark W.

    2013-01-01

    Today, corneal wounds are repaired using nylon sutures. Yet there are a number of complications associated with suturing the cornea, and thus there is interest in an adhesive to replace or supplement sutures in the repair of corneal wounds. We are designing and evaluating corneal adhesives prepared from dendrimers – single molecular weight, highly branched polymers. We have explored two strategies to form these ocular adhesives. The first involves a photocrosslinking reaction and the second uses a peptide ligation reactions to couple the individual dendrimers together to from the adhesive. These adhesives were successfully used to repair corneal perforations, close the flap produced in a LASIK procedure, and secure a corneal transplant. PMID:17889330

  20. Current comorbidity among consecutive adolescent psychiatric outpatients with DSM-IV mood disorders.

    Science.gov (United States)

    Karlsson, Linnea; Pelkonen, Mirjami; Ruuttu, Titta; Kiviruusu, Olli; Heilä, Hannele; Holi, Matti; Kettunen, Kirsi; Tuisku, Virpi; Tuulio-Henriksson, Annamari; Törrönen, Johanna; Marttunen, Mauri

    2006-06-01

    To compare selected characteristics (age, sex, age of onset for depression, impairment, severity of depression, somatic comorbidity, and treatment status) of adolescents with currently comorbid and non-comorbid depression. A sample of 218 consecutive adolescent (13-19 years) psychiatric outpatients with depressive disorders, and 200 age- and sex-matched school-attending controls were interviewed for DSM-IV Axis I and Axis II diagnoses. Current comorbidity, most commonly with anxiety disorders, was equally frequent (>70%) in outpatients and depressed controls. Younger age (OR 0.20; 95% CI 0.08, 0.51) and male gender (OR 0.02; 95% CI 0.09, 0.55) were associated with concurrent disruptive disorders. Current comorbidity with substance use disorders (SUD) was independent of age (OR 1.13; 95% CI 0.51, 2.49) and sex (OR 0.51; 95% CI 0.22, 1.17). Personality disorders associated with older age (OR 2.06; 95% CI 1.10, 3.86). In multivariable logistic regression analysis, impairment (GAF multiple co-occurring problem areas. While many clinical characteristics of adolescent depression are not affected by comorbidity, comorbidity associates with increased impairment.

  1. Changes in adolescents' conflict responses associated with consecutive presentation of hypothetical conflict situations.

    Science.gov (United States)

    Johnson, H D; LaVoie, J C; Eggenburg, E; Mahoney, M A; Pounds, L

    2001-10-01

    The advantages of using hypothetical situations are one reason they have been widely used to examine adolescents' responses to conflict situations. One frequently used research protocol involves presenting several conflict scenarios to participants during a single session. However, in real-life situations multiple conflicts rarely occur within short periods of time, and the nature of this presentation may be associated with changes in adolescents' reports of conflict behaviors. Trend analyses of emotional, conflict goal, and conflict tactic responses from grade 8, 10, 12, and college students to consecutively presented conflict situations showed that responses were associated with presentation of the hypothetical situations. Findings revealed an increase in reports of assertive conflict behaviors and a decrease in reports of constructive conflict behaviors with successive situation presentation. Results from the current study suggest that researchers must consider trends in responses when examining findings from successive situation presentation methodologies because adolescent reports of conflict behavior may change as situation presentation proceeds. Copyright 2001 The Association for Professionals in Services for Adolescents.

  2. MRI of placental adhesive disorder

    Science.gov (United States)

    Prapaisilp, P; Bangchokdee, S

    2014-01-01

    Placental adhesive disorder (PAD) is a serious pregnancy complication that occurs when the chorionic villi invade the myometrium. Placenta praevia and prior caesarean section are the two important risk factors. PAD is classified on the basis of the depth of myometrial invasion (placenta accreta, placenta increta and placenta percreta). MRI is the preferred image modality for pre-natal diagnosis of PAD and as complementary technique when ultrasonography is inconclusive. Imaging findings that are helpful for the diagnosis include dark intraplacental bands, direct invasion of adjacent structures by placental tissue, interruption of normal trilayered myometrium and uterine bulging. Clinicians should be aware of imaging features of PAD to facilitate optimal patient management. PMID:25060799

  3. Adhesives for orthodontic bracket bonding

    Directory of Open Access Journals (Sweden)

    Déborah Daniella Diniz Fonseca

    2010-04-01

    Full Text Available The advent of acid etching, introduced by Buonocore in 1955, brought the possibility of bonding between the bracket base and enamel, contributing to more esthetic and conservative orthodontics. This direct bracket bonding technique has brought benefits such as reduced cost and time in performing the treatment, as well as making it easier to perform oral hygiene. The aim of this study was to conduct a survey of published studies on orthodontic bracket bonding to dental enamel. It was verified that resin composites and glass ionomer are the most studied and researched materials for this purpose. Resin-modified glass ionomer, with its biocompatibility, capacity of releasing fluoride and no need for acid etching on the tooth structure, has become increasingly popular among dentists. However, due to the esthetic and mechanical properties of light polymerizable resin composite, it continues to be one of the adhesives of choice in the bracket bonding technique and its use is widely disseminated.

  4. Masticatory performance of complete denture wearers after using two adhesives: a crossover randomized clinical trial.

    Science.gov (United States)

    de Oliveira Junior, Norberto Martins; Rodriguez, Larissa Santana; Mendoza Marin, Danny Omar; Paleari, André Gustavo; Pero, Ana Carolina; Compagnoni, Marco Antonio

    2014-11-01

    Masticatory performance analysis of conventional complete denture wearers who use denture adhesives is scarce in the dental literature. The purpose of this study was to assess the effect of the use of 2 denture adhesives on the masticatory performance of conventional complete denture wearers by means of a crossover study. Forty individuals who were edentulous received new maxillary and mandibular complete dentures, and, after an adaptation period, were submitted to masticatory performance analysis without denture adhesive (control). The participants were randomly divided and assigned to 2 protocols: protocol 1, denture adhesive 1 (Ultra Corega cream tasteless) use during the first 15 days, followed by no use of denture adhesive over the next 15 days (washout), and then use of denture adhesive 2 (Ultra Corega powder tasteless) for 15 days; protocol 2, denture adhesive 2 (Ultra Corega powder tasteless) use during the first 15 days, followed by no use of denture adhesive during the next 15 days (washout), and then use of denture adhesive 1 (Ultra Corega cream tasteless) for 15 days. The masticatory performance was assessed immediately after the use of denture adhesive by means of the sieve method, in which participants were instructed to deliberately chew 5 almonds for 20 chewing strokes. Masticatory performance was calculated by the weight of comminuted material that passed through the sieves. Data were analyzed by a 1-way ANOVA for paired samples and the multiple comparison of means by using the Bonferroni test (α=.05). A significant increase in masticatory performance was noted after using the Ultra Corega cream (mean, 32.6%) and Ultra Corega powder (mean, 31.2%) when compared with the control group (mean, 19.8%) (Padhesives evaluated. The use of denture adhesive improved the masticatory performance of conventional complete denture wearers. No difference was found in masticatory performance with the use of cream or powder denture adhesive. Copyright © 2014

  5. Renal artery origins and variations: angiographic evaluation of 855 consecutive patients.

    Science.gov (United States)

    Ozkan, Uğur; Oğuzkurt, Levent; Tercan, Fahri; Kizilkiliç, Osman; Koç, Zafer; Koca, Nihal

    2006-12-01

    To determine angiographically the origins and variations of renal arteries. The study included 855 consecutive patients (163 females, 692 males; mean age, 61 years) living in the Cukurova region of Turkey, who underwent either aortofemoropopliteal (AFP) angiography for the investigation of peripheral arterial disease, or renal angiography for renovascular hypertension, and were prospectively evaluated. Renal arteries were visualized by non-selective catheterization during AFP angiography and by selective or non-selective catheterization during renal angiography. Locations of renal artery origins and renal artery variations, including the presence of extra renal arteries and division patterns were analyzed on angiograms. The origin of main renal arteries off the aorta was between the upper margin of L1 and lower margin of L2 vertebra in 98% of the patients, and in 74%, this was the origin of extra renal arteries. The most common location for renal artery origin was the L1-L2 intervertebral disc level. A single renal artery was present in both kidneys in 76% of patients. Renal artery variations included multiple arteries in 24%, bilateral multiple arteries in 5%, and early division in 8% of the cases. Additional renal arteries on the right side were found in 16% and on the left side in 13% of cases. Of all the extra renal arteries, the percentage of accessory and aberrant renal arteries were 49% and 51%, respectively. Renal arteries originated between the first and the second lumbar vertebral levels in most patients. Extra renal arteries were quite frequent. These results should be kept in mind when a non-invasive diagnostic search is performed for renal artery stenosis, or when renal surgery related to renal arteries is performed.

  6. Vascular complications following 1500 consecutive living and cadaveric donor renal transplantations: A single center study

    International Nuclear Information System (INIS)

    Salehipour, Mehdi; Salahi, Heshmatollah; Jalaeian, Hamed; Bahador, Ali; Nikeghbalian, Saman; Barzideh, Ehsan; Ariafar, Ali; Malek-Hosseini, Seyed Ali

    2009-01-01

    The aim of this study was to document vascular complications that occurred following cadaveric and living donor kidney transplants in order to assess the overall incidence of these complications at our center as well as to identify possible risk factors. In a retrospective cohort study, 1500 consecutive renal transplant recipients who received a living or cadaveric donor kidney between December 1988 and July 2006 were evaluated. The study was performed at the Nemazee Hospital, Shiraz, Iran. The assessment of the anatomy and number of renal arteries as well as the incidence of vascular complications was made by color doppler ultrasonography, angiography, and/or surgical exploration. Clinically apparent vascular complications were seen in 8.86% of all study patients (n = 133) with the most frequent being hemorrhage (n = 91; 6.1%) followed by allograft renal artery stenosis (n = 26; 1.7%), renal artery thrombosis (n = 9; 0.6%), and renal vein thrombosis (n = 7; 0.5%). Vascular complications were more frequent in recipients of cadaveric organs than recipients of allografts from living donors (12.5% vs. 7.97%; P0.017). The occurrence of vascular complications was significantly more frequent among recipients of renal allografts with multiple arteries when compared with recipients of kidneys with single artery (12.3% vs. 8.2%; P0.033). The same was true to venous complications as well (25.4% vs. 8.2%; P< 0.001). Our study shows that vascular complications were more frequent in allografts with multiple renal blood vessels. Also, the complications were much less frequent in recipients of living donor transplants. (author)

  7. Mechanics of the Adhesive Properties of Ivy Nanoparticles

    Science.gov (United States)

    2013-11-21

    centrifuged at 1000g to remove any remaining debris. Finally, the sample was dialyzed through a 300 kDa Spectra/Por cellulose ester dialysis membrane...macromolecule with multiple physiological functions in the growth of plants, such as signaling, cell wall plasticizer , guiding pollen tube growth, and many...927 KPa (2.5 fold higher than the pure CS) after 3d reaction. Compared to 0.1and 1 Au CSNC, the 0.5 Au CSNC showed a significantly higher adhesion

  8. Opto-acoustic microscopy reveals adhesion mechanics of single cells.

    Science.gov (United States)

    Abi Ghanem, Maroun; Dehoux, Thomas; Liu, Liwang; Le Saux, Guillaume; Plawinski, Laurent; Durrieu, Marie-Christine; Audoin, Bertrand

    2018-01-01

    Laser-generated GHz-ultrasonic-based technologies have shown the ability to image single cell adhesion and stiffness simultaneously. Using this new modality, we here demonstrate quantitative indicators to investigate contact mechanics and adhesion processes of the cell. We cultured human cells on a rigid substrate, and we used an inverted pulsed opto-acoustic microscope to generate acoustic pulses containing frequencies up to 100 GHz in the substrate. We map the reflection of the acoustic pulses at the cell-substrate interface to obtain images of the acoustic impedance of the cell, Z c , as well as of the stiffness of the interface, K, with 1 μm lateral resolution. Our results show that the standard deviation ΔZ c reveals differences between different cell types arising from the multiplicity of local conformations within the nucleus. From the distribution of K-values within the nuclear region, we extract a mean interfacial stiffness, K m , that quantifies the average contact force in areas of the cell displaying weak bonding. By analogy with classical contact mechanics, we also define the ratio of the real to nominal contact areas, S r /S t . We show that K m can be interpreted as a quantitative indicator of passive contact at metal-cell interfaces, while S r /S t is sensitive to active adhesive processes in the nuclear region. The ability to separate the contributions of passive and active adhesion processes should allow gaining insight into cell-substrate interactions, with important applications in tissue engineering.

  9. Preparation and study of new rubber to steel adhesive systems

    International Nuclear Information System (INIS)

    Labaj, I.; Ondrusova, D.; Dubec, A.; Pajtasova, M.; Kohutiar, M.

    2017-01-01

    The present paper deals with the preparation of new rubber to steel adhesive systems using the steel surface treatment by applying the adhesive coats based on Co (II) and Cu(II) salts. For demonstration of coats chemical composition EDX analysis was used. The topography and microstructure of prepared adhesive coats were investigated using Scanning Electron Microscopy. Finally the efficiency of adhesion between rubber blends and coated metal steel pieces was evaluated according to Test ASTM D429 Rubber to metal adhesion, method A. The adhesive strength resulting values of prepared steel samples with new adhesive coats were compared with samples covered with adhesive systems commonly used in industry. (authors)

  10. Limit of ratio of consecutive terms for general order-k linear homogeneous recurrences with constant coefficients

    International Nuclear Information System (INIS)

    Fiorenza, Alberto; Vincenzi, Giovanni

    2011-01-01

    Research highlights: → We prove a result true for all linear homogeneous recurrences with constant coefficients. → As a corollary of our results we immediately get the celebrated Poincare' theorem. → The limit of the ratio of adjacent terms is characterized as the unique leading root of the characteristic polynomial. → The Golden Ratio, Kepler limit of the classical Fibonacci sequence, is the unique leading root. → The Kepler limit may differ from the unique root of maximum modulus and multiplicity. - Abstract: For complex linear homogeneous recursive sequences with constant coefficients we find a necessary and sufficient condition for the existence of the limit of the ratio of consecutive terms. The result can be applied even if the characteristic polynomial has not necessarily roots with modulus pairwise distinct, as in the celebrated Poincare's theorem. In case of existence, we characterize the limit as a particular root of the characteristic polynomial, which depends on the initial conditions and that is not necessarily the unique root with maximum modulus and multiplicity. The result extends to a quite general context the way used to find the Golden mean as limit of ratio of consecutive terms of the classical Fibonacci sequence.

  11. Peritoneal adhesions after laparoscopic gastrointestinal surgery.

    Science.gov (United States)

    Mais, Valerio

    2014-05-07

    Although laparoscopy has the potential to reduce peritoneal trauma and post-operative peritoneal adhesion formation, only one randomized controlled trial and a few comparative retrospective clinical studies have addressed this issue. Laparoscopy reduces de novo adhesion formation but has no efficacy in reducing adhesion reformation after adhesiolysis. Moreover, several studies have suggested that the reduction of de novo post-operative adhesions does not seem to have a significant clinical impact. Experimental data in animal models have suggested that CO₂ pneumoperitoneum can cause acute peritoneal inflammation during laparoscopy depending on the insufflation pressure and the surgery duration. Broad peritoneal cavity protection by the insufflation of a low-temperature humidified gas mixture of CO₂, N₂O and O₂ seems to represent the best approach for reducing peritoneal inflammation due to pneumoperitoneum. However, these experimental data have not had a significant impact on the modification of laparoscopic instrumentation. In contrast, surgeons should train themselves to perform laparoscopy quickly, and they should complete their learning curves before testing chemical anti-adhesive agents and anti-adhesion barriers. Chemical anti-adhesive agents have the potential to exert broad peritoneal cavity protection against adhesion formation, but when these agents are used alone, the concentrations needed to prevent adhesions are too high and could cause major post-operative side effects. Anti-adhesion barriers have been used mainly in open surgery, but some clinical data from laparoscopic surgeries are already available. Sprays, gels, and fluid barriers are easier to apply in laparoscopic surgery than solid barriers. Results have been encouraging with solid barriers, spray barriers, and gel barriers, but they have been ambiguous with fluid barriers. Moreover, when barriers have been used alone, the maximum protection against adhesion formation has been no

  12. Circulating cellular adhesion molecules and risk of diabetes: the Multi-Ethnic Study of Atherosclerosis (MESA).

    Science.gov (United States)

    Pankow, J S; Decker, P A; Berardi, C; Hanson, N Q; Sale, M; Tang, W; Kanaya, A M; Larson, N B; Tsai, M Y; Wassel, C L; Bielinski, S J

    2016-07-01

    To test the hypothesis that soluble cellular adhesion molecules would be positively and independently associated with risk of diabetes. Soluble levels of six cellular adhesion molecules (ICAM-1, E-selectin, VCAM-1, E-cadherin, L-selectin and P-selectin) were measured in participants in the Multi-Ethnic Study of Atherosclerosis, a prospective cohort study. Participants were then followed for up to 10 years to ascertain incident diabetes. Sample sizes ranged from 826 to 2185. After adjusting for age, sex, race/ethnicity, BMI and fasting glucose or HbA1c , four cellular adhesion molecules (ICAM-1, E-selectin, VCAM-1 and E-cadherin) were positively associated with incident diabetes and there was a statistically significant trend across quartiles. Comparing the incidence of diabetes in the highest and lowest quartiles of each cellular adhesion molecule, the magnitude of association was largest for E-selectin (hazard ratio 2.49; 95% CI 1.26-4.93) and ICAM-1 (hazard ratio 1.76; 95% CI 1.22-2.55) in fully adjusted models. Tests of effect modification by racial/ethnic group and sex were not statistically significant for any of the cellular adhesion molecules (P > 0.05). The finding of significant associations between multiple cellular adhesion molecules and incident diabetes may lend further support to the hypothesis that microvascular endothelial dysfunction contributes to risk of diabetes. © 2016 Diabetes UK.

  13. New developments for the investigation of hard X-rays emitted by peeling adhesive tapes.

    Science.gov (United States)

    Krämer, D; Lützenkirchen-Hecht, D; Lühmann, B; Keite-Telgenbüscher, K; Frahm, R

    2013-05-01

    We realized an advanced apparatus for the investigation of emitted X-rays produced by peeling adhesive tape rolls under vacuum conditions. Two stepper motors can unwind and rewind a tape roll, and an additional roller with an optical encoder provides measurement and control of the tape speed. This way reproducible and consecutive experiments are feasible without having to change the tape or break the vacuum. The dependence of the X-ray emission on tape speed, gas pressure, type of adhesive tape, and detector angle has been investigated. The resulting spectra are continuous and span an X-ray energy range of typically 2-60 keV with high intensity. Furthermore, the new apparatus allows the in situ metalization of adhesive tape rolls by a gold sputter source. A significantly increased X-ray emission was observed for adhesive tapes with a metal coating. Thin metal foils have been placed between the tape and the detector, different K- and L-absorption edges could be measured. A considerable enhancement of the emission was achieved under the influence of the magnetic field of an NdFeB permanent magnet.

  14. An experimental study of double-peeling mechanism inspired by biological adhesive systems

    DEFF Research Database (Denmark)

    Heepe, Lars; Raguseo, Saverio; Gorb, Stanislav N.

    2017-01-01

    Double- (or multiple-) peeling systems consist of two (or numerous) tapes adhering to a substrate and having a common hinge, where the pulling force is applied. Biological systems, consisting of tape-like (or spatula-like) contact elements, are widely observed in adhesive pads of flies, beetles...

  15. Shear Adhesion of Tapered Nanopillar Arrays.

    Science.gov (United States)

    Cho, Younghyun; Minsky, Helen K; Jiang, Yijie; Yin, Kaiyang; Turner, Kevin T; Yang, Shu

    2018-04-04

    Tapered nanopillars with various cross sections, including cone-shaped, stepwise, and pencil-like structures (300 nm in diameter at the base of the pillars and 1.1 μm in height), are prepared from epoxy resin templated by nanoporous anodic aluminum oxide (AAO) membranes. The effect of pillar geometry on the shear adhesion behavior of these nanopillar arrays is investigated via sliding experiments in a nanoindentation system. In a previous study of arrays with the same geometry, it was shown that cone-shaped nanopillars exhibit the highest adhesion under normal loading while stepwise and pencil-like nanopillars exhibit lower normal adhesion strength due to significant deformation of the pillars that occurs with increasing indentation depth. Contrary to the previous studies, here, we show that pencil-like nanopillars exhibit the highest shear adhesion strength at all indentation depths among three types of nanopillar arrays and that the shear adhesion increases with greater indentation depth due to the higher bending stiffness and closer packing of the pencil-like nanopillar array. Finite element simulations are used to elucidate the deformation of the pillars during the sliding experiments and agree with the nanoindentation-based sliding measurements. The experiments and finite element simulations together demonstrate that the shape of the nanopillars plays a key role in shear adhesion and that the mechanism is quite different from that of adhesion under normal loading.

  16. Advances in biomaterials for preventing tissue adhesion.

    Science.gov (United States)

    Wu, Wei; Cheng, Ruoyu; das Neves, José; Tang, Jincheng; Xiao, Junyuan; Ni, Qing; Liu, Xinnong; Pan, Guoqing; Li, Dechun; Cui, Wenguo; Sarmento, Bruno

    2017-09-10

    Adhesion is one of the most common postsurgical complications, occurring simultaneously as the damaged tissue heals. Accompanied by symptoms such as inflammation, pain and even dyskinesia in particular circumstances, tissue adhesion has substantially compromised the quality of life of patients. Instead of passive treatment, which involves high cost and prolonged hospital stay, active intervention to prevent the adhesion from happening has been accepted as the optimized strategy against this complication. Herein, this paper will cover not only the mechanism of adhesion forming, but also the biomaterials and medicines used in its prevention. Apart from acting as a direct barrier, biomaterials also show promising anti-adhesive bioactivity though their intrinsic physical and chemical are still not completely unveiled. Considering the diversity of human tissue organization, it is imperative that various biomaterials in combination with specific medicine could be tuned to fit the microenvironment of targeted tissues. With the illustration of different adhesion mechanism and solutions, we hope this review can become a beacon and further inspires the development of anti-adhesion biomedicines. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Determinação da expressão da molécula de adesão CD56 em plasmócitos no mieloma múltiplo através de estudo imuno-histoquímico CD56 adhesion molecule expression by plasma cells in multiple myeloma immunohistochemistry

    Directory of Open Access Journals (Sweden)

    Ana L. Coradazzi

    2003-01-01

    Full Text Available O papel das moléculas de adesão celular, na fisiopatologia do mieloma múltiplo (MM, tem sido alvo de vários estudos nos últimos anos. A expressão de CD56 pelos plasmócitos tumorais está associada a comportamento clínico menos agressivo da doença, e sua perda tem sido descrita na fase de leucemização plasmocitária. A determinação da expressão da molécula CD56 pelos plasmócitos tumorais pode ser obtida através de citometria em fluxo, revelando positividade em 55% a 78% dos casos. No presente estudo, objetivamos verificar a expressão da molécula CD56 por plasmócitos tumorais na medula óssea de portadores de MM, utilizando o estudo imuno-histoquímico das amostras histológicas obtidas ao diagnóstico. Analisamos as amostras de medula óssea de vinte portadores de MM, e realizamos o estudo imuno-histoquímico para determinação da expressão das cadeias leves kappa e lambda e da molécula CD56 pelos plasmócitos tumorais. A expressão da molécula CD56 foi importante em três casos, moderada em seis, discreta em quatro e negativa em sete. O estudo imuno-histoquímico mostrou-se válido para determinação da expressão de CD56 por plasmócitos tumorais em portadores de MM, fornecendo resultados semelhantes aos descritos para os obtidos por citometria em fluxo. Através do estudo imuno-histoquímico, foi possível observar variações da expressão da molécula CD56.The role of adhesion molecules in the physiopathology of multiple myeloma has been the target of many studies over the last years. The CD56 expression by neoplastic plasma cells is related to a less aggressive clinical course, and its loss is described in plasma cell leukemia. The evaluation of the CD56 expression may be obtained by flow cytometry, with positivity in 55% to 78% of cases. In this study, we verified the CD56 expression by plasma cells in bone marrow of myeloma patients using immunohistochemistry in samples obtained at diagnosis. We analyzed bone

  18. Mediating Peer Teaching for Learning Games: An Action Research Intervention across Three Consecutive Sport Education Seasons

    Science.gov (United States)

    Farias, Cláudio; Mesquita, Isabel; Hastie, Peter A.; O'Donovan, Toni

    2018-01-01

    Purpose: The purpose of this study was to provide an integrated analysis of a teacher's peer-teaching mediation strategies, the student-coaches' instruction, and the students' gameplay development across 3 consecutive seasons of sport education. Method: Twenty-six 7th-grade students participated in 3 consecutive sport education seasons of invasion…

  19. Adhesion property of epoxidized natural rubber (ENR-based adhesives containing calcium carbonate

    Directory of Open Access Journals (Sweden)

    2008-06-01

    Full Text Available The adhesion property (i.e. viscosity, loop tack and peel strength of epoxidized natural rubber (ENR 25 and ENR 50 grade-based pressure-sensitive adhesive was studied in the presence of calcium carbonate. The range of calcium carbonate loaded was from 10 to 50 parts per hundred parts of rubber (phr. Coumarone-indene resin was used as the tackifier and its concentration was fixed at 80 phr. Toluene was chosen as the solvent throughout the investigation. The substrates (PET film/paper were coated with the adhesive using a SHEEN hand coater at a coating thickness of 60 µm. Viscosity of the adhesive was measured by a HAAKE Rotary Viscometer whereas loop tack and peel strength were determined by a Llyod Adhesion Tester operating at 30 cm/min. Results show that viscosity of ENR-based adhesives increases gradually with increase in calcium carbonate loading due to the concentration effect of the filler. However, for loop tack and peel strength, it passes through a maximum at 30 phr calcium carbonate, an observation which is attributed to the optimum wettability of adhesive on the substrate at this adhesive composition. ENR 25-based adhesive consistently exhibits higher adhesion property than ENR 50 for all calcium carbonate loadings studied.

  20. Deep UV patterning of acrylic masters for molding biomimetic dry adhesives

    International Nuclear Information System (INIS)

    Sameoto, D; Menon, C

    2010-01-01

    We present a novel fabrication method for the production of biomimetic dry adhesives that allows enormous variation in fiber shapes and sizes. The technology is based on deep-UV patterning of commercial acrylic with semi-collimated light available from germicidal lamps, and combined careful processing conditions, material selection and novel developer choices to produce relatively high-aspect-ratio fibers with overhanging caps on large areas. These acrylic fibers are used as a master mold for subsequent silicone rubber negative mold casting. Because the bulk acrylic demonstrates little inherent adhesion to silicone rubbers, the master molds created in this process do not require any surface treatments to achieve high-yield demolding of interlocked structures. Multiple polymers can be cast from silicone rubber negative molds and this process could be used to structure smart materials on areas over multiple square feet. Using direct photopatterning of acrylic allows many of the desired structures for biomimetic dry adhesives to be produced with relative ease compared to silicon-based molding processes, including angled fibers and hierarchical structures. Optimized fiber shapes for a variety of polymers can be produced using this process, and adhesion measurements on a well-characterized polyurethane, ST-1060, are used to determine the effect of fiber geometry on adhesion performance

  1. Consecutive successful pregnancies subsequent to intravenous immunoglobulin therapy in a patient with recurrent spontaneous miscarriage

    Directory of Open Access Journals (Sweden)

    Diejomaoh MF

    2015-12-01

    nonreassuring fetal status, a live female infant weighing 2.29 kg was delivered by emergency cesarean section on January 14, 2015, with an Apgar score of 8 and 9 and mild respiratory distress, and was admitted to the Special Care Baby Unit for intensive therapy. The mother and baby made satisfactory progress and were discharged on January 24, 2015. Conclusion: Two consecutive successful pregnancies in Mrs HM with multiple causes of RSM treated with other medications and IVIG strongly suggest that IVIG has a positive role in RSM. Keywords: recurrent, miscarriage, intravenous immunoglobulin, pregnancy outcome

  2. Individualized FAC on bottom tab subassemblies to minimize adhesive gap between emitter and optics

    Science.gov (United States)

    Sauer, Sebastian; Müller, Tobias; Haag, Sebastian; Beleke, Andreas; Zontar, Daniel; Baum, Christoph; Brecher, Christian

    2017-02-01

    High Power Diode Laser (HPDL) systems with short focal length fast-axis collimators (FAC) require submicron assembly precision. Conventional FAC-Lens assembly processes require adhesive gaps of 50 microns or more in order to compensate for component tolerances (e.g. deviation of back focal length) and previous assembly steps. In order to control volumetric shrinkage of fast-curing UV-adhesives shrinkage compensation is mandatory. The novel approach described in this paper aims to minimize the impact of volumetric shrinkage due to the adhesive gap between HPDL edge emitters and FAC-Lens. Firstly, the FAC is actively aligned to the edge emitter without adhesives or bottom tab. The relative position and orientation of FAC to emitter are measured and stored. Consecutively, an individual subassembly of FAC and bottom tab is assembled on Fraunhofer IPT's mounting station with a precision of +/-1 micron. Translational and lateral offsets can be compensated, so that a narrow and uniform glue gap for the consecutive bonding process of bottom tab to heatsink applies (Figure 4). Accordingly, FAC and bottom tab are mounted to the heatsink without major shrinkage compensation. Fraunhofer IPT's department assembly of optical systems and automation has made several publications regarding active alignment of FAC lenses [SPIE LASE 8241-12], volumetric shrinkage compensation [SPIE LASE 9730-28] and FAC on bottom tab assembly [SPIE LASE 9727-31] in automated production environments. The approach described in this paper combines these and is the logical continuation of that work towards higher quality of HPDLs.

  3. Molybdenum protective coatings adhesion to steel substrate

    Science.gov (United States)

    Blesman, A. I.; Postnikov, D. V.; Polonyankin, D. A.; Teplouhov, A. A.; Tyukin, A. V.; Tkachenko, E. A.

    2017-06-01

    Protection of the critical parts, components and assemblies from corrosion is an urgent engineering problem and many other industries. Protective coatings’ forming on surface of metal products is a promising way of corrosionprevention. The adhesion force is one of the main characteristics of coatings’ durability. The paper presents theoretical and experimental adhesion force assessment for coatings formed by molybdenum magnetron sputtering ontoa steel substrate. Validity and reliability of results obtained by simulation and sclerometry method allow applying the developed model for adhesion force evaluation in binary «steel-coating» systems.

  4. Adhesive bonding using variable frequency microwave energy

    Science.gov (United States)

    Lauf, Robert J.; McMillan, April D.; Paulauskas, Felix L.; Fathi, Zakaryae; Wei, Jianghua

    1998-01-01

    Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy.

  5. Adhesion Strength of Biomass Ash Deposits

    DEFF Research Database (Denmark)

    Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao

    2016-01-01

    . Therefore, timely removal of ash deposits is essential for optimal boiler operation. In order to improve the qualitative and quantitative understanding of deposit shedding in boilers, this study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash...... deposits were prepared on superheater tubes and sintered in an oven at temperatures up to 1000 °C. Subsequently, the deposits were sheared off by an electrically controlled arm, and the corresponding adhesion strength was measured. The results reveal the effect of temperature, ash/deposit composition......, sintering duration, and steel type on the adhesion strength....

  6. Adhesion Between Poly(dimethylsiloxane) Layers

    DEFF Research Database (Denmark)

    Yu, Liyun; Daugaard, Anders Egede; Skov, Anne Ladegaard

    Different adhesion methods of poly(dimethylsiloxane) (PDMS) layers were studied with respect to adhesional force and the resulting rheology of the two-layered PDMS films were investigated. The role of adhesion between PDMS layers on the performances of two-layer structures was studied with peel...... strength test and by SEM pictures. The rheology of the double-layered compared to the monolayer films changed in some cases which indicates that the adhesion process needs to be carefully introduced in order not to alter the final properties....

  7. Adhesion Strength of Biomass Ash Deposits

    DEFF Research Database (Denmark)

    Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao

    2015-01-01

    This study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash deposits were prepared on superheater tubes and sintered in an oven at temperatures up to 1000°C. Subsequently, the deposits were sheared off with the help of an electrically...... controlled arm. Higher sintering temperatures resulted in greater adhesion strengths, with a sharp increase observed near the melting point of the ash. Repetition of experiments with fixed operation conditions revealed considerable variation in the obtained adhesion strengths, portraying the stochastic...

  8. Vaginal epithelial cells regulate membrane adhesiveness to co-ordinate bacterial adhesion.

    Science.gov (United States)

    Younes, Jessica A; Klappe, Karin; Kok, Jan Willem; Busscher, Henk J; Reid, Gregor; van der Mei, Henny C

    2016-04-01

    Vaginal epithelium is colonized by different bacterial strains and species. The bacterial composition of vaginal biofilms controls the balance between health and disease. Little is known about the relative contribution of the epithelial and bacterial cell surfaces to bacterial adhesion and whether and how adhesion is regulated over cell membrane regions. Here, we show that bacterial adhesion forces with cell membrane regions not located above the nucleus are stronger than with regions above the nucleus both for vaginal pathogens and different commensal and probiotic lactobacillus strains involved in health. Importantly, adhesion force ratios over membrane regions away from and above the nucleus coincided with the ratios between numbers of adhering bacteria over both regions. Bacterial adhesion forces were dramatically decreased by depleting the epithelial cell membrane of cholesterol or sub-membrane cortical actin. Thus, epithelial cells can regulate membrane regions to which bacterial adhesion is discouraged, possibly to protect the nucleus. © 2015 John Wiley & Sons Ltd.

  9. Microleakage of hydrophilic adhesive systems in Class V composite restorations.

    Science.gov (United States)

    Amaral, C M; Hara, A T; Pimenta, L A; Rodrigues, A L

    2001-02-01

    To investigate the microleakage of four hydrophilic adhesive systems: one "multiple-bottles" (Scotchbond Multi-Purpose Plus); two "one-bottle" (Single Bond, Stae); and one self-etching (Etch & Prime 3.0). 120 bovine incisor teeth were divided into four groups (n = 30) and Class V cavities were prepared at the cemento-enamel junction. The cavities were restored with the adhesive systems and with Z100 composite. The teeth were thermocycled 1,000 times between 5+/-2 degrees C and 55+/-2 degrees C with a dwell time of 1 min, and then placed in a 2% methylene blue dye (pH 7.0) for 4 hrs, washed and sectioned vertically through the center of the restorations. The qualitative evaluation was made by three examiners who distributed pre-established scores (0-4) for each tooth using a stereomicroscope at x30 magnification. In enamel margins little microleakage was observed and the Kruskal-Wallis analysis did not show differences. In dentin margins the Kruskal-Wallis and multiple comparison analyses were applied: microleakage was significantly greater with Stae (median 3) and Scotchbond MP Plus (median 4). Single Bond (median 1) and Etch & Prime 3.0 (median 2) showed the best results in dentin margins, and the statistical analysis did not demonstrate differences in microleakage among these groups.

  10. Adhesion of multimode adhesives to enamel and dentin after one year of water storage.

    Science.gov (United States)

    Vermelho, Paulo Moreira; Reis, André Figueiredo; Ambrosano, Glaucia Maria Bovi; Giannini, Marcelo

    2017-06-01

    This study aimed to evaluate the ultramorphological characteristics of tooth-resin interfaces and the bond strength (BS) of multimode adhesive systems to enamel and dentin. Multimode adhesives (Scotchbond Universal (SBU) and All-Bond Universal) were tested in both self-etch and etch-and-rinse modes and compared to control groups (Optibond FL and Clearfil SE Bond (CSB)). Adhesives were applied to human molars and composite blocks were incrementally built up. Teeth were sectioned to obtain specimens for microtensile BS and TEM analysis. Specimens were tested after storage for either 24 h or 1 year. SEM analyses were performed to classify the failure pattern of beam specimens after BS testing. Etching increased the enamel BS of multimode adhesives; however, BS decreased after storage for 1 year. No significant differences in dentin BS were noted between multimode and control in either evaluation period. Storage for 1 year only reduced the dentin BS for SBU in self-etch mode. TEM analysis identified hybridization and interaction zones in dentin and enamel for all adhesives. Silver impregnation was detected on dentin-resin interfaces after storage of specimens for 1 year only with the SBU and CSB. Storage for 1 year reduced enamel BS when adhesives are applied on etched surface; however, BS of multimode adhesives did not differ from those of the control group. In dentin, no significant difference was noted between the multimode and control group adhesives, regardless of etching mode. In general, multimode adhesives showed similar behavior when compared to traditional adhesive techniques. Multimode adhesives are one-step self-etching adhesives that can also be used after enamel/dentin phosphoric acid etching, but each product may work better in specific conditions.

  11. HMAC layer adhesion through tack coat.

    Science.gov (United States)

    2017-02-01

    Tack coats are the asphaltic emulsions applied between pavement lifts to provide adequate bond between the two surfaces. The adhesive bond between the two layers helps the pavement system to behave as a monolithic structure and improves the structura...

  12. Synthesis of LTA zeolite for bacterial adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Belaabed, R.; Eabed, S.; Addaou, A.; Laajab, A.; Rodriguez, M.A.; Lahsini, A.

    2016-07-01

    High affinity and adhesion capacity for Gram-positive bacteria on minerals has been widely studied. In this work the adhesion of bacteria on synthesized zeolite has been studied. The Zeolite Linde Type A (LTA) has been synthesized using hydrothermal route using processing parameters to obtain low cost materials. For adhesion studies Staphylococcus aureus and Bacillus subtilis were used as Gram-positive bacteria, Escherichia coli and Pseudomonas aeruginosa are used as Gram-negative bacteria. X-ray diffraction, environmental scanning electron microscope and attenuated total reflection-Fourier transform infrared spectroscopy were used to characterize the synthesized zeolite. To evaluate the bacterial adhesion to zeolite LTA the hydrophobicity and surface properties are examined using contact angle measurement. (Author)

  13. Anti-adhesive properties of fish tropomyosins

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk; Bernbom, Nete; Gram, Lone

    2008-01-01

    Aims: We have recently found that preconditioning of stainless steel surfaces with an aqueous fish muscle extract can significantly impede bacterial adhesion. The purpose of this study was to identify and characterize the primary components associated with this bacteria-repelling effect. Methods...... to the formation of a proteinaceous conditioning film composed primarily of fish tropomyosins. These fibrous proteins formed a considerable anti-adhesive conditioning layer on and reduced bacterial adhesion to several different materials including polystyrene, vinyl plastic, stainless steel and glass. The protein...... the importance of substratum's physiochemical properties and exposure time with regards to protein adsorption/elution efficiency and subsequent bacterial adhesion. Significance and Impact of the Study: Fish tropomyosin-coatings could potentially offer a nontoxic and relatively inexpensive measure of reducing...

  14. Recent advances in nanostructured biomimetic dry adhesives

    Directory of Open Access Journals (Sweden)

    Andras ePattantyus-Abraham

    2013-12-01

    Full Text Available The relatively large size of the gecko and its ability to climb a multitude of structures with ease has often been cited as the inspiration upon which the field of dry adhesives is based. Since 2010, there have been many advances in the field of dry adhesives with much of the new research focusing on developing nanoscale and hierarchical features in a concentrated effort to develop synthetic gecko-like dry adhesives which are strong, durable and self-cleaning. A brief overview of the geckos and the hairs which it uses to adhere to many different surfaces is provided before delving into the current methods and materials used to fabricate synthetic gecko hairs. A summary of the recently published literature on bio-inspired, nanostructured dry adhesives is presented with an emphasis being placed on fabrication techniques.

  15. Handbook of adhesive bonded structural repair

    CERN Document Server

    Wegman, Raymond F

    1992-01-01

    Provides repair methods for adhesive bonded and composite structures; identifies suitable materials and equipment for repairs; describes damage evaluation criteria and techniques, and methods of inspection before and after repair.

  16. Clinical acceptability of two self-etch adhesive resins for the bonding of orthodontic brackets to enamel.

    Science.gov (United States)

    Schnebel, Bradley; Mateer, Scott; Maganzini, Anthony Louis; Freeman, Katherine

    2012-12-01

    To determine whether two self-adhesive resin cements, Clearfil SA and RelyX, can be used to successfully bond orthodontic brackets to enamel. Seventy extracted premolars were custom mounted, cleaned and randomly divided into three groups. In group 1 (control), orthodontic brackets were bonded to 25 premolars using the Transbond Plus and Transbond XT two step adhesive systerm adhesive. In group 2, brackets were bonded to 25 premolars using Clearfil SA. In group 3, brackets were bonded to 20 premolars using RelyX. The brackets were debonded using a universal testing machine and shear bond strengths recorded. After debonding, each tooth was examined under 20× magnification to evaluate the residual adhesive remaining. An ANOVA with Duncan's Multiple Range Test was used to determine whether there were significant differences in shear bond strength between the groups. A Kruskal-Wallis Test and a Bonferroni multiple comparison procedure were used to compare the bond failure modes (adhesive remnant index scores) between the groups. The mean shear bond strengths for the brackets bonded using Clearfil SA and RelyX were 5·930±1·840 and 3·334±1·953 MPa, respectively. Both were significantly lower than that for the brackets bonded using Transbond (7·875±3·611 MPa). Both self-etch adhesive resin cement groups showed a greater incidence of bracket failure at the enamel/adhesive interface while the Transbond group showed a higher incidence at the bracket/adhesive interface. The shear bond strengths of the self-etch adhesive resin cements may be inadequate to successfully bond orthodontic brackets to enamel.

  17. Reactive Nanocomposites for Controllable Adhesive Debonding

    Science.gov (United States)

    2011-08-01

    technologies include shape memory alloy (SMA)-based approach, a chemical foaming agent (CFA) approach, and a reactive nanocomposite (RNC) approach. SMA...anofoil (a) Component 1 Thermoset Adhesive Component 2 Nano-coating (b) Figure 2. Debonding approach where (a) freestanding...J. Controlled Adhesive Debonding of RAH-66 Comanche Chines Using Shape Memory Alloys ; ARL-TR-2937; U.S. Army Research Laboratory: Aberdeen Proving

  18. Adhesive capsulitis: review of imaging and treatment

    International Nuclear Information System (INIS)

    Harris, Guy; Bou-Haider, Pascal; Harris, Craig

    2013-01-01

    Adhesive capsulitis is one of the most common conditions affecting the shoulder; however, early clinical diagnosis can be challenging. Treatment is most effective when commenced prior to the onset of capsular thickening and contracture; consequently, the role of imaging is increasing. The aim of this review is to demonstrate the typical imaging appearances of adhesive capsulitis and to examine some of the evidence regarding each of these imaging modalities. An evaluation of the various management options available to the clinician is also presented.

  19. Adhesion between Polydimethylsiloxane Layers by Crosslinking

    DEFF Research Database (Denmark)

    Yu, Liyun; Daugaard, Anders Egede; Skov, Anne Ladegaard

    2013-01-01

    Adhesion between two surfaces may be strongly improved by chemical crosslinking of the interfaces. Polydimethylsiloxane (PDMS) is a widely used polymer that has received considerable attention due to its unique properties, such as relatively low price, biocompatibility, flexibility, high thermal...... investigated by rheology and microscopy. The objective of this work was to create adhesion of two layers without destroying the original viscoelastic properties of the PDMS films....

  20. Processable polyimide adhesive and matrix composite resin

    Science.gov (United States)

    Pratt, J. Richard (Inventor); St.clair, Terry L. (Inventor); Progar, Donald J. (Inventor)

    1990-01-01

    A high temperature polyimide composition prepared by reacting 4,4'-isophthaloyldiphthalic anhydride with metaphenylenediamine is employed to prepare matrix resins, adhesives, films, coatings, moldings, and laminates, especially those showing enhanced flow with retention of mechanical and adhesive properties. It can be used in the aerospace industry, for example, in joining metals to metals or metals to composite structures. One area of application is in the manufacture of lighter and stronger aircraft and spacecraft structures.

  1. Influence of Application Time and Etching Mode of Universal Adhesives on Enamel Adhesion.

    Science.gov (United States)

    Sai, Keiichi; Takamizawa, Toshiki; Imai, Arisa; Tsujimoto, Akimasa; Ishii, Ryo; Barkmeier, Wayne W; Latta, Mark A; Miyazaki, Masashi

    2018-01-01

    To investigate the influence of application time and etching mode of universal adhesives on enamel adhesion. Five universal adhesives, Adhese Universal, Bondmer Lightless, Clearfil Universal Bond Quick, G-Premio Bond, and Scotchbond Universal, were used. Bovine incisors were prepared and divided into four groups of ten teeth each. SBS, Ra, and SFE were determined after the following procedures: 1. self-etch mode with immediate air blowing after application (IA); 2. self-etch mode with prolonged application time (PA); 3. etch-and-rinse mode with IA; 4. etch-and-rinse mode with PA. After 24-h water storage, the bonded assemblies were subjected to shear bond strength (SBS) tests. For surface roughness (Ra) and surface free energy (SFE) measurements, the adhesives were simply applied to the enamel and rinsed with acetone and water before the measurements were carried out. Significantly higher SBS and Ra values were obtained with etch-and-rinse mode than with self-etch mode regardless of the application time or type of adhesive. Although most adhesives showed decreased SFE values with increased application time in self-etch mode, SFE values in etch-and-rinse mode were dependent on the adhesive type and application time. Etching mode, application time, and type of adhesive significantly influenced the SBS, Ra, and SFE values.

  2. Platelet adhesiveness: the effect of centrifugation on the measurement of adhesiveness in platelet-rich plasma

    Science.gov (United States)

    McBride, J. A.

    1968-01-01

    Platelet adhesiveness has been measured in citrated whole blood and in platelet-rich plasma obtained from normal subjects, splenectomized patients, and from patients in whom the diagnosis of recurrent venous thrombosis had been made. The duration of centrifugation used in the preparation of platelet-rich plasma was found to have a profound effect on the measurement of platelet adhesiveness because the figure for platelet adhesiveness measured in platelet-rich plasma obtained by centrifugation was considerably lower than that found in citrated whole blood. This effect was particularly marked when platelet-rich plasma was obtained from subjects in whom platelet adhesiveness measured in whole blood was increased. PMID:5699080

  3. Elimination of the reactivation process in the adhesion of chlorinated SBS rubber with polychloroprene adhesives

    Directory of Open Access Journals (Sweden)

    2007-04-01

    Full Text Available Chlorination treatment of a thermoplastic styrene-butadiene-styrene rubber (SBS with a 3 wt% solution of trichloroisocyanuric acid (TCI in methyl ethyl ketone (MEK introduces chlorinated and oxidized moieties on the rubber surface which increase its surface energy and produces surface microroughness. Consequently adhesion properties, evaluated by T-peel strength measurements in chlorinated SBS/solvent based-polyurethane adhesive/leather joints, are enhanced. In this study, two solvent-based polychloroprene adhesives (PCP0 and PCP30R have been considered as an alternative to the commonly used solvent-based polyurethane adhesive (PU. A thermoreactive phenolic resin was added to one of the polychloroprene adhesive formulations (PCP30R. This tackifier resin favors chlorination of the adhesive and reinforces the interface between the chlorinated adhesive and the chlorinated rubber surface. Besides, PCP30R adhesive does not need adhesive reactivation and considerable high T-peel strength value (5.7±0.3 kN/m was obtained. Elimination of the reactivation process implies a considerable improvement of the manufacturing process in the footwear industry.

  4. Critical analysis of consecutive unilateral cleft lip repairs: determining ideal sample size.

    Science.gov (United States)

    Power, Stephanie M; Matic, Damir B

    2013-03-01

    Objective : Cleft surgeons often show 10 consecutive lip repairs to reduce presentation bias, however the validity remains unknown. The purpose of this study is to determine the number of consecutive cases that represent average outcomes. Secondary objectives are to determine if outcomes correlate with cleft severity and to calculate interrater reliability. Design : Consecutive preoperative and 2-year postoperative photographs of the unilateral cleft lip-nose complex were randomized and evaluated by cleft surgeons. Parametric analysis was performed according to chronologic, consecutive order. The mean standard deviation over all raters enabled calculation of expected 95% confidence intervals around a mean tested for various sample sizes. Setting : Meeting of the American Cleft Palate-Craniofacial Association in 2009. Patients, Participants : Ten senior cleft surgeons evaluated 39 consecutive lip repairs. Main Outcome Measures : Preoperative severity and postoperative outcomes were evaluated using descriptive and quantitative scales. Results : Intraclass correlation coefficients for cleft severity and postoperative evaluations were 0.65 and 0.21, respectively. Outcomes did not correlate with cleft severity (P  =  .28). Calculations for 10 consecutive cases demonstrated wide 95% confidence intervals, spanning two points on both postoperative grading scales. Ninety-five percent confidence intervals narrowed within one qualitative grade (±0.30) and one point (±0.50) on the 10-point scale for 27 consecutive cases. Conclusions : Larger numbers of consecutive cases (n > 27) are increasingly representative of average results, but less practical in presentation format. Ten consecutive cases lack statistical support. Cleft surgeons showed low interrater reliability for postoperative assessments, which may reflect personal bias when evaluating another surgeon's results.

  5. 21 CFR 175.125 - Pressure-sensitive adhesives.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Pressure-sensitive adhesives. 175.125 Section 175...) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADHESIVES AND COMPONENTS OF COATINGS Substances for Use Only as Components of Adhesives § 175.125 Pressure-sensitive adhesives. Pressure-sensitive...

  6. Bloodstream infection following 217 consecutive systemic-enteric drained pancreas transplants

    Directory of Open Access Journals (Sweden)

    Mark Walter

    2006-08-01

    Full Text Available Abstract Background Combined kidney pancreas transplantation (PTx evolved as excellent treatment for diabetic nephropathy. Infections remain common and serious complications. Methods 217 consecutive enteric drained PTxs performed from 1997 to 2004 were retrospectively analyzed with regard to bloodstream infection. Immunosuppression consisted of antithymocyteglobuline induction, tacrolimus, mycophenolic acid and steroids for the majority of cases. Standard perioperative antimicrobial prophylaxis consisted of pipercillin/tazobactam in combination with ciprofloxacin and fluconazole. Results One year patient, pancreas and kidney graft survival were 96.4%, 88.5% and 94.8%, surgical complication rate was 35%, rejection rate 30% and rate of infection 59%. In total 46 sepsis episodes were diagnosed in 35 patients (16% with a median onset on day 12 (range 1–45 post transplant. Sepsis source was intraabdominal infection (IAI (n = 21, a contaminated central venous line (n = 10, wound infection (n = 5, urinary tract infection (n = 2 and graft transmitted (n = 2. Nine patients (4% experienced multiple episodes of sepsis. Overall 65 pathogens (IAI sepsis 39, line sepsis 15, others 11 were isolated from blood. Gram positive cocci accounted for 50 isolates (77%: Coagulase negative staphylococci (n = 28, i.e. 43% (nine multi-resistant, Staphylococcus aureus (n = 11, i.e. 17% (four multi-resistant, enterococci (n = 9, i.e. 14% (one E. faecium. Gram negative rods were cultured in twelve cases (18%. Patients with blood borne infection had a two year pancreas graft survival of 76.5% versus 89.4% for those without sepsis (p = 0.036, patient survival was not affected. Conclusion Sepsis remains a serious complication after PTx with significantly reduced pancreas graft, but not patient survival. The most common source is IAI.

  7. Factors influencing bacterial adhesion to contact lenses.

    Science.gov (United States)

    Dutta, Debarun; Cole, Nerida; Willcox, Mark

    2012-01-01

    The process of any contact lens related keratitis generally starts with the adhesion of opportunistic pathogens to contact lens surface. This article focuses on identifying the factors which have been reported to affect bacterial adhesion to contact lenses. Adhesion to lenses differs between various genera/species/strains of bacteria. Pseudomonas aeruginosa, which is the predominant causative organism, adheres in the highest numbers to both hydrogel and silicone hydrogel lenses in vitro. The adhesion of this strain reaches maximum numbers within 1h in most in vitro studies and a biofilm has generally formed within 24 h of cells adhering to the lens surface. Physical and chemical properties of contact lens material affect bacterial adhesion. The water content of hydroxyethylmethacrylate (HEMA)-based lenses and their iconicity affect the ability of bacteria to adhere. The higher hydrophobicity of silicone hydrogel lenses compared to HEMA-based lenses has been implicated in the higher numbers of bacteria that can adhere to their surfaces. Lens wear has different effects on bacterial adhesion, partly due to differences between wearers, responses of bacterial strains and the ability of certain tear film proteins when bound to a lens surface to kill certain types of bacteria.

  8. Use of Adhesion Promoters in Asphalt Mixtures

    Directory of Open Access Journals (Sweden)

    Cihlářová Denisa

    2018-03-01

    Full Text Available The purpose of asphalt binder as a significant binder in road constructions is to permanently bind aggregates of different compositions and grain sizes. The asphalt binder itself does not have suitable adhesiveness, so after a period of time, bare grains can appear. This results in a gradual separation of the grains from an asphalt layer and the presence of potholes in a pavement. Adhesion promoters or adhesive agents are important and proven promoters in practice. They are substances mainly based on the fatty acids of polyamides which should increase the reliability of the asphalt’s binder adhesion to the aggregates, thus increasing the lifetime period of the asphalt mixture as well as its resistance to mechanical strain. The amount of a promoter or agent added to the asphalt mixture is negligible and constitutes about 0.3% of the asphalt’s binder weight. Nevertheless, even this quantity significantly increases the adhesive qualities of an asphalt binder. The article was created in cooperatation with the Slovak University of Technology, in Bratislava, Slovakia, and focuses on proving the new AD2 adhesive additive and comparing it with the Addibit and Wetfix BE promoters used on aggregates from the Skuteč - Litická and Bystřec quarries.

  9. Advances in modeling and design of adhesively bonded systems

    CERN Document Server

    Kumar, S

    2013-01-01

    The book comprehensively charts a way for industry to employ adhesively bonded joints to make systems more efficient and cost-effective Adhesively bonded systems have found applications in a wide spectrum of industries (e.g., aerospace, electronics, construction, ship building, biomedical, etc.) for a variety of purposes. Emerging adhesive materials with improved mechanical properties have allowed adhesion strength approaching that of the bonded materials themselves. Due to advances in adhesive materials and the many potential merits that adhesive bonding offers, adhesive bonding has replac

  10. Tissue adhesives for simple traumatic lacerations.

    Science.gov (United States)

    Beam, Joel W

    2008-01-01

    Farion K, Osmond MH, Hartling L, et al. Tissue adhesives for traumatic lacerations in children and adults. Cochrane Database Syst Rev. 2001(4);CD003326. What is the clinical evidence base for tissue adhesives in the management of simple traumatic lacerations? Studies were identified by searches of the following databases: Cochrane Wounds Group Specialized Trials Register (September 2003), Cochrane Central Register of Controlled Trials (CENTRAL) (CDROM 2003, issue 3), MEDLINE (1966 to September 2003, week 1), EMBASE (1988 to 2003, week 36), Web of Science Science Citation Index (1975 to September 13, 2003) and various clinical trials registers (September 2003). Investigators and product manufacturers were contacted to identify additional eligible studies. The search terms included wounds and injuries, laceration, face injury, nose injury, tissue adhesives, and acrylates. Each study fulfilled the following criteria: (1) The study was a randomized controlled trial that compared tissue adhesives with standard wound closure (SWC) (sutures, staples, adhesive strips) or tissue adhesive with tissue adhesive. (2) The wounds were acute, linear lacerations less than 12 hours old, resulting from blunt or sharp trauma. (3) The wound length, width, and depth allowed for approximation of the edges with minimal tension after deep sutures were placed, if required. Studies were included with no language or publication status restriction, with participants of any age recruited in an emergency department, outpatient clinic, walk-in clinic, or other primary care setting. Studies were excluded if the wounds were stellate lacerations, puncture wounds, mammalian bites, infected, heavily contaminated or devitalized, crossing joints or mucocutaneous junctions, in hair-bearing areas, or in patients with keloid formation or chronic illness. The characteristics of the study and participants, interventions, outcome measures, and findings were extracted by one author and verified by a second

  11. Synthesis and Consecutive Reactions of α-Azido Ketones: A Review

    Directory of Open Access Journals (Sweden)

    Sadia Faiz

    2015-08-01

    Full Text Available This review paper covers the major synthetic approaches attempted towards the synthesis of α-azido ketones, as well as the synthetic applications/consecutive reactions of α-azido ketones.

  12. Factors predisposing to consecutive esotropia after surgery to correct intermittent exotropia.

    Science.gov (United States)

    Jang, Jung Hyun; Park, Jung Min; Lee, Soo Jung

    2012-10-01

    To investigate the incidence of and factors predisposing to consecutive esotropia after intermittent exotropia surgery, and to prevent the onset of consecutive esotropia. We retrospectively surveyed 226 patients who had been followed up for more than 1 year after surgery for intermittent exotropia conducted between February 2005 and September 2010. Consecutive esotropia was defined as an esotropia of at least 10 prism diopters (PD) at distance or near at least once in 2 weeks after surgery. Presumed risk factors for consecutive esotropia were analyzed. Gender, age at surgery, average binocular spherical equivalent, anisometropia, high myopia, amblyopia, preoperative angle of deviation, vertical deviation, A-V pattern strabismus, exotropia type, type of surgery, stereopsis, and suppression were investigated to evaluate factors influencing the onset of consecutive esotropia. Consecutive esotropia occurred in 22 patients (9.7 %). Significant correlations with occurrence of the condition were found with high myopia (P = 0.013), amblyopia (P = 0.047), preoperative angle of deviation of 25-40 PD at distance (P = 0.016), deviation at distance - deviation at near > 10 PD (P = 0.041), lateral incomitance (P = 0.007), tenacious proximal convergence fusion type (P = 0.001), unilateral lateral rectus muscle recession and medial rectus muscle resection (P = 0.001). High myopia, amblyopia, and lateral incomitance were predisposing factors for consecutive esotropia. Furthermore, the preoperative angle of deviation at distance, differences between the angle of deviation at near and at distance, the type of intermittent exotropia, and the type of surgery affected the incidence of consecutive esotropia. More attention must be paid to patients with such factors.

  13. Is nonoperative management of adhesive intestinal obstruction applicable to children in a resource-poor country?

    Directory of Open Access Journals (Sweden)

    Osifo Osarumwense

    2010-01-01

    Full Text Available Background: Nonoperative management of adhesive intestinal obstruction gives good results in adults but there are scant studies on its outcome in children. This study reports outcomes and experiences with nonoperative and operative management of adhesive intestinal obstruction in children in a resource-poor country. Patients and Methods: This is a retrospective analysis of records of children who were managed with adhesive intestinal obstruction at the University of Benin Teaching Hospital between January 2002 and December 2008. Results: Adhesive intestinal obstruction accounted for 21 (8.8% of 238 children managed with intestinal obstruction. They were aged between 7 weeks and 16 years (mean 3 ± 6.4 years, comprising 13 males and eight females (ratio 1.6:1. Prior laparotomy for gangrenous/perforated intussusception (seven, 33.3%, perforated appendix (five, 23.8%, perforated volvulus (three, 14.3%, penetrating abdominal trauma (two, 9.5% and perforated typhoid (two, 9.5% were major aetiologies. Adhesive obstruction occurred between 6 weeks and 7 years after the index laparotomies. All the 21 children had initial nonoperative management without success, owing to lack of total parenteral nutrition and monitoring facilities. Outcomes of open adhesiolysis performed between 26 and 48 h in six (28.6% children due to poor response to nonoperative management, 11-13 days in 12 (57.1% who responded minimally and 2-5 weeks in three (14.3% who had relapse of symptoms were encouraging. Exploration of the 21 adhesive obstructions confirmed small bowel obstruction due to solitary bands (two, 9.5%, multiple bands/adhesions (13, 61.9% and encasement, including one bowel gangrene (six, 28.6%. Postoperatively, the only child who had recurrence during 1-6 years of follow-up did well after a repeat adhesiolysis. Conclusion: Nonoperative management was unsuccessful in this setting. Open adhesiolysis may be adopted in children to prevent avoidable morbidities and

  14. Adhesive performance of precoated brackets after expiration.

    Science.gov (United States)

    Cloud, Cayce C; Trojan, Terry M; Suliman, Sam N; Tantbirojn, Daranee; Versluis, Antheunis

    2016-03-01

    To evaluate adhesive performance in terms of debonding forces of precoated metal and ceramic brackets 4 years after expiration. Buccal and lingual surfaces of embedded extracted maxillary premolars were etched with 34% Tooth Conditioner Gel (Dentsply Caulk, Milford, Del), rinsed, and dried. Transbond MIP (3M Unitek, Monrovia, Calif) was applied prior to placing adhesive precoated brackets (APC II Victory stainless steel and APC Plus Clarity ceramic brackets, 3M Unitek). The preexpiration brackets had 29-35 months before, and the postexpiration brackets were 45-52 months past, their expiration dates. Sample size was 17-21 per group. Debonding forces were determined by subjecting the bonded brackets to a shear force in a universal testing machine. Debonding forces were compared using two-way ANOVA. Debonded surfaces were examined under a stereomicroscope to determine failure modes, which were compared using the chi-square test. No statistically significant difference was found in debonding forces (P  =  .8581) or failure modes (P  =  .4538) between expired and unexpired brackets. Metal brackets required statistically significantly higher debonding forces than did ceramic brackets (P  =  .0001). For both expired and unexpired brackets, failure modes were mostly cohesive in the adhesive layer for ceramic brackets, and mixed between adhesive and cohesive failure in the adhesive layer for metal brackets. Adhesive precoated brackets did not have any reduction in enamel-adhesion properties up to 4 years after their expiration date. Extended shelf life testing for precoated dental brackets may be worth considering.

  15. Multiple Perspectives / Multiple Readings

    Directory of Open Access Journals (Sweden)

    Simon Biggs

    2005-01-01

    Full Text Available People experience things from their own physical point of view. What they see is usually a function of where they are and what physical attitude they adopt relative to the subject. With augmented vision (periscopes, mirrors, remote cameras, etc we are able to see things from places where we are not present. With time-shifting technologies, such as the video recorder, we can also see things from the past; a time and a place we may never have visited.In recent artistic work I have been exploring the implications of digital technology, interactivity and internet connectivity that allow people to not so much space/time-shift their visual experience of things but rather see what happens when everybody is simultaneously able to see what everybody else can see. This is extrapolated through the remote networking of sites that are actual installation spaces; where the physical movements of viewers in the space generate multiple perspectives, linked to other similar sites at remote locations or to other viewers entering the shared data-space through a web based version of the work.This text explores the processes involved in such a practice and reflects on related questions regarding the non-singularity of being and the sense of self as linked to time and place.

  16. Epoxy-resin adhesive and method for bonding using such an epoxy resin adhesive

    NARCIS (Netherlands)

    Bhowmik, S.; Poulis, J.A.; Benedictus, R.

    2008-01-01

    The invention relates to an epoxy resin adhesive comprising a dotation of nano-substances, wherein the nano- substances are selected from the group comprising carbon-fibre nanotubes, carbon nano-fibres, silicate nano powders, and wherein the nano-substances are dispersed in the adhesive with a

  17. Adhesion and adhesion changes at the copper metal-(acrylonitrile-butadiene-styrene) polymer interface

    NARCIS (Netherlands)

    Kisin, S.; Varst, van der P.G.T.; With, de G.

    2007-01-01

    It is known that the adhesive strength of metallic films on polymer substrates often changes in the course of time. To study this effect in more detail, the adhesion energy of sputtered and galvanically strengthened copper coatings on acrylonitrile–butadiene–styrene polymer substrate was determined

  18. Adhesion force imaging in air and liquid by adhesion mode atomic force microscopy

    NARCIS (Netherlands)

    van der Werf, Kees; Putman, C.A.J.; Putman, Constant A.; de Grooth, B.G.; Greve, Jan

    1994-01-01

    A new imaging mode for the atomic force microscope(AFM), yielding images mapping the adhesion force between tip and sample, is introduced. The adhesion mode AFM takes a force curve at each pixel by ramping a piezoactuator, moving the silicon‐nitride tip up and down towards the sample. During the

  19. Focal adhesion kinase maintains, but not increases the adhesion of dental pulp cells.

    Science.gov (United States)

    Qian, Yuyan; Shao, Meiying; Zou, Wenlin; Wang, Linyan; Cheng, Ran; Hu, Tao

    2017-04-01

    Focal adhesion kinase (FAK) functions as a key enzyme in the integrin-mediated adhesion-signalling pathway. Here, we aimed to investigate the effects of FAK on adhesion of human dental pulp (HDP) cells. We transfected lentiviral vectors to silence or overexpress FAK in HDP cells ex vivo. Early cell adhesion, cell survival and focal contacts (FCs)-related proteins (FAK and paxillin) were examined. By using immunofluorescence, the formation of FCs and cytoskeleton was detected, respectively. We found that both adhesion and survival of HDP cells were suppressed by FAK inhibition. However, FAK overexpression slightly inhibited cell adhesion and exhibited no change in cell survival compared with the control. A thick rim of cytoskeleton accumulated and smaller dot-shaped FCs appeared in FAK knockdown cells. Phosphorylation of paxillin (p-paxillin) was inhibited in FAK knockdown cells, verifying that the adhesion was inhibited. Less cytoskeleton and elongated FCs were observed in FAK-overexpressed cells. However, p-paxillin had no significant difference compared with the control. In conclusion, the data suggest that FAK maintains cell adhesion, survival and cytoskeleton formation, but excessive FAK has no positive effects on these aspects.

  20. Cell surface clustering of Cadherin adhesion complex induced by antibody coated beads

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Cadherin receptors mediate cell-cell adhesion, signal transduction and assembly of cytoskeletons. How a single transmembrane molecule Cadherin can be involved in multiple functions through modulating its binding activities with many membrane adhesion molecules and cytoskeletal components is an unanswered question which can be elucidated by clues from bead experiments. Human lung cells expressing N-Cadherin were examined. After co-incubation with anti-N-Cadherin monoclonal antibody coated beads, cell surface clustering of N-Cadherin was induced. Immunofluorescent detection demonstrated that in addition to Cadherin, β-Catenin, α-Catenin, α-Actinin and Actin fluorescence also aggregated respectively at the membrane site of bead attachment. Myosin heavy chain (MHC), another major component of Actin cytoskeleton, did not aggregate at the membrane site of bead attachment. Adhesion unrelated protein Con A and polylysine conjugated beads did not induce the clustering of adhesion molecules. It is indicated that the Cadherin/Catenins/α-Actinin/Actin complex is formed at Cadherin mediated cell adherens junction; occupancy and cell surface clustering of Cadherin is crucial for the formation of Cadherin adhesion protein complexes.

  1. Adhesion analysis for chromium nitride thin films deposited by reactive magnetron sputtering

    Science.gov (United States)

    Rusu, F. M.; Merie, V. V.; Pintea, I. M.; Molea, A.

    2016-08-01

    The thin film industry is continuously growing due to the wide range of applications that require the fabrication of advanced components such as sensors, biological implants, micro-electromechanical devices, optical coatings and so on. The selection regarding the deposition materials, as well as the deposition technology influences the properties of the material and determines the suitability of devices for certain real-world applications. This paper is focused on the adhesion force for several chromium nitride thin films obtained by reactive magnetron sputtering. All chromium nitride thin films were deposited on a silicon substrate, the discharge current and the argon flow being kept constant. The main purpose of the paper is to determine the influence of deposition parameters on the adhesion force. Therefore some of the deposition parameters were varied in order to study their effect on the adhesion force. Experimentally, the values of the adhesion force were determined in multiple points for each sample using the spectroscopy in point mode of the atomic force microscope. The obtained values were used to estimate the surface energy of the CrN thin films based on two existing mathematical models for the adhesion force when considering the contact between two bodies.

  2. Multiscale evaluation of cellular adhesion alteration and cytoskeleton remodeling by magnetic bead twisting.

    Science.gov (United States)

    Isabey, Daniel; Pelle, Gabriel; André Dias, Sofia; Bottier, Mathieu; Nguyen, Ngoc-Minh; Filoche, Marcel; Louis, Bruno

    2016-08-01

    Cellular adhesion forces depend on local biological conditions meaning that adhesion characterization must be performed while preserving cellular integrity. We presently postulate that magnetic bead twisting provides an appropriate stress, i.e., basically a clamp, for assessment in living cells of both cellular adhesion and mechanical properties of the cytoskeleton. A global dissociation rate obeying a Bell-type model was used to determine the natural dissociation rate ([Formula: see text]) and a reference stress ([Formula: see text]). These adhesion parameters were determined in parallel to the mechanical properties for a variety of biological conditions in which either adhesion or cytoskeleton was selectively weakened or strengthened by changing successively ligand concentration, actin polymerization level (by treating with cytochalasin D), level of exerted stress (by increasing magnetic torque), and cell environment (by using rigid and soft 3D matrices). On the whole, this multiscale evaluation of the cellular and molecular responses to a controlled stress reveals an evolution which is consistent with stochastic multiple bond theories and with literature results obtained with other molecular techniques. Present results confirm the validity of the proposed bead-twisting approach for its capability to probe cellular and molecular responses in a variety of biological conditions.

  3. Integrin and glycocalyx mediated contributions to cell adhesion identified by single cell force spectroscopy

    International Nuclear Information System (INIS)

    Boettiger, D; Wehrle-Haller, B

    2010-01-01

    The measurement of cell adhesion using single cell force spectroscopy methods was compared with earlier methods for measuring cell adhesion. This comparison provided a means and rationale for separating components of the measurement retract curve that were due to interactions between the substrate and the glycocalyx, and interactions that were due to cell surface integrins binding to a substrate-bound ligand. The glycocalyx adhesion was characterized by multiple jumps with dispersed jump sizes that extended from 5 to 30 μm from the origin. The integrin mediated adhesion was represented by the F max (maximum detachment force), was generally within the first 5 μm and commonly detached with a single rupture cascade. The integrin peak (F max ) increases with time and the rate of increase shows large cell to cell variability with a peak ∼ 50 nN s -1 and an average rate of increase of 75 pN s -1 . This is a measure of the rate of increase in the number of adhesive integrin-ligand bonds/cell as a function of contact time.

  4. Detection of Intracellular Adhesion (ica and Biofilm Formation Genes in Staphylococcus aureus Isolates from Clinical Samples

    Directory of Open Access Journals (Sweden)

    Khadije Rezaie Keikhaie

    2017-02-01

    Full Text Available Introduction: Nosocomial infections that result in the formation of biofilms on the surfaces of biomedical implants are a leading cause of sepsis and are often associated with colonization of the implants by Staphylococcus epidermidis. Biofilm formation is thought to require two sequential steps: adhesion of cells to a solid substrate followed by cell-cell adhesion, creating multiple layers of cells. Intercellular adhesion requires the polysaccharide intercellular adhesion (PIA, which is composed of linear β-1, 6-linked glucosaminylglycans and can be synthesized in vitro from UDP-N-acetylglucosamine by products of the intercellular adhesion (ica locus. We have investigated a variety of Staphylococcus aureus strains and find that all strains tested contain the ica locus and that several can form biofilms in vitro. Material and Method: A total of 31 clinical S. aureus isolates were collected from Zabol, Iran. In vitro biofilm formation ability was determined by microliter tissue culture plates. All clinical isolates were examined for determination the ica locus by using PCR method. Result: The results of this study showed that 40 strains of Staphylococcus aureus, 12 strains carrying the gene Cocos icaA (30% and 8 strains carrying the gene icaD (20% and the number of five strains (12.5% containing both genes ica A and has been ica D. Conclusions:  S. aureus clinical isolates have different ability to form biofilm. This may be caused by the differences in the expression of biofilm related genes, genetic make-up and physiological conditions.

  5. Adaptive simplification and the evolution of gecko locomotion: Morphological and biomechanical consequences of losing adhesion

    Science.gov (United States)

    Higham, Timothy E.; Birn-Jeffery, Aleksandra V.; Collins, Clint E.; Hulsey, C. Darrin; Russell, Anthony P.

    2015-01-01

    Innovations permit the diversification of lineages, but they may also impose functional constraints on behaviors such as locomotion. Thus, it is not surprising that secondary simplification of novel locomotory traits has occurred several times among vertebrates and could potentially lead to exceptional divergence when constraints are relaxed. For example, the gecko adhesive system is a remarkable innovation that permits locomotion on surfaces unavailable to other animals, but has been lost or simplified in species that have reverted to a terrestrial lifestyle. We examined the functional and morphological consequences of this adaptive simplification in the Pachydactylus radiation of geckos, which exhibits multiple unambiguous losses or bouts of simplification of the adhesive system. We found that the rates of morphological and 3D locomotor kinematic evolution are elevated in those species that have simplified or lost adhesive capabilities. This finding suggests that the constraints associated with adhesion have been circumvented, permitting these species to either run faster or burrow. The association between a terrestrial lifestyle and the loss/reduction of adhesion suggests a direct link between morphology, biomechanics, and ecology. PMID:25548182

  6. Influence of Heat-Treatment on the Adhesive Strength between a Micro-Sized Bonded Component and a Silicon Substrate under Bend and Shear Loading Conditions

    International Nuclear Information System (INIS)

    Ishiyama, Chiemi

    2012-01-01

    Adhesive bend and shear tests of micro-sized bonded component have been performed to clarify the relationship between effects of heat-treatment on the adhesive strength and the bonded specimen shape using Weibull analysis. Multiple micro-sized SU-8 columns with four different diameters were fabricated on a Si substrate under the same fabrication condition. Heat-treatment can improve both of the adhesive bend and shear strength. The improvement rate of the adhesive shear strength is much larger than that of the adhesive bend strength, because the residual stress, which must change by heat-treatment, should effect more strongly on the shear loading. In case of bend type test, the adhesive bend strength in the smaller diameters (50 and 75 μm) widely vary, because the critical size of the natural defect (micro-crack) should vary more widely in the smaller diameters. In contrast, in case of shear type test, the adhesive shear strengths in each diameter of the columns little vary. This suggests that the size of the natural defects may not strongly influence on the adhesive shear strength. All the result suggests that both of the adhesive bend and shear strengths should be complicatedly affected by heat-treatment and the bonded columnar diameter

  7. Segment-Specific Adhesion as a Driver of Convergent Extension

    Science.gov (United States)

    Vroomans, Renske M. A.; Hogeweg, Paulien; ten Tusscher, Kirsten H. W. J.

    2015-01-01

    Convergent extension, the simultaneous extension and narrowing of tissues, is a crucial event in the formation of the main body axis during embryonic development. It involves processes on multiple scales: the sub-cellular, cellular and tissue level, which interact via explicit or intrinsic feedback mechanisms. Computational modelling studies play an important role in unravelling the multiscale feedbacks underlying convergent extension. Convergent extension usually operates in tissue which has been patterned or is currently being patterned into distinct domains of gene expression. How such tissue patterns are maintained during the large scale tissue movements of convergent extension has thus far not been investigated. Intriguingly, experimental data indicate that in certain cases these tissue patterns may drive convergent extension rather than requiring safeguarding against convergent extension. Here we use a 2D Cellular Potts Model (CPM) of a tissue prepatterned into segments, to show that convergent extension tends to disrupt this pre-existing segmental pattern. However, when cells preferentially adhere to cells of the same segment type, segment integrity is maintained without any reduction in tissue extension. Strikingly, we demonstrate that this segment-specific adhesion is by itself sufficient to drive convergent extension. Convergent extension is enhanced when we endow our in silico cells with persistence of motion, which in vivo would naturally follow from cytoskeletal dynamics. Finally, we extend our model to confirm the generality of our results. We demonstrate a similar effect of differential adhesion on convergent extension in tissues that can only extend in a single direction (as often occurs due to the inertia of the head region of the embryo), and in tissues prepatterned into a sequence of domains resulting in two opposing adhesive gradients, rather than alternating segments. PMID:25706823

  8. A CLINICAL STUDY OF ADHESIVE INTESTINAL OBSTRUCTION

    Directory of Open Access Journals (Sweden)

    Haricharan

    2015-09-01

    Full Text Available INTRODUCTION: Adhesive intestinal obstruction is an inevitable complication of abdominal surgeries. It has high morbidity with associated poor quality of life and predisposition to repeated hospitalization. Commonest cause of bowel obstruction in developed countries is postoperative adhesions with extrinsic compression of the intestine. Most of them can be managed conservatively. METHODS: A retrospective study of 30 patients admitted with the diagnosis of post - operative adhesive partial bowel obstruction was conducted by analyzing their medical records. Demographic data, clinical presentation including duration, previous surgical procedures, treatments received for the condition and successful conservative approach versus requirement of operative intervention were assesse d. RESULTS: The median age was 31yrs, most in their third decade of life. Male predominance was noted. Pelvic surgeries and gynecological surgeries (26% were found to be the most common cause of adhesive bowel obstruction followed by appendectomy (16%. M ore than two third of the patients (76.7% developed symptoms within two years of the initial surgery. Successful conservative treatment was noted in 22 patients (73.3% and discharged on fourth day of admission. Eight patients (26.6% underwent surgery. T hey all underwent adhesiolysis and had good outcome. CONCLUSIONS: The time - honored practice of expectant management of adhesive partial bowel obstruction has equally good outcome, as compared to various interventions practiced

  9. Endothelial cell adhesion to ion implanted polymers

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Y; Kusakabe, M [SONY Corp., Tokyo (Japan); Lee, J S; Kaibara, M; Iwaki, M; Sasabe, H [RIKEN (Inst. of Physical and Chemical Research), Saitama (Japan)

    1992-03-01

    The biocompatibility of ion implanted polymers has been studied by means of adhesion measurements of bovine aorta endothelial cells in vitro. The specimens used were polystyrene (PS) and segmented polyurethane (SPU). Na{sup +}, N{sub 2}{sup +}, O{sub 2}{sup +} and Kr{sup +} ion implantations were performed at an energy of 150 keV with fluences ranging from 1x10{sup 15} to 3x10{sup 17} ions/cm{sup 2} at room temperature. The chemical and physical structures of ion-implanted polymers have been investigated in order to analyze their tissue compatibility such as improvement of endothelial cell adhesion. The ion implanted SPU have been found to exhibit remarkably higher adhesion and spreading of endothelial cells than unimplanted specimens. By contrast, ion implanted PS demonstrated a little improvement of adhesion of cells in this assay. Results of FT-IR-ATR showed that ion implantation broke the original chemical bond to form new radicals such as OH, ....C=O, SiH and condensed rings. The results of Raman spectroscopy showed that ion implantation always produced a peak near 1500 cm{sup -1}, which indicated that these ion implanted PS and SPU had the same carbon structure. This structure is considered to bring the dramatic increase in the extent of cell adhesion and spreading to these ion implanted PS and SPU. (orig.).

  10. Dextran and gelatin based photocrosslinkable tissue adhesive.

    Science.gov (United States)

    Wang, Tao; Nie, Jun; Yang, Dongzhi

    2012-11-06

    A two-component tissue adhesive based on biocompatible and bio-degradable polymers (oxidized urethane dextran (Dex-U-AD) and gelatin) was prepared and photocrosslinked under the ultraviolet (UV) irradiation. The adhesive could adhere to surface of gelatin, which simulated the human tissue steadily. The structures of above Dex-U-AD were characterized by FTIR, (1)H NMR spectroscopy and XRD. The adhesion property of result products was evaluated by lap-shear test. The maximum adhesion strength could reach to 4.16±0.72 MPa which was significantly higher than that of fibrin glue. The photopolymerization process of Dex-U-AD/gelatin was monitored by real time infrared spectroscopy (RTIR). It took less than 5 min to complete the curing process. The cytotoxicity of Dex-U-AD/gelatin also was evaluated which indicated that Dex-U-AD/gelatin gels were nontoxic to L929 cell. The relationship between all the above-mentioned properties and degree of oxidization of Dex-U-AD was assessed. The obtained products have the potential to serve as tissue adhesive in the future. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Bacterial adhesion to unworn and worn silicone hydrogel lenses.

    Science.gov (United States)

    Vijay, Ajay Kumar; Zhu, Hua; Ozkan, Jerome; Wu, Duojia; Masoudi, Simin; Bandara, Rani; Borazjani, Roya N; Willcox, Mark D P

    2012-08-01

    The objective of this study was to determine the bacterial adhesion to various silicone hydrogel lens materials and to determine whether lens wear modulated adhesion. Bacterial adhesion (total and viable cells) of Staphylococcus aureus (31, 38, and ATCC 6538) and Pseudomonas aeruginosa (6294, 6206, and GSU-3) to 10 commercially available different unworn and worn silicone hydrogel lenses was measured. Results of adhesion were correlated to polymer and surface properties of contact lenses. S. aureus adhesion to unworn lenses ranged from 2.8 × 10 to 4.4 × 10 colony forming units per lens. The highest adhesion was to lotrafilcon A lenses, and the lowest adhesion was to asmofilcon A lenses. P. aeruginosa adhesion to unworn lenses ranged from 8.9 × 10 to 3.2 × 10 colony forming units per lens. The highest adhesion was to comfilcon A lenses, and the lowest adhesion was to asmofilcon A and balafilcon A lenses. Lens wear altered bacterial adhesion, but the effect was specific to lens and strain type. Adhesion of bacteria, regardless of genera/species or lens wear, was generally correlated with the hydrophobicity of the lens; the less hydrophobic the lens surface, the greater the adhesion. P. aeruginosa adhered in higher numbers to lenses in comparison with S. aureus strains, regardless of the lens type or lens wear. The effect of lens wear was specific to strain and lens. Hydrophobicity of the silicone hydrogel lens surface influenced the adhesion of bacterial cells.

  12. Tensin stabilizes integrin adhesive contacts in Drosophila.

    Science.gov (United States)

    Torgler, Catherine N; Narasimha, Maithreyi; Knox, Andrea L; Zervas, Christos G; Vernon, Matthew C; Brown, Nicholas H

    2004-03-01

    We report the functional characterization of the Drosophila ortholog of tensin, a protein implicated in linking integrins to the cytoskeleton and signaling pathways. A tensin null was generated and is viable with wing blisters, a phenotype characteristic of loss of integrin adhesion. In tensin mutants, mechanical abrasion is required during wing expansion to cause wing blisters, suggesting that tensin strengthens integrin adhesion. The localization of tensin requires integrins, talin, and integrin-linked kinase. The N-terminal domain and C-terminal PTB domain of tensin provide essential recruitment signals. The intervening SH2 domain is not localized on its own. We suggest a model where tensin is recruited to sites of integrin adhesion via its PTB and N-terminal domains, localizing the SH2 domain so that it can interact with phosphotyrosine-containing proteins, which stabilize the integrin link to the cytoskeleton.

  13. Systemic Inflammatory Response and Adhesion Molecules

    Directory of Open Access Journals (Sweden)

    L. V. Molchanova

    2005-01-01

    Full Text Available The lecture presents the materials of foreign studies on the mechanisms responsible for the formation of a systemic inflammatory response syndrome (SIRS. The hypotheses accounting for the occurrence of SIRS in emergencies are described. Adhesion molecules (AM and endothelial dysfunction are apparent to be involved in the inflammatory process, no matter what the causes of SIRS are. The current classification of AM and adhesion cascades with altered blood flow is presented. There are two lines in the studies of AM. One line is to measure the concentration of AM in the plasma of patients with emergencies of various etiology. The other is to study the impact of antiadhesion therapy on the alleviation of the severity of terminal state and its outcome. The studies provide evidence for that an adhesive process is a peculiar prelude to a systemic inflammatory response.

  14. Apparatus for Removing Remaining Adhesives of Filter

    International Nuclear Information System (INIS)

    Kang, Il Sik; Kim, Tae Kuk; Hong, Dae Seok; Ji, Young Yong; Ryu, Woo Seog

    2010-01-01

    A Large amount of ventilation filter was used at radiation areas not only in nuclear power plants but also in nuclear facilities. These spent ventilation filters are generated as radioactive waste and composed of a steel frame, glass fiber media and aluminum separator. When treated, the spent filter is separated into filter media for air purification and frame. After separation, while the filter media is collected using steel drum for reducing internal exposure, the filter frame is treated further to remove adhesives for recycling the frame as many as possible in order to reduce waste and cost and improve working conditions. Usually, the adhesives are separated from the filter frame manually. As a result, a lot of time and labor is required. So, the objective of this study is to develop a motor-driven apparatus for removing adhesives efficiently

  15. Prevention of root caries with dentin adhesives.

    Science.gov (United States)

    Grogono, A L; Mayo, J A

    1994-04-01

    This in vitro investigation determined the feasibility of using dentin adhesives to protect root surfaces against caries. The roots of 22 recently extracted human teeth were all painted with a protective lacquer leaving two unprotected small windows. On each specimen, one window (control) was left untreated and the other window (experimental) was treated using a dentin adhesive (Scotchbond Multi-Purpose). The roots were then immersed in an in vitro acetate/calcium/phosphate demineralization model at pH 4.3. After 70 days, the samples were removed and sectioned through the windows. The undecalcified ground sections were examined under transmitted and polarized light. Lesions characteristic of natural root caries were seen in the untreated control windows. No such lesions were apparent in the experimental windows. The results of this preliminary study suggest that dentin adhesives may provide protection against root caries.

  16. Melting Can Hinder Impact-Induced Adhesion

    Science.gov (United States)

    Hassani-Gangaraj, Mostafa; Veysset, David; Nelson, Keith A.; Schuh, Christopher A.

    2017-10-01

    Melting has long been used to join metallic materials, from welding to selective laser melting in additive manufacturing. In the same school of thought, localized melting has been generally perceived as an advantage, if not the main mechanism, for the adhesion of metallic microparticles to substrates during a supersonic impact. Here, we conduct the first in situ supersonic impact observations of individual metallic microparticles aimed at the explicit study of melting effects. Counterintuitively, we find that under at least some conditions melting is disadvantageous and hinders impact-induced adhesion. In the parameter space explored, i.e., ˜10 μ m particle size and ˜1 km /s particle velocity, we argue that the solidification time is much longer than the residence time of the particle on the substrate, so that resolidification cannot be a significant factor in adhesion.

  17. Regulation of promyogenic signal transduction by cell-cell contact and adhesion

    International Nuclear Information System (INIS)

    Krauss, Robert S.

    2010-01-01

    Skeletal myoblast differentiation involves acquisition of the muscle-specific transcriptional program and morphological changes, including fusion into multinucleated myofibers. Differentiation is regulated by extracellular signaling cues, including cell-cell contact and adhesion. Cadherin and Ig adhesion receptors have been implicated in distinct but overlapping stages of myogenesis. N-cadherin signals through the Ig receptor Cdo to activate p38 MAP kinase, while the Ig receptor neogenin signals to activate FAK; both processes promote muscle-specific gene expression and myoblast fusion. M-cadherin activates Rac1 to enhance fusion. Specific Ig receptors (Kirre and Sns) are essential for myoblast fusion in Drosophila, also signaling through Rac, and vertebrate orthologs of Kirre and Sns have partially conserved function. Mice lacking specific cytoplasmic signaling factors activated by multiple receptors (e.g., Rac1) have strong muscle phenotypes in vivo. In contrast, mice lacking individual adhesion receptors that lie upstream of these factors have modest phenotypes. Redundancy among receptors may account for this. Many of the mammalian Ig receptors and cadherins associate with each other, and multivalent interactions within these complexes may require removal of multiple components to reveal dramatic defects in vivo. Nevertheless, it is possible that the murine adhesion receptors rate-limiting in vivo have not yet been identified or fully assessed.

  18. Regulation of promyogenic signal transduction by cell-cell contact and adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, Robert S., E-mail: Robert.Krauss@mssm.edu [Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029 (United States)

    2010-11-01

    Skeletal myoblast differentiation involves acquisition of the muscle-specific transcriptional program and morphological changes, including fusion into multinucleated myofibers. Differentiation is regulated by extracellular signaling cues, including cell-cell contact and adhesion. Cadherin and Ig adhesion receptors have been implicated in distinct but overlapping stages of myogenesis. N-cadherin signals through the Ig receptor Cdo to activate p38 MAP kinase, while the Ig receptor neogenin signals to activate FAK; both processes promote muscle-specific gene expression and myoblast fusion. M-cadherin activates Rac1 to enhance fusion. Specific Ig receptors (Kirre and Sns) are essential for myoblast fusion in Drosophila, also signaling through Rac, and vertebrate orthologs of Kirre and Sns have partially conserved function. Mice lacking specific cytoplasmic signaling factors activated by multiple receptors (e.g., Rac1) have strong muscle phenotypes in vivo. In contrast, mice lacking individual adhesion receptors that lie upstream of these factors have modest phenotypes. Redundancy among receptors may account for this. Many of the mammalian Ig receptors and cadherins associate with each other, and multivalent interactions within these complexes may require removal of multiple components to reveal dramatic defects in vivo. Nevertheless, it is possible that the murine adhesion receptors rate-limiting in vivo have not yet been identified or fully assessed.

  19. Multiple sclerosis

    Science.gov (United States)

    ... indwelling catheter Osteoporosis or thinning of the bones Pressure sores Side effects of medicines used to treat the ... Daily bowel care program Multiple sclerosis - discharge Preventing pressure ulcers Swallowing problems Images Multiple sclerosis MRI of the ...

  20. Intraspinal anomalies in scoliosis: An MRI analysis of 177 consecutive scoliosis patients

    Directory of Open Access Journals (Sweden)

    Rajasekaran S

    2010-01-01

    Full Text Available Background : The association of intraspinal neural anomalies with scoliosis is known for more than six decades. However, there are no studies documenting the incidence of association of intraspinal anomalies in scoliotic patients in the Indian population. The guide lines to obtain an magnetic resonance imaging (MRI scan to rule out neuro-axial abnormalities in presumed adolescent idiopathic scoliosis are also not clear. We conducted a prospective study (a to document and analyze the incidence and types of intraspinal anomalies in different types of scoliosis in Indian patients. (b to identify clinico-radiological ′indicators′ that best predict the findings of neuro-axial abnormalities in patients with presumed adolescent idiopathic scoliosis, which will alert the physician to the possible presence of intraspinal anomalies and optimize the use of MRI in this sub group of patients. Materials and Methods : The data from 177 consecutive scoliotic patients aged less than 21 years were analyzed. Patients were categorized into three groups; Group A - congenital scoliosis (n=60, group B -presumed idiopathic scoliosis (n=94 and group C - scoliosis secondary to neurofibromatosis, neuromuscular and connective tissue disorders (n=23. The presence and type of anomaly in the MRI was correlated to patient symptoms, clinical signs and curve characteristics. Results : The incidence of intraspinal anomalies in congenital scoliosis was 35% (21/60, with tethered cord due to filum terminale being the commonest anomaly (10/21. Patients with multiple vertebral anomalies had the highest incidence (48% of neural anomalies and isolated hemi vertebrae had none. In presumed ′idiopathic′ scoliosis patients the incidence was higher (16% than previously reported. Arnold Chiari-I malformation (AC-I with syringomyelia was the most common neural anomaly (9/15 and the incidence was higher in the presence of neurological findings (100%, apical kyphosis (66.6% and early

  1. Reaction Times to Consecutive Automation Failures: A Function of Working Memory and Sustained Attention.

    Science.gov (United States)

    Jipp, Meike

    2016-12-01

    This study explored whether working memory and sustained attention influence cognitive lock-up, which is a delay in the response to consecutive automation failures. Previous research has demonstrated that the information that automation provides about failures and the time pressure that is associated with a task influence cognitive lock-up. Previous research has also demonstrated considerable variability in cognitive lock-up between participants. This is why individual differences might influence cognitive lock-up. The present study tested whether working memory-including flexibility in executive functioning-and sustained attention might be crucial in this regard. Eighty-five participants were asked to monitor automated aircraft functions. The experimental manipulation consisted of whether or not an initial automation failure was followed by a consecutive failure. Reaction times to the failures were recorded. Participants' working-memory and sustained-attention abilities were assessed with standardized tests. As expected, participants' reactions to consecutive failures were slower than their reactions to initial failures. In addition, working-memory and sustained-attention abilities enhanced the speed with which participants reacted to failures, more so with regard to consecutive than to initial failures. The findings highlight that operators with better working memory and sustained attention have small advantages when initial failures occur, but their advantages increase across consecutive failures. The results stress the need to consider personnel selection strategies to mitigate cognitive lock-up in general and training procedures to enhance the performance of low ability operators. © 2016, Human Factors and Ergonomics Society.

  2. The Mechanisms of Adhesion of Enteromorpha Clathrata.

    Science.gov (United States)

    1982-08-24

    extracellular polymer was responsible for adhesion to a substrate (21,23,26,39,40,42,59,62,63,74,78, 86,91). The adhesion of Chlorella vulgaris may also depend...marine Chlorella vulgaris to glass. Can. J. Microbiol. 21:1025-1031. 88. Van Baalen, C., 1962. Studies on marine blue-green .4 algae. Bot. Mar. 4:129...also been observed with the unicellular green alga, Chlorella (68). Other negatively charged groups that could be present are phosphatidic groups (46

  3. Differential expression of cell adhesion genes

    DEFF Research Database (Denmark)

    Stein, Wilfred D; Litman, Thomas; Fojo, Tito

    2005-01-01

    that compare cells grown in suspension to similar cells grown attached to one another as aggregates have suggested that it is adhesion to the extracellular matrix of the basal membrane that confers resistance to apoptosis and, hence, resistance to cytotoxins. The genes whose expression correlates with poor...... in cell adhesion and the cytoskeleton. If the proteins involved in tethering cells to the extracellular matrix are important in conferring drug resistance, it may be possible to improve chemotherapy by designing drugs that target these proteins....

  4. Bilateral contact problem with adhesion and damage

    Directory of Open Access Journals (Sweden)

    Adel Aissaoui

    2014-05-01

    Full Text Available We study a mathematical problem describing the frictionless adhesive contact between a viscoelastic material with damage and a foundation. The adhesion process is modeled by a bonding field on the contact surface. The contact is bilateral and the tangential shear due to the bonding field is included. We establish a variational formulation for the problem and prove the existence and uniqueness of the solution. The existence of a unique weak solution for the problem is established using arguments of nonlinear evolution equations with monotone operators, a classical existence and uniqueness result for parabolic inequalities, and Banach's fixed point theorem.

  5. Reversible low adhesive to high adhesive superhydrophobicity transition on ZnO nanoparticle surfaces

    International Nuclear Information System (INIS)

    Li, Jian; Jing, Zhijiao; Yang, Yaoxia; Zha, Fei; Yan, Long; Lei, Ziqiang

    2014-01-01

    Superhydrophobic ZnO surfaces with water contact angle of 162° and sliding angle of 2° were fabricated successfully by spraying hydrophobic ZnO nanoparticle suspensions without limitations the shape and size of substrates. The as-prepared superhydrophobic ZnO surfaces are low adhesive and a water droplet easily rolls off with the surface slightly tilted. However, after being irradiated by UV light through a photomask, it becomes highly adhesive, on which a water droplet is firmly pinned without any movement. Further annealing the irradiated film, water droplets can roll off the surface again. Reversible transition between the low adhesive rolling state and high adhesive pinning state can be realized simply by UV illumination and heat treatment alternately. At the same time, the maximum adhesive force between the superhydrophobic ZnO surfaces and the water droplet changes from extreme low (∼5.1 μN) to very high (∼136.1 μN). When irradiated without a photomask, the surface became hydrophilic. Additionally, a water droplet can be transfered from the low adhesive superhydrophobic ZnO surfaces to the hydrophilic ZnO surfaces using the high adhesive superhydrophobic ZnO surfaces as a mechanical hand.

  6. Adhesive properties and adhesive joints strength of graphite/epoxy composites

    Science.gov (United States)

    Rudawska, Anna; Stančeková, Dana; Cubonova, Nadezda; Vitenko, Tetiana; Müller, Miroslav; Valášek, Petr

    2017-05-01

    The article presents the results of experimental research of the adhesive joints strength of graphite/epoxy composites and the results of the surface free energy of the composite surfaces. Two types of graphite/epoxy composites with different thickness were tested which are used to aircraft structure. The single-lap adhesive joints of epoxy composites were considered. Adhesive properties were described by surface free energy. Owens-Wendt method was used to determine surface free energy. The epoxy two-component adhesive was used to preparing the adhesive joints. Zwick/Roell 100 strength device were used to determination the shear strength of adhesive joints of epoxy composites. The strength test results showed that the highest value was obtained for adhesive joints of graphite-epoxy composite of smaller material thickness (0.48 mm). Statistical analysis of the results obtained, the study showed statistically significant differences between the values of the strength of the confidence level of 0.95. The statistical analysis of the results also showed that there are no statistical significant differences in average values of surface free energy (0.95 confidence level). It was noted that in each of the results the dispersion component of surface free energy was much greater than polar component of surface free energy.

  7. Gastrin-releasing peptide induces monocyte adhesion to vascular endothelium by upregulating endothelial adhesion molecules

    International Nuclear Information System (INIS)

    Kim, Mi-Kyoung; Park, Hyun-Joo; Kim, Yeon; Kim, Hyung Joon; Bae, Soo-Kyung; Bae, Moon-Kyoung

    2017-01-01

    Gastrin-releasing peptide (GRP) is a neuropeptide that plays roles in various pathophysiological conditions including inflammatory diseases in peripheral tissues; however, little is known about whether GRP can directly regulate endothelial inflammatory processes. In this study, we showed that GRP promotes the adhesion of leukocytes to human umbilical vein endothelial cells (HUVECs) and the aortic endothelium. GRP increased the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) by activating nuclear factor-κB (NF-κB) in endothelial cells. In addition, GRP activated extracellular signal-regulated kinase 1/2 (ERK1/2), p38MAPK, and AKT, and the inhibition of these signaling pathways significantly reduced GRP-induced monocyte adhesion to the endothelium. Overall, our results suggested that GRP may cause endothelial dysfunction, which could be of particular relevance in the development of vascular inflammatory disorders. - Highlights: • GRP induces adhesion of monocytes to vascular endothelium. • GRP increases the expression of endothelial adhesion molecules through the activation of NF-κB. • ERK1/2, p38MAPK, and Akt pathways are involved in the GRP-induced leukocyte adhesiveness to endothelium.

  8. A simple surface treatment and characterization of AA 6061 aluminum alloy surface for adhesive bonding applications

    International Nuclear Information System (INIS)

    Saleema, N.; Sarkar, D.K.; Paynter, R.W.; Gallant, D.; Eskandarian, M.

    2012-01-01

    Highlights: ► A very simple surface treatment method to achieve excellent and durable aluminum adhesive bonding. ► Our method involves simple immersion of aluminum in very dilute NaOH solution at room temperature with no involvement of strong acids or multiple procedures. ► Surface analysis via various surface characterization techniques showed morphological and chemical modifications favorable for obtaining highly durable bond strengths on the treated surface. ► Safe, economical, reproducible and simple method, easily applicable in industries. - Abstract: Structural adhesive bonding of aluminum is widely used in aircraft and automotive industries. It has been widely noted that surface preparation of aluminum surfaces prior to adhesive bonding plays a significant role in improving the strength of the adhesive bond. Surface cleanliness, surface roughness, surface wettability and surface chemistry are controlled primarily by proper surface treatment methods. In this study, we have employed a very simple technique influencing all these criteria by simply immersing aluminum substrates in a very dilute solution of sodium hydroxide (NaOH) and we have studied the effect of varying the treatment period on the adhesive bonding characteristics. A bi-component epoxy adhesive was used to join the treated surfaces and the bond strengths were evaluated via single lap shear (SLS) tests in pristine as well as degraded conditions. Surface morphology, chemistry, crystalline nature and wettability of the NaOH treated surfaces were characterized using various surface analytical tools such as scanning electron microscopy and energy dispersive X-ray analysis (SEM/EDX), optical profilometry, infrared reflection absorption spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and contact angle goniometry. Excellent adhesion characteristics with complete cohesive failure of the adhesive were encountered on the NaOH treated surfaces that are comparable to the benchmark

  9. Postoperative morbidity after reconstruction of alveolar bone defects with chin bone transplants in cleft patients - 111 consecutive patients

    DEFF Research Database (Denmark)

    Andersen, Kristian; Nørholt, Sven Erik; Knudsen, Johan

    Postoperative morbidity after reconstruction of alveolar bone defects with chin bone transplants in cleft patients - 111 consecutive patients......Postoperative morbidity after reconstruction of alveolar bone defects with chin bone transplants in cleft patients - 111 consecutive patients...

  10. Automated margin analysis of contemporary adhesive systems in vitro: evaluation of discriminatory variables.

    Science.gov (United States)

    Heintze, Siegward D; Forjanic, Monika; Roulet, François-Jean

    2007-08-01

    Using an optical sensor, to automatically evaluate the marginal seal of restorations placed with 21 adhesive systems of all four adhesive categories in cylindrical cavities of bovine dentin applying different outcome variables, and to evaluate their discriminatory power. Twenty-one adhesive systems were evaluated: three 3-step etch-and-rinse systems, three 2-step etch-and-rinse systems, five 2-step self-etching systems, and ten 1-step self-etching systems. All adhesives were applied in cylindrical cavities in bovine dentin together with Tetric Ceram (n=8). In the control group, no adhesive system was used. After 24 h of storage in water at 37 degrees C, the surface was polished with 4000-grit SiC paper, and epoxy resin replicas were produced. An optical sensor (FRT MicroProf) created 100 profiles of the restoration margin, and an algorithm detected gaps and calculated their depths and widths. The following evaluation criteria were used: percentage of specimens without gaps, the percentage of gap-free profiles in relation to all profiles per specimen, mean gap width, mean gap depth, largest gap, modified marginal integrity index MI. The statistical analysis was carried out on log-transformed data for all variables with ANOVA and post-hoc Tukey's test for multiple comparisons. The correlation between the variables was tested with regression analysis, and the pooled data accordingto the four adhesive categories were compared by applying the Mann-Whitney nonparametric test (p adhesive systems demonstrated the best marginal adaptation, followed by the 2-step self-etching and the 1-step self-etching adhesives; the latter showed the highest variability in test results between materials and within the same material. The only exception to this rule was Xeno IV, which showed a marginal adaptation that was comparable to that of the best 3-step etch-and-rinse systems. Except for the variables "largest gap" and "mean gap depth", all the other variables had a similar ability to

  11. Aluminum and steel adhesion with polyurethanes from castor oil adhesives submitted to gamma irradiation

    International Nuclear Information System (INIS)

    Azevedo, Elaine C.; Assumpcao, Roberto L.; Nascimento, Eduardo M. do; Claro Neto, Salvador; Soboll, Daniel S.

    2009-01-01

    Polyurethanes adhesive from castor oil is used to join aluminum and steel pieces. The effect of gamma radiation on the resistance to tension tests is investigated. The aluminum and steel pieces after being glued with the adhesive were submitted to gamma irradiation in doses of 1 kGy, 25 kGy and 100 kGy. The rupture strength of the joints after irradiation have a slightly increase or remains practically unchanged indicating that the adhesive properties is not affected by the gamma radiation. (author)

  12. MULTIPLE OBJECTS

    Directory of Open Access Journals (Sweden)

    A. A. Bosov

    2015-04-01

    Full Text Available Purpose. The development of complicated techniques of production and management processes, information systems, computer science, applied objects of systems theory and others requires improvement of mathematical methods, new approaches for researches of application systems. And the variety and diversity of subject systems makes necessary the development of a model that generalizes the classical sets and their development – sets of sets. Multiple objects unlike sets are constructed by multiple structures and represented by the structure and content. The aim of the work is the analysis of multiple structures, generating multiple objects, the further development of operations on these objects in application systems. Methodology. To achieve the objectives of the researches, the structure of multiple objects represents as constructive trio, consisting of media, signatures and axiomatic. Multiple object is determined by the structure and content, as well as represented by hybrid superposition, composed of sets, multi-sets, ordered sets (lists and heterogeneous sets (sequences, corteges. Findings. In this paper we study the properties and characteristics of the components of hybrid multiple objects of complex systems, proposed assessments of their complexity, shown the rules of internal and external operations on objects of implementation. We introduce the relation of arbitrary order over multiple objects, we define the description of functions and display on objects of multiple structures. Originality.In this paper we consider the development of multiple structures, generating multiple objects.Practical value. The transition from the abstract to the subject of multiple structures requires the transformation of the system and multiple objects. Transformation involves three successive stages: specification (binding to the domain, interpretation (multiple sites and particularization (goals. The proposed describe systems approach based on hybrid sets

  13. Heparan sulfate chain valency controls syndecan-4 function in cell adhesion

    DEFF Research Database (Denmark)

    Gopal, Sandeep; Bober, Adam; Whiteford, James R

    2010-01-01

    , clustering of one-chain syndecan-4 forms with antibodies overcame the block, indicating that valency of interactions with ligands is a key component of syndecan-4 function. Measurements of focal contact/adhesion size and focal adhesion kinase phosphorylation correlated with syndecan-4 status and alpha...... of the core protein cytoplasmic domain, though not interactions with PDZ proteins. A second key requirement is multiple heparan sulfate chains. Mutant syndecan-4 with no chains, or only one chain, failed to restore the wild type phenotype, while those expressing two or three were competent. However......-smooth muscle actin organization, being reduced where syndecan-4 function was compromised by a lack of multiple heparan sulfate chains....

  14. ADHESION OF BIOCOMPATIBLE TiNb COATING

    Directory of Open Access Journals (Sweden)

    Tomas Kolegar

    2017-06-01

    Full Text Available Preparation of a coating with a high quality requires good adhesion of the film to the substrate. The paper deals with the adhesion of biocompatible TiNb coating with different base materials. Several materials such as titanium CP grade 2, titanium alloys Ti6Al4V and stainless steel AISI 316L were measured. Testing samples were made in the shape of small discs. Those samples were coated with a TiNb layer by using the PVD method (magnetron sputtering. Onto the measured layer of TiNb an assistant cylinder was stuck using a high strength epoxy adhesive E1100S. The sample with the assistant cylinder was fixed into a special fixture and the whole assembly underwent pull-off testing for adhesion. The main result of this experiment was determining the strength needed to peel the layer and morphology and size of the breakaway. As a result, we will be able to determine the best base material and conditions where the coating will be remain intact with the base material.

  15. Film adhesion in amorphous silicon solar cells

    Indian Academy of Sciences (India)

    TECS

    Film adhesion in amorphous silicon solar cells. A R M YUSOFF*, M N SYAHRUL and K HENKEL. Malaysia Energy Centre, 8th Floor, North Wing, Sapura @ Mines, 7, Jalan Tasik, The Mines Resort City,. 43300 Seri Kembangan, Selangor Darul Ehsan. MS received 11 April 2007. Abstract. A major issue encountered ...

  16. Antibodies against Shigella flexneri adhesion molecule outer ...

    African Journals Online (AJOL)

    OMP) as an adhesion factor and examine its ability to cross-react with the OMPs of other Shigella species. Methods: OMP was isolated from the bacterium S. flexneri after shaving the pili using a pili bacterial cutter in a solution of 0.5 ...

  17. Microbial adhesion in flow displacement systems

    NARCIS (Netherlands)

    Busscher, HJ; van der Mei, HC

    Flow displacement systems are superior to many other (static) systems for studying microbial adhesion to surfaces because mass transport and prevailing shear conditions can be adequately controlled and notoriously ill-defined slight rinsing steps to remove so-called "loosely adhering organisms" can

  18. Two Models of Adhesive Debonding of Sylgard

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, Ralph Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-14

    This report begins with a brief summary of the range of modeling methods used to simulate adhesive debonding. Then the mechanical simulation of the blister debonding test, and the thermomechanical simulation of the potted hemisphere problem are described. For both simulations, details of the chosen modeling techniques, and the reasons for choosing them (and rejecting alternate modeling approaches) will be discussed.

  19. Interface Fracture in Adhesively Bonded Shell Structures

    DEFF Research Database (Denmark)

    Jensen, Henrik Myhre

    2008-01-01

    Two methods for the prediction of crack propagation through the interface of adhesively bonded shells are discussed. One is based on a fracture mechanics approach; the other is based on a cohesive zone approach. Attention is focussed on predicting the shape of the crack front and the critical...

  20. Wood adhesives containing proteins and carbohydrates

    Science.gov (United States)

    In recent years there has been resurgent interest in using biopolymers as sustainable and environmentally friendly ingredients in wood adhesive formulations. Among them, proteins and carbohydrates are the most commonly used. In this chapter, an overview is given of protein-based and carbohydrate-...

  1. Photolithography of polytetrafluoroethylene for tailored adhesion

    International Nuclear Information System (INIS)

    Rye, R.R.; Martinez, R.J.

    1988-01-01

    Irradiation of polytetrafluoroethylene (PTFE) with Mg (Kα) x-rays is shown to protect the surface against the chemical etching steps used to prepare PTFE for adhesion. Pre-irradiated etched samples of PTFE have adhesions strengths of less than 3% of that for non-irradiated etched samples. The major portion of this decrease in adhesion strength occurs for x-ray exposures of less than 10 min ∼4.8 x10 3 mrads) and failure in every case occurs in PTFE and not in the bonded transition region. XPS measurements (20 angstrom sampling depth) show little difference in F content between irradiated and non-irradiated samples, but thermal desorption shows increasing fluorocarbon desorption with irradiation time. These results are consistent with the known radiation chemistry of PTFE. Irradiation produced free radicals lead to branching and/ or cross-linking, and a surface rich in low molecular weight fluorocarbons. The more rigid cross-linked surface is resistant to deep (10,000 angstrom chemical attack and the bond formed is with a surface rich in short chain flurocarbons. Both a thin boundary region and bonding to short chain species is expected to lead to weak adhesive bonding. Electron irradiation is shown to lead to protection against chemical etching comparable to that obtained with X-rays. With electrons one has the patterns with resolution limited by the beam diameter

  2. Radiation polymerized hot melt pressure sensitive adhesives

    International Nuclear Information System (INIS)

    Pastor, S.D.; Skoultchi, M.M.

    1977-01-01

    Hot melt pressure sensitive adhesive compositions formed by copolymerizing at least one 3-(chlorinated aryloxy)-2-hydroxypropyl ester of an alpha, beta unsaturated carboxylic acid with acrylate based copolymerizable monomers, are described. The resultant ethylenically saturated prepolymer is heated to a temperature sufficient to render it fluid and flowable. This composition is coated onto a substrate and exposed to ultraviolet radiation

  3. Underwater Adhesives Retrofit Pipelines with Advanced Sensors

    Science.gov (United States)

    2015-01-01

    Houston-based Astro Technology Inc. used a partnership with Johnson Space Center to pioneer an advanced fiber-optic monitoring system for offshore oil pipelines. The company's underwater adhesives allow it to retrofit older deepwater systems in order to measure pressure, temperature, strain, and flow properties, giving energy companies crucial data in real time and significantly decreasing the risk of a catastrophe.

  4. Adhesive Bioactive Coatings Inspired by Sea Life.

    Science.gov (United States)

    Rego, Sónia J; Vale, Ana C; Luz, Gisela M; Mano, João F; Alves, Natália M

    2016-01-19

    Inspired by nature, in particular by the marine mussels adhesive proteins (MAPs) and by the tough brick-and-mortar nacre-like structure, novel multilayered films are prepared in the present work. Organic-inorganic multilayered films, with an architecture similar to nacre based on bioactive glass nanoparticles (BG), chitosan, and hyaluronic acid modified with catechol groups, which are the main components responsible for the outstanding adhesion in MAPs, are developed for the first time. The biomimetic conjugate is prepared by carbodiimide chemistry and analyzed by ultraviolet-visible spectrophotometry. The buildup of the multilayered films is monitored with a quartz crystal microbalance with dissipation monitoring, and their topography is characterized by atomic force microscopy. The mechanical properties reveal that the films containing catechol groups and BG present an enhanced adhesion. Moreover, the bioactivity of the films upon immersion in a simulated body fluid solution is evaluated by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. It was found that the constructed films promote the formation of bonelike apatite in vitro. Such multifunctional mussel inspired LbL films, which combine enhanced adhesion and bioactivity, could be potentially used as coatings of a variety of implants for orthopedic applications.

  5. Chitosan adhesive for laser tissue repair

    Science.gov (United States)

    Lauto, A.; Stoodley, M.; Avolio, A.; Foster, L. J. R.

    2006-02-01

    Background. Laser tissue repair usually relies on haemoderivate solders, based on serum albumin. These solders have intrinsic limitations that impair their widespread use, such as limited repair strength, high solubility, brittleness and viral transmission. Furthermore, the solder activation temperature (65-70 °C) can induce significant damage to tissue. In this study, a new laser-activated biomaterial for tissue repair was developed and tested in vitro and in vivo to overcome some of the shortcomings of traditional solders. Materials and Methods. Flexible and insoluble strips of chitosan adhesive (surface area ~34 mm2, thickness ~20 μm) were developed and bonded on sheep intestine with a laser fluence and irradiance of 52 +/- 2 J/cm2 and ~15 W/cm2 respectively. The temperature between tissue and adhesive was measured using small thermocouples. The strength of repaired tissue was tested by a calibrated tensiometer. The adhesive was also bonded in vivo to the sciatic nerve of rats to assess the thermal damage induced by the laser (fluence = 65 +/- 11 J/cm2, irradiance = 15 W/cm2) four days post-operatively. Results. Chitosan adhesives successfully repaired intestine tissue, achieving a repair strength of 0.50 +/- 0.15 N (shear stress = 14.7 +/- 4.7 KPa, n=30) at a temperature of 60-65 °C. The laser caused demyelination of axons at the operated site; nevertheless, the myelinated axons retained their normal morphology proximally and distally.

  6. Epoxy adhesive plays crucial role at CERN

    CERN Multimedia

    2007-01-01

    "Epoxy adhesives are set to play a vital role in Europe's biggest-ever scientific experiment at the European Centrefor Nuclear Research (CERN) in Geneva, Switzerland, thereby helping scientists gain a better understanding of the origins of the universe." (1/2 page)

  7. Epoxy adhesive plays crucial role at CERN

    CERN Multimedia

    2006-01-01

    "Epoxy adhesives are set to play a vital role in Europe's biggest-ever scientific experiment at the European Centre for Nuclear Research (CERN) in Geneva, Switzerland, thereby helping scientists gain a better understanding of the origins of the universe." (1 page)

  8. Plasma treatment of polymers for improved adhesion

    International Nuclear Information System (INIS)

    Kelber, J.A.

    1988-01-01

    A variety of plasma treatments of polymer sufaces for improved adhesion are reviewed: noble and reactive has treatment of fluoropolymers; noble and reactive treatment of polyolefins, and plasma-induced amination of polymer fibers. The plasma induced surface chemical and morphological changer are discussed, as are the mechanisms of adhersion to polymeric adhesives, particularly epoxy. Noble has plasma eching of fluoropolymers produces a partially defluorinated, textured surface. The mechanical interlocking of this textured surface is the primary cause of improved adhsion to epoxy. Reactive has plasma also induce defluorination, but oxygen containing gases cause continual ablation of the fluoropolymer surface. Noble and reactive gas (except for hydrogen) etching of polyolefins results in surface oxidation and imrprove adhesion via hydrogen bonding of these exygen containing groups across the interface. The introduction of amine groups to a polymer surface by ammonia or amine plasma treatment generally results in improved adhesion to epoxy. However, amine-epoxy ring interactions can be severely effected by steric factors due to chemical group surrounding the amine

  9. Microfabricated adhesive mimicking gecko foot-hair

    Science.gov (United States)

    Geim, A. K.; Dubonos, S. V.; Grigorieva, I. V.; Novoselov, K. S.; Zhukov, A. A.; Shapoval, S. Yu.

    2003-07-01

    The amazing climbing ability of geckos has attracted the interest of philosophers and scientists alike for centuries. However, only in the past few years has progress been made in understanding the mechanism behind this ability, which relies on submicrometre keratin hairs covering the soles of geckos. Each hair produces a miniscule force ~10-7 N (due to van der Waals and/or capillary interactions) but millions of hairs acting together create a formidable adhesion of ~10 N cm-2: sufficient to keep geckos firmly on their feet, even when upside down on a glass ceiling. It is very tempting to create a new type of adhesive by mimicking the gecko mechanism. Here we report on a prototype of such 'gecko tape' made by microfabrication of dense arrays of flexible plastic pillars, the geometry of which is optimized to ensure their collective adhesion. Our approach shows a way to manufacture self-cleaning, re-attachable dry adhesives, although problems related to their durability and mass production are yet to be resolved.

  10. Corrosion, haemocompatibility and bacterial adhesion behaviour of ...

    Indian Academy of Sciences (India)

    TiZrN coating was deposited on 316L stainless steel (SS) by the reactive magnetron co-sputtering technique. Cubic phase of TiZrN with uniform surface morphology was observed by X-ray diffraction and atomic force microscopy. Bacterial adhesion, haemocompatibility and corrosion behaviour of TiZrN coating were ...

  11. Sliding Adhesion Dynamics of Isolated Gecko Setal Arrays

    Science.gov (United States)

    Sponberg, Simon; Autumn, Kellar

    2003-03-01

    The tokay gecko (Gekko gecko) can adhere to nearly any surface through van der Waals interactions of the specialized setae (b-keratin "hairs") of its toe pads. Our recent research has suggested that a gecko is substantially overbuilt for static adhesion requiring as little as 0.03of its theoretical adhesive capacity. We performed the first sliding adhesion experiments on this novel biological adhesive to determine its response to dynamic loading. We isolated arrays of setae and constructed a precision controlled Robo-toe to study sliding effects. Our results indicate that, unlike many typical adhesives, gecko setal arrays exhibit an increased frictional force upon sliding (mk > ms) which further increases with velocity, suggesting that perturbation rejection may be an evolutionary design principle underlying the evolution of the gecko adhesive. We compare these dynamic properties with those of other adhesives and explore the impacts of these results on the design of artificial adhesives.

  12. Adhesion of Antireflective Coatings in Multijunction Photovoltaics: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Brock, Ryan; Dauskardt, Reinhold H.; Miller, David C.

    2016-06-16

    The development of a new composite dual cantilever beam (cDCB) thin-film adhesion testing method is reported, which allows the measurement of adhesion on the fragile thin substrates used in multijunction photovoltaics. We address the adhesion of several antireflective coating systems on multijunction cells. By varying interface chemistry and morphology, we demonstrate the ensuing effects on adhesion and help to develop an understanding of how high adhesion can be achieved, as adhesion values ranging from 0.5 J/m2 to 10 J/m2 were measured. Damp Heat (85 degrees C/85% RH) was used to invoke degradation of interfacial adhesion. We show that even with germanium substrates that fracture easily, quantitative measurements of adhesion can still be made at high test yield. The cDCB test is discussed as an important new methodology, which can be broadly applied to any system that makes use of thin, brittle, or otherwise fragile substrates.

  13. Role of flexural stiffness of leukocyte microvilli in adhesion dynamics

    Science.gov (United States)

    Wu, Tai-Hsien; Qi, Dewei

    2018-03-01

    Previous work reported that microvillus deformation has an important influence on dynamics of cell adhesion. However, the existing studies were limited to the extensional deformation of microvilli and did not consider the effects of their bending deformation on cell adhesion. This Rapid Communication investigates the effects of flexural stiffness of microvilli on the rolling process related to adhesion of leukocytes by using a lattice-Boltzmann lattice-spring method (LLM) combined with adhesive dynamics (AD) simulations. The simulation results reveal that the flexural stiffness of microvilli and their bending deformation have a profound effect on rolling velocity and adhesive forces. As the flexural stiffness of the microvilli decreases, their bending angles increase, resulting in an increase in the number of receptor-ligand bonds and adhesive bonding force and a decrease in the rolling velocity of leukocytes. The effects of flexural stiffness on deformation and adhesion represent crucial factors involved in cell adhesion.

  14. Bacterial adhesion to host tissues : mechanisms and consequences

    National Research Council Canada - National Science Library

    Wilson, Michael, 1947

    2002-01-01

    "This book is about the adhesion of bacteria to their human hosts. Although adhesion is essential for maintaining members of the normal microflora in/on their host, it is also the crucial first stage in any infectious disease...

  15. Bacterial adhesion of porphyromonas gingivalis on provisional fixed prosthetic materials

    Directory of Open Access Journals (Sweden)

    Mustafa Zortuk

    2010-01-01

    Conclusion : The quantity of bacterial adhesion and surface roughness differed among the assessed provisional fixed prosthodontic materials. The light-polymerized provisional material Revotek LC had rougher surface and more bacterial adhesion compared with the others.

  16. Leakage Testing for Different Adhesive Systems and Composites to ...

    African Journals Online (AJOL)

    2015-11-16

    Nov 16, 2015 ... resin composite, the fifth group – two‑stage SE adhesive applied and cavities filled with ... KEYWORDS: Adhesives, composite, evaluation, leakage ... the glass ionomers. ... systems are realized in one or two clinical step(s).[5].

  17. A Novel Electrostatic/Microstructured Adhesive with Dust Mitigation Capabilities

    Data.gov (United States)

    National Aeronautics and Space Administration — This work will develop a novel electrostatic/gecko-like adhesive that will demonstrate an order-of-magnitude improvement of electrostatic adhesion pressure coupled...

  18. Development and In vitro Evaluation of Betahistine Adhesive-Type ...

    African Journals Online (AJOL)

    Purpose: To develop a transdermal betahistine (BTH) delivery system using different pressure sensitive adhesives (PSAs) including acrylics, polyisobutylene and styrenic rubber solution. Methods: Formulations were prepared by solvent casting and adhesive transfer method. PSAs - acrylate vinylacetate (AVA), hydrophilic ...

  19. Evaluation of high temperature structural adhesives for extended service

    Science.gov (United States)

    Hendricks, C. L.; Hill, S. G.

    1984-01-01

    High temperature stable adhesive systems were evaluated for potential Supersonic Cruise Research (SCR) vehicle applications. The program was divided into two major phases: Phase I 'Adhesive Screening' evaluated eleven selected polyimide (PI) and polyphenylquinoxaline (PPQ) adhesive resins using eight different titanium (6Al-4V) adherend surface preparations; Phase II 'Adhesive Optimization and Characterization' extensively evaluated two adhesive systems, selected from Phase I studies, for chemical characterization and environmental durability. The adhesive systems which exhibited superior thermal and environmental bond properties were LARC-TPI polyimide and polyphenylquinoxaline both developed at NASA Langley. The latter adhesive system did develop bond failures at extended thermal aging due primarily to incompatibility between the surface preparation and the polymer. However, this study did demonstrate that suitable adhesive systems are available for extended supersonic cruise vehicle design applications.

  20. Wet adhesion with application to tree frog adhesive toe pads and tires

    International Nuclear Information System (INIS)

    Persson, B N J

    2007-01-01

    Strong adhesion between solids with rough surfaces is only possible if at least one of the solids is elastically very soft. Some lizards and spiders are able to adhere (dry adhesion) and move on very rough vertical surfaces due to very compliant surface layers on their attachment pads. Flies, bugs, grasshoppers and tree frogs have less compliant pad surface layers, and in these cases adhesion to rough surfaces is only possible because the animals inject a wetting liquid into the pad-substrate contact area, which generates a relative long-range attractive interaction due to the formation of capillary bridges. In this presentation I will discuss some aspects of wet adhesion for tree frogs and give some comments related to tire applications

  1. Wet adhesion with application to tree frog adhesive toe pads and tires

    Energy Technology Data Exchange (ETDEWEB)

    Persson, B N J [IFF, FZ-Juelich, 52425 Juelich (Germany)

    2007-09-19

    Strong adhesion between solids with rough surfaces is only possible if at least one of the solids is elastically very soft. Some lizards and spiders are able to adhere (dry adhesion) and move on very rough vertical surfaces due to very compliant surface layers on their attachment pads. Flies, bugs, grasshoppers and tree frogs have less compliant pad surface layers, and in these cases adhesion to rough surfaces is only possible because the animals inject a wetting liquid into the pad-substrate contact area, which generates a relative long-range attractive interaction due to the formation of capillary bridges. In this presentation I will discuss some aspects of wet adhesion for tree frogs and give some comments related to tire applications.

  2. Evidence for van der Waals adhesion in gecko setae

    OpenAIRE

    Autumn, Kellar; Sitti, Metin; Liang, Yiching A.; Peattie, Anne M.; Hansen, Wendy R.; Sponberg, Simon; Kenny, Thomas W.; Fearing, Ronald; Israelachvili, Jacob N.; Full, Robert J.

    2002-01-01

    Geckos have evolved one of the most versatile and effective adhesives known. The mechanism of dry adhesion in the millions of setae on the toes of geckos has been the focus of scientific study for over a century. We provide the first direct experimental evidence for dry adhesion of gecko setae by van der Waals forces, and reject the use of mechanisms relying on high surface polarity, including capillary adhesion. The toes of live Tokay geckos were highly hydrophobic, and adhered equally well ...

  3. Amperometric Adhesion Signals of Liposomes, Cells and Droplets

    OpenAIRE

    Ivošević DeNardis, N.; Žutić, V.; Svetličić, V.; Frkanec, R.

    2009-01-01

    Individual soft microparticles (liposomes, living cells and organic droplets) in aqueous media are characterized by their adhesion signals using amperometry at the dropping mercury electrode. We confirmed that the general mechanism established for adhesion of hydrocarbon droplets and cells is valid as well for liposome adhesion within a wide range of surface charge densities. Incidents and shape of adhesion signals in liposome suspensions reflect liposome polydispersity, surface charge den...

  4. How do liquids confined at the nanoscale influence adhesion?

    International Nuclear Information System (INIS)

    Yang, C; Tartaglino, U; Persson, B N J

    2006-01-01

    Liquids play an important role in adhesion and sliding friction. They behave as lubricants in human bodies, especially in the joints. However, in many biological attachment systems they act like adhesives, e.g. facilitating insects to move on ceilings or vertical walls. Here we use molecular dynamics to study how liquids confined at the nanoscale influence the adhesion between solid bodies with smooth and rough surfaces. We show that a monolayer of liquid may strongly affect the adhesion

  5. Adhesive capsulitis of the shoulder: MR arthrography

    International Nuclear Information System (INIS)

    Kim, Hyun Jeong; Han, Tae Il; Lee, Kwang Won; Choi, Youn Seon; Kim, Dae Hong; Han, Hyun Young; Song, Mun Kab; Kwon, Soon Tae

    2001-01-01

    Adhesive capsulitis is a clinical syndrome involving pain and decreased joint motion caused by thickening and contraction of the joint capsule. The purpose of this study is to describe the MR arthrographic findings of this syndrome. Twenty-nine sets of MR arthrographic images were included in the study. Fourteen patients had adhesive capsulitis diagnosed by physical examination and arthrography, and their MR arthrographic findings were compared with those of 15 subjects in the control group. The images were retrospectively reviewed with specific attention to the thickness of the joint capsule, volume of the axillary pouch (length, width, height(depth)), thinkness of the coracohumeral ligament, presence of extra-articular contrast extravasation, and contrst filling of the subcoracoid bursa. Mean capsular thickness measured at the inferior portion of the axillary pouch was 4.1 mm in patients with adhesive capsulitis and 1.5 mm in the control group. The mean width of the axillary pouch was 2.5 mm in patients and 9.5 mm in controls. In patients, the capsule was significantly thicker and the axillary pouch significantly narrower than in controls (p<0.05). Capsule thickness greater than 2.5 mm at the inferior portion of the axillary pouch (sensitivity 93%, specificity 80%) and a pouch narrower than 3.5 mm (sensitivity 93%, specificity 100%) were useful criteria for the diagnosis of adhesive capsulitis. In patients with this condition, extra-articular contrast extravasation was noted in six patients (43%) and contrast filling of the subcoracoid bursa in three (21%). The MR arthrographic findings of adhesive capsulitis are capsular thickening, a low-volume axillary pouch, extra-articular contrast extravasation, and contrast filling of the subcoracoid bursa. Capsule thickness greater than 2.5 mm at the inferior portion of the axillary pouch and a pouch width of less than 3.5 mm are useful diagnostic imaging characteristics

  6. Surface pretreatments for medical application of adhesion

    Directory of Open Access Journals (Sweden)

    Weber Michael

    2003-09-01

    Full Text Available Abstract Medical implants and prostheses (artificial hips, tendono- and ligament plasties usually are multi-component systems that may be machined from one of three material classes: metals, plastics and ceramics. Typically, the body-sided bonding element is bone. The purpose of this contribution is to describe developments carried out to optimize the techniques , connecting prosthesis to bone, to be joined by an adhesive bone cement at their interface. Although bonding of organic polymers to inorganic or organic surfaces and to bone has a long history, there remains a serious obstacle in realizing long-term high-bonding strengths in the in vivo body environment of ever present high humidity. Therefore, different pretreatments, individually adapted to the actual combination of materials, are needed to assure long term adhesive strength and stability against hydrolysis. This pretreatment for metal alloys may be silica layering; for PE-plastics, a specific plasma activation; and for bone, amphiphilic layering systems such that the hydrophilic properties of bone become better adapted to the hydrophobic properties of the bone cement. Amphiphilic layering systems are related to those developed in dentistry for dentine bonding. Specific pretreatment can significantly increase bond strengths, particularly after long term immersion in water under conditions similar to those in the human body. The bond strength between bone and plastic for example can be increased by a factor approaching 50 (pealing work increasing from 30 N/m to 1500 N/m. This review article summarizes the multi-disciplined subject of adhesion and adhesives, considering the technology involved in the formation and mechanical performance of adhesives joints inside the human body.

  7. Effects of solvent evaporation time on immediate adhesive properties of universal adhesives to dentin.

    Science.gov (United States)

    Luque-Martinez, Issis V; Perdigão, Jorge; Muñoz, Miguel A; Sezinando, Ana; Reis, Alessandra; Loguercio, Alessandro D

    2014-10-01

    To evaluate the microtensile bond strengths (μTBS) and nanoleakage (NL) of three universal or multi-mode adhesives, applied with increasing solvent evaporation times. One-hundred and forty caries-free extracted third molars were divided into 20 groups for bond strength testing, according to three factors: (1) Adhesive - All-Bond Universal (ABU, Bisco, Inc.), Prime&Bond Elect (PBE, Dentsply), and Scotchbond Universal Adhesive (SBU, 3M ESPE); (2) Bonding strategy - self-etch (SE) or etch-and-rinse (ER); and (3) Adhesive solvent evaporation time - 5s, 15s, and 25s. Two extra groups were prepared with ABU because the respective manufacturer recommends a solvent evaporation time of 10s. After restorations were constructed, specimens were stored in water (37°C/24h). Resin-dentin beams (0.8mm(2)) were tested at 0.5mm/min (μTBS). For NL, forty extracted molars were randomly assigned to each of the 20 groups. Dentin disks were restored, immersed in ammoniacal silver nitrate, sectioned and processed for evaluation under a FESEM in backscattered mode. Data from μTBS were analyzed using two-way ANOVA (adhesive vs. drying time) for each strategy, and Tukey's test (α=0.05). NL data were computed with non-parametric tests (Kruskal-Wallis and Mann-Whitney tests, α=0.05). Increasing solvent evaporation time from 5s to 25s resulted in statistically higher mean μTBS for all adhesives when used in ER mode. Regarding NL, ER resulted in greater NL than SE for each of the evaporation times regardless of the adhesive used. A solvent evaporation time of 25s resulted in the lowest NL for SBU-ER. Residual water and/or solvent may compromise the performance of universal adhesives, which may be improved with extended evaporation times. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  8. Adhesion of Pharmaceutical Binding Agents I-Adhesion to polymeric materials

    Directory of Open Access Journals (Sweden)

    Hossain Orafai

    1996-08-01

    Full Text Available Adhesion of three commonly used pharmaceutical binding agents, HPMC , PVP and Gelatin to five different polymeric sheet materials was studied. After conditioning, the bond strength of the specimens were measured by shear testing method using a suitablely designed apparatus. The results were correlated to the surface energies and the solubiiity parameters of the adherends. It is concluded that the thermodynamic properties and the solubility parameters are dominant when the mechanisms of adhesion are by adsorption and diffusion respectively.

  9. Geometry- and rate-dependent adhesive failure of micropatterned surfaces

    NARCIS (Netherlands)

    Bakker, H.; Lindstrom, S.B.; Sprakel, J.H.B.

    2012-01-01

    The dynamic nature of adhesive interface failure remains poorly understood, especially when the contact between the two surfaces is localized in microscopic points of adhesion. Here, we explore the dynamic failure of adhesive interfaces composed of a large number of micron-sized pillars against

  10. Adhesion of tissue glues to different biological substrates

    NARCIS (Netherlands)

    Bochynska, A. I.; Hannink, G.; Buma, P.; Grijpma, D. W.

    2017-01-01

    Tissue adhesives are attractive materials with potential to replace the use of sutures and staples in the repair of the injured tissues. The research field of tissue adhesives is dynamically growing, and different methods and tissue models are employed to evaluate the adhesive properties of newly

  11. Adhesion of tissue glues to different biological substrates

    NARCIS (Netherlands)

    Bochynska, Agnieszka; Hannink, G.; Buma, P.; Grijpma, Dirk W.

    2016-01-01

    Tissue adhesives are attractive materials with potential to replace the use of sutures and staples in the repair of the injured tissues. The research field of tissue adhesives is dynamically growing, and different methods and tissue models are employed to evaluate the adhesive properties of newly

  12. Anisotropic Adhesion Properties of Triangular-Tip-Shaped Micropillars

    KAUST Repository

    Kwak, Moon Kyu

    2011-06-01

    Directional dry adhesive microstructures consisting of high-density triangular-tip-shaped micropillars are described. The wide-tip structures allow for unique directional shear adhesion properties with respect to the peeling direction, along with relatively high normal adhesion. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. A comprehensive toxicological evaluation of three adhesives using experimental cigarettes.

    Science.gov (United States)

    Coggins, Christopher R E; Jerome, Ann M; Lilly, Patrick D; McKinney, Willie J; Oldham, Michael J

    2013-01-01

    Adhesives are used in several different manufacturing operations in the production of cigarettes. The use of new, "high-speed-manufacture" adhesives (e.g. vinyl acetate based) could affect the smoke chemistry and toxicology of cigarettes, compared with older "low-speed-manufacture" adhesives (e.g. starch based). This study was conducted to determine whether the inclusion of different levels of three adhesives (ethylene vinyl acetate, polyvinyl acetate and starch) in experimental cigarettes results in different smoke chemistry and toxicological responses in in vitro and in vivo assays. A battery of tests (analytical chemistry, in vitro and in vivo assays) was used to compare the chemistry and toxicology of smoke from experimental cigarettes made with different combinations of the three adhesives. Varying levels of the different side-seam adhesives, as well as the transfer of adhesives from packaging materials, were tested. There were differences in some mainstream cigarette smoke constituents as a function of the level of adhesive added to experimental cigarettes and between the tested adhesives. None of these differences translated into statistically significant differences in the in vitro or in vivo assays. The use of newer "high-speed-manufacture" vinyl acetate-based adhesives in cigarettes does not produce toxicological profiles that prevent the adhesives from replacing the older "low-speed-manufacture" adhesives (such as starch).

  14. 16 CFR 1500.133 - Extremely flammable contact adhesives; labeling.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Extremely flammable contact adhesives... REGULATIONS § 1500.133 Extremely flammable contact adhesives; labeling. (a) Extremely flammable contact adhesives, also known as contact bonding cements, when distributed in containers intended or suitable for...

  15. Characterizing phenolformaldehyde adhesive cure chemistry within the wood cell wall

    Science.gov (United States)

    Daniel J. Yelle; John Ralph

    2016-01-01

    Adhesive bonding of wood using phenol-formaldehyde remains the industrial standard in wood product bond durability. Not only does this adhesive infiltrate the cell wall, it also is believed to form primary bonds with wood cell wall polymers, particularly guaiacyl lignin. However, the mechanism by which phenol-formaldehyde adhesive intergrally interacts and bonds to...

  16. Anisotropic Adhesion Properties of Triangular-Tip-Shaped Micropillars

    KAUST Repository

    Kwak, Moon Kyu; Jeong, Hoon Eui; Bae, Won Gyu; Jung, Ho-Sup; Suh, Kahp Y.

    2011-01-01

    Directional dry adhesive microstructures consisting of high-density triangular-tip-shaped micropillars are described. The wide-tip structures allow for unique directional shear adhesion properties with respect to the peeling direction, along with relatively high normal adhesion. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Leakage testing for different adhesive systems and composites to ...

    African Journals Online (AJOL)

    The teeth were randomly assigned to six groups of 14 teeth each as follows: The first group – etch‑rinse adhesive applied and cavities filled with flowable composite, the second group – etch‑rinse adhesive applied and cavities filled with bulk‑fill resin composite, the third group – one‑stage self‑etch (SE) adhesive applied ...

  18. Increased error rates in preliminary reports issued by radiology residents working more than 10 consecutive hours overnight.

    Science.gov (United States)

    Ruutiainen, Alexander T; Durand, Daniel J; Scanlon, Mary H; Itri, Jason N

    2013-03-01

    To determine if the rate of major discrepancies between resident preliminary reports and faculty final reports increases during the final hours of consecutive 12-hour overnight call shifts. Institutional review board exemption status was obtained for this study. All overnight radiology reports interpreted by residents on-call between January 2010 and June 2010 were reviewed by board-certified faculty and categorized as major discrepancies if they contained a change in interpretation with the potential to impact patient management or outcome. Initial determination of a major discrepancy was at the discretion of individual faculty radiologists based on this general definition. Studies categorized as major discrepancies were secondarily reviewed by the residency program director (M.H.S.) to ensure consistent application of the major discrepancy designation. Multiple variables associated with each report were collected and analyzed, including the time of preliminary interpretation, time into shift study was interpreted, volume of studies interpreted during each shift, day of the week, patient location (inpatient or emergency department), block of shift (2-hour blocks for 12-hour shifts), imaging modality, patient age and gender, resident identification, and faculty identification. Univariate risk factor analysis was performed to determine the optimal data format of each variable (ie, continuous versus categorical). A multivariate logistic regression model was then constructed to account for confounding between variables and identify independent risk factors for major discrepancies. We analyzed 8062 preliminary resident reports with 79 major discrepancies (1.0%). There was a statistically significant increase in major discrepancy rate during the final 2 hours of consecutive 12-hour call shifts. Multivariate analysis confirmed that interpretation during the last 2 hours of 12-hour call shifts (odds ratio (OR) 1.94, 95% confidence interval (CI) 1.18-3.21), cross

  19. Effect of Pitching Consecutive Days in Youth Fast-Pitch Softball Tournaments on Objective Shoulder Strength and Subjective Shoulder Symptoms.

    Science.gov (United States)

    Skillington, S Andrew; Brophy, Robert H; Wright, Rick W; Smith, Matthew V

    2017-05-01

    The windmill pitching motion has been associated with risk for shoulder injury. Because there are no pitching limits on youth fast-pitch softball pitchers, these athletes often pitch multiple games across consecutive days. Strength changes, fatigue levels, and shoulder pain that develop among female fast-pitch pitchers over the course of consecutive days of pitching have not been investigated. Over the course of 2- and 3-day fast-pitch softball tournaments, pitchers will develop progressive objective weakness and increased subjective shoulder fatigue and pain without complete recovery between days. Cross-sectional study; Level of evidence, 3. Fourteen female fast-pitch softball pitchers between the ages of 14 and 18 years were evaluated for strength and fatigue changes across 2- and 3-day tournaments. At the beginning and end of each day of tournament play, pitchers were asked to quantify shoulder fatigue and shoulder pain levels of their dominant throwing arm using a 10-point visual analog scale (VAS). Shoulder abduction, flexion, external rotation, internal rotation, elbow flexion, and elbow extension strength measurements were gathered using a handheld dynamometer. Over the course of an average single day of tournament participation, pitchers developed significant increases in VAS scores for shoulder fatigue (median, 2.0; 95% CI, 1.3-3.0) and pain (median, 1.3; 95% CI, 0.5-2.3) and significant strength loss in all tested motions. Pitchers also developed significant increases in VAS shoulder fatigue (median, 3.5; 95% CI, 1.5-5.5), VAS shoulder pain (median, 2.5; 95% CI, 1.0-4.5), and strength loss in all tested motions over the entire tournament. Shoulder pain, fatigue, and strength do not fully recover between days. The accumulation of subjective shoulder pain and fatigue over the course of tournament play were closely correlated. Among youth female fast-pitch softball pitchers, there is a progressive increase in shoulder fatigue, pain, and weakness over the

  20. Effect of pitching consecutive days in youth softball tournaments on objective shoulder strength and subjective shoulder symptoms

    Science.gov (United States)

    Skillington, S. Andrew; Brophy, Robert H.; Wright, Rick W.; Smith, Matthew V.

    2017-01-01

    Background The windmill pitching motion has been associated with risk for shoulder injury. Since there are no pitching limits on youth fast-pitch softball pitchers, these athletes often pitch multiple games across consecutive days. Strength changes, fatigue levels, and shoulder pain that develop among female fast-pitch pitchers over the course of consecutive days of pitching have not been investigated. Hypothesis Over the course of 2 and 3-day fast-pitch softball tournaments, pitchers will develop progressive objective weakness and increased subjective shoulder fatigue and pain without complete recovery between days. Study Design Cross-Sectional Study. Methods Female fast-pitch softball pitchers between the ages of 14 and 18 who were pitching in 2 and 3-day tournaments were recruited for study participation. At the beginning and end of each day of tournament play, pitchers were asked to quantify shoulder fatigue and shoulder pain levels of their dominant throwing arm using a 10-point visual analog scale (VAS). Shoulder abduction, flexion, external rotation, internal rotation, elbow flexion, and elbow extension strength measurements were gathered using a hand-held dynamometer. Results Over the course of an average single day of tournament participation, pitchers developed significant increases in VAS shoulder fatigue (2.0, 95% CI: 1.3 to 3.0), and pain (1.3, 95% CI: 0.5 to 2.3) and significant strength loss in all tested motions. Pitchers also developed significant increases in VAS shoulder fatigue (3.5, 95% CI: 1.5 to 5.5), VAS shoulder pain (2.5, 95% CI: 1.0 to 4.5) and strength loss in all tested motions over the entire tournament. Shoulder pain, fatigue, and strength do not fully recover between days. The accumulation of subjective shoulder pain and fatigue over the course of tournament play were closely correlated. Conclusion Among youth female fast-pitch softball pitchers, there is a progressive increase in shoulder fatigue, pain, and weakness over the course

  1. Influence of Conditioning Time of Universal Adhesives on Adhesive Properties and Enamel-Etching Pattern.

    Science.gov (United States)

    Cardenas, A M; Siqueira, F; Rocha, J; Szesz, A L; Anwar, M; El-Askary, F; Reis, A; Loguercio, A

    2016-01-01

    To evaluate the effect of application protocol in resin-enamel microshear bond strength (μSBS), in situ degree of conversion, and etching pattern of three universal adhesive systems. Sixty-three extracted third molars were sectioned in four parts (buccal, lingual, and proximals) and divided into nine groups, according to the combination of the main factors-Adhesive (Clearfil Universal, Kuraray Noritake Dental Inc, Tokyo, Japan; Futurabond U, VOCO, Cuxhaven, Germany; and Scotchbond Universal Adhesive, 3M ESPE, St Paul, MN, USA)-and enamel treatment/application time (etch-and-rinse mode [ER], self-etch [SE] application for 20 seconds [SE20], and SE application for 40 seconds [SE40]). Specimens were stored in water (37°C/24 h) and tested at 1.0 mm/min (μSBS). The degree of conversion of the adhesives at the resin-enamel interfaces was evaluated using micro-Raman spectroscopy. The enamel-etching pattern was evaluated under a scanning electron microscope. Data were analyzed with two-way analysis of variance and Tukey test (α=0.05). In general, the application of the universal adhesives in the SE40 produced μSBS and degree of conversion that were higher than in the SE20 (puniversal adhesives in the SE mode may be a viable alternative to increase the degree of conversion, etching pattern, and resin-enamel bond strength.

  2. Temperature Effects on Adhesive Bond Strengths and Modulus for Commonly Used Spacecraft Structural Adhesives

    Science.gov (United States)

    Ojeda, Cassandra E.; Oakes, Eric J.; Hill, Jennifer R.; Aldi, Dominic; Forsberg, Gustaf A.

    2011-01-01

    A study was performed to observe how changes in temperature and substrate material affected the strength and modulus of an adhesive bondline. Seven different adhesives commonly used in aerospace bonded structures were tested. Aluminum, titanium and Invar adherends were cleaned and primed, then bonded using the manufacturer's recommendations. Following surface preparation, the coupons were bonded with the adhesives. The single lap shear coupons were then pull tested per ASTM D 1002 Standard Test Method for Apparent Shear Strength of Single- Lap-Joint over a temperature range from -150 deg C up to +150 deg C. The ultimate strength was calculated and the resulting data were converted into B-basis design allowables. Average and Bbasis results were compared. Results obtained using aluminum adherends are reported. The effects of using different adherend materials and temperature were also studied and will be reported in a subsequent paper. Dynamic Mechanical Analysis (DMA) was used to study variations in adhesive modulus with temperature. This work resulted in a highly useful database for comparing adhesive performance over a wide range of temperatures, and has facilitated selection of the appropriate adhesive for spacecraft structure applications.

  3. Hierarchical macroscopic fibrillar adhesives: in situ study of buckling and adhesion mechanisms on wavy substrates.

    Science.gov (United States)

    Bauer, Christina T; Kroner, Elmar; Fleck, Norman A; Arzt, Eduard

    2015-10-23

    Nature uses hierarchical fibrillar structures to mediate temporary adhesion to arbitrary substrates. Such structures provide high compliance such that the flat fibril tips can be better positioned with respect to asperities of a wavy rough substrate. We investigated the buckling and adhesion of hierarchically structured adhesives in contact with flat smooth, flat rough and wavy rough substrates. A macroscopic model for the structural adhesive was fabricated by molding polydimethylsiloxane into pillars of diameter in the range of 0.3-4.8 mm, with up to three different hierarchy levels. Both flat-ended and mushroom-shaped hierarchical samples buckled at preloads one quarter that of the single level structures. We explain this behavior by a change in the buckling mode; buckling leads to a loss of contact and diminishes adhesion. Our results indicate that hierarchical structures can have a strong influence on the degree of adhesion on both flat and wavy substrates. Strategies are discussed that achieve highly compliant substrates which adhere to rough substrates.

  4. Enhancing the Adhesive Strength of a Plywood Adhesive Developed from Hydrolyzed Specified Risk Materials

    Directory of Open Access Journals (Sweden)

    Birendra B. Adhikari

    2016-08-01

    Full Text Available The current production of wood composites relies mostly on formaldehyde-based adhesives such as urea formaldehyde (UF and phenol formaldehyde (PF resins. As these resins are produced from non-renewable resources, and there are some ongoing issues with possible health hazard due to formaldehyde emission from such products, the purpose of this research was to develop a formaldehyde-free plywood adhesive utilizing waste protein as a renewable feedstock. The feedstock for this work was specified risk material (SRM, which is currently being disposed of either by incineration or by landfilling. In this report, we describe a technology for utilization of SRM for the development of an environmentally friendly plywood adhesive. SRM was thermally hydrolyzed using a Canadian government-approved protocol, and the peptides were recovered from the hydrolyzate. The recovered peptides were chemically crosslinked with polyamidoamine-epichlorohydrin (PAE resin to develop an adhesive system for bonding of plywood specimens. The effects of crosslinking time, peptides/crosslinking agent ratio, and temperature of hot pressing of plywood specimens on the strength of formulated adhesives were investigated. Formulations containing as much as 78% (wt/wt peptides met the ASTM (American Society for Testing and Materials specifications of minimum dry and soaked shear strength requirement for UF resin type adhesives. Under the optimum conditions tested, the peptides–PAE resin-based formulations resulted in plywood specimens having comparable dry as well as soaked shear strength to that of commercial PF resin.

  5. Intercellular adhesion molecule-1 augments myoblast adhesion and fusion through homophilic trans-interactions.

    Science.gov (United States)

    Pizza, Francis X; Martin, Ryan A; Springer, Evan M; Leffler, Maxwell S; Woelmer, Bryce R; Recker, Isaac J; Leaman, Douglas W

    2017-07-11

    The overall objective of the study was to identify mechanisms through which intercellular adhesion molecule-1 (ICAM-1) augments the adhesive and fusogenic properties of myogenic cells. Hypotheses were tested using cultured myoblasts and fibroblasts, which do not constitutively express ICAM-1, and myoblasts and fibroblasts forced to express full length ICAM-1 or a truncated form lacking the cytoplasmic domain of ICAM-1. ICAM-1 mediated myoblast adhesion and fusion were quantified using novel assays and cell mixing experiments. We report that ICAM-1 augments myoblast adhesion to myoblasts and myotubes through homophilic trans-interactions. Such adhesive interactions enhanced levels of active Rac in adherent and fusing myoblasts, as well as triggered lamellipodia, spreading, and fusion of myoblasts through the signaling function of the cytoplasmic domain of ICAM-1. Rac inhibition negated ICAM-1 mediated lamellipodia, spreading, and fusion of myoblasts. The fusogenic property of ICAM-1-ICAM-1 interactions was restricted to myogenic cells, as forced expression of ICAM-1 by fibroblasts did not augment their fusion to ICAM-1+ myoblasts/myotubes. We conclude that ICAM-1 augments myoblast adhesion and fusion through its ability to self-associate and initiate Rac-mediated remodeling of the actin cytoskeleton.

  6. Rheology and adhesion of poly(acrylic acid)/laponite nanocomposite hydrogels as biocompatible adhesives.

    Science.gov (United States)

    Shen, Muxian; Li, Li; Sun, Yimin; Xu, Jun; Guo, Xuhong; Prud'homme, Robert K

    2014-02-18

    Biocompatible nanocomposite hydrogels (NC gels) consisting of poly(acrylic acid) (PAA) and nanosized clay (Laponite) were successfully synthesized by in situ free-radical polymerization of acrylic acid (AA) in aqueous solutions of Laponite. The obtained NC gels were uniform and transparent. Their viscosity, storage modulus G', and loss modulus G″ increased significantly upon increasing the content of Laponite and the dose of AA, while exhibiting a maximum with increasing the neutralization degree of AA. They showed tunable adhesion by changing the dose of Laponite and monomer as well as the neutralization degree of AA, as determined by 180° peel strength measurement. The maximal adhesion was shown when reaching a balance between cohesion and fluidity. A homemade Johnson-Kendall-Roberts (JKR) instrument was employed to study the surface adhesion behavior of the NC gels. The combination of peel strength, rheology, and JKR measurements offers the opportunity of insight into the mechanism of adhesion of hydrogels. The NC gels with tunable adhesion should be ideal candidates for dental adhesive, wound dressing, and tissue engineering.

  7. Primary Adhesion in Enteromorpha. Cue Detection and Surface Selection in the Settlement and Adhesion of Enteromorpha Spores

    National Research Council Canada - National Science Library

    Callow, James

    2001-01-01

    .... spore settlement and adhesion. Our results provide the most comprehensive characterisation of the settlement and adhesion processes and the roles of surface-associated cues, of any soft-fouling species to date, We have shown...

  8. Conjugates of Cell Adhesion Peptides for Therapeutics and Diagnostics Against Cancer and Autoimmune Diseases.

    Science.gov (United States)

    Moral, Mario E G; Siahaan, Teruna J

    2017-01-01

    Overexpressed cell-surface receptors are hallmarks of many disease states and are often used as markers for targeting diseased cells over healthy counterparts. Cell adhesion peptides, which are often derived from interacting regions of these receptor-ligand proteins, mimic surfaces of intact proteins and, thus, have been studied as targeting agents for various payloads to certain cell targets for cancers and autoimmune diseases. Because many cytotoxic agents in the free form are often harmful to healthy cells, the use of cell adhesion peptides in targeting their delivery to diseased cells has been studied to potentially reduce required effective doses and associated harmful side-effects. In this review, multiple cell adhesion peptides from extracellular matrix and ICAM proteins were used to selectively direct drug payloads, signal-inhibitor peptides, and diagnostic molecules, to diseased cells over normal counterparts. RGD constructs have been used to improve the selectivity and efficacy of diagnostic and drug-peptide conjugates against cancer cells. From this precedent, novel conjugates of antigenic and cell adhesion peptides, called Bifunctional Peptide Inhibitors (BPIs), have been designed to selectively regulate immune cells and suppress harmful inflammatory responses in autoimmune diseases. Similar peptide conjugations with imaging agents have delivered promising diagnostic methods in animal models of rheumatoid arthritis. BPIs have also been shown to generate immune tolerance and suppress autoimmune diseases in animal models of type-1 diabetes, rheumatoid arthritis, and multiple sclerosis. Collectively, these studies show the potential of cell adhesion peptides in improving the delivery of drugs and diagnostic agents to diseased cells in clinical settings. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  9. Regional aspects of cerebral cysticercosis. Incidence and evaluation by computerized tomography in 1000 consecutive studies

    Energy Technology Data Exchange (ETDEWEB)

    Jozzolino, D.A. (Instituto de Tomografia Axial Computadorizada de Londrina (Brazil))

    One thousand consecutive studies of the entire brain were performed and 122 patients with tomographic diagnosis of cysticercosis were found. The high incidence of this disease is discussed and its endemic characteristics as well. Various forms and types are described, the most frequent being the presence of calcifications; other tests performed at the time of computerized tomography are mentioned.

  10. Systematic front distortion and presence of consecutive fronts in a precipitation system

    NARCIS (Netherlands)

    Volford, A.; Izsak, F.; Ripszam, M.; Lagzi, I.

    2006-01-01

    A new simple reaction-diffusion system is presented focusing on pattern formation phenomena as consecutive precipitation fronts and distortion of the precipitation front.The chemical system investigated here is based on the amphoteric property of aluminum hydroxide and exhibits two unique phenomena.

  11. Numerical Simulations of Competitive-Consecutive Reactions in Turbulent Channel Flow

    NARCIS (Netherlands)

    Vrieling, A.J.

    2003-01-01

    This thesis deals with mixing of passive scalars in a turbulent flow. The passive scalars are released in a turbulent plane channel flow and interpreted as either non-reactive components or reactive components that are involved in a competitive-consecutive reaction system. The evolution of these

  12. Automatic lameness detection based on consecutive 3D-video recordings

    NARCIS (Netherlands)

    Hertem, van T.; Viazzi, S.; Steensels, M.; Maltz, E.; Antler, A.; Alchanatis, V.; Schlageter-Tello, A.; Lokhorst, C.; Romanini, C.E.B.; Bahr, C.; Berckmans, D.; Halachmi, I.

    2014-01-01

    Manual locomotion scoring for lameness detection is a time-consuming and subjective procedure. Therefore, the objective of this study is to optimise the classification output of a computer vision based algorithm for automated lameness scoring. Cow gait recordings were made during four consecutive

  13. TRANSURETHRAL RADIOFREQUENCY HEATING OR THERMOTHERAPY FOR BENIGN PROSTATIC HYPERTROPHY - A PROSPECTIVE TRIAL ON 65 CONSECUTIVE CASES

    NARCIS (Netherlands)

    MEIER, AHP; WEIL, EHJ; VANDOORN, ESCV; VERHAEGH, GTCM; JANKNEGT, RA

    1992-01-01

    65 consecutive cases with symptomatic benign prostate hypertrophy were treated with transurethral radiowave thermotherapy (TURF) using the Thermex-II at a temperature of 44.5-degrees-C. We report uroflowmetry and symptom scores after a follow-up of 6 months. The mean age was 63 years, the mean

  14. La interpretacion consecutiva: metodologia y tecnicas (Consecutive Interpretation: Methodology and Techniques).

    Science.gov (United States)

    Drallny, Ines

    1987-01-01

    Describes the purpose and appropriate methodology for various levels of interpreter training, for both consecutive and simultaneous interpretation. The importance of relating the intent of the text to the explicit language forms through which that intent is realized is discussed, and appropriate criteria for evaluation of student interpreters are…

  15. Effect of consecutive driving on accident risk: a comparison between passenger and freight train driving.

    Science.gov (United States)

    Chang, Hsin-Li; Ju, Lai-Shun

    2008-11-01

    This study combined driver-responsible accidents with on-board driving hours to examine the effect of consecutive driving on the accident risk of train operations. The data collected from the Taiwan Railway Administration for the period 1996-2006 was used to compute accident rates for varied accumulated driving hours for passenger and freight trains. The results showed that accident risk grew with increased consecutive driving hours for both passenger and freight trains, and doubled that of the first hour after four consecutive hours of driving. Additional accident risk was found for freight trains during the first hour due to required shunting in the marshalling yards where there are complex track layouts and semi-automatic traffic controls. Also, accident risk for train driving increased more quickly over consecutive driving hours than for automobile driving, and accumulated fatigue caused by high working pressure and monotony of the working environment are considered to be the part of the reason. To prevent human errors accidents, enhancing safety equipment, driver training programs, and establishing a sound auditing system are suggested and discussed.

  16. Acute effects of heavy-load squats on consecutive squat jump performance.

    Science.gov (United States)

    Weber, Kurt R; Brown, Lee E; Coburn, Jared W; Zinder, Steven M

    2008-05-01

    Postactivation potentiation (PAP) and complex training have generated interest within the strength and conditioning community in recent years, but much of the research to date has produced confounding results. The purpose of this study was to observe the acute effects of a heavy-load back squat [85% 1 repetition maximum (1RM)] condition on consecutive squat jump performance. Twelve in-season Division I male track-and-field athletes participated in two randomized testing conditions: a five-repetition back squat at 85% 1RM (BS) and a five-repetition squat jump (SJ). The BS condition consisted of seven consecutive squat jumps (BS-PRE), followed by five repetitions of the BS at 85% 1RM, followed by another set of seven consecutive squat jumps (BS-POST). The SJ condition was exactly the same as the BS condition except that five consecutive SJs replaced the five BSs, with 3 minutes' rest between each set. BS-PRE, BS-POST, SJ-PRE, and SJ-POST were analyzed and compared for mean and peak jump height, as well as mean and peak ground reaction force (GRF). The BS condition's mean and peak jump height and peak GRF increased 5.8% +/- 4.8%, 4.7% +/- 4.8%, and 4.6% +/- 7.4%, respectively, whereas the SJ condition's mean and peak jump height and peak GRF decreased 2.7% +/- 5.0%, 4.0% +/- 4.9%, and 1.3% +/- 7.5%, respectively. The results indicate that performing a heavy-load back squat before a set of consecutive SJs may enhance acute performance in average and peak jump height, as well as peak GRF.

  17. Labtracker+, a medical smartphone app for the interpretation of consecutive laboratory results: an external validation study.

    Science.gov (United States)

    Hilderink, Judith M; Rennenberg, Roger J M W; Vanmolkot, Floris H M; Bekers, Otto; Koopmans, Richard P; Meex, Steven J R

    2017-09-01

    When monitoring patients over time, clinicians may struggle to distinguish 'real changes' in consecutive blood parameters from so-called natural fluctuations. In practice, they have to do so by relying on their clinical experience and intuition. We developed Labtracker+ , a medical app that calculates the probability that an increase or decrease over time in a specific blood parameter is real, given the time between measurements. We presented patient cases to 135 participants to examine whether there is a difference between medical students, residents and experienced clinicians when it comes to interpreting changes between consecutive laboratory results. Participants were asked to interpret if changes in consecutive laboratory values were likely to be 'real' or rather due to natural fluctuations. The answers of the study participants were compared with the calculated probabilities by the app Labtracker+ and the concordance rates were assessed. Medical students (n=92), medical residents from the department of internal medicine (n=19) and internists (n=24) at a Dutch University Medical Centre. Concordance rates between the study participants and the calculated probabilities by the app Labtracker+ were compared. Besides, we tested whether physicians with clinical experience scored better concordance rates with the app Labtracker+ than inexperienced clinicians. Medical residents and internists showed significantly better concordance rates with the calculated probabilities by the app Labtracker+ than medical students, regarding their interpretation of differences between consecutive laboratory results (p=0.009 and p<0.001, respectively). The app Labtracker+ could serve as a clinical decision tool in the interpretation of consecutive laboratory test results and could contribute to rapid recognition of parameter changes by physicians. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial

  18. Normally Oriented Adhesion versus Friction Forces in Bacterial Adhesion to Polymer-Brush Functionalized Surfaces Under Fluid Flow

    NARCIS (Netherlands)

    Swartjes, Jan J. T. M.; Veeregowda, Deepak H.; van der Mei, Henny C.; Busscher, Henk J.; Sharma, Prashant K.

    2014-01-01

    Bacterial adhesion is problematic in many diverse applications. Coatings of hydrophilic polymer chains in a brush configuration reduce bacterial adhesion by orders of magnitude, but not to zero. Here, the mechanism by which polymer-brush functionalized surfaces reduce bacterial adhesion from a

  19. Profiling pathological narcissism according to DSM-5 domains and traits: A study on consecutively admitted Italian psychotherapy patients.

    Science.gov (United States)

    Fossati, Andrea; Somma, Antonella; Borroni, Serena; Pincus, Aaron L; Markon, Kristian E; Krueger, Robert F

    2017-11-01

    [Correction Notice: An Erratum for this article was reported in Vol 29(11) of Psychological Assessment (see record 2016-56886-001). In the article, several values were reversed and the mean was misreported in Table 2. The corrected table is present in the erratum.] Pathological narcissism represents a clinically relevant, albeit controversial personality construct, with multiple conceptualizations that are operationalized by different measures. Even in the recently published Diagnostic and Statistical Manual for Mental Disorders-Fifth Edition (DSM-5), 2 different views of narcissistic personality disorder (NPD) are formulated (i.e., Section II and Section III). The DSM-5 Section III alternative PD model diagnosis of NPD is based on self and interpersonal dysfunction (Criterion A) and a profile of maladaptive personality traits (Criterion B), specifically elevated scores on Attention Seeking and Grandiosity. Given the diversity of conceptualizations of pathological narcissism, we evaluated the convergences and divergences in DSM-5 trait profiles characterizing multiple measures of narcissism in a clinical sample of 278 consecutively admitted Italian psychotherapy patients. Patients were administered the Italian versions of the Personality Inventory for DSM-5 (PID-5) and 4 measures of NPD, (a) the Narcissistic Personality Inventory (NPI); (b) the NPD scale of the Personality Diagnostic Questionnaire-4+; (c) the Structured Clinical Interview for Axis II Personality Disorders, Version 2.0 (SCID-II) as an observer-rated measure of NPD; and (d) the Pathological Narcissism Inventory (PNI). Multiple regression analyses showed that PID-5 traits explained from 13% to more than 60% of the variance in the different NPD measures. Attention Seeking was consistently associated with all measures of NPD, whereas Grandiosity was associated with some of the NPD measures. All measures of NPD were also significantly related to additional DSM-5 maladaptive traits. (PsycINFO Database

  20. Multiple sclerosis

    International Nuclear Information System (INIS)

    Grunwald, I.Q.; Kuehn, A.L.; Backens, M.; Papanagiotou, P.; Shariat, K.; Kostopoulos, P.

    2008-01-01

    Multiple sclerosis is the most common chronic inflammatory disease of myelin with interspersed lesions in the white matter of the central nervous system. Magnetic resonance imaging (MRI) plays a key role in the diagnosis and monitoring of white matter diseases. This article focuses on key findings in multiple sclerosis as detected by MRI. (orig.) [de

  1. Adhesion of silver films to ion-bombarded alumina

    International Nuclear Information System (INIS)

    Erck, R.A.; Fenske, G.R.

    1990-01-01

    This paper reports on silver films deposited on alumina substrates using ion bombardment. Adhesion strength was measured as a function of deposition conditions, sputter-cleaning time, and bombarding ion species, using a pull-type adhesion tester. Argon- and argon/oxygen-ion sputtering produced large increases in adhesion strength, with the greatest increases occurring for oxygen-ion bombardment. Adhesion strength increased monotonically as a function of ion sputtering time. At a given deposition rate, further enhancement of adhesion is seen with concurrent ion bombardment

  2. Elastic-plastic adhesive contact of rough surfaces using n-point asperity model

    International Nuclear Information System (INIS)

    Sahoo, Prasanta; Mitra, Anirban; Saha, Kashinath

    2009-01-01

    This study considers an analysis of the elastic-plastic contact of rough surfaces in the presence of adhesion using an n-point asperity model. The multiple-point asperity model, developed by Hariri et al (2006 Trans ASME: J. Tribol. 128 505-14) is integrated into the elastic-plastic adhesive contact model developed by Roy Chowdhury and Ghosh (1994 Wear 174 9-19). This n-point asperity model differs from the conventional Greenwood and Williamson model (1966 Proc. R. Soc. Lond. A 295 300-19) in considering the asperities not as fixed entities but as those that change through the contact process, and hence it represents the asperities in a more realistic manner. The newly defined adhesion index and plasticity index defined for the n-point asperity model are used to consider the different conditions that arise because of varying load, surface and material parameters. A comparison between the load-separation behaviour of the new model and the conventional one shows a significant difference between the two depending on combinations of mean separation, adhesion index and plasticity index.

  3. Bacterial filamentation accelerates colonization of adhesive spots embedded in biopassive surfaces

    International Nuclear Information System (INIS)

    Möller, Jens; Emge, Philippe; Vizcarra, Ima Avalos; Kollmannsberger, Philip; Vogel, Viola

    2013-01-01

    Sessile bacteria adhere to engineered surfaces and host tissues and pose a substantial clinical and economical risk when growing into biofilms. Most engineered and biological interfaces are of chemically heterogeneous nature and provide adhesive islands for bacterial attachment and growth. To mimic either defects in a surface coating of biomedical implants or heterogeneities within mucosal layers (Peyer's patches), we embedded micrometre-sized adhesive islands in a poly(ethylene glycol) biopassive background. We show experimentally and computationally that filamentation of Escherichia coli can significantly accelerate the bacterial surface colonization under physiological flow conditions. Filamentation can thus provide an advantage to a bacterial population to bridge non-adhesive distances exceeding 5 μm. Bacterial filamentation, caused by blocking of bacterial division, is common among bacterial species and can be triggered by environmental conditions or antibiotic treatment. While great awareness exists that the build-up of antibiotic resistance serves as intrinsic survival strategy, we show here that antibiotic treatment can actually promote surface colonization by triggering filamentation, which in turn prevents daughter cells from being washed away. Our combined microfabrication and computational approaches provide quantitative insights into mechanisms that enable biofouling of biopassive surfaces with embedded adhesive spots, even for spot distances that are multiples of the bacterial length. (paper)

  4. Flavonoids purified from parsley inhibit human blood platelet aggregation and adhesion to collagen under flow.

    Science.gov (United States)

    Gadi, Dounia; Bnouham, Mohamed; Aziz, Mohammed; Ziyyat, Abderrahim; Legssyer, Abdelkhaleq; Bruel, Arlette; Berrabah, Mohamed; Legrand, Chantal; Fauvel-Lafeve, Françoise; Mekhfi, Hassane

    2012-08-10

    Blood platelets are directly involved in both haemostatic and pathologic thrombotic processes, through their adhesion, secretion and aggregation. In this study, we investigated the effect of genins (aglycone flavonoids without sugar group) isolated from parsley (Petroselinum crispum) leaves in vitro on human platelet aggregation and adhesion to a collagen-coated surface under physiologic flow conditions. The aggregation and adhesion studies were monitored after pre-incubation of platelets with genins. Genins inhibited dose dependently aggregation induced by thrombin, ADP and collagen. The strongest effect was observed in collagen induced aggregation (IC50 = 0.08 ± 0.01 mg/ml). The HPLC identification of genins compounds revealed the presence of keampferol, apigenin and other not identified compounds. The aggregation tests showed that these compounds have anti-aggregating activity. In addition, adhesion of human platelets to collagen was greatly decreased (over 75 %) by genins (0.3 mg/ml). While the mechanism by which genins act is unclear, we suggest that these compounds may interfere with a multiple target step in the haemostasis process. These results show that genins isolated from parsley has a potent antiplatelet activity. It may be an important source of beneficial antiplatelet compounds that decrease thrombosis and cardiovascular diseases.

  5. Bacterial filamentation accelerates colonization of adhesive spots embedded in biopassive surfaces

    Science.gov (United States)

    Möller, Jens; Emge, Philippe; Avalos Vizcarra, Ima; Kollmannsberger, Philip; Vogel, Viola

    2013-12-01

    Sessile bacteria adhere to engineered surfaces and host tissues and pose a substantial clinical and economical risk when growing into biofilms. Most engineered and biological interfaces are of chemically heterogeneous nature and provide adhesive islands for bacterial attachment and growth. To mimic either defects in a surface coating of biomedical implants or heterogeneities within mucosal layers (Peyer's patches), we embedded micrometre-sized adhesive islands in a poly(ethylene glycol) biopassive background. We show experimentally and computationally that filamentation of Escherichia coli can significantly accelerate the bacterial surface colonization under physiological flow conditions. Filamentation can thus provide an advantage to a bacterial population to bridge non-adhesive distances exceeding 5 μm. Bacterial filamentation, caused by blocking of bacterial division, is common among bacterial species and can be triggered by environmental conditions or antibiotic treatment. While great awareness exists that the build-up of antibiotic resistance serves as intrinsic survival strategy, we show here that antibiotic treatment can actually promote surface colonization by triggering filamentation, which in turn prevents daughter cells from being washed away. Our combined microfabrication and computational approaches provide quantitative insights into mechanisms that enable biofouling of biopassive surfaces with embedded adhesive spots, even for spot distances that are multiples of the bacterial length.

  6. FAK dimerization controls its kinase-dependent functions at focal adhesions

    KAUST Repository

    Brami-Cherrier, Karen; Gervasi, Nicolas; Arsenieva, Diana A.; Walkiewicz, Katarzyna; Boutterin, Marie Claude; Ortega, Á lvaro Darí o; Leonard, Paul G.; Seantier, Bastien; Gasmi, Laï la; Bouceba, Tahar; Kadaré , Gress; Girault -, Jean Antoine; Arold, Stefan T.

    2014-01-01

    Focal adhesion kinase (FAK) controls adhesion-dependent cell motility, survival, and proliferation. FAK has kinase-dependent and kinase-independent functions, both of which play major roles in embryogenesis and tumor invasiveness. The precise mechanisms of FAK activation are not known. Using x-ray crystallography, small angle x-ray scattering, and biochemical and functional analyses, we show that the key step for activation of FAK's kinase-dependent functions-autophosphorylation of tyrosine-397-requires site-specific dimerization of FAK. The dimers form via the association of the N-terminal FERM domain of FAK and are stabilized by an interaction between FERM and the C-terminal FAT domain. FAT binds to a basic motif on FERM that regulates co-activation and nuclear localization. FAK dimerization requires local enrichment, which occurs specifically at focal adhesions. Paxillin plays a dual role, by recruiting FAK to focal adhesions and by reinforcing the FAT:FERM interaction. Our results provide a structural and mechanistic framework to explain how FAK combines multiple stimuli into a site-specific function. The dimer interfaces we describe are promising targets for blocking FAK activation. © 2014 The Authors.

  7. Effect of mechanical properties of fillers on the grindability of composite resin adhesives.

    Science.gov (United States)

    Iijima, Masahiro; Muguruma, Takeshi; Brantley, William A; Yuasa, Toshihiro; Uechi, Jun; Mizoguchi, Itaru

    2010-10-01

    The purpose of this study was to investigate the effect of filler properties on the grindability of composite resin adhesives. Six composite resin products were selected: Transbond XT (3M Unitek, Monrovia, Calif), Transbond Plus (3M Unitek), Enlight (Ormco, Glendora, Calif), Kurasper F (Kuraray Medical, Tokyo, Japan), Beauty Ortho Bond (Shofu, Kyoto, Japan), and Beauty Ortho Bond Salivatect (Shofu). Compositions and weight fractions of fillers were determined by x-ray fluorescence analysis and ash test, respectively. The polished surface of each resin specimen was examined with a scanning electron microscope. Vickers hardness of plate specimens (15 × 10 × 3 mm) was measured, and nano-indentation was performed on large filler particles (>10 μm). Grindability for a low-speed tungsten-carbide bur was estimated. Data were compared with anlaysis of variance (ANOVA) and the Tukey multiple range test. Relationships among grindability, filler content, filler nano-indentation hardness (nano-hardness), filler elastic modulus, and Vickers hardness of the composite resins were investigated with the Pearson correlation coefficient test. Morphology and filler size of these adhesives showed great variations. The products could be divided into 2 groups, based on composition, which affected grindability. Vickers hardness of the adhesives did not correlate (r = 0.140) with filler nano-hardness, which showed a significant negative correlation (r = -0.664) with grindability. Filler nano-hardness greatly influences the grindability of composite resin adhesives. Copyright © 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  8. FAK dimerization controls its kinase-dependent functions at focal adhesions

    KAUST Repository

    Brami-Cherrier, Karen

    2014-01-30

    Focal adhesion kinase (FAK) controls adhesion-dependent cell motility, survival, and proliferation. FAK has kinase-dependent and kinase-independent functions, both of which play major roles in embryogenesis and tumor invasiveness. The precise mechanisms of FAK activation are not known. Using x-ray crystallography, small angle x-ray scattering, and biochemical and functional analyses, we show that the key step for activation of FAK\\'s kinase-dependent functions-autophosphorylation of tyrosine-397-requires site-specific dimerization of FAK. The dimers form via the association of the N-terminal FERM domain of FAK and are stabilized by an interaction between FERM and the C-terminal FAT domain. FAT binds to a basic motif on FERM that regulates co-activation and nuclear localization. FAK dimerization requires local enrichment, which occurs specifically at focal adhesions. Paxillin plays a dual role, by recruiting FAK to focal adhesions and by reinforcing the FAT:FERM interaction. Our results provide a structural and mechanistic framework to explain how FAK combines multiple stimuli into a site-specific function. The dimer interfaces we describe are promising targets for blocking FAK activation. © 2014 The Authors.

  9. Adhesion mechanisms of nanoparticle silver to substrate materials: identification

    International Nuclear Information System (INIS)

    Joo, Sungchul; Baldwin, Daniel F

    2010-01-01

    Nanoparticle silver (NPS) conductors are increasingly being investigated for printed electronics applications. However, the adhesion mechanism of the nanoparticle silver to substrate materials has not been identified yet. In particular, the adhesion of NPS to organic materials such as the widely used polyimide Kapton HN and Kapton FPC dry films is concerned with low adhesion strength because the processed polymer surface is chemically inert. Moreover, its adhesion to substrate materials such as benzocyclobutene (BCB), copper and aluminum was found to be very weak. Therefore, in this paper, the mechanisms of NPS adhesion to organic and inorganic materials are identified as the first step in improving NPS adhesion strength. Improving the adhesion strength of NPS will be the key issue for printed electronics applications. The adhesion of NPS to substrate materials was found to be mainly attributed to van der Waals forces based on particle adhesion mechanisms. This finding provides the initiative of developing an adhesion prediction model of NPS to substrate materials in order to provide guidelines for improving the NPS adhesion strength to the substrate materials used in printed electronics.

  10. Heterogeneity of Focal Adhesions and Focal Contacts in Motile Fibroblasts.

    Science.gov (United States)

    Gladkikh, Aleena; Kovaleva, Anastasia; Tvorogova, Anna; Vorobjev, Ivan A

    2018-01-01

    Cell-extracellular matrix (ECM) adhesion is an important property of virtually all cells in multicellular organisms. Cell-ECM adhesion studies, therefore, are very significant both for biology and medicine. Over the last three decades, biomedical studies resulted in a tremendous advance in our understanding of the molecular basis and functions of cell-ECM adhesion. Based on morphological and molecular criteria, several different types of model cell-ECM adhesion structures including focal adhesions, focal complexes, fibrillar adhesions, podosomes, and three-dimensional matrix adhesions have been described. All the subcellular structures that mediate cell-ECM adhesion are quite heterogeneous, often varying in size, shape, distribution, dynamics, and, to a certain extent, molecular constituents. The morphological "plasticity" of cell-ECM adhesion perhaps reflects the needs of cells to sense, adapt, and respond to a variety of extracellular environments. In addition, cell type (e.g., differentiation status, oncogenic transformation, etc.) often exerts marked influence on the structure of cell-ECM adhesions. Although molecular, genetic, biochemical, and structural studies provide important maps or "snapshots" of cell-ECM adhesions, the area of research that is equally valuable is to study the heterogeneity of FA subpopulations within cells. Recently time-lapse observations on the FA dynamics become feasible, and behavior of individual FA gives additional information on cell-ECM interactions. Here we describe a robust method of labeling of FA using plasmids with fluorescent markers for paxillin and vinculin and quantifying the morphological and dynamical parameters of FA.

  11. Enamel Wetness Effects on Microshear Bond Strength of Different Bonding Agents (Adhesive Systems): An in vitro Comparative Evaluation Study.

    Science.gov (United States)

    Kulkarni, Girish; Mishra, Vinay K

    2016-05-01

    The purpose of this study was to compare the effect of enamel wetness on microshear bond strength using different adhesive systems. To evaluate microshear bond strength of three bonding agents on dry enamel; to evaluate microshear bond strength of three bonding agents on wet enamel; and to compare microshear bond strength of three different bonding agents on dry and wet enamel. Sixty extracted noncarious human premolars were selected for this study. Flat enamel surfaces of approximately 3 mm were obtained by grinding the buccal surfaces of premolars with water-cooled diamond disks. This study evaluated one etch-and-rinse adhesive system (Single Bond 2) and two self-etching adhesive systems (Clearfil SE Bond and Xeno-V). The specimens were divided into two groups (n = 30). Group I (dry) was air-dried for 30 seconds and in group II (wet) surfaces were blotted with absorbent paper to remove excess water. These groups were further divided into six subgroups (n = 10) according to the adhesives used. The resin composite, Filtek Z 250, was bonded to flat enamel surfaces that had been treated with one of the adhesives, following the manufacturer's instructions. After being stored in water at 37°C for 24 hours, bonded specimens were stressed in universal testing machine (Fig. 3) at a crosshead speed of 1 mm/min. The data were evaluated with one-way and two-way analysis of variance (ANOVA), t-test, and Tukey's Multiple Post hoc tests (a = 0.05). The two-way ANOVA and Tukey's Multiple Post hoc tests showed significant differences among adhesive systems, but wetness did not influence microshear bond strength (p = 0.1762). The one-way ANOVA and t-test showed that the all-in-one adhesive (Xeno-V) was the only material influenced by the presence of water on the enamel surface. Xeno-V showed significantly higher microshear bond strength when the enamel was kept wet. Single Bond 2 adhesive showed significantly higher microshear bond strength as compared with Xeno-V adhesive but no

  12. Isolation and biochemical characterization of underwater adhesives from diatoms.

    Science.gov (United States)

    Poulsen, Nicole; Kröger, Nils; Harrington, Matthew J; Brunner, Eike; Paasch, Silvia; Buhmann, Matthias T

    2014-01-01

    Many aquatic organisms are able to colonize surfaces through the secretion of underwater adhesives. Diatoms are unicellular algae that have the capability to colonize any natural and man-made submerged surfaces. There is great technological interest in both mimicking and preventing diatom adhesion, yet the biomolecules responsible have so far remained unidentified. A new method for the isolation of diatom adhesive material is described and its amino acid and carbohydrate composition determined. The adhesive materials from two model diatoms show differences in their amino acid and carbohydrate compositions, but also share characteristic features including a high content of uronic acids, the predominance of hydrophilic amino acid residues, and the presence of 3,4-dihydroxyproline, an extremely rare amino acid. Proteins containing dihydroxyphenylalanine, which mediate underwater adhesion of mussels, are absent. The data on the composition of diatom adhesives are consistent with an adhesion mechanism based on complex coacervation of polyelectrolyte-like biomolecules.

  13. Preparation and characterization of UV-curable cationic composite adhesive

    International Nuclear Information System (INIS)

    Shen Yan; Yang Wenbin; Li Yintao; Xie Changqiong; Li Yingjun; Cheng Yafei; Zhou Yuanlin; Lu Zhongyuan

    2011-01-01

    UV-curable cationic composite adhesives containing TiO 2 nanostructures were prepared by using 3, 4-epoxycyclohexylmethyl-3, 4-epoxycyclohexanecarboxylate(CE) as monomer, triphenylsulfonium hexafluorophosphate salt (PI-432) as photoinitiator and titanium isopropoxide (TIP) as inorganic precursor. The morphology of the composite adhesives was characterized by atom force microscopy (AFM). The effect of TIP content on refractive index and transmittance of adhesives were studied. The results show that TiO 2 nanostructures, the average diameter of which is 20 nm or so, can be uniformly dispersed in polymers of composite adhesives. The refractive index of adhesives can be adjusted from 1.501 9 to 1.544 9 with the change of TIP content. The transmittance of adhesives has a slight reduce with the increase of TIP content. When TIP content is up to 40%, the transmittance of composite adhesives remains around 90% or so. (authors)

  14. High-performance mussel-inspired adhesives of reduced complexity.

    Science.gov (United States)

    Ahn, B Kollbe; Das, Saurabh; Linstadt, Roscoe; Kaufman, Yair; Martinez-Rodriguez, Nadine R; Mirshafian, Razieh; Kesselman, Ellina; Talmon, Yeshayahu; Lipshutz, Bruce H; Israelachvili, Jacob N; Waite, J Herbert

    2015-10-19

    Despite the recent progress in and demand for wet adhesives, practical underwater adhesion remains limited or non-existent for diverse applications. Translation of mussel-inspired wet adhesion typically entails catechol functionalization of polymers and/or polyelectrolytes, and solution processing of many complex components and steps that require optimization and stabilization. Here we reduced the complexity of a wet adhesive primer to synthetic low-molecular-weight catecholic zwitterionic surfactants that show very strong adhesion (∼50 mJ m(-2)) and retain the ability to coacervate. This catecholic zwitterion adheres to diverse surfaces and self-assembles into a molecularly smooth, thin (adhesive for nanofabrication. This study significantly simplifies bio-inspired themes for wet adhesion by combining catechol with hydrophobic and electrostatic functional groups in a small molecule.

  15. Adhesion of non-selective CVD tungsten to silicon dioxide

    International Nuclear Information System (INIS)

    Woodruff, D.W.; Wilson, R.H.; Sanchez-Martinez, R.A.

    1986-01-01

    Adhesion of non-selective, CVD tungsten to silicon dioxide is a critical issue in the development of tungsten as a metalization for VLSI circuitry. Without special adhesion promoters, tungsten deposited from WF/sub 6/ and H/sub 2/ has typically failed a standard tape test over all types of silicon oxides and nitrides. The reasons for failure of thin films, and CVD tungsten in particular are explored along with standard techniques for improving adhesion of thin films. Experiments are reported which include a number of sputtered metals as adhesion promoters, as well as chemical and plasma treatment of the oxide surface. Sputtered molybdenum is clearly the superior adhesion promoting layer from these tests. Traditional adhesion layers such as chromium or titanium failed as adhesion layers for CVD tungsten possibly due to chemical reactions between the WF/sub 6/ and Cr or Ti

  16. Design rules for biomolecular adhesion: lessons from force measurements.

    Science.gov (United States)

    Leckband, Deborah

    2010-01-01

    Cell adhesion to matrix, other cells, or pathogens plays a pivotal role in many processes in biomolecular engineering. Early macroscopic methods of quantifying adhesion led to the development of quantitative models of cell adhesion and migration. The more recent use of sensitive probes to quantify the forces that alter or manipulate adhesion proteins has revealed much greater functional diversity than was apparent from population average measurements of cell adhesion. This review highlights theoretical and experimental methods that identified force-dependent molecular properties that are central to the biological activity of adhesion proteins. Experimental and theoretical methods emphasized in this review include the surface force apparatus, atomic force microscopy, and vesicle-based probes. Specific examples given illustrate how these tools have revealed unique properties of adhesion proteins and their structural origins.

  17. Understanding Surface Adhesion in Nature: A Peeling Model.

    Science.gov (United States)

    Gu, Zhen; Li, Siheng; Zhang, Feilong; Wang, Shutao

    2016-07-01

    Nature often exhibits various interesting and unique adhesive surfaces. The attempt to understand the natural adhesion phenomena can continuously guide the design of artificial adhesive surfaces by proposing simplified models of surface adhesion. Among those models, a peeling model can often effectively reflect the adhesive property between two surfaces during their attachment and detachment processes. In the context, this review summarizes the recent advances about the peeling model in understanding unique adhesive properties on natural and artificial surfaces. It mainly includes four parts: a brief introduction to natural surface adhesion, the theoretical basis and progress of the peeling model, application of the peeling model, and finally, conclusions. It is believed that this review is helpful to various fields, such as surface engineering, biomedicine, microelectronics, and so on.

  18. Cell adhesion on nanotextured slippery superhydrophobic substrates.

    Science.gov (United States)

    Di Mundo, Rosa; Nardulli, Marina; Milella, Antonella; Favia, Pietro; d'Agostino, Riccardo; Gristina, Roberto

    2011-04-19

    In this work, the response of Saos2 cells to polymeric surfaces with different roughness/density of nanometric dots produced by a tailored plasma-etching process has been studied. Topographical features have been evaluated by atomic force microscopy, while wetting behavior, in terms of water-surface adhesion energy, has been evaluated by measurements of drop sliding angle. Saos2 cytocompatibility has been investigated by scanning electron microscopy, fluorescent microscopy, and optical microscopy. The similarity in outer chemical composition has allowed isolation of the impact of the topographical features on cellular behavior. The results indicate that Saos2 cells respond differently to surfaces with different nanoscale topographical features, clearly showing a certain inhibition in cell adhesion when the nanoscale is particularly small. This effect appears to be attenuated in surfaces with relatively bigger nanofeatures, though these express a more pronounced slippery/dry wetting character. © 2011 American Chemical Society

  19. Engineering emergent multicellular behavior through synthetic adhesion

    Science.gov (United States)

    Glass, David; Riedel-Kruse, Ingmar

    In over a decade, synthetic biology has developed increasingly robust gene networks within single cells, but constructed very few systems that demonstrate multicellular spatio-temporal dynamics. We are filling this gap in synthetic biology's toolbox by developing an E. coli self-assembly platform based on modular cell-cell adhesion. We developed a system in which adhesive selectivity is provided by a library of outer membrane-displayed peptides with intra-library specificities, while affinity is provided by consistent expression across the entire library. We further provide a biophysical model to help understand the parameter regimes in which this tool can be used to self-assemble into cellular clusters, filaments, or meshes. The combined platform will enable future development of synthetic multicellular systems for use in consortia-based metabolic engineering, in living materials, and in controlled study of minimal multicellular systems. Stanford Bio-X Bowes Fellowship.

  20. Adhesion aspects of polyurethane foam sandwich panels.

    OpenAIRE

    Ng, Simon L.

    2016-01-01

    Sandwich panels, polyurethane foam sandwiched between two sheets of steel, form the walls and roofs in the construction of buildings. ArcelorMittal is a manufacturer of the steel as well as these finished panels. For this project they combined with a supplier of the polyurethane foams, Huntsman Polyurethanes, to joint-fund a research project investigating the fundamental mechanisms of adhesion, as well as the causes of failures in the product which manifests primarily in two different ways...

  1. Radiation curable pressure sensitive adhesive composition

    International Nuclear Information System (INIS)

    Steuben, K.C.

    1978-01-01

    Radiation curable pressure sensitive adhesive composition comprises: a polyoxyalkylene homo- or copolymer which is either a polyoxyethylene homopolymer or a poly (oxyethylene-oxypropylene) copolymer, or mixture thereof, having a molecular weight of from 1,700 to 90,000, in which at least 40 percent by weight of the oxyalkylene units are oxyethylene units; a liquid carbamyloxy alkyl acrylate; and, optionally, a photoinitiator

  2. Embedded adhesive connection for laminated glass plates

    DEFF Research Database (Denmark)

    Hansen, Jens Zangenberg; Poulsen, S.H.; Bagger, A.

    2012-01-01

    The structural behavior of a new connection design, the embedded adhesive connection, used for laminated glass plates is investigated. The connection consists of an aluminum plate encapsulated in-between two adjacent triple layered laminated glass plates. Fastening between glass and aluminum...... usage in a design situation. The embedded connection shows promising potential as a future fastening system for load-carrying laminated glass plates....

  3. Role of Confined Water in Underwater Adhesion

    Science.gov (United States)

    Dhinojwala, Ali

    Surface bound water is a strong deterrent for forming strong bonds between two surfaces underwater and expelling that bound water is important for strong adhesion. I will discuss examples of different strategies used by geckos, spiders, and mussels to handle this last layer of bound water. Recent results using infrared-visible sum frequency generation spectroscopy to probe the structure of this bound water will be discussed. National Science Foundation.

  4. Cartilage proteoglycans inhibit fibronectin-mediated adhesion

    Science.gov (United States)

    Rich, A. M.; Pearlstein, E.; Weissmann, G.; Hoffstein, S. T.

    1981-09-01

    Normal tissues and organs show, on histological examination, a pattern of cellular and acellular zones that is characteristic and unique for each organ or tissue. This pattern is maintained in health but is sometimes destroyed by disease. For example, in mobile joints, the articular surfaces consist of relatively acellular hyaline cartilage, and the joint space is enclosed by a capsule of loose connective tissue with a lining of fibroblasts and macrophages. In the normal joint these cells are confined to the synovial lining and the articular surface remains acellular. In in vitro culture, macrophages and their precursor monocytes are very adhesive, and fibroblasts can migrate and overgrow surfaces such as collagen or plastic used for tissue culture. The fibroblasts adhere to collagen by means of fibronectin, which they synthesize and secrete1. Because the collagen of cartilage is capable of binding serum fibronectin2 and fibronectin is present in cartilage during its development3, these cells should, in theory, slowly migrate from the synovial lining to the articular surface. It is their absence from the articular cartilage in normal circumstances, and then presence in such pathological states as rheumatoid arthritis, that is striking. We therefore set out to determine whether a component of cartilage could prevent fibroblast adherence in a defined adhesion assay. As normal cartilage is composed of 50% proteoglycans and 50% collagen by dry weight4, we tested the possibility that the proteoglycans in cartilage inhibit fibroblast adhesion to collagen. We present here evidence that fibroblast spreading and adhesion to collagenous substrates is inhibited by cartilage proteoglycans.

  5. Cell adhesion during bullet motion in capillaries.

    Science.gov (United States)

    Takeishi, Naoki; Imai, Yohsuke; Ishida, Shunichi; Omori, Toshihiro; Kamm, Roger D; Ishikawa, Takuji

    2016-08-01

    A numerical analysis is presented of cell adhesion in capillaries whose diameter is comparable to or smaller than that of the cell. In contrast to a large number of previous efforts on leukocyte and tumor cell rolling, much is still unknown about cell motion in capillaries. The solid and fluid mechanics of a cell in flow was coupled with a slip bond model of ligand-receptor interactions. When the size of a capillary was reduced, the cell always transitioned to "bullet-like" motion, with a consequent decrease in the velocity of the cell. A state diagram was obtained for various values of capillary diameter and receptor density. We found that bullet motion enables firm adhesion of a cell to the capillary wall even for a weak ligand-receptor binding. We also quantified effects of various parameters, including the dissociation rate constant, the spring constant, and the reactive compliance on the characteristics of cell motion. Our results suggest that even under the interaction between P-selectin glycoprotein ligand-1 (PSGL-1) and P-selectin, which is mainly responsible for leukocyte rolling, a cell is able to show firm adhesion in a small capillary. These findings may help in understanding such phenomena as leukocyte plugging and cancer metastasis. Copyright © 2016 the American Physiological Society.

  6. Focal adhesions, stress fibers and mechanical tension

    Energy Technology Data Exchange (ETDEWEB)

    Burridge, Keith, E-mail: Keith_Burridge@med.unc.edu [Department of Cell Biology and Physiology, and Lineberger Comprehensive Cancer Center, 12-016 Lineberger, CB#7295, University of North Carolina, Chapel Hill, NC (United States); Guilluy, Christophe, E-mail: christophe.guilluy@univ-nantes.fr [Inserm UMR-S1087, CNRS UMR-C6291, L' institut du Thorax, and Université de Nantes, Nantes (France)

    2016-04-10

    Stress fibers and focal adhesions are complex protein arrays that produce, transmit and sense mechanical tension. Evidence accumulated over many years led to the conclusion that mechanical tension generated within stress fibers contributes to the assembly of both stress fibers themselves and their associated focal adhesions. However, several lines of evidence have recently been presented against this model. Here we discuss the evidence for and against the role of mechanical tension in driving the assembly of these structures. We also consider how their assembly is influenced by the rigidity of the substratum to which cells are adhering. Finally, we discuss the recently identified connections between stress fibers and the nucleus, and the roles that these may play, both in cell migration and regulating nuclear function. - Highlights: • The different types of stress fiber and focal adhesion are described. • We discuss the controversy about tension and assembly of these structures. • We describe the different models used to investigate assembly of these structures. • The influence of substratum rigidity is discussed. • Stress fiber connections to the nucleus are reviewed.

  7. Mouse lung adhesion assay for Bordetella pertussis

    Energy Technology Data Exchange (ETDEWEB)

    Burns, K A; Freer, J H [Department of Microbiology, Alexander Stone Building, Bearsden, Glasgow, Scotland

    1982-03-01

    The ability of Bordetella pertussis to adhere to cell surfaces has been demonstrated by adhesion to tissue culture cells and adhesion to chicken, hamster or rabbit trachea in organ culture. In this report a mouse lung assay for adhesion is described and the results obtained using two virulent strains of B. pertussis and their avirulent counterparts. These were a C modulation of one of the original virulent strains and a phase IV variant of the other virulent strain. Organisms were radiolabelled by adding 1 ..mu..Ci (37 K Bq) of (/sup 14/C)glutamic acid per 10 ml of culture medium before inoculation and incubation for 5 days. The lungs were washed by perfusion in situ with at least two volumes (1 ml) of sterile 1% (w/v) casamino acids. The percentage of the inoculated organisms retained in the lungs was determined, after removal of the lungs, by one of the following two methods: viable count or radioactive count. Results for both methods were expressed as the percentage of the inoculum retained in the lungs plus or minus one standard deviation.

  8. Cell adhesion pattern created by OSTE polymers.

    Science.gov (United States)

    Liu, Wenjia; Li, Yiyang; Ding, Xianting

    2017-04-24

    Engineering surfaces with functional polymers is a crucial issue in the field of micro/nanofabrication and cell-material interface studies. For many applications of surface patterning, it does not need cells to attach on the whole surface. Herein, we introduce a novel polymer fabrication protocol of off-stoichiometry thiol-ene (OSTE) polymers to create heterogeneity on the surface by utilizing 3D printing and soft-lithography. By choosing two OSTE polymers with different functional groups, we create a pattern where only parts of the surface can facilitate cell adhesion. We also study the hydrophilic property of OSTE polymers by mixing poly(ethylene glycol) (PEG) directly with pre-polymers and plasma treatments afterwards. Moreover, we investigate the effect of functional groups' excess ratio and hydrophilic property on the cell adhesion ability of OSTE polymers. The results show that the cell adhesion ability of OSTE materials can be tuned within a wide range by the coupling effect of functional groups' excess ratio and hydrophilic property. Meanwhile, by mixing PEG with pre-polymers and undergoing oxygen plasma treatment afterward can significantly improve the hydrophilic property of OSTE polymers.

  9. Mouse lung adhesion assay for Bordetella pertussis

    International Nuclear Information System (INIS)

    Burns, K.A.; Freer, J.H.

    1982-01-01

    The ability of Bordetella pertussis to adhere to cell surfaces has been demonstrated by adhesion to tissue culture cells and adhesion to chicken, hamster or rabbit trachea in organ culture. In this report a mouse lung assay for adhesion is described and the results obtained using two virulent strains of B. pertussis and their avirulent counterparts. These were a C modulation of one of the original virulent strains and a phase IV variant of the other virulent strain. Organisms were radiolabelled by adding 1 μCi (37 K Bq) of [ 14 C]glutamic acid per 10 ml of culture medium before inoculation and incubation for 5 days. The lungs were washed by perfusion in situ with at least two volumes (1 ml) of sterile 1% (w/v) casamino acids. The percentage of the inoculated organisms retained in the lungs was determined, after removal of the lungs, by one of the following two methods: viable count or radioactive count. Results for both methods were expressed as the percentage of the inoculum retained in the lungs plus or minus one standard deviation. (Auth.)

  10. Development of Screenable Pressure Sensitive Adhesives

    Energy Technology Data Exchange (ETDEWEB)

    Steven J. Severtson

    2003-11-29

    An industrial research area of high activity in recent years has been the development of pressure sensitive adhesive (PSA) products that do not interfere with the processing of post-consumer waste. The problem of PSA contamination is arguably the most important technical challenge in expanding the use of recycled fiber. The presence of PSAs in recovered paper creates problems that reduce the efficiency of recycling and papermaking operations and diminish product quality. The widespread use of PSAs engineered to avoid these problems, often referred to as environmentally benign PSAs, could greatly increase the commercial viability of utilizing secondary fiber. Much of the research efforts in this area have focused on the development of PSAs that are designed for enhanced removal with cleaning equipment currently utilized by recycling plants. Most removal occurs at the pressure screens with the size and shape of residual contaminants in the process being the primary criteria for their separation. A viable approach for developing environmentally benign PSAs is their reformulation to inhibit fragmentation. The reduction of adhesives to small particles occurs almost exclusively during repulping; a process in which water and mechanical energy are used to swell and reduce paper products to their constituent fiber. Engineering PSA products to promote the formation of larger adhesive particles during repulping will greatly enhance their removal and reduce or eliminate their impact on the recycling process.

  11. Strategies to improve the adhesion of rubbers to adhesives by means of plasma surface modification

    Science.gov (United States)

    Martín-Martínez, J. M.; Romero-Sánchez, M. D.

    2006-05-01

    The surface modifications produced by treatment of a synthetic sulfur vulcanized styrene-butadiene rubber with oxidizing (oxygen, air, carbon dioxide) and non oxidizing (nitrogen, argon) RF low pressure plasmas, and by treatment with atmospheric plasma torch have been assessed by ATR-IR and XPS spectroscopy, SEM, and contact angle measurements. The effectiveness of the low pressure plasma treatment depended on the gas atmosphere used to generate the plasma. A lack of relationship between surface polarity and wettability, and peel strength values was obtained, likely due to the cohesive failure in the rubber obtained in the adhesive joints. In general, acceptable adhesion values of plasma treated rubber were obtained for all plasmas, except for nitrogen plasma treatment during 15 minutes due to the creation of low molecular weight moieties on the outermost rubber layer. A toluene wiping of the N{2 } plasma treated rubber surface for 15 min removed those moieties and increased adhesion was obtained. On the other hand, the treatment of the rubber with atmospheric pressure by means of a plasma torch was proposed. The wettability of the rubber was improved by decreasing the rubber-plasma torch distance and by increasing the duration because a partial removal of paraffin wax from the rubber surface was produced. The rubber surface was oxidized by the plasma torch treatment, and the longer the duration of the plasma torch treatment, the higher the degree of surface oxidation (mainly creation of C O moieties). However, although the rubber surface was effectively modified by the plasma torch treatment, the adhesion was not greatly improved, due to the migration of paraffin wax to the treated rubber-polyurethane adhesive interface once the adhesive joint was produced. On the other hand, the extended treatment with plasma torch facilitated the migration of zinc stearate to the rubber-adhesive interface, also contributing to deteriorate the adhesion in greater extent. Finally

  12. Multiple homicides.

    Science.gov (United States)

    Copeland, A R

    1989-09-01

    A study of multiple homicides or multiple deaths involving a solitary incident of violence by another individual was performed on the case files of the Office of the Medical Examiner of Metropolitan Dade County in Miami, Florida, during 1983-1987. A total of 107 multiple homicides were studied: 88 double, 17 triple, one quadruple, and one quintuple. The 236 victims were analyzed regarding age, race, sex, cause of death, toxicologic data, perpetrator, locale of the incident, and reason for the incident. This article compares this type of slaying with other types of homicide including those perpetrated by serial killers. Suggestions for future research in this field are offered.

  13. Development of Recycling Compatible Pressure-Sensitive Adhesives and Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Steven J. Severtson

    2010-02-15

    The objective of this project was the design of new water-based pressure-sensitive adhesive (PSA) products and coatings engineered for enhanced removal during the processing of recycled fiber. Research included the formulation, characterization, and performance measurements of new screenable coatings, testing of modified paper and board substrates and the design of test methods to characterize the inhibition of adhesive and coating fragmentation and relative removal efficiencies of developed formulations. This project was operated under the requirements that included commercially viable approaches be the focus, that findings be published in the open literature and that new strategies could not require changes in the methods and equipment used to produce PSA and PS labels or in the recycling process. The industrial partners benefited through the building of expertise in their company that they would not, and likely could not, have pursued if it had not been for the partnership. Results of research on water-based PSAs clearly identifies which PSA and paper facestock properties govern the fragmentation of the adhesive and provide multiple strategies for making (pressure-sensitive) PS labels for which the PSA is removed at very high efficiencies from recycling operations. The application of these results has led to the identification of several commercial products in Franklin International’s (industrial partner) product line that are recycling compatible. Several new formulations were also designed and are currently being scaled-up. Work on recycling compatible barrier coatings for corrugated containers examined the reinforcement of coatings using a small amount of exfoliated organically modified montmorillonite (OMMT). These OMMT/paraffin wax nanocomposites demonstrated significantly improved mechanical properties. Paraffin waxes containing clay were found to have significantly higher Young’s moduli and yield stress relative to the wax matrix, but the most

  14. Automatic identification of bullet signatures based on consecutive matching striae (CMS) criteria.

    Science.gov (United States)

    Chu, Wei; Thompson, Robert M; Song, John; Vorburger, Theodore V

    2013-09-10

    The consecutive matching striae (CMS) numeric criteria for firearm and toolmark identifications have been widely accepted by forensic examiners, although there have been questions concerning its observer subjectivity and limited statistical support. In this paper, based on signal processing and extraction, a model for the automatic and objective counting of CMS is proposed. The position and shape information of the striae on the bullet land is represented by a feature profile, which is used for determining the CMS number automatically. Rapid counting of CMS number provides a basis for ballistics correlations with large databases and further statistical and probability analysis. Experimental results in this report using bullets fired from ten consecutively manufactured barrels support this developed model. Published by Elsevier Ireland Ltd.

  15. Normal dynamic deformation characteristics of non-consecutive jointed rock masses under impact loads

    Science.gov (United States)

    Zeng, Sheng; Jiang, Bowei; Sun, Bing

    2017-08-01

    In order to study deformation characteristics of non-consecutive single jointed rock masses under impact loads, we used the cement mortar materials to make simulative jointed rock mass samples, and tested the samples under impact loads by the drop hammer. Through analyzing the time-history signal of the force and the displacement, first we find that the dynamic compression displacement of the jointed rock mass is significantly larger than that of the intact jointless rock mass, the compression displacement is positively correlated with the joint length and the impact height. Secondly, the vertical compressive displacement of the jointed rock mass is mainly due to the closure of opening joints under small impact loads. Finally, the peak intensity of the intact rock mass is larger than that of the non-consecutive jointed rock mass and negatively correlated with the joint length under the same impact energy.

  16. Interset stretching does not influence the kinematic profile of consecutive bench-press sets.

    Science.gov (United States)

    García-López, David; Izquierdo, Mikel; Rodríguez, Sergio; González-Calvo, Gustavo; Sainz, Nuria; Abadía, Olaia; Herrero, Azael J

    2010-05-01

    This study was undertaken to examine the role of interset stretching on the time course of acceleration portion AP and mean velocity profile during the concentric phase of 2 bench-press sets with a submaximal load (60% of the 1 repetition maximum). Twenty-five college students carried out, in 3 different days, 2 consecutive bench-press sets leading to failure, performing between sets static stretching, ballistic stretching, or no stretching. Acceleration portion and lifting velocity patterns of the concentric phase were not altered during the second set, regardless of the stretching treatment performed. However, when velocity was expressed in absolute terms, static stretching reduced significantly (p velocity during the second set compared to the first one. Therefore, if maintenance of a high absolute velocity over consecutive sets is important for training-related adaptations, static stretching should be avoided or replaced by ballistic stretching.

  17. Spectral-domain optical coherence tomography findings of the macula in 500 consecutive patients with uveitis.

    Science.gov (United States)

    Grajewski, R S; Boelke, A C; Adler, W; Meyer, S; Caramoy, A; Kirchhof, B; Cursiefen, C; Heindl, L M

    2016-11-01

    PurposeTo analyze the macular structure in a large series of consecutive patients with different types of uveitis using spectral-domain optical coherence tomography (SD-OCT).Patients and methodsFive hundred eyes of 500 consecutive patients with anterior, intermediate, posterior, and panuveitis underwent standardized macular examination using SD-OCT. Central retinal thickness (CRT), macular volume (MV), and presence of cystoid macular edema (CME), diffuse macular edema (DME), serous retinal detachment (SRD), epiretinal membrane with (ERM+) and without (ERM-) retinal surface wrinkling were determined.ResultsThe anatomic location of inflammation affected significantly CRT and MV (Pmacula is recommended for all uveitis patients. CRT, MV, and the incidence of CME were highest in intermediate and panuveitis.

  18. Functionalization of CoCr surfaces with cell adhesive peptides to promote HUVECs adhesion and proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Castellanos, Maria Isabel, E-mail: maria.isabel.castellanos@upc.edu [Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Technical University of Catalonia (UPC), ETSEIB, 08028 Barcelona (Spain); Centre for Research in Nanoengineering (CRNE), UPC, 08028 Barcelona (Spain); Mas-Moruno, Carlos, E-mail: carles.mas.moruno@upc.edu [Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Technical University of Catalonia (UPC), ETSEIB, 08028 Barcelona (Spain); Centre for Research in Nanoengineering (CRNE), UPC, 08028 Barcelona (Spain); Grau, Anna, E-mail: agraugar@gmail.com [Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Technical University of Catalonia (UPC), ETSEIB, 08028 Barcelona (Spain); Centre for Research in Nanoengineering (CRNE), UPC, 08028 Barcelona (Spain); Serra-Picamal, Xavier, E-mail: xserrapicamal@gmail.com [Institute for Bioengineering of Catalonia (IBEC), 08028 Barcelona (Spain); University of Barcelona and CIBER-BBN, 08036 Barcelona (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona (Spain); Trepat, Xavier, E-mail: xtrepat@ub.edu [Institute for Bioengineering of Catalonia (IBEC), 08028 Barcelona (Spain); University of Barcelona and CIBER-BBN, 08036 Barcelona (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona (Spain); Albericio, Fernando, E-mail: fernando.albericio@irbbarcelona.org [Department of Chemistry, University of Barcelona, CIBER-BBN, 08028 Barcelona (Spain); Joner, Michael, E-mail: michaeljoner@me.com [Department of Cardiology, Deutsches Herzzentrum München, 80636 Munich (Germany); CVPath Institute, Gaithersburg, MD 20878 (United States); and others

    2017-01-30

    Highlights: • We immobilized peptides on CoCr alloy through physisorption and covalent bonding. • Surface activation is an essential step prior to silanization to enhance peptide attachment. • Biofunctionalized surface characteristics were discussed. • RGDS, YIGSR and combination peptides display an improved HUVECs adhesion and proliferation. - Abstract: Biomimetic surface modification with peptides that have specific cell-binding moieties is a promising approach to improve endothelialization of metal-based stents. In this study, we functionalized CoCr surfaces with RGDS, REDV, YIGSR peptides and their combinations to promote endothelial cells (ECs) adhesion and proliferation. An extensive characterization of the functionalized surfaces was performed by XPS analysis, surface charge and quartz crystal microbalance with dissipation monitoring (QCM-D), which demonstrated the successful immobilization of the peptides to the surface. Cell studies demonstrated that the covalent functionalization of CoCr surfaces with an equimolar combination of RGDS and YIGSR represents the most powerful strategy to enhance the early stages of ECs adhesion and proliferation, indicating a positive synergistic effect between the two peptide motifs. Although these peptide sequences slightly increased smooth muscle cells (SMCs) adhesion, these values were ten times lower than those observed for ECs. The combination of RGDS with the REDV sequence did not show synergistic effects in promoting the adhesion or proliferation of ECs. The strategy presented in this study holds great potential to overcome clinical limitations of current metal stents by enhancing their capacity to support surface endothelialization.

  19. SOLUTION OF SIGNAL UNCERTAINTY PROBLEM AT ANALYTICAL DESIGN OF CONSECUTIVE COMPENSATOR IN PIEZO ACTUATOR CONTROL

    Directory of Open Access Journals (Sweden)

    S.V. Bystrov

    2016-05-01

    Full Text Available Subject of Research.We present research results for the signal uncertainty problem that naturally arises for the developers of servomechanisms, including analytical design of serial compensators, delivering the required quality indexes for servomechanisms. Method. The problem was solved with the use of Besekerskiy engineering approach, formulated in 1958. This gave the possibility to reduce requirements for input signal composition of servomechanisms by using only two of their quantitative characteristics, such as maximum speed and acceleration. Information about input signal maximum speed and acceleration allows entering into consideration the equivalent harmonic input signal with calculated amplitude and frequency. In combination with requirements for maximum tracking error, the amplitude and frequency of the equivalent harmonic effects make it possible to estimate analytically the value of the amplitude characteristics of the system by error and then convert it to amplitude characteristic of open-loop system transfer function. While previously Besekerskiy approach was mainly used in relation to the apparatus of logarithmic characteristics, we use this approach for analytical synthesis of consecutive compensators. Main Results. Proposed technique is used to create analytical representation of "input–output" and "error–output" polynomial dynamic models of the designed system. In turn, the desired model of the designed system in the "error–output" form of analytical representation of transfer functions is the basis for the design of consecutive compensator, that delivers the desired placement of state matrix eigenvalues and, consequently, the necessary set of dynamic indexes for the designed system. The given procedure of consecutive compensator analytical design on the basis of Besekerskiy engineering approach under conditions of signal uncertainty is illustrated by an example. Practical Relevance. The obtained theoretical results are

  20. Laparoscopic Cholecystectomy: One Surgeon’s Experience in 100 Consecutive Cases

    OpenAIRE

    1994-01-01

    Initial 100 consecutive laparoscopic cholecystectomies performed by one surgeon were studied prospectively. The standard technique was modified in that the gallbladder removal was accomplished through the upper epigastric incision; there was no need to change the location of the camera. The conversion rate to open cholecystectomy was 2%. There were no major complications and no mortality. Minor complications occurred in 9% of the patients. Laparoscopic cholecystectomy can be performed safely ...

  1. Spectrum of perforation peritonitis in India-review of 504 consecutive cases

    OpenAIRE

    Jhobta, Rajender Singh; Attri, Ashok Kumar; Kaushik, Robin; Sharma, Rajeev; Jhobta, Anupam

    2006-01-01

    Abstract Background/objective Perforation peritonitis is the most common surgical emergency in India. The spectrum of etiology of perforation in Tropical countries continues to be different from its Western counterpart. The objective of the study was to highlight the spectrum of perforation peritonitis as encountered by us at Government Medical College and Hospital (GMCH), Chandigarh. Methods Five hundred and four consecutive cases of perforation peritonitis over a period of five years were r...

  2. Comparison of single and consecutive dual frequency induction surface hardening of gear wheels

    Science.gov (United States)

    Barglik, J.; Ducki, K.; Kukla, D.; Mizera, J.; Mrówka-Nowotnik, G.; Sieniawski, J.; Smalcerz, A.

    2018-05-01

    Mathematical modelling of single and consecutive dual - frequency induction surface hardening systems are presented and compared. The both models are solved by the 3D FEM-based professional software supported by a number of own numerical procedures. The methodology is illustrated with some examples of surface induction hardening of a gear wheel made of steel 41Cr4. The computations are in a good accordance with experiments provided on the laboratory stand.

  3. Iron Supplementation during Three Consecutive Days of Endurance Training Augmented Hepcidin Levels

    Directory of Open Access Journals (Sweden)

    Aya Ishibashi

    2017-07-01

    Full Text Available Iron supplementation contributes an effort to improving iron status among athletes, but it does not always prevent iron deficiency. In the present study, we explored the effect of three consecutive days of endurance training (twice daily on the hepcidin-25 (hepcidin level. The effect of iron supplementation during this period was also determined. Fourteen male endurance athletes were enrolled and randomly assigned to either an iron-treated condition (Fe condition, n = 7 or a placebo condition (Control condition; CON, n = 7. They engaged in two 75-min sessions of treadmill running at 75% of maximal oxygen uptake on three consecutive days (days 1–3. The Fe condition took 12 mg of iron twice daily (24 mg/day, and the CON condition did not. On day 1, both conditions exhibited significant increases in serum hepcidin and plasma interleukin-6 levels after exercise (p < 0.05. In the CON condition, the hepcidin level did not change significantly throughout the training period. However, in the Fe condition, the serum hepcidin level on day 4 was significantly higher than that of the CON condition (p < 0.05. In conclusion, the hepcidin level was significantly elevated following three consecutive days of endurance training when moderate doses of iron were taken.

  4. Iron Supplementation during Three Consecutive Days of Endurance Training Augmented Hepcidin Levels.

    Science.gov (United States)

    Ishibashi, Aya; Maeda, Naho; Kamei, Akiko; Goto, Kazushige

    2017-07-30

    Iron supplementation contributes an effort to improving iron status among athletes, but it does not always prevent iron deficiency. In the present study, we explored the effect of three consecutive days of endurance training (twice daily) on the hepcidin-25 (hepcidin) level. The effect of iron supplementation during this period was also determined. Fourteen male endurance athletes were enrolled and randomly assigned to either an iron-treated condition (Fe condition, n = 7) or a placebo condition (Control condition; CON, n = 7). They engaged in two 75-min sessions of treadmill running at 75% of maximal oxygen uptake on three consecutive days (days 1-3). The Fe condition took 12 mg of iron twice daily (24 mg/day), and the CON condition did not. On day 1, both conditions exhibited significant increases in serum hepcidin and plasma interleukin-6 levels after exercise ( p < 0.05). In the CON condition, the hepcidin level did not change significantly throughout the training period. However, in the Fe condition, the serum hepcidin level on day 4 was significantly higher than that of the CON condition ( p < 0.05). In conclusion, the hepcidin level was significantly elevated following three consecutive days of endurance training when moderate doses of iron were taken.

  5. Minimum distance determination between consecutive carriers in the gamma irradiator IR-200 K trajectory

    International Nuclear Information System (INIS)

    Achmad Suntoro

    2014-01-01

    A design to determine the minimum distance between the consecutive carriers at the trajectory of gamma irradiators IR-200K is implemented. Equilibrium between centrifugal force of a moving carrier in circular trajectory and its gravity force as well as carrier dimensions are used as parameters in determining such a minimum distance. The minimum distance between the consecutive carriers in the design is defined 1.2 meters. The distance is 11.5% greater than the minimum distance theoretically calculated, namely 1,076 meters. Errors tolerance in construction/installation of the trajectory and other unexpected things during irradiator's operation are part of the consideration to enlarge the minimum distance from its theoretical value. The distance between the consecutive carriers will not affect throughput and efficiency of using radiation due to the straight trajectory segments do not need to follow such the minimum distance between the carriers, as the trajectory segments around the i radiation sources are straight. (author)

  6. Signal-to-noise ratio measurement in parallel MRI with subtraction mapping and consecutive methods

    International Nuclear Information System (INIS)

    Imai, Hiroshi; Miyati, Tosiaki; Ogura, Akio; Doi, Tsukasa; Tsuchihashi, Toshio; Machida, Yoshio; Kobayashi, Masato; Shimizu, Kouzou; Kitou, Yoshihiro

    2008-01-01

    When measuring the signal-to-noise ratio (SNR) of an image the used parallel magnetic resonance imaging, it was confirmed that there was a problem in the application of past SNR measurement. With the method of measuring the noise from the background signal, SNR with parallel imaging was higher than that without parallel imaging. In the subtraction method (NEMA standard), which sets a wide region of interest, the white noise was not evaluated correctly although SNR was close to the theoretical value. We proposed two techniques because SNR in parallel imaging was not uniform according to inhomogeneity of the coil sensitivity distribution and geometry factor. Using the first method (subtraction mapping), two images were scanned with identical parameters. The SNR in each pixel divided the running mean (7 by 7 pixels in neighborhood) by standard deviation/√2 in the same region of interest. Using the second (consecutive) method, more than fifty consecutive scans of the uniform phantom were obtained with identical scan parameters. Then the SNR was calculated from the ratio of mean signal intensity to the standard deviation in each pixel on a series of images. Moreover, geometry factors were calculated from SNRs with and without parallel imaging. The SNR and geometry factor using parallel imaging in the subtraction mapping method agreed with those of the consecutive method. Both methods make it possible to obtain a more detailed determination of SNR in parallel imaging and to calculate the geometry factor. (author)

  7. Multiple Sclerosis

    Science.gov (United States)

    Multiple sclerosis (MS) is a nervous system disease that affects your brain and spinal cord. It damages the myelin sheath, the material that surrounds and protects your nerve cells. This damage slows down ...

  8. Multiple myeloma.

    LENUS (Irish Health Repository)

    Collins, Conor D

    2012-02-01

    Advances in the imaging and treatment of multiple myeloma have occurred over the past decade. This article summarises the current status and highlights how an understanding of both is necessary for optimum management.

  9. Multiple mononeuropathy

    Science.gov (United States)

    ... with multiple mononeuropathy are prone to new nerve injuries at pressure points such as the knees and elbows. They should avoid putting pressure on these areas, for example, by not leaning on the elbows, crossing the knees, ...

  10. Eight-point Compass Rose Underlay Technique in 72 Consecutive Elderly Patients with Large Incisional Hernia

    Directory of Open Access Journals (Sweden)

    Attilio Ignazio Lo Monte

    2011-09-01

    Conclusion: This surgical procedure, like laparoscopic treatment, allows the surgeon to avoid dissection of the abdominal layer and improves prosthesis adhesion with reinforcement of the incisional area near the abdominal defect. The reduction in operation time is remarkable. Despite good results in terms of safety and minimal recurrence for laparoscopy in the management of IH, the use of minimally invasive techniques for large incisional wall defects, especially in elderly patients, is still controversial and practiced by few surgeons. This open technique avoids cardiopulmonary complications arising from pneumoperitoneum in the elderly.

  11. Surface Modifications in Adhesion and Wetting

    Science.gov (United States)

    Longley, Jonathan

    Advances in surface modification are changing the world. Changing surface properties of bulk materials with nanometer scale coatings enables inventions ranging from the familiar non-stick frying pan to advanced composite aircraft. Nanometer or monolayer coatings used to modify a surface affect the macro-scale properties of a system; for example, composite adhesive joints between the fuselage and internal frame of Boeing's 787 Dreamliner play a vital role in the structural stability of the aircraft. This dissertation focuses on a collection of surface modification techniques that are used in the areas of adhesion and wetting. Adhesive joints are rapidly replacing the familiar bolt and rivet assemblies used by the aerospace and automotive industries. This transition is fueled by the incorporation of composite materials into aircraft and high performance road vehicles. Adhesive joints have several advantages over the traditional rivet, including, significant weight reduction and efficient stress transfer between bonded materials. As fuel costs continue to rise, the weight reduction is accelerating this transition. Traditional surface pretreatments designed to improve the adhesion of polymeric materials to metallic surfaces are extremely toxic. Replacement adhesive technologies must be compatible with the environment without sacrificing adhesive performance. Silane-coupling agents have emerged as ideal surface modifications for improving composite joint strength. As these coatings are generally applied as very thin layers (coatings using the buckling instability formed between two materials of a large elastic mismatch. The elastic modulus is found to effectively predict the joint strength of an epoxy/aluminum joint that has been reinforced with silane coupling agents. This buckling technique is extended to investigate the effects of chemical composition on the elastic modulus. Finally, the effect of macro-scale roughness on silane-reinforced joints is investigated

  12. Evidence for van der Waals adhesion in gecko setae.

    Science.gov (United States)

    Autumn, Kellar; Sitti, Metin; Liang, Yiching A; Peattie, Anne M; Hansen, Wendy R; Sponberg, Simon; Kenny, Thomas W; Fearing, Ronald; Israelachvili, Jacob N; Full, Robert J

    2002-09-17

    Geckos have evolved one of the most versatile and effective adhesives known. The mechanism of dry adhesion in the millions of setae on the toes of geckos has been the focus of scientific study for over a century. We provide the first direct experimental evidence for dry adhesion of gecko setae by van der Waals forces, and reject the use of mechanisms relying on high surface polarity, including capillary adhesion. The toes of live Tokay geckos were highly hydrophobic, and adhered equally well to strongly hydrophobic and strongly hydrophilic, polarizable surfaces. Adhesion of a single isolated gecko seta was equally effective on the hydrophobic and hydrophilic surfaces of a microelectro-mechanical systems force sensor. A van der Waals mechanism implies that the remarkable adhesive properties of gecko setae are merely a result of the size and shape of the tips, and are not strongly affected by surface chemistry. Theory predicts greater adhesive forces simply from subdividing setae to increase surface density, and suggests a possible design principle underlying the repeated, convergent evolution of dry adhesive microstructures in gecko, anoles, skinks, and insects. Estimates using a standard adhesion model and our measured forces come remarkably close to predicting the tip size of Tokay gecko seta. We verified the dependence on size and not surface type by using physical models of setal tips nanofabricated from two different materials. Both artificial setal tips stuck as predicted and provide a path to manufacturing the first dry, adhesive microstructures.

  13. Controllable biomimetic adhesion using embedded phase change material

    International Nuclear Information System (INIS)

    Krahn, J; Sameoto, D; Menon, C

    2011-01-01

    In many cases, such as in the instance of climbing robots or temporary adhesives, there is the need to be able to dynamically control the level of adhesion a biomimetic dry adhesive can provide. In this study, the effect of changing the backing layer stiffness of a dry adhesive is examined. Embedding a phase change material within the backing of a synthetic dry adhesive sheet allows the stiffness to be tailored at different points of a preload and adhesion cycle. Larger contact areas and more equal load sharing between adhesive fibres can be achieved by increasing the backing layer stiffness after initial deformation when the adhesive backing is loaded in its softened state. Adhesion behaviour is examined when the backing layer is maintained in solid and softened phases during complete load cycles and for load cycles under the condition of contact with the softened phase backing followed by pull-off during the solid phase. Absolute adhesion force is increased for trials in which a soft backing layer hardens prior to pull-off. This effect is due to the increased contact area made between the rounded probe and the softened material during preloading and the more equal load sharing condition during pull-off when the backing layer becomes stiff again

  14. Structural Evaluation of the RSRM Nozzle Replacement Adhesive

    Science.gov (United States)

    Batista-Rodriguez, A.; McLennan, M. L.; Palumbos, A. V.; Richardson, D. E.

    1999-01-01

    This paper describes the structural performance evaluation of a replacement adhesive for the Reusable Solid Rocket Motor (RSRM) nozzle utilizing finite element analysis. Due to material obsolescence and industrial safety issues, the two current structural adhesives, EA 913 and EA 946 are to be replaced with a new adhesive. TIGA 321. The structural evaluation in support of the adhesive replacement effort includes residual stress, transportation, and flight analyses. Factors of safety are calculated using the stress response from each analysis. The factors of safety are used as the limiting criteria to compare the replacement adhesive against the current adhesives. Included in this paper are the analytical approach, assumptions and modeling techniques as well as the results of the evaluation. An important factor to the evaluation is the similarity in constitutive material properties (elastic modulus and Poisson's ratio) between TIGA 321 and EA 913. This similarity leads to equivalent material response from the two adhesives. However, TIGA 321 surpasses EA 913's performance due to higher material capabilities. Conversely, the change in stress response from EA 946 to TIGA 321 is more apparent: this is primarily attributed to the difference in the modulii of the two adhesives, which differ by two orders of magnitude. The results of the bondline evaluation indicate that the replacement adhesive provides superior performance than the current adhesives with only minor exceptions. Furthermore, TIGA 321 causes only a minor chance in the response of the phenolic and metal components.

  15. Shear Bond Strengths of Different Adhesive Systems to Biodentine

    Science.gov (United States)

    Odabaş, Mesut Enes; Bani, Mehmet; Tirali, Resmiye Ebru

    2013-01-01

    The aim of this study was to measure the shear bond strength of different adhesive systems to Biodentine with different time intervals. Eighty specimens of Biodentine were prepared and divided into 8 groups. After 12 minutes, 40 samples were randomly selected and divided into 4 groups of 10 each: group 1: (etch-and-rinse adhesive system) Prime & Bond NT; group 2: (2-step self-etch adhesive system) Clearfil SE Bond; group 3: (1-step self-etch adhesive systems) Clearfil S3 Bond; group 4: control (no adhesive). After the application of adhesive systems, composite resin was applied over Biodentine. This procedure was repeated 24 hours after mixing additional 40 samples, respectively. Shear bond strengths were measured using a universal testing machine, and the data were subjected to 1-way analysis of variance and Scheffé post hoc test. No significant differences were found between all of the adhesive groups at the same time intervals (12 minutes and 24 hours) (P > .05). Among the two time intervals, the lowest value was obtained for group 1 (etch-and-rinse adhesive) at a 12-minute period, and the highest was obtained for group 2 (two-step self-etch adhesive) at a 24-hour period. The placement of composite resin used with self-etch adhesive systems over Biodentine showed better shear bond strength. PMID:24222742

  16. ADHESIVE SYSTEM AFFECTS REPAIR BOND STRENGTH OF RESIN COMPOSITE

    Directory of Open Access Journals (Sweden)

    Özgür IRMAK

    2017-10-01

    Full Text Available Purpose: This study evaluated the effects of different adhesive systems on repair bond strength of aged resin composites. Materials and Methods: Ninety composite discs were built and half of them were subjected to thermal aging. Aged and non-aged specimens were repaired with resin composite using three different adhesive systems; a two-step self-etch adhesive, a two-step total-etch adhesive and a one-step self-etch adhesive; then they were subjected to shear forces. Data were analyzed statistically. Results: Adhesive type and aging significantly affected the repair bond strengths (p<0.0001. No statistical difference was found in aged composite groups repaired with two-step self- etch or two-step total-etch adhesive. One-step self-etch adhesive showed lower bond strength values in aged composite repair (p<0.0001. Conclusion: In the repair of aged resin composite, two-step self-etch and two-step total-etch adhesives exhibited higher shear bond strength values than that of one-step self-etch adhesive.

  17. Mutant matrix metalloproteinase-9 reduces postoperative peritoneal adhesions in rats.

    Science.gov (United States)

    Atta, Hussein; El-Rehany, Mahmoud; Roeb, Elke; Abdel-Ghany, Hend; Ramzy, Maggie; Gaber, Shereen

    2016-02-01

    Postoperative peritoneal adhesions continue to be a major source of morbidity and occasional mortality. Studies have shown that matrix metalloproteinase-9 (MMP-9) levels are decreased postoperatively which may limits matrix degradation and participate in the development of peritoneal adhesions. In this proof-of-principle study, we evaluated the effect of gene therapy with catalytically inactive mutant MMP-9 on postoperative peritoneal adhesions in rats. Adenovirus encoding mutant MMP-9 (Ad-mMMP-9) or saline was instilled in the peritoneal cavity after cecal and parietal peritoneal injury in rats. Expression of mutant MMP-9 transcript was verified by sequencing. Adenovirus E4 gene expression, adhesion scores, MMP-9, tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) and transforming growth factor-β1 (TGF-β1) expression were evaluated at sacrifice one week after treatment. Both mutant MMP-9 transcripts and adenovirus E4 gene were expressed in Ad-mMMP-9 treated adhesions. Adhesions severity decreased significantly (p = 0.036) in the Ad-mMMP-9-treated compared with saline-treated adhesions. Expression of MMP-9 mRNA and protein were elevated (p = 0.001 and p = 0.029, respectively) in the Ad-mMMP-9-treated adhesions compared with saline-treated adhesions. While tPA levels were increased (p = 0.02) in Ad-mMMP-9 treated adhesions compared with saline-treated adhesions, TGF-β1 and PAI-1 levels were decreased (p = 0.017 and p = 0.042, respectively). No difference in mortality were found between groups (p = 0.64). Mutant MMP-9 gene therapy effectively transduced peritoneal adhesions resulting in reduction of severity of primary peritoneal adhesions. Copyright © 2016 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

  18. Improving adhesion of seasonings to crackers with hydrocolloid solutions.

    Science.gov (United States)

    Armstrong, Matthew E; Barringer, Sheryl A

    2013-11-01

    Food powders were applied on crackers that had been coated using water, oil, emulsion, sucrose, or hydrocolloid solutions. The hydrocolloids that were used include gellan gum, kappa-carrageenan, methylcellulose, gum karaya, gum tragacanth, gum arabic, guar gum, modified starch, and maltodextrin. Solutions of similar hydrophobicity to the powder gave the greatest adhesion. NaCl, barbecue (BBQ), ranch, and sour cream & onion (SC&O) seasoning showed greatest adhesion with water, cheese powder with an emulsion of 12.5% to 25% oil, and cocoa powder with oil. For NaCl, BBQ, ranch, and SC&O seasoning, hydrocolloids improved the adhesion over using water alone, with gellan gum providing the greatest adhesion. Hydrocolloid structural differences, including the presence or absence of branching, substitution of sugar units, and molecular weight affect water binding and thickening of the hydrocolloid spray that seemed to be significant factors affecting adhesion of powders to the target surface. For cheese powder, hydrocolloids were capable of replacing the oil within an emulsion while improving or maintaining the same level of adhesion, with gum arabic providing the greatest adhesion. For cocoa powder, hydrocolloid solutions were ineffective adhesives due to differences in hydrophilicity that result in insolubility. The effect of hydrocolloid concentration on adhesion was dependent both on the hydrocolloid type and the concentration that is sprayable, with 0.5% being the optimum concentration for most gums. Adhesion using sucrose solutions was determined by particle size and relative hydrophobicity. Increasing sucrose concentration decreased adhesion of smaller particles, but increased adhesion of larger particles. Adhesion of NaCl significantly increased with decreasing NaCl size using oil, water, and sucrose solutions. © 2013 Institute of Food Technologists®

  19. Enhancement of Fracture Resistance by Multiple Cracks in Layered Structures under Mode I and Mix Mode Loading

    DEFF Research Database (Denmark)

    Goutianos, Stergios; Sørensen, Bent F.

    beams bonded together with a thermoset adhesive, more delamination cracks could be developed next to the main/primary adhesive/laminate crack. An analytical model, based on the J integral, was developed for multiple delaminations [3]. It is shown that the maximum possible increase (upper limit...

  20. Aesthetic refinements and reoperative procedures following 370 consecutive DIEP and SIEA flap breast reconstructions: important considerations for patient consent.

    Science.gov (United States)

    Enajat, Morteza; Smit, Jeroen M; Rozen, Warren M; Hartman, Ed H M; Liss, Anders; Kildal, Morten; Audolfsson, Thorir; Acosta, Rafael

    2010-06-01

    Breast reconstruction often requires multiple operations. In addition to potential complications requiring reoperation, additional procedures are frequently essential in order to complete the reconstructive process, with aesthetic outcome and breast symmetry shown to be the most important factors in patient satisfaction. Despite the importance of these reoperations in decision-making and the consent process, a thorough review of the need for such operations has not been definitively explored. A review of 370 consecutive autologous breast reconstructions (326 patients) was undertaken, comprising 365 deep inferior epigastric artery perforator (DIEP) flaps and 5 superficial inferior epigastric artery (SIEA) flaps. The need for additional procedures for either complications or aesthetic refinement following initial breast reconstruction was assessed. Overall, there was an average of 1.06 additional interventions for every patient carried out after primary reconstructive surgery. Of 326 patients, 46 underwent early postoperative operations for surgical complications (0.17 additional operations per patient as a consequence of complications). Procedures for aesthetic refinement included those performed on the reconstructed breast, contralateral breast, or abdominal donor site. Procedures for aesthetic refinement included nipple reconstruction, nipple-areola complex tattooing, dog-ear correction, liposuction, lipofilling, scar revision, mastopexy, and reduction mammaplasty. While DIEP flap surgery for breast reconstruction provides favorable results, patients frequently require additional procedures to improve aesthetic outcomes. The need for reoperation is an important part of the consent process prior to reconstructive surgery, and patients should recognize the likelihood of at least one additional procedure following initial reconstruction.

  1. Aquaporin-4 Immuneglobulin G testing in 36 consecutive Jamaican patients with inflammatory central nervous system demyelinating disease

    Directory of Open Access Journals (Sweden)

    Sherri Sandy

    2014-08-01

    Full Text Available Epidemiological studies of neuromyelitis optica (NMO in Jamaica are lacking. Here we reviewed the clinical records of 700 patients undergoing neurological evaluation at the Kingston Public Hospital, the largest tertiary institution in Jamaica over a 4 month period. We investigated the diagnostic utility of Aquaporin-4 ImmuneglobulinG (AQP4-IgG testing in 36 consecutive patients with a diagnosis of an inflammatory demyelinating disorder (IDD of the central nervous system (CNS. Patients were classified into 3 categories: i NMO, n=10; ii multiple sclerosis (MS, n=14 and iii unclassified IDD (n=12. All sera were tested for AQP-IgG status by cell binding assay (Euroimmun. No MS cases were positive. Ninety per cent of NMO cases were positive. Four of 12 patients with unclassified IDD tested positive for AQP4-IgG. AQP4-IgG seropositivity was associated with a lower socioeconomic status, higher EDSS (P=0.04 and lower pulmonary function than the seronegative cases (P=0.007. Aquaporin-4 autoimmunity may account for a significant proportion of Jamaican CNS IDDs.

  2. Recurrent hydatidiform mole: A case report of six consecutive molar pregnancies complicated by choriocarcinoma, and review of the literature

    Directory of Open Access Journals (Sweden)

    Ahlam A Al-Ghamdi

    2011-01-01

    Full Text Available Hydatidiform mole (HM is the most common form of gestational trophoblastic neoplasia. Recurrence of HM is extremely rare. Here, we report the case of a patient with six consecutive partial HMs without normal pregnancy. A 42-year-old lady who was referred to us at King Fahad Hospital of the University, Al Khobar, initially as a case of 26-year-old with persistent trophoblastic disease after three recurrent molar pregnancies that were confirmed histologically in the referring hospital. She underwent evacuation and curettage and was followed up by serial β-human chorionic gonadotropin levels, and did not require chemotherapy. She then had three more molar pregnancies in 1995, 1996, and 2004; all molar pregnancies were evacuated by suction curettage at her base hospital, but in the last event, she complained of shortness of breath and abdominal pain. Diagnostic workup in our hospital confirmed choriocarcinoma, for which she received multiple regimen chemotherapy and was cured. Unfortunately, she lately presented with symptoms suggestive of premature menopause.

  3. Flight Hours in 7 Consecutive Days and Physical Exercise among the Civil Pilot in Indonesia

    Directory of Open Access Journals (Sweden)

    Harry Wicaksana

    2017-07-01

    Full Text Available Abstrak Latar belakang Tidak tersedianya waktu merupakan salah satu hambatan melakukan latihan fisik yang sering dilaporkan di negara berkembang. Berdasarkan Peraturan Keselamatan Penerbangan Sipil bagian 121, jam terbang maksimal pilot sipil komersial dalam 7 hari terakhir adalah 30 jam. Oleh karena itu perlu dilakukan penelitian mengenai hubungan jam terbang 7 hari terakhir terhadap kebiasaan latihan fisik pada pilot sipil di Indonesia. Metode Penelitian potong lintang terhadap 600 orang pilot sipil yang melakukan pengujian kesehatan personil penerbangan di Balai Kesehatan Penerbangan pada bulan April 2016 dan memenuhi kriteria inklusi/ekslusi.  Data yang dikumpulkan yaitu karakteristik demografi, pekerjaan, kebiasaan olahraga, tinggi dan berat badan. Pengambilan data dilakukan dengan wawancara dan pemeriksaan fisik. Pilot dikategorikan memiliki kebiasaan latihan fisik sesuai rekomendasi ACSM apabila melakukan latihan fisik dengan intensitas sedang selama 150 menit per minggu atau latihan fisik dengan intensitas berat selama 75 menit per minggu. Hasil Jam terbang 7 hari terakhir merupakan faktor dominan terhadap kebiasaan latihan fisik. Jika dibandingkan dengan pilot dengan jam terbang 7 hari terakhir < 3,5 jam, maka pilot dengan jam terbang 7 hari terakhir 3,5-14 jam berisiko 24% lebih rendah memiliki kebiasaan latihan fisik sesuai [RRa= 0,76; p=0,032]. Simpulan Faktor risiko yang berpengaruh terhadap kebiasaan latihan fisik adalah jam terbang 7 hari terakhir. Kata kunci: Jam terbang 7 hari terakhir, kebiasaan latihan fisik, pilot sipil Indonesia  Background The most frequently reported barrier of doing physical exercise in developed countries is lack of time. Based on the Civil Aviation Safety Regulation part 121, the maximum working hour for commercial pilot in 7 consecutive days is 30 hours. The study objective is to identify the relation between flight hours in 7 consecutive days and the physical exercise habit among the civil pilots in

  4. Mapping molecular adhesion sites inside SMIL coated capillaries using atomic force microscopy recognition imaging

    Energy Technology Data Exchange (ETDEWEB)

    Leitner, Michael [Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz (Austria); Stock, Lorenz G. [Division of Chemistry and Bioanalytics, Department of Molecular Biology, University Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg (Austria); Christian Doppler Laboratory for Innovative Tools for the Characterization of Biosimilars, University Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg (Austria); Traxler, Lukas [Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz (Austria); Leclercq, Laurent [Institut des Biomolécules Max Mousseron (IBMM, UMR 5247, CNRS, Université de Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier), Place Eugène Bataillon, CC 1706, 34095 Montpellier (France); Bonazza, Klaus; Friedbacher, Gernot [Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164, 1060 Vienna (Austria); Cottet, Hervé [Institut des Biomolécules Max Mousseron (IBMM, UMR 5247, CNRS, Université de Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier), Place Eugène Bataillon, CC 1706, 34095 Montpellier (France); Stutz, Hanno [Division of Chemistry and Bioanalytics, Department of Molecular Biology, University Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg (Austria); Christian Doppler Laboratory for Innovative Tools for the Characterization of Biosimilars, University Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg (Austria); Ebner, Andreas, E-mail: andreas.ebner@jku.at [Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz (Austria)

    2016-08-03

    Capillary zone electrophoresis (CZE) is a powerful analytical technique for fast and efficient separation of different analytes ranging from small inorganic ions to large proteins. However electrophoretic resolution significantly depends on the coating of the inner capillary surface. High technical efforts like Successive Multiple Ionic Polymer Layer (SMIL) generation have been taken to develop stable coatings with switchable surface charges fulfilling the requirements needed for optimal separation. Although the performance can be easily proven in normalized test runs, characterization of the coating itself remains challenging. Atomic force microscopy (AFM) allows for topographical investigation of biological and analytical relevant surfaces with nanometer resolution and yields information about the surface roughness and homogeneity. Upgrading the scanning tip to a molecular biosensor by adhesive molecules (like partly inverted charged molecules) allows for performing topography and recognition imaging (TREC). As a result, simultaneously acquired sample topography and adhesion maps can be recorded. We optimized this technique for electrophoresis capillaries and investigated the charge distribution of differently composed and treated SMIL coatings. By using the positively charged protein avidin as a single molecule sensor, we compared these SMIL coatings with respect to negative charges, resulting in adhesion maps with nanometer resolution. The capability of TREC as a functional investigation technique at the nanoscale was successfully demonstrated. - Highlights: • SMIL coating allows generation of homogeneous ultra-flat surfaces. • Molecular electrostatic adhesion forces can be determined in the inner wall of CZE capillary with picoNewton accuracy. • Topographical images and simultaneously acquired adhesion maps yield morphological and chemical information at the nanoscale.

  5. Accelerated aging of adhesive-mediated fiber post-resin composite bonds: A modeling approach.

    Science.gov (United States)

    Radovic, Ivana; Monticelli, Francesca; Papacchini, Federica; Magni, Elisa; Cury, Alvaro Hafiz; Vulicevic, Zoran R; Ferrari, Marco

    2007-08-01

    Although fiber posts luted in root canals are not directly exposed to oral fluids, water storage is considered as in vitro accelerated aging test for bonded interfaces. The aim of the study was to evaluate the influence of accelerated water aging on fiber post-resin composite adhesion. Forty fiber posts (DT Light Post, RTD) were randomly divided into two main groups, according to the surface treatment performed. Group I: XPBond adhesive (Dentsply Caulk); Group II: sandblasting (Rocatec-Pre, 3M ESPE) and XPBond. Dual-cured resin cement (Calibra, Dentsply Caulk) and flowable composite (X-Flow, Dentsply Caulk) were applied on the posts to produce cylindrical specimens. The bond strength at the interface between post and cement/composite was measured with the microtensile test according to the non-trimming technique. Half of the sticks were tested immediately for bond strength, while in the other half testing was performed after 1 month of water storage at 37 degrees C. Post-cement/composite interfaces were evaluated under SEM prior and after water aging. Statistical analysis was performed using the Kruskal-Wallis ANOVA followed by Dunn's multiple range test (p<0.05). Immediate bond strength was higher on sandblasted posts. After water aging the two post surface treatments resulted comparable in bond strength. Resin cement achieved higher bond strength to fiber posts than flowable composite. Water aging significantly reduced bond strength. Sandblasting followed by adhesive coating may improve immediate post-resin bond strength in comparison to adhesive alone. However, fiber post-resin bond strength mediated by hydrophilic adhesive tends to decrease after water aging.

  6. Inhibition of oxygen scavengers realized by peritoneal macrophages: an adhesion prevention target?

    Directory of Open Access Journals (Sweden)

    Mynbaev OA

    2014-11-01

    Full Text Available Ospan A Mynbaev,1–4 Marina Yu Eliseeva,1,2 Oktay T Kadayifci,1,5 Tahar Benhidjeb,1,6 Michael Stark1,41The International Translational Medicine and Biomodeling Research team, MIPT center for human physiology studies, Laboratory of Cellular and Molecular Technologies, The Department of Applied Mathematics, Moscow Institute of Physics and Technology (State University, Moscow Region, Russia; 2The Department of Obstetrics, Gynecology and Reproductive Medicine, Peoples’ Friendship University of Russia, Moscow, Russia; 3Laboratory of Pilot Projects, Moscow State University of Medicine and Dentistry, Moscow, Russia; 4The New European Surgical Academy, Berlin, Germany; 5Onkim Stem Cell Technologies Inc., Istanbul, Turkey; 6Department of Surgery, Burjeel Hospital, Abu Dhabi, United Arab EmiratesOur team, general surgeons and gynecologists look constantly for ways to prevent postsurgical adhesions, and hence, we appreciate the platform you have established through multiple publications.1–3 This is especially because postsurgical adhesions may result in several complications such as the small bowel obstruction, secondary infertility, dyspareunia, chronic abdominal/pelvic pain and many others.Prevention of postsurgical adhesions is still an unsolved problem in spite of the suggested modifications of current surgical methods and application of various barriers, sprays, and use of other antiadhesive medications. We have already pointed out that a design of ideal nanoparticles should become a target of personalized adhesion prevention strategy in the future4,5 and therefore, we read with great interest the article by Shin et al that was recently published in your journal.6 This article explores the potential of postoperative adhesion prevention by nanofibers of poly(lactic-co-glycolic acid (PLGA loaded with epigallocatechin-3-O-gallate (EGCG, which is the most bioactive polyphenolic compound extracted from green tea.Read the original article by Shin and

  7. Improving outcomes in microsurgical breast reconstruction: lessons learnt from 406 consecutive DIEP/TRAM flaps performed by a single surgeon.

    Science.gov (United States)

    Damen, Tim H C; Morritt, Andrew N; Zhong, Toni; Ahmad, Jamil; Hofer, Stefan O P

    2013-08-01

    Multiple preoperative, intraoperative and postoperative decisions can influence the outcome of microsurgical breast reconstruction. We have simplified the decision-making process by incorporating a number of algorithms into our microsurgical breast reconstruction practice and critically review our results in this study. Prospectively maintained databases for all microsurgical breast reconstructions performed by a single surgeon over a nine-year period were examined to determine: patient demographics; operative details including flap choice, donor and recipient vessel selection; and, details of intraoperative and early postoperative (406 Consecutive free flap microsurgical breast reconstructions (164 unilateral and 121 bilateral) were performed in 285 patients over the study period. Deep inferior epigastric artery perforator (DIEP) flaps (88%, n=359) were used most commonly followed by muscle-sparing transverse rectus abdominis musculocutaneous (MS-TRAM) flaps (11%, n=44), and fascial-sparing TRAM (FS-TRAM) flaps (0.7%, n=3). One-hundred-seventy-one (48%) DIEP flaps were based on a single perforator while 188 (52%) had multiple perforators. The internal mammary (IM) artery and vein were used as the recipient vessels for 99% (n=403) of flaps. A second venous anastomosis was required for 11.8 percent (n=48) of flaps. Partial flap failure occurred in nine (2.2%) flaps while total flap failure occurred in two flaps (0.5%). Minimum follow-up was three months. Incorporating a number of algorithms into our practice has enabled us to simplify the decision-making processes involved in microsurgical breast reconstruction and to consistently obtain successful surgical outcomes. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  8. Treatment of oligodontia with endo-osseous fixtures: experience in eight consecutive patients at the end of dental growth.

    Science.gov (United States)

    Becelli, Roberto; Morello, Roberto; Renzi, Giancarlo; Dominici, Chiara

    2007-11-01

    Clinical manifestations of oligodontia consist in agenesia of multiple teeth eventually with deciduous retained teeth, atrophy of alveolar ridge, aberrations of teeth dimension, and shape, with consequent aesthetic and functional defects. The first choice treatment is based on a team collaboration of maxillo-facial surgeon, orthodontist, and prosthodontist, and is conditioned by various clinical parameters as number and site of lacking teeth, age and dental development of patients, eventual alveolar ridge atrophy. Treatment planning should be individualized for each patient. In our experience, based on 8 consecutive patients at the end of dental growth affected by oligodontia, endo-osseous fixtures positioning was carried out in consideration of long-lasting stability and optimal aesthetical characteristics. In 5 patients rehabilitative preprosthetic surgical procedures were performed, consisting in 2 sinus lift with immediate positioning of 3 fixtures in both cases, 4 heterologous bone graft in postextractive sites with retained ankylotic deciduous teeth and 1 positioning of reabsorbable biomembrane. A temporary removable denture was positioned immediately after surgery in order to obtain a prompt aesthetical and psychosocial restore. Osseointegration ratio as observed at 8.5 years follow-up was analyzed according to surgical variables and differences in prosthetic rehabilitation (fixtures supporting single crown versus multiple crowns). Successful osteointegration was observed at 8.5 years mean follow-up in 58 fixtures, corresponding to a 96.6% ratio. Failure of integration was encountered in fixtures immediately positioned in postextractive sites having a mild grade of bone atrophy, supporting single crown. A rate of success of 100% was observed in cases of immediate or delayed positioning in postextractive or traditional sites.Fixtures positioning in patients affected by isolated oligodontia, without malformative syndromes, and at the end of dental development

  9. Long-term In Vitro Adhesion of Polyalkenoate-based Adhesives to Dentin.

    Science.gov (United States)

    Sezinando, Ana; Perdigão, Jorge; Ceballos, Laura

    2017-01-01

    To study the influence of a polyalkenoate copolymer (VCP) on the immediate (24 h) and 6-month dentin bonding stability of VCP-based adhesives, using microtensile bond strength (μTBS), nanoleakage (NL), and ultramorphological analyses (FE-SEM). Eighty-four caries-free molars were randomly assigned to seven adhesives: Clearfil SE Bond (CSE, Kuraray Noritake); Adper Single Bond Plus (SB, 3M ESPE); SB without VCP (SBnoVCP, 3M ESPE); Scotchbond Universal Adhesive applied as a etch-and-rinse adhesive (SBU_ER); SBU without VCP applied as an etch-and-rinse adhesive (SBUnoVCP_ER); SBU applied as a self-etch adhesive (SBU_SE, 3M ESPE); SBU without VCP applied as a self-etch adhesive (SBUnoVCP_SE, 3M ESPE). Half of the beams were tested after 24 h, and the other half was aged in water for 6 months prior to testing. For each tooth/evaluation time, two beams were randomly selected for NL analysis. Statistical analyses of µTBS results were performed using two-way ANOVA, Tukey's post-hoc tests, and Student's t-test for paired data (α = 0.05). Nanoleakage was statistically analyzed using the Kruskal-Wallis and Mann-Whitney tests, with Wilcoxon's test for paired data. For FE-SEM, four caries-free molars were assigned to each of the seven groups. Dentin disks were restored and cross sectioned into halves. One half was observed at 24 h, and the other at 6 months. The highest 6-month mean μTBS was obtained with SBU_SE/SBUnoVCP_SE and SBUnoVCP_ER. SBUnoVCP_SE resulted in greater silver deposition at 6 months. FE-SEM observations showed that CSE and SBU_SE specimens resulted in a submicron hybrid layer without signs of degradation at 6 months. VCP may contribute to the long-term bonding stability of VCP-based adhesives.

  10. Morphological Evaluation of the Adhesive/Enamel interfaces of Two-step Self-etching Adhesives and Multimode One-bottle Self-etching Adhesives.

    Science.gov (United States)

    Sato, Takaaki; Takagaki, Tomohiro; Matsui, Naoko; Hamba, Hidenori; Sadr, Alireza; Nikaido, Toru; Tagami, Junji

    To evaluate the acid-base resistant zone (ABRZ) at the adhesive/enamel interface of self-etching adhesives with or without prior phosphoric acid etching. Four adhesives were used in 8 groups: Clearfil SE Bond (SEB), Optibond XTR (XTR), Scotchbond Universal Adhesive (SBU), and Clearfil BOND SE ONE (ONE) without prior phosphoric-acid etching, and each adhesive with phosphoric acid etching for 10 s (P-SEB, P-XTR, P-SBU and P-ONE, respectively). After application of self-etching adhesives on ground enamel surfaces of human teeth, a flowable composite was placed. For observation of the acid-base resistant zone (ABRZ), the bonded interface was exposed to demineralizing solution (pH 4.5) for 4.5 h, followed by 5% NaOCl with ultrasonication for 20 min. After the acid-base challenge, morphological attributes of the interface were observed using SEM. ABRZ formation was confirmed in all groups. The funnel-shaped erosion beneath the interface was present in SBU and ONE, where nearly 10 to 15 μm of enamel was dissolved. With phosphoric acid etching, the ABRZs were obviously thicker compared with no phosphoric acid etching. Enamel beneath the bonding interface was more susceptible to acid dissolution in SBU and ONE. In the case of the one-bottle self-etching adhesives and universal adhesives that intrinsically have higher pH values, enamel etching should be recommended to improve the interfacial quality.

  11. Numerical implementation of multiple peeling theory and its application to spider web anchorages.

    Science.gov (United States)

    Brely, Lucas; Bosia, Federico; Pugno, Nicola M

    2015-02-06

    Adhesion of spider web anchorages has been studied in recent years, including the specific functionalities achieved through different architectures. To better understand the delamination mechanisms of these and other biological or artificial fibrillar adhesives, and how their adhesion can be optimized, we develop a novel numerical model to simulate the multiple peeling of structures with arbitrary branching and adhesion angles, including complex architectures. The numerical model is based on a recently developed multiple peeling theory, which extends the energy-based single peeling theory of Kendall, and can be applied to arbitrarily complex structures. In particular, we numerically show that a multiple peeling problem can be treated as the superposition of single peeling configurations even for complex structures. Finally, we apply the developed numerical approach to study spider web anchorages, showing how their function is achieved through optimal geometrical configurations.

  12. Decreasing adhesions and avoiding further surgery in a pediatric patient involved in a severe pedestrian versus motor vehicle accident

    Directory of Open Access Journals (Sweden)

    Amanda D. Rice

    2014-02-01

    Full Text Available In this case study, we report the use of manual physical therapy in a pediatric patient experiencing complications from a life-threatening motor vehicle accident that necessitated 19 surgeries over the course of 12 months. Post-surgical adhesions decreased the patient’s quality of life. He developed multiple medical conditions including recurrent partial bowel obstructions and an ascending testicle. In an effort to avoid further surgery for bowel obstruction and the ascending testicle, the patient was effectively treated with a manual physical therapy regimen focused on decreasing adhesions. The therapy allowed return to an improved quality of life, significant decrease in subjective reports of pain and dysfunction, and apparent decreases in adhesive processes without further surgery, which are important goals for all patients, but especially for pediatric patients.

  13. [Multiple meningiomas].

    Science.gov (United States)

    Terrier, L-M; François, P

    2016-06-01

    Multiple meningiomas (MMs) or meningiomatosis are defined by the presence of at least 2 lesions that appear simultaneously or not, at different intracranial locations, without the association of neurofibromatosis. They present 1-9 % of meningiomas with a female predominance. The occurrence of multiple meningiomas is not clear. There are 2 main hypotheses for their development, one that supports the independent evolution of these tumors and the other, completely opposite, that suggests the propagation of tumor cells of a unique clone transformation, through cerebrospinal fluid. NF2 gene mutation is an important intrinsic risk factor in the etiology of multiple meningiomas and some exogenous risk factors have been suspected but only ionizing radiation exposure has been proven. These tumors can grow anywhere in the skull but they are more frequently observed in supratentorial locations. Their histologic types are similar to unique meningiomas of psammomatous, fibroblastic, meningothelial or transitional type and in most cases are benign tumors. The prognosis of these tumors is eventually good and does not differ from the unique tumors except for the cases of radiation-induced multiple meningiomas, in the context of NF2 or when diagnosed in children where the outcome is less favorable. Each meningioma lesion should be dealt with individually and their multiple character should not justify their resection at all costs. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  14. Comparative genome-based identification of a cell wall-anchored protein from Lactobacillus plantarum increases adhesion of Lactococcus lactis to human epithelial cells.

    Science.gov (United States)

    Zhang, Bo; Zuo, Fanglei; Yu, Rui; Zeng, Zhu; Ma, Huiqin; Chen, Shangwu

    2015-09-15

    Adhesion to host cells is considered important for Lactobacillus plantarum as well as other lactic acid bacteria (LAB) to persist in human gut and thus exert probiotic effects. Here, we sequenced the genome of Lt. plantarum strain NL42 originating from a traditional Chinese dairy product, performed comparative genomic analysis and characterized a novel adhesion factor. The genome of NL42 was highly divergent from its closest neighbors, especially in six large genomic regions. NL42 harbors a total of 42 genes encoding adhesion-associated proteins; among them, cwaA encodes a protein containing multiple domains, including five cell wall surface anchor repeat domains and an LPxTG-like cell wall anchor motif. Expression of cwaA in Lactococcus lactis significantly increased its autoaggregation and hydrophobicity, and conferred the new ability to adhere to human colonic epithelial HT-29 cells by targeting cellular surface proteins, and not carbohydrate moieties, for CwaA adhesion. In addition, the recombinant Lc. lactis inhibited adhesion of Staphylococcus aureus and Escherichia coli to HT-29 cells, mainly by exclusion. We conclude that CwaA is a novel adhesion factor in Lt. plantarum and a potential candidate for improving the adhesion ability of probiotics or other bacteria of interest.

  15. The effect of interlayer adhesion on the mechanical behaviors of macroscopic graphene oxide papers.

    Science.gov (United States)

    Gao, Yun; Liu, Lu-Qi; Zu, Sheng-Zhen; Peng, Ke; Zhou, Ding; Han, Bao-Hang; Zhang, Zhong

    2011-03-22

    High mechanical performances of macroscopic graphene oxide (GO) papers are attracting great interest owing to their merits of lightweight and multiple functionalities. However, the loading role of individual nanosheets and its effect on the mechanical properties of the macroscopic GO papers are not yet well understood. Herein, we effectively tailored the interlayer adhesions of the GO papers by introducing small molecules, that is, glutaraldehyde (GA) and water molecules, into the gallery regions. With the help of in situ Raman spectroscopy, we compared the varied load-reinforcing roles of nanosheets, and further predicted the Young's moduli of the GO papers. Systematic mechanical tests have proven that the enhancement of the tensile modulus and strength of the GA-treated GO paper arose from the improved load-bearing capability of the nanosheets. On the basis of Raman and macroscopic mechanical tests, the influences of interlayer adhesions on the fracture mechanisms of the strained GO papers were inferred.

  16. Effect of saliva contamination on cementation of orthodontic brackets using different adhesive systems.

    Science.gov (United States)

    Robaski, Aliden-Willian; Pamato, Saulo; Tomás-de Oliveira, Marcelo; Pereira, Jefferson-Ricardo

    2017-07-01

    The enamel condition and the quality of surface are points that need to be considered for achieving optimal efficiency in the treatment with orthodontic brackets. The aim of this study was to assess the immediate bond strength of metallic brackets cemented to dental. Forty human premolars were double-sectioned, placed in PVC matrices and randomly divided into 10 groups (n=8). They received artificial saliva contamination before or after the application of adhesive systems, except for the control groups. The metallic brackets were cemented using two orthodontic cements (Transbond™ Plus Color Change, 3M Unitek e Transbond™ XT Light, 3M Unitek). The specimens were subjected to mechanical shear bond strength testing and classified according to the fracture pattern. The results were analyzed using a two-way ANOVA and Tukey's test for multiple comparisons ( p brackets cemented on the dental enamel. Key words: Bonding, orthodontic brackets, shear bond strength, saliva, adhesive systems.

  17. Heterocellular cadherin connections: coordinating adhesive cues in homeostasis and cancer [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Silvia Fontenete

    2017-06-01

    Full Text Available This short insight covers some of the recent topics relevant to the field of cadherin–catenin adhesion in mediating connections between different cell types, so-called heterotypic or heterocellular connections, in both homeostasis and cancer. These scientific discoveries are increasing our understanding of how multiple cells residing in complex tissues can be instructed by cadherin adhesion receptors to regulate tissue architecture and function and how these cadherin-mediated heterocellular connections spur tumor growth and the acquisition of malignant characteristics in tumor cells. Overall, the findings that have emerged over the past few years are elucidating the complexity of the functional roles of the cadherin–catenin complexes. Future exciting research lies ahead in order to understand the physical basis of these heterotypic interactions and their influence on the behavior of heterogeneous cellular populations as well as their roles in mediating phenotypic and genetic changes as cells evolve through complex environments during morphogenesis and cancer.

  18. Organization of cellular receptors into a nanoscale junction during HIV-1 adhesion.

    Directory of Open Access Journals (Sweden)

    Terrence M Dobrowsky

    2010-07-01

    Full Text Available The fusion of the human immunodeficiency virus type 1 (HIV-1 with its host cell is the target for new antiretroviral therapies. Viral particles interact with the flexible plasma membrane via viral surface protein gp120 which binds its primary cellular receptor CD4 and subsequently the coreceptor CCR5. However, whether and how these receptors become organized at the adhesive junction between cell and virion are unknown. Here, stochastic modeling predicts that, regarding binding to gp120, cellular receptors CD4 and CCR5 form an organized, ring-like, nanoscale structure beneath the virion, which locally deforms the plasma membrane. This organized adhesive junction between cell and virion, which we name the viral junction, is reminiscent of the well-characterized immunological synapse, albeit at much smaller length scales. The formation of an organized viral junction under multiple physiopathologically relevant conditions may represent a novel intermediate step in productive infection.

  19. Amalgam shear bond strength to dentin using single-bottle primer/adhesive systems.

    Science.gov (United States)

    Cobb, D S; Denehy, G E; Vargas, M A

    1999-10-01

    To evaluate the in vitro shear bond strengths (SBS) of a spherical amalgam alloy (Tytin) to dentin using several single-bottle primer/adhesive systems both alone: Single Bond (SB), OptiBond Solo (Sol), Prime & Bond 2.1 (PB), One-Step (OS) and in combination with the manufacturer's supplemental amalgam bonding agent: Single Bond w/3M RelyX ARC (SBX) and Prime & Bond 2.1 w/Amalgam Bonding Accessory Kit (PBA). Two, three-component adhesive systems, Scotchbond Multi-Purpose (SBMP) and Scotchbond Multi-Purpose Plus w/light curing (S + V) and w/o light curing (S+) were used for comparison. One hundred eight extracted human third molars were mounted lengthwise in phenolic rings with acrylic resin. The proximal surfaces were ground to expose a flat dentin surface, then polished to 600 grit silicon carbide paper. The teeth were randomly assigned to 9 groups (n = 12), and dentin surfaces in each group were treated with an adhesive system according to the manufacturer's instructions, except for S + V specimens, where the adhesive was light cured for 10 s before placing the amalgam. Specimens were then secured in a split Teflon mold, having a 3 mm diameter opening and amalgam was triturated and condensed onto the treated dentin surfaces. Twenty minutes after condensation, the split mold was separated. Specimens were placed in distilled water for 24 hrs, then thermocycled (300 cycles, between 5 degrees C and 55 degrees C, with 12 s dwell time). All specimens were stored in 37 degrees C distilled water for 7 days, prior to shear strength testing using a Zwick Universal Testing Machine at a cross-head speed of 0.5 mm/min. The highest to the lowest mean dentin shear bond strength values (MPa) for the adhesive systems tested were: S + V (10.3 +/- 2.3), SBX (10.2 +/- 3.5), PBA, (6.4 +/- 3.6), SOL (5.8 +/- 2.5), SBMP (5.7 +/- 1.8), S+ (4.8 +/- 2.3), PB (2.7 +/- 2.6), SB (2.7 +/- 1.1) and OS (2.5 +/- 1.8). One-way ANOVA and Duncan's Multiple Range Test indicated significant

  20. Preparation and Properties of Cassava Starch-based Wood Adhesives

    Directory of Open Access Journals (Sweden)

    Qing Xu

    2016-06-01

    Full Text Available A biodegradable, environmentally friendly starch-based wood adhesive with cassava starch as a raw material and butyl acrylate (BA as a co-monomer was synthesized. Results revealed that this cassava starch-based wood adhesive (SWA was more stable than corn starch-based wood adhesive, and its bonding performance was close to that of commercial PVAc emulsion, even after 90 days of storage. Further analysis found that the improved stability of the adhesive could be attributed to its low minimum film forming temperature (MFFT and glass transition temperature (Tg of cassava starch. Moreover, the amount of total volatile organic compounds (TVOCs emitted by the cassava starch-based wood adhesive were much lower than the Chinese national standard control criteria. Therefore, cassava SWA might be a potential alternative to traditional petrochemical-based wood adhesives.

  1. Adhesion of streptococcus rattus and streptococcus mutans to metal surfaces

    International Nuclear Information System (INIS)

    Branting, C.; Linder, L.E.; Sund, M.-L.; Oden, A.; Wiatr-Adamczak, E.

    1988-01-01

    The adhesion of Streptococcus rattus BHT and Streptococcus mutans IB to metal specimens of amalgam, silver, tin and copper was studied using (6- 3 H) thymidine labeled cells. In the standard assay the metal specimens were suspended by a nylon thread in an adhesion solution containing a chemically defined bacterial growth medium (FMC), sucrose, and radiolabeled bacteria. Maximum amounts of adhering bacteria were obtained after about 100 min of incubation. Saturation of the metal specimens with bacteria was not observed. Both strains also adhered in the absence of sucrose, indicating that glucan formation was not necessary for adhesion. However, in the presence of glucose, adhesion was only 26-45% of that observed in the presence of equimolar sucrose. Sucrose-dependent stimulation of adhesion seemed to be due to increased cell-to-cell adhesion capacity. Isolated radiolabeled water-insoluble and water-soluble polysaccharides produced from sucrose by S. rattus BHT were not adsorbed to the metal surfaces. (author)

  2. Adhesion of streptococcus rattus and streptococcus mutans to metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Branting, C.; Linder, L.E.; Sund, M.-L.; Oden, A.; Wiatr-Adamczak, E.

    1988-01-01

    The adhesion of Streptococcus rattus BHT and Streptococcus mutans IB to metal specimens of amalgam, silver, tin and copper was studied using (6-/sup 3/H) thymidine labeled cells. In the standard assay the metal specimens were suspended by a nylon thread in an adhesion solution containing a chemically defined bacterial growth medium (FMC), sucrose, and radiolabeled bacteria. Maximum amounts of adhering bacteria were obtained after about 100 min of incubation. Saturation of the metal specimens with bacteria was not observed. Both strains also adhered in the absence of sucrose, indicating that glucan formation was not necessary for adhesion. However, in the presence of glucose, adhesion was only 26-45% of that observed in the presence of equimolar sucrose. Sucrose-dependent stimulation of adhesion seemed to be due to increased cell-to-cell adhesion capacity. Isolated radiolabeled water-insoluble and water-soluble polysaccharides produced from sucrose by S. rattus BHT were not adsorbed to the metal surfaces.

  3. Immunotherapeutic modulation of intraperitoneal adhesions by Asparagus racemosus.

    Directory of Open Access Journals (Sweden)

    Rege N

    1989-10-01

    Full Text Available The hypothesis that macrophages appear to play a pivotal role in the development of intraperitoneal adhesions and that modulation of macrophage activity, therefore, is likely to provide a tool for prevention of adhesions, was tested in the present study. Effect of Asparagus racemosus, an indigenous agent with immunostimulant properties, was evaluated in an animal model of intraperitoneal adhesions induced by caecal rubbing. Animals were sacrificed 15 days following surgery. The peritoneal macrophages were collected to assess their activity. At the same time, peritoneal cavity was examined for the presence of adhesions, which were graded. A significant decrease was observed in the adhesion scores attained by animals receiving Asparagus racemosus. This was associated with significant increase in the activity of macrophages (70.1 +/- 2.52, compared to that in surgical controls (53.77 +/- 10.8. These findings support our hypothesis and provide a novel approach for the prevention and management of post-operative adhesions.

  4. Syndecan-4 and integrins: combinatorial signaling in cell adhesion

    DEFF Research Database (Denmark)

    Couchman, J R; Woods, A

    1999-01-01

    It is now becoming clear that additional transmembrane components can modify integrin-mediated adhesion. Syndecan-4 is a transmembrane heparan sulfate proteoglycan whose external glycosaminoglycan chains can bind extracellular matrix ligands and whose core protein cytoplasmic domain can signal...... during adhesion. Two papers in this issue of JCS demonstrate, through transfection studies, that syndecan-4 plays roles in the formation of focal adhesions and stress fibers. Overexpression of syndecan-4 increases focal adhesion formation, whereas a partially truncated core protein that lacks the binding...... site for protein kinase C(&agr;) and phosphatidylinositol 4, 5-bisphosphate acts as a dominant negative inhibitor of focal adhesion formation. Focal adhesion induction does not require interaction between heparan sulfate glycosaminoglycan and ligand but can occur when non-glycanated core protein...

  5. Probing bacterial adhesion at the single-cell level

    DEFF Research Database (Denmark)

    Zeng, Guanghong; Müller, Torsten; Meyer, Rikke Louise

    be considered. We have developed a simple and versatile method to make single-cell bacterial probes for measuring single cell adhesion by force spectroscopy using atomic force microscopy (AFM). A single-cell probe was readily made by picking up a bacterial cell from a glass surface by approaching a tipless AFM...... cantilever coated with the commercial cell adhesive CellTakTM. We applied the method to study adhesion of living cells to abiotic surfaces at the single-cell level. Immobilisation of single bacterial cells to the cantilever was stable for several hours, and viability was confirmed by Live/Dead staining...... on the adhesion force, we explored the bond formation and adhesive strength of four different bacterial strains towards three abiotic substrates with variable hydrophobicity and surface roughness. The adhesion force and final rupture length were dependent on bacterial strains, surfaces properties, and time...

  6. Insights into adhesion of abalone: A mechanical approach.

    Science.gov (United States)

    Li, Jing; Zhang, Yun; Liu, Sai; Liu, Jianlin

    2018-01-01

    Many living creatures possess extremely strong capability of adhesion, which has aroused great attention of many scientists and engineers. Based on the self-developed equipment, we measured the normal and shear adhesion strength of the abalone underwater and out of water on different contact surfaces. It is found that the adhesion force of the abalone can amount to 200 or 300 times its body weight. The effects of wettability and roughness of the surface, and the frictional coefficient of mucus on the adhesion strength have been discussed. The theoretical calculation manifests that the normal adhesion force mainly stems from the suction pressure, van der Waals force and capillary force of the pedal, and their limit values are given. These findings may provide some inspirations to engineer new-typed materials, micro-devices, adhesives and medicine. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Influence of hydrostatic pulpal pressure on the microtensile bond strength of all-in-one self-etching adhesives.

    Science.gov (United States)

    Hosaka, Keiichi; Nakajima, Masatoshi; Monticelli, Francesca; Carrilho, Marcela; Yamauti, Monica; Aksornmuang, Juthatip; Nishitani, Yoshihiro; Tay, Franklin R; Pashley, David H; Tagami, Junji

    2007-10-01

    To evaluate the microtensile bond strength (microTBS) of two all-in-one self-etching adhesive systems and two self-etching adhesives with and without simulated hydrostatic pulpal pressure (PP). Flat coronal dentin surfaces of extracted human molars were prepared. Two all-in-one self-etching adhesive systems, One-Up Bond F (OBF; Tokuyama) and Clearfil S3 Bond (Tri-S, Kuraray Medical) and two self-etching primer adhesives, Clearfil Protect Bond (PB; Kuraray) and Clearfil SE Bond (SE; Kuraray) were applied to the dentin surfaces according to manufacturers' instructions under either a pulpal pressure (PP) of zero or 15 cm H2O. A hybrid resin composite (Clearfil AP-X, Kuraray) was used for the coronal buildup. Specimens bonded under PP were stored in water at 37 degrees C under 15 cm H2O for 24 h. Specimens not bonded under PP were stored under a PP of zero. After storage, the bonded specimens were sectioned into slabs that were trimmed to hourglass-shaped specimens, and were subjected to microtensile bond testing (microTBS). The bond strength data were statistically analyzed using two-way ANOVA and the Holm-Sidak method for multiple comparison tests (alpha = 0.05). The surface area percentage of different failure modes for each material was also statistically analyzed with three one-way ANOVAs and Tukey's multiple comparison tests. The microTBS of OBF and Tri-S fell significantly under PP. However, in the, PB and SE bonded specimens under PP, there were no significant differences compared with the control groups without PP. The microTBS of the two all-in-one adhesive systems decreased when PP was applied. However, the microTBS of both self-etching primer adhesives did not decrease under PP.

  8. The effect of acute physical and mental stress on soluble cellular adhesion molecule concentration.

    Science.gov (United States)

    Crabb, E Blake; Franco, R Lee; Caslin, Heather L; Blanks, Anson M; Bowen, Mary K; Acevedo, Edmund O

    2016-07-15

    This study investigated the impact of acute physical and mental stress on serum concentrations of vascular cell adhesion molecule (VCAM)-1 and CX3CL1/fractalkine. Male volunteers (n=20; 21.3±0.55years of age) completed a graded treadmill test to exhaustion and a 20-minute mental stress task (Stroop Color-Word Test, mental arithmetic) on separate, non-consecutive days. Heart rate (HR) was measured at baseline and throughout exercise and mental stress. Blood was collected at baseline (PRE), immediately following (POST) and 30min after (POST30) exercise and mental stress. Soluble VCAM-1 and fractalkine were quantified in participant serum via enzyme-linked immunosorbent assays. Both treadmill exercise and the mental stress task significantly increased participant HR; although, exercise resulted in a substantially greater increase in participant HR compared to mental stress (197.82±11.99 vs. 38.67±3.10% [pstress task did not significantly alter serum VCAM-1 or fractalkine at any time point. In conclusion, maximal aerobic exercise results in a significant elevation of the soluble adhesion molecules VCAM-1 and fractalkine in the serum of adult males that does not occur following laboratory-induced mental stress. The findings of the current investigation may suggest a novel protective role for acute aerobic exercise in vascular health via exercise-induced CAM proteolysis. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Bonding Durability of Four Adhesive Systems

    Directory of Open Access Journals (Sweden)

    Leila Atash Biz Yeganeh

    2016-04-01

    Full Text Available Objectives: This study aimed to compare the durability of four adhesive systems by assessing their microtensile bond strength (MTBS and microleakage during six months of water storage.Materials and Methods: A total of 128 human third molars were used. The adhesives tested were Scotch Bond Multipurpose (SBMP, Single Bond (SB, Clearfil-SE bond (CSEB, and All-Bond SE (ABSE. After sample preparation for MTBS testing, the microspecimens were subjected to microtensile tester after one day and six months of water storage. For microleakage evaluation, facial and lingual class V cavities were prepared and restored with composite. After thermocycling, microleakage was evaluated. Bond strength values were subjected to one-way ANOVA and Tamhane’s test, and the microleakage data were analyzed by the Kruskal-Wallis, Dunn, Mann Whitney and Wilcoxon tests (P<0.05.Results: Single Bond yielded the highest and ABSE yielded the lowest bond strength at one day and six months. Short-term bond strength of SBMP and CSEB was similar. After six months, a significant decrease in bond strength was observed in ABSE and SBMP groups. At one day, ABSE showed the highest microleakage at the occlusal margin; however, at the gingival margin, there was no significant difference among groups. Long-term microleakage of all groups at the occlusal margins was similar, whilst gingival margins of SBMP and SB showed significantly higher microleakage.Conclusion: The highest MTBS and favorable sealability were obtained by Clearfil SE bond. Water storage had no effect on microleakage of self-etch adhesives at the gingival margin or MTBS of CSEB and SB. 

  10. Multiple sclerosis

    DEFF Research Database (Denmark)

    Stenager, Egon; Stenager, E N; Knudsen, Lone

    1994-01-01

    In a cross-sectional study of 117 randomly selected patients (52 men, 65 women) with definite multiple sclerosis, it was found that 76 percent were married or cohabitant, 8 percent divorced. Social contacts remained unchanged for 70 percent, but outgoing social contacts were reduced for 45 percent......, need for structural changes in home and need for pension became greater with increasing physical handicap. No significant differences between gender were found. It is concluded that patients and relatives are under increased social strain, when multiple sclerosis progresses to a moderate handicap...

  11. Self-recognition of high-mannose type glycans mediating adhesion of embryonal fibroblasts.

    Science.gov (United States)

    Yoon, Seon-Joo; Utkina, Natalia; Sadilek, Martin; Yagi, Hirokazu; Kato, Koichi; Hakomori, Sen-itiroh

    2013-07-01

    High-mannose type N-linked glycan with 6 mannosyl residues, termed "M6Gn2", displayed clear binding to the same M6Gn2, conjugated with ceramide mimetic (cer-m) and incorporated in liposome, or coated on polystyrene plates. However, the conjugate of M6Gn2-cer-m did not interact with complex-type N-linked glycan with various structures having multiple GlcNAc termini, conjugated with cer-m. The following observations indicate that hamster embryonic fibroblast NIL-2 K cells display homotypic autoadhesion, mediated through the self-recognition capability of high-mannose type glycans expressed on these cells: (i) NIL-2 K cells display clear binding to lectins capable of binding to high-mannose type glycans (e.g., ConA), but not to other lectins capable of binding to other carbohydrates (e.g. GS-II). (ii) NIL-2 K cells adhere strongly to plates coated with M6Gn2-cer-m, but not to plates coated with complex-type N-linked glycans having multiple GlcNAc termini, conjugated with cer-m; (iii) degree of NIL-2 K cell adhesion to plates coated with M6Gn2-cer-m showed a clear dose-dependence on the amount of M6Gn2-cer-m; and (iv) the degree of NIL-2 K adhesion to plates coated with M6Gn2-cer-m was inhibited in a dose-dependent manner by α1,4-L-mannonolactone, the specific inhibitor in high-mannose type glycans addition. These data indicate that adhesion of NIL-2 K is mediated by self-aggregation of high mannose type glycan. Further studies are to be addressed on auto-adhesion of other types of cells based on self interaction of high mannose type glycans.

  12. Study of the adhesion interaction using 51Cr labelling method between the myeloma cell lines and the endothelial cells

    International Nuclear Information System (INIS)

    Zhang Xueguang; Wang Jiangfang; Mao Zijun

    1995-06-01

    Using 51 Cr labelled multiple myeloma (MM) cell lines U266/XG-7, the regulatory effect of cytokines on the adhesive interaction between myeloma-cell lines U266/XG-7 and the endothelial cells, and the effects of these cytokines on expression of adhesion molecules and secretion of other cytokines were studied. The experimental results were as follows: (1) IL-6 and IL-6 Rgp 130-associated growth factors (such as GM-CSF) are not only myeloma cell growth factors, but also can enhance the adhesion between MM cells and endothelial cells and thus facilitated the metastasis of tumor cells. (2) Cytokines could induce increase in the expression of CD54 and CD44 on the endothelial cells and the secretion of IL-6 and TNF by the endothelial cells. On the other hand, the adhesion could also cause the change of CD11a, CD54, CD44 and VLA-4 on surface of myeloma cells XG-7. Finally, the interaction between MM cells and stromal cells from murine bone marrow could rapidly induce autocrine of IL-6 in human IL-6-dependent MM cells. (3) The interaction between stromal cells and tumor cells regulated by the cytokines and adhesion molecules was a key element in the pathogenesis and development of human MM. Among these factors, VLA-4 might be one of the molecules involved in U266/XG-7-EC interaction. (5 tabs., 8 figs.)

  13. Adhesion aspects in MEMS/NEMS

    CERN Document Server

    Kim, Seong H; Mittal, Kash L

    2012-01-01

    Phenomena associated with the adhesion interaction of surfaces have been a critical aspect of micro- and nanosystem development and performance since the first MicroElectroMechanicalSystems(MEMS) were fabricated. These phenomena are ubiquitous in nature and are present in all systems, however MEMS devices are particularly sensitive to their effects owing to their small size and limited actuation force that can be generated. Extension of MEMS technology concepts to the nanoscale and development of NanoElectroMechanicalSystems(NEMS) will result in systems even more strongly influenced by surface

  14. BUCCAL DRUG DELIVERY USING ADHESIVE POLYMERIC PATCHES

    OpenAIRE

    R. Venkatalakshmi

    2012-01-01

    The buccal mucosa has been investigated for local drug therapy and the systemic delivery of therapeutic peptides and other drugs that are subjected to first-pass metabolism or are unstable within the rest of the gastrointestinal tract. The mucosa of the oral cavity presents a formidable barrier to drug penetration, and one method of optimizing drug delivery is by the use of adhesive dosage forms and the mucosa has a rich blood supply and it is relatively permeable. The buccal mucosa is very s...

  15. EB application in pressure sensitive adhesives

    International Nuclear Information System (INIS)

    Hisashi Itoh; Ichiro Enomoto

    1999-01-01

    Two kinds of pressure sensitive adhesives (PSA's), that were formulations of radiation cross-linkable styrene-isoprene block copolymer (SIS) and complete hydrogenated aliphatic tackifying resin or non-hydrogenated, were prepared and the electron beam (EB) irradiation effect on these PSA performances such as peel strength against some kinds of adherends was studied. The results from measuring of PSA performance exhibit the close correlation between EB irradiation effect of these and the miscibility of the tackifying resin against SIS. Further it was clarified that PSA performance was influenced by the surface tension of adherends

  16. Self Diagnostic Adhesive for Bonded Joints in Aircraft Structures

    Science.gov (United States)

    2016-10-04

    validated under the fatigue /dynamic loading condition. 3) Both SEM (Spectral Element Modeling) and FEM (Finite Element Modeling) simulation of the...between input voltage and output charge provide the real and imaginary impedance as illustrated in Figure 3. (a) Adhesive + plate (ΩS) PZT (ΩP...3 m m 0.45mm Adhesive 3.18mm dia. PZT disc (0.25mm thick) 8 Self-Diagnostic Adhesive for Bonded Joints in Aircraft Structures

  17. Control and prevention of peritoneal adhesions in gynecologic surgery.

    Science.gov (United States)

    2006-11-01

    Postoperative adhesion formation is a natural consequence of surgical tissue trauma and healing and may result in infertility, pain, and bowel obstruction. Microsurgical principles and minimally invasive surgery may help decrease adhesion formation, but anti-inflammatory agents and peritoneal instillates have no demonstrable benefit. Although some surgical barriers are effective for reducing postoperative adhesions, none has been shown to improve fertility or to decrease pain or the incidence of postoperative bowel obstruction.

  18. Epoxy Nanocomposites - Curing Rheokinetics, Wetting and Adhesion to Fibers

    International Nuclear Information System (INIS)

    Ilyin, S. O.; Kotomin, S. V.; Kulichikhin, V. G.

    2010-01-01

    Epoxy nanocomposites considered as challenging polymeric matrix for advanced reinforced plastics. Nanofillers change rheokinetics of epoxy resin curing, affect wetting and adhesion to aramid and carbon fibers. In all cases extreme dependence of adhesive strength vs filler content in the binder was observed. New experimental techniques were developed to study wettability and fiber-matrix adhesion interaction, using yarn penetration path length, aramid fiber knot pull-up test and electrical admittance of the fracture surface of CFRP.

  19. Thin film adhesion by nanoindentation-induced superlayers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gerberich, William W.; Volinsky, A.A.

    2001-06-01

    This work has analyzed the key variables of indentation tip radius, contact radius, delamination radius, residual stress and superlayer/film/interlayer properties on nanoindentation measurements of adhesion. The goal to connect practical works of adhesion for very thin films to true works of adhesion has been achieved. A review of this work titled ''Interfacial toughness measurements of thin metal films,'' which has been submitted to Acta Materialia, is included.

  20. Evaluation of an Experimental Adhesive Resin for Orthodontic Bonding

    Science.gov (United States)

    Durgesh, B. H.; Alkheraif, A. A.; Pavithra, D.; Hashem, M. I.; Alkhudhairy, F.; Elsharawy, M.; Divakar, D. D.; Vallittu, P. K.; Matinlinna, J. P.

    2017-07-01

    The aim of this study was to evaluate in vitro the effect of an experimental adhesive resin for orthodontic bonding by measuring some the chemical and mechanical properties. The resin demonstrated increased values of nanohardness and elastic modulus, but the differences were not significant compared with those for the Transbond XT adhesives. The experimental adhesive resin could be a feasible choice or a substitute for the traditional bis-GMA-based resins used in bonding orthodontic attachments.