A study is presented of delamination at the interface between a thin elastic film bonded to a substrate under conditions in which the film is subject to equi-biaxial compression. The focus is on initially circular delaminations. When the initial delamination is sufficiently large it buckles away from the substrate producing a blister which in turn induces a driving force on the interface crack tip. A two-part theoretical analysis of the coupled buckling/fracture problem is conducted: the axisymmetric growth of the circular blister, and the stability of the circular blister to nonaxisymmetric perturbations of the interface crack front. A simple criterion is identified which excludes the possibility of wide-spread delamination. Experiments are reported for a model film/substrate system (mica bonded to aluminum) chosen to allow visualization of the interface and to permit compressive stresses in the film to be generated over the full range of interest by exploiting the large thermal expansion mismatch of the system. The experiments bear out the theoretical prediction of a regime of axisymmetric growth which gives way to nonaxisymmetric blisters after a blister becomes sufficiently large. The study suggests that the wavy-circular and worm-like blister morphologies which are usually observed for delaminated films are a manifestation of the configurational instability of the interface crack front.
A small revolution is remaking the world. The only problem is, we can't see it. This book uses dazzling images and evocative descriptions to reveal the virtually invisible realities and possibilities of nanoscience. An introduction to the science and technology of small things, No Small Matter explains science on the nanoscale. Authors Felice C. Frankel and George M. Whitesides offer an overview of recent scientific advances that have given us our ever-shrinking microtechnology - for instance, an information processor connected by wires only 1,000 atoms wide. They describe the new methods used to study nanostructures, suggest ways of understanding their often bizarre behavior, and outline their uses in technology. This book explains the various means of making nanostructures and speculates about their importance for critical developments in information processing, computation, biomedicine, and other areas. No Small Matter considers both the benefits and the risks of nano/microtechnology - from the potential of quantum computers and single-molecule genomic sequencers to the concerns about self-replicating nanosystems. By making the practical and probable realities of nanoscience as comprehensible and clear as possible, the book provides a unique vision of work at the very boundaries of modern science.
A study is presented of the post-buckling behaviour and imperfection sensitivity of complete spherical shells subject to uniform external pressure. The study builds on and extends the major contribution to spherical shell buckling by Koiter in the 1960s. Numerical results are presented for the axisymmetric large deflection behaviour of perfect spheres followed by an extensive analysis of the role axisymmetric imperfections play in reducing the buckling pressure. Several types of middle surface imperfections are considered including dimple-shaped undulations and sinusoidal-shaped equatorial undulations. Buckling occurs either as the attainment of a maximum pressure in the axisymmetric state or as a non-axisymmetric bifurcation from the axisymmetric state. Several new findings emerge: the abrupt mode localization that occurs immediately after the onset of buckling, the existence of an apparent lower limit to the buckling pressure for realistically large imperfections, and comparable reductions of the buckling pressure for dimple and sinusoidal equatorial imperfections.
This report describes the use of surface plasmon spectroscopy to study the effect of surface wettability on the nonspecific adsorption of proteins and detergents to self-assembled monolayers (SAMs) of alkanethiolates on gold. The adsorption of both proteins and detergents to uncharged SAMs showed a general dependence on the wettability of the surface as determined by the contact angle of water on the SAM under cyclooctane (θco). The effect of the wettability of the SAMs on the adsorption of sodium dodecyl sulfate (SDS) was dependent on whether micelles were present. Above the critical micelle concentration (cmc), SDS adsorbed only on surfaces that gave contact angles with values of cos θco < 0 (i.e., the transfer of the surface from water to cyclooctane has a favorable free energy). Below the cmc, the requirement for adsorption was much more stringent: SDS adsorbed only on the surfaces that gave values of cos θco < −0.9. Similarly, the effect of the wettability of the SAMs on the adsorption of proteins showed a dependence on the size of the proteins. The smaller proteins tested (ribonuclease A and lysozyme) adsorbed only on the least wettable surfaces tested (cos θco < −0.83). The larger proteins tested (pyruvate kinase, fibrinogen, and γ-globulin) also adsorbed best to the least wettable surfaces, but adsorbed to some extent on almost all the surfaces; the single exception was a SAM presenting hexa(ethylene glycol) groups at the surface, to which no protein adsorbed. Films of adsorbed proteins were desorbed from the SAMs by treatment with detergent.
It has recently been suggested that an atopic phenotype may already be programmed in utero. We examine here the association between prenatal factors and the subsequent development of allergic rhinitis and eczema among offspring.The analyses were based on 8088 children in a population-based prospective birth cohort started in northern Finland in 1985-6.The prevalences of allergic rhinitis and allergic eczema by the age of 7 years among 8088 children were 3.3% and 6.7%, respectively. The results indicate that low parity, febrile infections in pregnancy, and the use of contraceptives before pregnancy increased the risk of allergic disorders among children. Bleeding in the first trimester and a greater weight gain during pregnancy appeared to be risk factors for rhinitis only. Children whose mothers experienced infections in the first trimester had ORs of 2.65 (95% CI 1.50-4.69) for rhinitis and 1.63 (95% CI 1.00-2.69) for eczema after adjustment for potential confounders.Obstetric complications and infection in pregnancy may increase the risk of allergic disorders among the offspring.
<h3>Abstract</h3> World Health Organization has declared human monkeypox as a global health emergency on 23 July 2022. This indicates that the outbreak poses a serious risk to global health and requires a united worldwide response to stop the virus from spreading and possibly turning into a pandemic. Vaccines can play a vital role in this context, contributing to pre- and post-exposure prophylaxis. The aim of our rapid review was to go through the background of the vaccine approach for human monkeypox over the years and to find out what current guidelines are highlighting relating to it. 22 relevant published articles from MEDLINE bibliographic database and 8 vaccine recommendations from manual searching have been deliberated here. The significant synopsis of this review is that the smallpox vaccine is the only immunization option for monkeypox so far, and it is up to 85% effective to prevent the infection. Third-generation smallpox vaccines are advised over first and second generations due to their minimal side effects. Healthcare providers and lab professionals at risk are on the priority list to get vaccinated, as well as pregnant women or lactating mothers, immunocompromised or chronic ill patients, can get vaccinated if they are surely exposed to the monkeypox infection. Lastly, JYNNEOS/IMVAMUNE is the current most preferable smallpox vaccine that is highly advised for the latest outbreak of human monkeypox but more clinical trial on humans should be conducted to evaluate its safety, efficacy, and adverse events.
It has been well documented that obesity is a major risk factor for the development of the hypertensive state. The correlation between body mass index and blood pressure level is well established. Nevertheless, the exact mechanisms which contribute to obesity-related hypertension remain poorly understood. In the last years, we have realized that the white adipose tissue is not just an inert organ for nutrient storage and isolation but rather depending on the body mass index the biggest endocrinological organ. Thus, the possible contribution of adipokines to the blood pressure elevation becomes an attractive hypothesis to explain the hypertensive state that often occurs in obesity. In this review, we consider direct and indirect effects of main adipokines on structural and functional changes in the cardiovascular system.
No abstract is provided for this article.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRelative Signs of the 31P-1H and 31P-C-1H Nuclear Magnetic Resonance Coupling ConstantsGeorge M. Whitesides, Jesse L. Beauchamp, and John D. RobertsCite this: J. Am. Chem. Soc. 1963, 85, 17, 2665–2666Publication Date (Print):September 1, 1963Publication History Published online1 May 2002Published inissue 1 September 1963https://pubs.acs.org/doi/10.1021/ja00900a032https://doi.org/10.1021/ja00900a032research-articleACS PublicationsRequest reuse permissionsArticle Views318Altmetric-Citations27LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
