ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTWet chemical approaches to the characterization of organic surfaces: self-assembled monolayers, wetting, and the physical-organic chemistry of the solid-liquid interfaceGeorge M. Whitesides and Paul E. LaibinisCite this: Langmuir 1990, 6, 1, 87–96Publication Date (Print):January 1, 1990Publication History Published online1 May 2002Published inissue 1 January 1990https://pubs.acs.org/doi/10.1021/la00091a013https://doi.org/10.1021/la00091a013research-articleACS PublicationsRequest reuse permissionsArticle Views4755Altmetric-Citations792LEARN 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
Cross-sectional studies suggest that women who have irregular menstrual cycles and hyperandrogenism may be at increased risk for cardiovascular disease (CVD). However, prospective data are lacking on the relationship between menstrual cycle irregularity and subsequent CVD risk. The objective of this study was to assess prospectively the risk for coronary heart disease (CHD) and stroke associated with a history of irregular menstrual cycles. The study design was a prospective cohort study of 82,439 female nurses who provided information in 1982 on prior menstrual regularity (at ages 20-35 yr) and were followed through 1996 for cardiovascular events. Incident reports of nonfatal myocardial infarction, fatal CHD, and nonfatal and fatal stroke were made. Medical records were reviewed for confirmation. During 14 yr (1,155,915 person-yr) of follow-up, there were 1417 incident cases of CHD and 838 incident cases of stroke, including 471 cases of ischemic stroke. Compared with women reporting a history of very regular menstrual cycles, women reporting usually irregular or very irregular cycles had an increased risk for nonfatal or fatal CHD [age-adjusted relative risks (RR), 1.25 and 1.67, respectively; 95% confidence intervals (CI), 1.07-1.47 and 1.35-2.06, respectively]. Increased risks for CHD associated with prior cycle irregularity remained significant after adjustment for body mass index and several potential confounders. There was a nonsignificant increase in overall stroke risk (RR, 1.30; 95% CI = 0.97-1.74) and in ischemic stroke risk (RR, 1.40; 95% CI = 0.97-2.04) associated with very irregular cycles. Menstrual cycle irregularity may be a marker of metabolic abnormalities predisposing to increased risk for CVD.
We study the stability of steady sliding between elastically deformable continua using rate and state dependent friction laws. That is done for both elastically identical and elastically dissimilar solids. The focus is on linearized response to perturbations of steady-state sliding, and on studying how the positive direct effect (instantaneous increase or decrease of shear strength in response to a respective instantaneous increase or decrease of slip rate) of those laws allows the existence of a quasi-static range of response to perturbations at sufficiently low slip rate. We discuss the physical basis of rate and state laws, including the likely basis for the direct effect in thermally activated processes allowing creep slippage at asperity contacts, and estimate activation parameters for quartzite and granite. Also, a class of rate and state laws suitable for variable normal stress is presented. As part of the work, we show that compromises from the rate and state framework for describing velocity-weakening friction lead to paradoxical results, like supersonic propagation of slip perturbations, or to ill-posedness, when applied to sliding between elastically deformable solids. The case of sliding between elastically dissimilar solids has the inherently destabilizing feature that spatially inhomogeneous slip leads to an alteration of normal stress, hence of frictional resistance. We show that the rate and state friction laws nevertheless lead to stability of response to sufficiently short wavelength perturbations, at very slow slip rates. Further, for slow sliding between dissimilar solids, we show that there is a critical amplitude of velocity-strengthening above which there is stability to perturbations of all wavelengths.
No abstract is provided for this article.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemically etched silicon surfaces viewed at the atomic level by force microscopyYun Kim and Charles M. LieberCite this: J. Am. Chem. Soc. 1991, 113, 6, 2333–2335Publication Date (Print):March 1, 1991Publication History Published online1 May 2002Published inissue 1 March 1991https://pubs.acs.org/doi/10.1021/ja00006a079https://doi.org/10.1021/ja00006a079research-articleACS PublicationsRequest reuse permissionsArticle Views152Altmetric-Citations31LEARN 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
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Microfluidic paper-based analytical devices (μPADs) are a new class of point-of-care diagnostic devices that are inexpensive, easy to use, and designed specifically for use in developing countries. (To listen to a podcast about this feature, please go to the Analytical Chemistry multimedia page at pubs.acs.org/page/ancham/audio/index.html.)