6,332 publications from this institution
Background. Deterioration in school achievement may pre-date adult mental disorders. We studied the association between compulsory school performance and later onset hospital-treated psychiatric morbidity experienced by the Northern Finland 1966 Birth Cohort ( N =11017) in adult life. Methods. School performance was operationalized in two ways: school class level (in normal, i.e. age-appropriate class v . not in normal class, i.e. class below age level or in special school) at the age of 14, and marks for individual school subjects at the age of 16. School class level was ascertained by postal questionnaire and school marks from national application register. These were linked to data on psychiatric morbidity from the National Finnish Hospital Discharge Register. By the end of 1994 (between ages 16 and 28 years), a total of 383 subjects had psychiatric illness. DSM-III-R diagnoses were grouped into three categories: schizophrenia; other psychoses; and non-psychotic disorders. The remaining population with no psychiatric hospitalization served as a single comparison group. School class level and values of school marks in the three diagnostic categories were each compared with this comparison group, stratified by sex. Results. In the comparison group 6·8% of boys and 3·4% of girls were not in their normal class. In all the diagnosis groups the proportions of those not in normal class were from 2 to 8 times higher than in the comparison group. A majority of those not in normal class and having psychiatric diagnosis were intellectually subnormal (IQ<85). Among adolescents who later developed non-psychotic disorders, means of school marks were lower ( P <0·05, adjusted for social class and place of residence) than in the comparison group. Lower marks were not found in categories schizophrenia or other psychoses. Logistic regression analysis confirmed these findings after adjustment for confounding factors. Conclusions. Not being in the normal class at age 14 predicted future hospital-treated disorders, but low school marks at age 16 predicted only non-psychotic disorders. These findings may be an early manifestation of the disorders themselves, or a marker of vulnerability or other risk factors. The mechanisms may differ between diagnoses.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSN2 displacements and reductive coupling of ketones with olefins in N,N-diethylacetamide and N-ethylpyrrolidoneAllan F. Sowinski and George M. WhitesidesCite this: J. Org. Chem. 1979, 44, 14, 2369–2376Publication Date (Print):July 1, 1979Publication History Published online1 May 2002Published inissue 1 July 1979https://pubs.acs.org/doi/10.1021/jo01328a008https://doi.org/10.1021/jo01328a008research-articleACS PublicationsRequest reuse permissionsArticle Views571Altmetric-Citations60LEARN 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
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTApparent fluxionality in diethyl(triethylphosphine)platinum(II), a coordinatively unsaturated intermediate in .beta.-hydride eliminationThomas J. McCarthy, Ralph G. Nuzzo, and George M. WhitesidesCite this: J. Am. Chem. Soc. 1981, 103, 7, 1676–1678Publication Date (Print):April 1, 1981Publication History Published online1 May 2002Published inissue 1 April 1981https://pubs.acs.org/doi/10.1021/ja00397a014https://doi.org/10.1021/ja00397a014research-articleACS PublicationsRequest reuse permissionsArticle Views146Altmetric-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
Capacitance wave probes have been traditionally used at DTMB for measuring the wave heights in the Kelvin wake of towed surface ship models. Two new wave height measurement systems have recently been developed at DTMB: a laser wave height probe, using a linear array of charged couple devices, and a surface sensing mechanical probe. These devices represent improvements to the capacitance probes in the form of reduced and/or eliminated susceptibility to contamination and increased frequency response. In this paper, the physics of operation of the measurement systems and design considerations for their optimization will be discussed. Measurements of the free surface in a regular wave field, and for longitudinal wavecuts with a ship-model, over a wide Froude number range, have been made. Based on experimental results, evaluations of the various attributes and shortcomings of each type of probe will be made.
The mechanical behavior of thin elastic films deposited onto structural alloys plays a critical role in determining film durability. This paper presents analysis of an impression experiment designed to evaluate some of the relevant properties of these films. The modeling provides quantitative strain information which can be used to estimate the fracture toughness of the film, the static friction coefficient of the surface and the constitutive behavior of the substrate. Results are presented for radial and circumferential strain distributions in the film relevant to the interpretation of cracking patterns. Additionally, load-displacement curves are provided that may be used to evaluate the plastic properties of the substrate. To facilitate estimates of the film cracking strain through correlation with experiments, the radial strain distributions are presented as functions of impression depth, yield strain and hardening exponent.
liams's letter (10 October, p 987) about the management of gastrointestinal bleeding, and agree entirely with your comment.I would take exception, however, to his last sentence, which implies that an "alcoholic binge" may lead to an upper gastrointestinal haemorrhage and that this does not require investigation.It is our experience that when alcoholic excess leads to a massive bleed there is usually a chronic underlying cause, and I would suggest that these patients most certainly should be investigated.
We have employed electroless deposition to prepare smooth films (mirrors) of silver that could be used as substrates in microcontact printing (μCP) of alkanethiols. Good-quality SAMs of hexadecanethiolate were formed on thin films of electroless silver by printing with an elastomeric stamp; these SAMs were effective resists in protecting the underlying silver from etching in an aqueous ferricyanide solution. Thin films of silver prepared by electroless deposition show a granular morphology (the grain sizes are ∼30−60 nm) and have a rougher surface than those prepared using e-beam or thermal evaporation. As a result, hexadecanethiol liquid spreads more rapidly on electroless silver than on evaporated silver when μCP is carried out in air. This process of reactive spreading limits the resolution and fidelity of pattern transfer to electroless silver films by μCP, but could also be used as a convenient method for reducing the sizes of features of SAMs generated using μCP. The smallest features that we have fabricated using this method were trenches etched in electroless silver (∼40 nm thick) with lateral dimensions of ∼200 nm. The procedure demonstrated here allows us to form micropatterns and microstructures without the metal evaporation usually used to prepare the substrates for μCP, and thus opens μCP and related techniques of microfabrication to those who do not have access to the equipment required for evaporation or sputtering of silver. It also makes it possible to carry out micropatterning on hidden surfaces that could not be silvered by evaporation (for example, the inside surface of a glass tube or flask).
The in-plane extension of two dissimilar materials with cracks or fault lines along their common interface is considered. A method is offered for solving such problems by the application of complex variables integrated with the eigenfunction-expansion technique presented in an earlier paper. The solution to any problem is resolved to finding a single complex potential resulting in a marked economy of effort as contrasted with the more laborious conventional methods which have not yielded satisfactory results. Boundary problems are formulated and solutions are given in closed form. The results of these evaluations also give stress-intensity factors (which determine the onset of rapid fracture in the theory of Griffith-Irwin) for plane problems.
Scanning tunneling microscopy (STM) has been used to characterize the structure and electronic properties of molybdenum selenide $({\mathrm{Mo}}_{6}{\mathrm{Se}}_{6})$ molecular wires. STM images resolve the 0.45 nm unit cell repeat in isolated molecular wires and bundles of wires. Tunneling spectroscopy measurements exhibit sharp peaks in the local density of states that are consistent with the Van Hove singularities expected for a one-dimensional (1D) system. These data have been compared with previous band structure calculations. Preliminary measurements at 5 K show no evidence of a gap opening at low temperatures. The implications of these results to metal-insulator transitions in 1D systems are discussed.
We used chemical force microscopy (CFM) to study adhesive forces between surfaces of epoxy resin and self-assembled monolayers (SAMs) capable of hydrogen bonding to different extents. The influence of the liquid medium in which the experiments were carried out was also examined systematically. The molecular character of the tip, polymer, and liquid all influenced the adhesion. Complementary macroscopic contact angle measurements were used to assist in the quantitative interpretation of the CFM data. A direct correlation between surface free energy and adhesion forces was observed in mixed alcohol−water solvents. An increase in surface energy from 2 to 50 mJ/m2 resulted in an increase in adhesion from 4−8 nN to 150−300 nN for tips with radii of 50−150 nm. The interfacial surface energy for identical nonpolar surface groups of SAMs was found not to exceed 2 mJ/m2. An analysis of adhesion data suggests that the solvent was fully excluded from the zone of contact between functional groups on the tip and sample. With a nonpolar SAM, the force of adhesion increased monotonically in mixed solvents of higher water content; whereas, with a polar SAM (one having a hydrogen bonding component), higher water content led to decreased adhesion. The intermolecular force components theory was used for the interpretation of adhesion force measurements in polar solvents. Competition between hydrogen bonding within the solvent and hydrogen bonding of surface groups and the solvent was shown to provide the main contribution to adhesion forces. We demonstrate how the trends in the magnitude of the adhesion forces for chemically heterogeneous systems (solvents and surfaces) measured with CFM can be quantitatively rationalized using the surface tension components approach. For epoxy polymer, inelastic deformations also contributed heavily to measured adhesion forces.
