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The moderator effect of gender on (i) the relation between adolescents' sexual experience on the one hand; and (ii) their orientations towards the type of relational and emotional commitment that they expect to be present before engaging in a sexual relationship, and (iii) having a steady partner on the other was examined. We hypothesized that the relations between these facets would be stronger for women. We utilized a random sample of 253 British adolescents interviewed twice with a 1-year interval LISREL multigroup analysis with mean structures was used to test the hypotheses, thus offering the opportunity of detecting moderator as well as main effects of gender. Differential effects of emotional and relational commitment and having a steady partner relationship on sexual experience supported the hypotheses. 相似文献
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Teun P De Boer Bart Kok Kirsten I E Neuteboom Nicole Spieker Jochum De Graaf Olivier H J Destrée Martin B Rook Toon A B Van Veen Habo J Jongsma Marc A Vos Jacques M T De Bakker Marcel A G Van Der Heyden 《Developmental dynamics》2005,233(3):864-871
Connexin-containing gap junctions play an essential role in vertebrate development. More than 20 connexin isoforms have been identified in mammals. However, the number identified in Xenopus trails with only six isoforms described. Here, identification of a new connexin isoform from Xenopus laevis is described. Connexin40.4 was found by screening expressed sequence tag databases and carrying out polymerase chain reaction on genomic DNA. This new connexin has limited amino acid identity with mammalian (<50%) connexins, but conservation is higher (approximately 62%) with fish. During Xenopus laevis development, connexin40.4 was first expressed after the mid-blastula transition. There was prominent expression in the presomitic paraxial mesoderm and later in the developing somites. In adult frogs, expression was detected in kidney and stomach as well as in brain, heart, and skeletal muscle. Ectopic expression of connexin40.4 in HEK293 cells, resulted in formation of gap junction like structures at the cell interfaces. Similar ectopic expression in neural N2A cells resulted in functional electrical coupling, displaying mild, asymmetric voltage dependence. We thus cloned a novel connexin from Xenopus laevis, strongly expressed in developing somites, with no apparent orthologue in mammals. 相似文献
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van Veen TA van Rijen HV Wiegerinck RF Opthof T Colbert MC Clement S de Bakker JM Jongsma HJ 《Journal of molecular and cellular cardiology》2002,34(10):1411-1423
BACKGROUND: Beta-MHC-hRARalpha transgenic mice express a constitutively active (truncated) form of the human retinoic acid receptor which triggers development of dilated cardiomyopathy. In those hearts, we studied expression of gap junction proteins in relation to electrical impulse propagation. METHODS AND RESULTS: As compared to wildtype mice, hearts of 4-6 month old mice with 7-12 inserted hRARalpha copies are marked by an increased heart weight/body weight- and heart weight/tibia length ratio. 3-extremity lead ECGs revealed prolongation of the Q-j interval suggesting delayed ventricular activation. Mapping of electrical activity of epi- and endocardial left ventricular free wall revealed activation delay, increased heterogeneity in conduction and regional conduction block. Ventricular tachycardias did not occur spontaneously nor could be induced by ventricular pacing. Immunohistochemical analysis showed profound and heterogeneous redistribution and down-regulation of the gap junction protein connexin43 (Cx43) in the left ventricular free wall. Here, hRARalpha expression induced re-expression of the hypertrophic markers alpha-skeletal actin and beta-MHC, and in 3 out of 10 severely affected mice, re-expression of Cx40. Concomitant with changes in expression/distribution of Cx43, changes in expression and distribution of beta-catenin and N-cadherin (two other intercalated disk associated proteins) were observed. CONCLUSIONS: Beta-MHC-hRARalpha transgenic hearts show heterogeneous re-expression of (early) sarcomeric genes while expression of connexin43, N-cadherin and beta-catenin is down-regulated. We postulate that the resulting aberrant ventricular activation does not trigger development of lethal arrhythmias due to the small size of remaining healthy ventricular tissue where the transgene is not expressed. 相似文献
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Tabazadeh A Drdla K Schoeberl MR Hamill P Toon OB 《Proceedings of the National Academy of Sciences of the United States of America》2002,99(5):2609-2612
Optical depth records indicate that volcanic aerosols from major eruptions often produce clouds that have greater surface area than typical Arctic polar stratospheric clouds (PSCs). A trajectory cloud-chemistry model is used to study how volcanic aerosols could affect springtime Arctic ozone loss processes, such as chlorine activation and denitrification, in a cold winter within the current range of natural variability. Several studies indicate that severe denitrification can increase Arctic ozone loss by up to 30%. We show large PSC particles that cause denitrification in a nonvolcanic stratosphere cannot efficiently form in a volcanic environment. However, volcanic aerosols, when present at low altitudes, where Arctic PSCs cannot form, can extend the vertical range of chemical ozone loss in the lower stratosphere. Chemical processing on volcanic aerosols over a 10-km altitude range could increase the current levels of springtime column ozone loss by up to 70% independent of denitrification. Climate models predict that the lower stratosphere is cooling as a result of greenhouse gas built-up in the troposphere. The magnitude of column ozone loss calculated here for the 1999--2000 Arctic winter, in an assumed volcanic state, is similar to that projected for a colder future nonvolcanic stratosphere in the 2010 decade. 相似文献
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Phong Teck Lee Chai Keat See Paul Toon Lim Chiam Soo Teik Lim 《Singapore medical journal》2015,56(1):e1-e3
Pericarditis and myocarditis are characterised by electrocardiographic changes and elevated cardiac enzymes, respectively, and patients with perimyocarditis often complain of chest discomfort. These findings are nonspecific and often lead to diagnostic difficulties, as ST-elevation myocardial infarction commonly presents in a similar fashion. Clinical differentiation between perimyocarditis and myocardial infarction are especially important because adverse side effects can occur if reperfusion therapy is administered for a patient with acute pericarditis or if a diagnosis of acute myocardial infarction is missed. We herein describe a case of perimyocarditis with ST elevation and raised cardiac markers, which led to two emergency coronary angiographies that were subsequently found to be normal. We include the three serial electrocardiographies (ECGs) performed to show the characteristic features of perimyocarditis and further discuss the importance of identifying typical and atypical ECG features of pericarditis. 相似文献
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Stamatis Adamopoulos Jean‐Paul Schmid Paul Dendale Daniel Poerschke Dominique Hansen Athanasios Dritsas Alexandros Kouloubinis Toon Alders Aggeliki Gkouziouta Ilse Reyckers Vasiliki Vartela Nikos Plessas Costas Doulaptsis Hugo Saner Ioannis D. Laoutaris 《European journal of heart failure》2014,16(5):574-582