bluuebunny/crossref_metadata_2025_split huggingface dataset:
Syntheses of 5‐alkylthio‐1,3‐diaryl‐1,2,4‐triazoles
Authors: Navidpour Latifeh , Karimi Leila , Amini Mohsen , Vosooghi Mohssen , Shafiee Abbas 
Published: March 2009

AbstractArylation of the readily available 3‐alkythio‐5‐aryl‐1,2,4‐triazoles gave 5‐alkylthio‐1,3‐diaryl‐1,2,4‐triazoles in moderate yield. The structures of the latter were confirmed by NOE and 13C‐NMR.
Investigation on the condensation of α and β ketoaldehydes with hydroxyaromatic compounds
Authors: Talinli Naciye , Karliga Bekir 
Published: March 2009

AbstractMechanism of the condensation reactions of methylglyoxal, phenylglyoxal and benzoylacetaldehyde with phenolic compounds have been discussed. It was observed that the reaction mechanisms changed depending on the type of the phenolic and also dicarbonyl compounds. While, methylglyoxal gave the angular methyl derivative of naphthofuraranonaphthofuran with 2‐naphthol, phenylglyoxal and its p‐chloro and p‐methoxy derivatives formed benzo[b]naphtho[2,1‐f]oxepine‐13‐ones. However, resorcinol behaved different and gave 2‐phenyl‐3‐(2,4‐dihydroxy)‐6‐hydroxy‐benzo[b]furans with phenylglyoxal derivatives. 2‐Phenyl‐4‐(2‐hydroxynaphmyl)‐4H‐naphtho[b]pyran was produced from the reaction of benzoylacetaldehyde and 2‐naphthol, but the reaction product was 3,9‐dihydroxy‐6‐phenyl‐6,12‐methano‐12H‐dibenzo[1,3]dioxocin when the same carbonyl compound reacted with resorcinol.
Synthesis and structure of cycloalkane‐ and norbornane‐condensed 6‐aryl‐1,2,4,5‐tetrahydropyridazinones
Authors: Csende Ferenc , Hetényi Anasztárzia , Stájer Géza , Fülöp Ferenc 
Published: March 2009

AbstractThe C=N double bond of certain cis‐ or trans‐cycloalkane and diexo‐ or diendo‐norbornane‐condensed pyridazinones was reduced with NaBH3CN. The cis‐ or trans nature of the starting cycloalkane derivatives was always retained in the saturated products, with a high degree of diastereoselectivity: the hydrogen on the new stereocenter and the annelational hydrogen next to the carbonyl always exhibited the same steric orientation. The stereostructures were determined by means of nmr measurements and confirmed by molecular modelling.
Efficient synthesis in three steps and spectral determination of methyl‐5‐[(o‐, m‐, and p‐substituted‐phenylthio]‐2‐benzimidazolecarbamates
Authors: Cortés Eduardo Cortés , Mendoza Rafael Sosa , Gutiérrez Maximiliano Santibáñez , De Cortés Olivia Garcéa‐Mellado 
Published: March 2009

AbstractThe preparation and spectral properties often novel methyl 5‐[(o‐, m‐, and p‐substituted)‐phenylthio]‐2‐benzimidazolecarbamates with possible pharmacological activity as antihelmintics is described; by condensation and cyclization between 5‐methylthioures sulfate chloroformic acid methyl ester and 3,4‐diaminophenyl‐substituted‐phenylthio ether dissolved in ethanol. The structures of all final products were corroborated by ir; 1H‐nmr, 13C‐nmr and ms.
Diazoniapentaphenes. Synthesis from pyridine‐2‐carboxaldehyde and structural verifications
Authors: Krapcho A. Paul , Cadamuro Sergio A. 
Published: March 2009

AbstractReactions of pyridine‐2‐carboxaldehyde (9) with α,α′‐dibromo‐o‐ and p‐xylenes led to the corresponding bis‐pyridinium aldehydes 10 and 14. These aldehydes were quite reactive and the respective hydrates 11 and 15 were also formed. Cyclization of 10 or 11 with 48% HBr led to 12 while cyclization with PPA followed by conversion to the bis tribromide and loss of bromine led to 1. Cyclization of 14 or 15 with 48% HBr led to 3. Attempts to react α,α′‐dibromo‐m‐xylene with pyridine‐2‐carboxaldehyde (9) were not successful for the preparation of the bis‐pyridinium aldehyde 13. The bis‐pyridinium acetals 4, 5 and 6 were prepared and cyclized to afford 1, 2 and 3, respectively, by the previously reported procedures. The structures of 1 and 2 were verified by 1H‐NMR and 13C‐NMR spectroscopy while that of 3 was confirmed by X‐ray analysis.
The preparation of 3‐substituted 1,2‐benzisothiazole 1,1‐dioxides from lithiated intermediates or grignard reagents and methyl 2‐(aminosulfonyl)benzoate
Authors: Dunn S. Patrick , Hajiaghamohseni Laela M. , Lioi Sara B. , Meierhoefer Michelle A. , Walters Matthew J. , Beam Charles F. 
Published: March 2009

AbstractA polylithiated β‐ketoester, β‐diketone, or β‐ketoamide was condensed‐cyclized with lithiated methyl 2‐(aminosulfonyl)benzoate, to afford new 3‐substituted 1,2‐benzisothiazole 1,1‐dioxides. Some Grignard or organolithium reagents were also condensed‐cyclized with methyl 2‐(aminosulfonyl)benzoate to give 3‐substituted 1,2‐benzisothiazole 1,1‐dioxides.
Synthesis of polyfunctionally substituted heteroaromatic compounds via benzotriazolyl chalcones with antimicrobial and antifungal activities
Authors: Al‐Omran Fatima , El‐Khair Adel Abou 
Published: March 2009

AbstractThe utility of both 3‐(1‐benzotriazolyl) chalcone derivatives 3a‐c and 2‐(1‐benzotriazolyl)‐1,4‐pentadien‐3‐one (18) in the synthesis of some new 2‐(1H)‐pyridone, pyridine, pyrazole and isoxazole derivatives is reported. Antimicrobial and antifungal screening of some selected examples from the synthesized products were carried out. The structure of the newly synthesized compounds was elucidated by elemental analysis, ir, 1H and 13C nmr investigations.
A new regioselective synthesis and bioactivity of 1H‐pyrazolo[3,4‐d]pyrimidin‐4(5H)‐one derivatives
Authors: Wang Hong‐Qing , Liu Zhao‐Jie , Yang Li‐Min , Ding Ming‐Wu 
Published: March 2009

AbstractA series of new 1H‐pyrazolo[3,4‐d]pyrimidin‐4(5H)‐one Derivatives 5 has been designed and regio‐selectively synthesized via a tandem aza‐Wittig reaction. The structures of all compounds prepared have been confirmed by 1H NMR, IR, EI‐MS spectroscopy and elemental analyses. The results of preliminary bioassay indicate that most compounds 5 possess an inhibition effect against Botrytis cinereapers and Pyricularia oryzae at the concentration of 50 mg/L.
Oxazepines and thiazepines. 41 . Synthesis of 4‐aryl‐2,3‐dihydro‐2‐styryl‐1,5‐benzothiazepines by the reaction of (E,E)‐cinnamylideneacetophenones with 2‐aminothiophenol and their conversion into 2,2‐disubstituted 3‐acetyl‐2,3‐dihydrobezothiazoles
Authors: Lévai Albert 
Published: March 2009

AbstractNew 4‐aryl‐2,3‐dihydro‐2‐styryl‐1,5‐benzothiazepines 8–13 have been synthesized by an acid catalyzed reaction of 2‐arninothiophenol (1) and (E,E)‐cinnamylideneacetophenones 2–7. Ring contraction of 1,5‐benzothiazepines 8–13 provided 2,2‐disubstituted 3‐acetyl‐2,3‐dihydrobenzothiazoles 14–19 under acetylating conditions.
An efficient synthesis of 1‐H‐pyrazole‐4‐carboxylic acid esters with vilsmeier reagent under neat conditions
Authors: Sridhar R. , Sivaprasad G. , Perumal P. T. 
Published: March 2009

AbstractA convenient, solvent‐free Vilsmeier reagent is experimented under neat condition (both thermal and microwave conditions). An efficient method for the synthesis of various substituted 1H‐pyrazole‐4‐carboxylic acid esters is reported.
Consecutive isomerization and cyclization of 3‐(2‐aminophenyl)‐1‐arylprop‐2‐yn‐1‐ols leading to 2‐arylquinolines in the presence of potassium hydroxide
Authors: Cho Chan Sik , Lee Na Young , Kim Tae‐Jeong , Shim Sang Chul 
Published: March 2009

Abstract3‐(2‐Aminophenyl)‐1‐arylprop‐2‐yn‐1‐ols are readily converted to 2‐arylquinolines in good yields in ethanol at 80° in the presence of potassium hydroxide via domino isomerization and cyclization.
New one step synthesis of crown compounds containing a 1,3,4‐thiadiazole moiety
Authors: Bentiss Fouad , Lebrini Mounim , Lagrenée Michel 
Published: March 2009

AbstractNew macrocyclic polyether compounds containing a 2,5‐bis(2‐hydroxyphenyl)‐1,3,4‐thiadiazole moiety have been prepared by a nucleophilic substitution reaction involving ethylene or polyethylene glycol ditosylate and a bisphenol, the 2,5‐bis(2‐hydroxyphenyl)‐1,3,4‐thiadiazole, with solid anhydrous carbonate as a base. The structures of the macrocycles obtained were firmly established by 1H and 13C nmr spectroscopy and their mass spectra.
Regioselective epoxidation of 3‐(3‐Oxo‐3‐arylpropenyl)chromen‐4‐ones by dimethyldioxirane
Authors: Lévai Albert , Jekő József 
Published: March 2009

AbstractRegioselective epoxidation of 3‐(3‐oxo‐3‐arylpropenyl)chromen‐4‐ones 1a‐h by isolated dimethyldioxirane provided epoxides 2a‐h as sole detectable and isolable products in good (75–86%) yields.
An expedient synthesis of an isofervenulin analogue
Authors: Bach Andrew , Jiang Xinglong , Mckenna Joseph , Prasad Kapa , Repic Oljan , Shieh Wen‐Chung 
Published: March 2009

AbstractAn efficient approach has been developed for the synthesis of an isofervenulin analogue 1 employing a one‐pot condensation‐substitution reaction of a chlorocarboethoxytriazine (electrophile) with a urea (nucleophile). The resulting cyclization reaction resulted in the synthesis of a pyrimido‐heterocycle in good yield in either acidic or basic media. The former was assisted by utilizing trimethylsilyl chloride.
A facile synthesis of cytogenin (8‐hydroxy‐3‐hydroxymethyl‐6‐methoxyisocoumarin)
Authors: Saeed Aamer 
Published: March 2009

AbstractA facile and straightforward synthesis of cytogenin 1 (8‐hydroxy‐3‐hydroxymethyl‐6‐methoxyisocoumarin) metabolite of Streptoverticillium eurocidicum and Certocystis fimbriata has been achieved. Condensation of chloroacetyl chloride with 3,5‐dimethoxyhomophthalic acid 2 directly furnished 3‐chloromethyl‐6,8‐dimethoxyisocoumarin 3 which was hydrolyzed to 6,8‐dimethoxy‐3‐hydroxymethylisocoumarin 4 using 0.05% aqueous sodium hydroxide in THF. Regioselective demethylation of 4 yielded cytogenin 1. In model experiments, 3‐chloromethylisocoumarin was prepared and converted into 3‐hydroxymethyl isocoumarin.
Transformation of schiff bases derived from alpha‐naphthaldehyde. Synthesis, spectral data and biological activity of new‐3‐aryl‐2‐(α‐naphtyl)‐4‐thiazolidinones and N‐aryl‐N‐[1‐(α‐naphthyl)but‐3‐enyl]amines
Authors: Kouznetsov Vladimir , Rodríguez William , Stashenko Elena , Ochoa Carmen , Vega Celeste , Rolón Miriam , Pereira David Montero , Escario José A. , Barrio Alicia Gémez 
Published: March 2009

AbstractNew N‐aryl substituted 2‐(α‐naphthyl)‐4‐thiazolidinones were prepared by the cyclocondensation of α‐mercaptoacetic acid and corresponding N‐(α‐naphthyliden)anilines. The same starting materials were utilized to obtain a new series of N‐aryl‐N‐[1‐(α‐naphthyl)but‐3‐enyl]amines, which was synthesized through an addition of the Grignard reagent (allylmagnesium bromide) to the double bond CN of the aldimines. The antichagasic and trichomonacidal in vitro activity, as well as, the antifungal and cytotoxic properties of some of these compounds were evaluated.
Random poly(fluorenylene‐vinylene)s containing 3,7‐Dibenzothiophene‐5,5‐dioxide units: Synthesis, photophysical, and electroluminescence properties
Authors: Grisorio Roberto , Piliego Claudia , Cosma Pinalysa , Fini Paola , Mastrorilli Piero , Gigli Giuseppe , Suranna Gian Paolo , Nobile Cosimo Francesco 
Published: March 2009

AbstractThe synthesis of new random poly(arylene‐vinylene)s containing the electron withdrawing 3,7‐dibenzothiophene‐5,5‐dioxide unit was achieved by the Suzuki–Heck cascade polymerization reaction. The properties of poly[9,9‐bis(2‐ethylhexyl)‐2,7‐fluorenylene‐vinylene‐co‐3,7‐dibenzothiophene‐5,5‐dioxide‐vinylene] (50/50 mol/mol, P1) and poly[1,4‐bis(2‐ethylhexyloxy)‐2,5‐phenylene‐vinylene‐co‐3,7‐dibenzothiophene‐5,5‐dioxide‐vinylene] (50/50 mol/mol, P2) were compared with those of terpolymers obtained by combining the fluorene, dibenzothiophene, and 1,4‐bis(2‐ethylexyloxy)benzene in 20/40/40 (P3), 50/25/25 (P4), and 80/10/10 (P5) molar ratios. The polymers were characterized by 1H NMR and IR, whereas their thermal properties were investigated by TGA and DSC. Polymers P1–5 are blue–green emitters in solution (λem between 481 and 521 nm) whereas a profound red shift observed in the solid state is emission (λem from 578 to 608 nm) that can be attributed both to the charge transfer stabilization exerted by the polar medium and to intermolecular interactions occurring in the solid state. Cyclic voltammetry permitted the evaluation of the ionization potentials and also revealed a quasi‐reversible behavior in the reduction scans for the polymers (P1–4) containing the higher amounts of 3,7‐dibenzothiophene‐5,5‐dioxide units. Electroluminescent devices with both ITO/PEDOT‐PSS/P1–5/Ca/Al (Type I) and ITO/PEDOT‐PSS/P1–5/Alq3/Ca/Al (Type II) configuration were fabricated showing a yellow to yellow–green emission. In the case of P4, a luminance of 1835 cd/m2 and an efficiency of 0.25 cd/A at 14 V were obtained for the Type II devices. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2093–2104, 2009
Polyelectrolyte complex nanoparticles from N‐carboxyethylchitosan and polycationic double hydrophilic diblock copolymers
Authors: Mincheva Rosica , Bougard François , Paneva Dilyana , Vachaudez Magali , Fustin Charles‐André , Gohy Jean‐François , Manolova Nevena , Rashkov Iliya , Dubois Philippe 
Published: March 2009

AbstractFor the first time, the polyelectrolyte complex (PEC) formation tool was used for preparation of core‐shell nanoparticles form the natural polyampholyte N‐carboxyethylchitosan (CECh) and weak polycationic (protonated) polyoxyethylene‐b‐poly[2‐(dimethyl‐amino)ethyl methacrylate] (POE‐b‐PDMAEMA) diblock copolymers. The performed dynamic light scattering analyses revealed that nanoparticles with a PEC core and a POE shell could be formed at mixing ratio between the oppositely charged groups equal to 1/1 depending on CECh molar mass, polymerization degree of PDMAEMA block and ionic strength. The results were confirmed by the performed AFM and cryo‐TEM analyses. When high molar mass CECh was used, core‐shell nanoparticles were obtained with the diblock copolymer of the shortest PDMAEMA block at ionic strength (I) of 0.01. At ionic strength value close to the physiological one (I = 0.1) secondary aggregation occurred. Spherical nanoparticles at I = 0.1 were obtained upon lowering the CECh molar mass. Depending on the polymer partners and medium parameters the size of the obtained particles varied from 60 to 600 nm. The X‐ray photoelectron spectra evidenced the hydrophilic POE‐block shell—coacervate CECh/PDMAEMA‐block core structure. The nanoparticles are stable in a rather narrow pH range around 7.0, thus revealing the high pH‐sensitivity of the obtained core‐shell particles. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2105–2117, 2009
Removal of Model Proteins Using Beams of Argon Ions, Oxygen Atoms and Molecules: Mimicking the Action of Low‐Pressure Ar/O2 ICP Discharges
Authors: Kylián Ondřej , Benedikt Jan , Sirghi Lucel , Reuter Rüdiger , Rauscher Hubert , von Keudell Achim , Rossi François 
Published: March 2009

AbstractThe action of Ar/O2 plasmas with proteins is mimicked by employing a particle beam experiment with individually controllable and absolutely calibrated sources of O atoms/O2 molecules and of argon ions. It is demonstrated that beams of thermal O atoms and of O2 molecules with fluences up to jO = 8.6 × 1018 cm−2 and jO2 = 5.4 × 1020 cm−2 have no measurable effect on the proteins at room temperature, whereas the combination of an O/O2 beam and of an 100 eV Ar+ ion beam induces very efficient protein removal, which is accompanied by a significant increase of their surface roughness. These observations are attributed to the process of chemical sputtering caused by the simultaneous impact of incident radicals and energetic ions.magnified image
Overexpression of cyclin E messenger ribonucleic acid in nasopharyngeal carcinoma correlates with poor prognosis
Authors: Ko M-T , Su C-Y , Huang S-C , Chen C-H , Hwang C-F 
Published: March 2009

AbstractAims:S-phase kinase-associated protein 2 is required for the degradation of p27 protein, which is a negative regulator of cyclin E/cyclin-dependent kinase 2 complex. The present study examined the expression of cyclin E, S-phase kinase-associated protein 2 and p27 protein in nasopharyngeal carcinoma.Methods:Tissue from 35 cases of nasopharyngeal carcinoma and 10 normal nasopharyngeal tissue samples underwent reverse polymerase chain reaction to detect messenger ribonucleic acid. Immunohistochemical analysis was performed on 29 nasopharyngeal tissue samples in order to detect protein expression.Results:Messenger ribonucleic acid expression in the nasopharyngeal carcinoma tissue samples analysed indicated a 1.75-fold change in the amount of S-phase kinase-associated protein 2, a 0.34-fold change in the amount of cyclin E and a 0.31-fold change in the amount of p27 protein, compared with positive controls. High levels of cyclin E significantly correlated with late-stage nasopharyngeal carcinoma (p = 0.009) and a poor overall survival (p = 0.010). Immunohistochemical analysis indicated positive expression of S-phase kinase-associated protein 2 in 16/29 nasopharyngeal tissue samples (55 per cent), of cyclin E in 13/29 samples (45 per cent) and of p27 protein in 17/29 (59 per cent) samples.Conclusions:Overexpression of cyclin E messenger ribonucleic acid showed an adverse prognostic significance, correlating with an advanced stage of nasopharyngeal carcinoma and a low overall survival rate.
‘Insolence and pride’: problems with the representation of the South-East Asian Portuguese communities in Alexander Hamilton's ‘A New Account of the East Indies’ (1727)
Authors: HALIKOWSKI-SMITH STEFAN 
Published: March 2009

AbstractOne of the most influential European printed sources on South-East Asia at the turn of the eighteenth century was the Scottish sea-captain Alexander Hamilton's memoirs. The picture he paints of the Portuguese communities that had existed since the period of Portuguese ascendancy in the sixteenth century is overwhelmingly negative. But a close textual and empirical analysis of his text shows that not only was he frequently misinformed in terms of the historical developments relating to that community, but that he merely conforms to a set of standard rhetorical tropes we can associate with the Black Legend, which had grown up in Protestant countries of northern Europe since the 16th century to denigrate Portugal and her achievements. This article urges that this key text consequently be used with far greater circumspection than has hitherto been the case.
Retiform uterine tumours resembling ovarian sex cord tumours. A comparative immunohistochemical study with retiform structures of the female genital tract
Authors: Nogales Francisco F , Stolnicu Simona , Harilal Kadappayil R , Mooney Eoghan , García‐Galvis Olga F 
Published: March 2009

Aims:  To analyse both the clinicopathological and immunohistochemical findings in six cases of uterine tumours resembling ovarian sex cord tumours with a predominant epithelial retiform component resembling the rete ovarii (RUTROSCT) and to compare their immunophenotype with tissues containing retiform structures such as the normal rete ovarii, retiform Wolffian adnexal tumour (RWAT) and ovarian retiform areas of Sertoli‐Leydig cell tumours (ORSLCT).Methods and results:  Six RUTROSCTs were analysed. The average age of patients was 65 years, and all tumours behaved in a benign fashion. Four were intracavitary and two intramural. Two cases were misdiagnosed as malignant in endometrial biopsy specimens and one in the hysterectomy specimen. Histologically they had a tubulopapillary or glomeruloid formation; a sex‐cord‐like or endometrial stromal component was absent or comprised at most 30% of the tumour. RUTROCST showed consistent positivity for CAM5.2, cytokeratin (CK) 7, vimentin, calretinin, progesterone receptor and apical CD10. CD56 and α‐inhibin were positive in half of the cases. Epithelial membrane antigen, desmin, smooth muscle actin and calponin were negative. Comparatively, rete ovarii and RWAT had a similar positivity for CK7, CD56, CD10 and calretinin. ORSLCT differed in its conspicuous positivity to CD56, CD10, α‐inhibin and calretinin, but absent CK7 expression.Conclusions:  RUTROSCTs have benign behaviour but may be confused with various uterine adenocarcinomas or metastases. Correct diagnosis should avoid overtreatment. The immunophenotype of retiform areas is similar to that of adult rete ovarii and RWAT with minor divergence from ORSLCT.
Sex‐specific adult dispersal and its selective consequences in the brown anole,Anolis sagrei
Authors: Calsbeek Ryan 
Published: March 2009

SummaryDispersal behaviour is a potentially risky life‐history strategy that can impact habitat use as well as competition over territories and mates.I studied natural selection on dispersal behaviour over the course of four breeding seasons in a Bahamian population of brown anoles (Anolis sagrei).Both males and females showed extremely high site fidelity over the course of each reproductive season. Movement distance in males was negatively correlated with body size at first capture in spring (small males dispersed further). Moreover, differences in body size between dispersing males and the body size of the male territory residents that they replaced were correlated with the distance that males dispersed. Relatively larger males dispersed shorter distances compared with relatively smaller males. There was no relationship between dispersal distance and body size in females. However, females were more likely to disperse away from areas of low female density and into areas of higher female density, and female dispersal distances were negatively correlated with the number of female neighbours at the site of capture in spring (before dispersal).These data suggest that, whereas male dispersal is driven by inter‐male competition, female dispersal is more likely related to variation in territory quality.Natural selection acted on dispersal distance in conjunction with male, but not female body size. Although smaller males were the more likely to disperse, these males paid a high cost in terms of viability indicating that dispersal is a potentially risky strategy.
Anonymous non‐response analysis in the ABCD cohort study enabled by probabilistic record linkage
Authors: Tromp M. , Van Eijsden M. , Ravelli A. C. J. , Bonsel G. J. 
Published: March 2009

SummarySelective non‐response is an important threat to study validity as it can lead to selection bias. The Amsterdam Born Children and their Development study (ABCD‐study) is a large cohort study addressing the relationship between life style, psychological conditions, nutrition and sociodemographic background of pregnant women and their children's health. Possible selective non‐response and selection bias in the ABCD‐study were analysed using national perinatal registry data. ABCD‐study data were linked with national perinatal registry data by probabilistic medical record linkage techniques. Differences in the prevalence of relevant risk factors (sociodemographic and care‐related factors) and birth outcomes between respondents and non‐respondents were tested using Pearson chi‐squared tests. Selection bias (i.e. bias in the association between risk factors and specific outcomes) was analysed by regression analysis with and without adjustment for participation status.The ABCD non‐respondents were significantly younger, more often non‐western, and more often multiparae. Non‐respondents entered antenatal care later, were more often under supervision of an obstetrician and had a spontaneous delivery more often. Non‐response however, was not significantly associated with preterm birth (odds ratio 1.10; 95% CI 0.93, 1.29) or low birthweight (odds ratio 1.16; 95% CI 0.98, 1.37) after adjustment for sociodemographic risk factors. The associations found between risk factors and adverse pregnancy outcomes were similar for respondents and non‐respondents. Anonymised record linkage of cohort study data with national registry data indicated that selective non‐response was present in the ABCD‐study, but selection bias was acceptably low and did not influence the main study questions.