Adolescent snus use in Finland in 1981-2003: trend, total sales ban and acquisition

Objective

To study changes in adolescent snus use from 1981 to 2003, the effects of the total snus sales ban (1995) and snus acquisition.

Design

Biennial postal surveys in 1981–2003.

Setting and participants

Entire Finland; 12‐, 14‐, 16‐, and 18‐year‐olds (n  =  73 946; 3105−8390 per year).

Main outcome measures

Snus use (experimental, daily/occasionally), snus acquisition (2001, 2003).

Results

Snus experimentation grew in popularity before the total sales ban in 16‐ and 18‐year‐old boys and after the ban in all age and sex groups. A decrease was seen between 2001 and 2003, except for 18‐year‐old boys. Daily/occasional use mainly followed the same pattern in boys while in girls the daily/occasional use was rare and no significant changes were observed. In 2003, boys experimented with snus more often than girls (12‐year‐olds 1% v 0%, 14‐year‐olds 9% v 4%, 16‐year‐olds 30% v 12%, 18‐year‐olds 44% v 18%). Hardly any girls used snus daily/occasionally, but 1% of 14‐year‐old boys, 7% of 16‐year‐olds, and 9% of 18‐year‐olds did. Of daily/occasional users, 84% acquired snus from friends or acquaintances, 55% from tourist trips to neighbouring countries (Estonia, Sweden), and 7% through sport teams; 24% obtained it from under‐the‐counter sources. For experimenters, the corresponding figures were 79%, 18%, 0.3%, and 5%.

Conclusions

The total sales ban did not stop snus use; instead, the increase continued after the ban. Friends who travel to neighbouring countries act as go‐betweens reselling snus. Snus is used even by the youngest adolescents, thus contributing to the nicotine dependence process.     

Comparison of polyphenolic composition and antioxidant activity of wild Italian blueberries and some cultivated varieties

Four varieties of cultivated blueberries (Vaccinium corymbosum) and a wild crop (Vaccinium miyrtillus) originating form the Modena region in Italy (Mirtillo nero dell’Appennino Modenese) and protected by the mark of origin, were examined in order to determine their antioxidant activity as related to their phenolic composition. The antioxidant activity was measured as radical scavenging activity, ferric reducing activity, and by an amperometric method; the total phenolics and total anthocyanins were determined by colorimetric methods; individual anthocyanins were evaluated by HPLC. Results showed that total phenolics and total anthocyanin concentrations were, respectively two fold and three fold higher in the wild fruits, which also had a higher anthocyanin-to-total phenolic ratio. Determination of individual anthocyanins put in evidence some differences between the cultivated and wild varieties, in particular the absence of acylated anthocyanins in wild blueberries. The antioxidant activity was much higher in wild blueberries than in the cultivated ones, and it was more related to the total phenolic rather that to the anthocyanin concentration.     

Regular trees and the free iterative theory

This paper establishes the relationship between regular trees, equationally defined trees, and Elgot's iterative algebraic theories; in particular, it provides a regular tree characterization of the free iterative theory and an equational tree characterization of the free iterative theory. These tree characterizations have implications for decision problems involving flowchart schemes interpreted in iterative theories and they also help to explicate the connections between order theoretic and non-order theoretic fixed point models for iteration.     

In vitro host response assessment of biomaterials for cardiovascular stent manufacture

The deployment of a vascular stent during angioplasty has greatly reduced the risks of restenosis. However, the presence of the device still induces a host response as well as a mechanical action on the blood vessel wall and an alteration of the haemodynamics. Platelet and inflammatory cells can adhere on the stent surface and be activated to produce biochemical signals able to stimulate an excessive proliferation of the smooth muscle cells with the consequent obstruction of the vessel lumen. For these reasons, the host response to two of the materials used in stent manufacture, stainless steel and diamond-like carbon, was investigated in vitro. The data showed that stainless steel induced a higher level of host response both in terms of platelet aggregation and macrophage activation. However, the spreading of inflammatory cells was more accentuated on diamond-like carbon. The inflammatory cells produced levels of platelet-derived growth factor, a key signal in smooth muscle cell proliferation, similar to stainless steel thus suggesting that carbon coatings may not be able to prevent restenosis.     

Modeling of multilayer microholographic data storage

We focus on the investigation of multilayer recording in microholographic data storage. We have developed a numerical model for calculating the electromagnetic scattering from thick microholographic gratings using the Born approximation and the direct volume integral. The signal-to-noise ratio and bit error rate were calculated to estimate the noise arising from interlayer and interhologram cross talk. Measurements were done to prove the validity of the model. The results of our calculations and the measurements show good agreement. We present the application of the model to the investigation of confocal filtering at the image plane and to the evaluation of positioning and wavelength tolerances.     

Microstructure and fatigue properties of friction stir welded high-strength steel plates

The weldability of high-strength steels (HSSs) is limited by their loss of strength, toughness and fatigue properties. In demanding applications, the fatigue properties of welds are among the strictest requirements. This paper presents a weldability analysis focusing on the microstructure and fatigue properties of 6?mm thick S690 and S355 HSS plates joined by friction stir welding. Their fatigue properties are compared to design recommendations and to fatigue properties obtained with other welding techniques. Results show that the high-quality friction stir welded steel joints outperform high-quality arc welds and FAT80 design recommendations. The fatigue strength of the friction stir welded joints is increased with material yield strength. The mechanisms governing crack initiation at different maximum stress levels are discussed.     

Pharmacophore‐Based Design of Novel Oxadiazoles as Selective Sphingosine‐1‐phosphate (S1P) Receptor Agonists with in vivo Efficacy

Sphingosine‐1‐phosphate (S1P) receptor agonists have shown promise as therapeutic agents for multiple sclerosis (MS) due to their regulatory roles within the immune, central nervous system, and cardiovascular system. Here, the design and optimization of novel [1,2,4]oxadiazole derivatives as selective S1P receptor agonists are described. The structure–activity relationship exploration was carried out on the three dominant segments of the series: modification of the polar head group (P), replacement of the oxadiazole linker (L) with different five‐membered heterocycles, and the use of diverse 2,2′‐disubstituted biphenyl moieties as the hydrophobic tail (H). All three segments have a significant impact on potency, S1P receptor subtype selectivity, physicochemical properties, and in vitro absorption, distribution, metabolism, excretion and toxicity (ADMET) profile of the compounds. From these optimization studies, a selective S1P₁ agonist, N‐methyl‐N‐(4‐{5‐[2‐methyl‐2′‐(trifluoromethyl)biphenyl‐4‐yl]‐1,2,4‐oxadiazol‐3‐yl}benzyl)glycine ( 45 ), and a dual S1P_1,5 agonist, N‐methyl‐N‐(3‐{5‐[2′‐methyl‐2‐(trifluoromethyl)biphenyl‐4‐yl]‐1,2,4‐oxadiazol‐3‐yl}benzyl)glycine ( 49 ), emerged as frontrunners. These compounds distribute predominantly in lymph nodes and brain over plasma and induce long lasting decreases in lymphocyte count after oral administration. When evaluated head‐to‐head in an experimental autoimmune encephalomyelitis mouse model, together with the marketed drug fingolimod, a pan‐S1P receptor agonist, S1P_1,5 agonist 49 demonstrated comparable efficacy while S1P₁‐selective agonist 45 was less potent. Compound 49 is not a prodrug, and its improved property profile should translate into a safer treatment of relapsing forms of MS.     

Hydroperoxide formation during autoxidation of conjugated linoleic acid methyl ester

The aim of this study was to investigate whether hydroperoxides are formed in the autoxidation of conjugated linoleic acid (CLA) methyl ester both in the presence and absence of α‐tocopherol. The existence of hydroperoxide protons was confirmed by D₂O exchange and by chemoselective reduction of the hydroperoxide groups into hydroxyl groups using NaBH₄. These experiments were followed by nuclear magnetic resonance (NMR) spectroscopy. The ¹³C and ¹HNMR spectra of a mixture of 9‐hydroper‐oxy‐10‐trans,12‐cis‐octadecadienoic acid methyl ester (9‐OOH) and 13‐hydroperoxy‐9‐cis, 11‐trans‐octadecadienoic acid methyl ester (13‐OOH), which are formed during the autoxidation of methyl linoleate, were studied in detail to allow the comparison between the two linoleate hydroperoxides and the CLA methyl ester hydroperoxides. The ¹³CNMR spectra of samples enriched with one of the two linoleate hydroperoxide isomers were assigned using 2D NMR techniques, namely Correlated Spectroscopy (COSY), gradient Heteronuclear Multiple Bond Correlation (gHMBC), and gradient Heteronuclear Single Quantum Correlation (gHSQC). The ¹³C and ¹H NMR experiments performed in this study show that hydroperoxides are formed during the autoxidation of CLA methyl ester both in the presence and absence of α‐tocopherol and that the major isomers of CLA methyl ester hydroperoxides have a conjugated monohydroperoxydiene structure similar to that in linoleate hydroperoxides.