An Improvement of Mechanical Properties of Two Kinds of Silicone Resins Containing Ladder Segments by Chemical Modification with Trimethylborate.

We suggest a new method for postsynthesis modification of silicones containing silanol groups. It was found that trimethylborate is an effective catalyst for dehydrative condensation of silanol groups with the formation of ladder-like blocks. The utility of this approach was demonstrated on postsynthesis modification of poly-(block poly(dimethylsiloxane)-block ladder-like poly(phenylsiloxane)) and poly-(block poly((3,3',3″-trifluoropropyl-methyl)siloxane)-block ladder-like poly(phenylsiloxane) with a combination of linear and ladder-like blocks having silanol groups. The postsynthesis modification leads to a 75% increase in tensile strength and 116% elongation on break in comparison with the starting polymer.

Linear/Ladder-Like Polysiloxane Block Copolymers with Methyl-, Trifluoropropyl- and Phenyl- Siloxane Units for Surface Modification.

Multiblock copolymers containing linear polydimethylsiloxane or polymethyltrifluoropropylsiloxane and ladder-like polyphenylsiloxane were synthesized in a one-step pathway. The functional homopolymer blocks and final multiblock copolymers were characterized using solution and solid-state multinuclear 1H, 13C, 19F, and 29Si NMR spectroscopy. It was shown that the ladder-like block contains silanol units, which influence the adhesion properties of multiblock copolymers and morphology of their casted films. The adhesion to metals and mechanical properties of multiblock copolymers were tested. The SEM study of casted films of multiblock copolymers shows the variety of formed morphologies, including long-strip-like or globular.

Unusual pyrimidine participation: efficient stereoselective synthesis of potent dual orexin receptor antagonist MK-6096.

An asymmetric synthesis of dual orexin receptor antagonist MK-6096 (1) is described. Key steps for the trans-2,5-disubstituted piperidinyl ether fragment include a biocatalytic transamination, a trans-selective Mukaiyama aldol, and a regioselective pyridyl SNAr process. The pyrimidyl benzoic acid was synthesized via a Negishi coupling and a nitrile hydrolysis. Coupling of the two fragments via a catalytic T3P-mediated amidation completed the synthesis. Unusual behaviors in the hydrolysis of pyrimidyl benzonitrile and the amide coupling of the pyrimidyl benzoic acid are also described.

Social and lifestyle determinants of depression, anxiety, sleeping disorders and self-evaluated quality of life in Russia--a population-based study in Arkhangelsk.

BACKGROUND: The paper investigates social and lifestyle determinants of depression, anxiety, sleeping disorders and self-evaluated low quality of life in a population sample from the northwest of Russia. METHODS: Altogether 1968 men and 1737 women aged 18-90 years participated in a population-based study in Arkhangelsk, Russia, in the period 1999-2000. Depression, anxiety, and sleeping disorders were evaluated by a questionnaire with the formulations that have been previously used in population studies in Northern Norway. Alcohol dependence was diagnosed by the Alcohol Use Disorders Identification Test (AUDIT). Quality of life was evaluated by a 10-score Cantril Ladder. A score lower than five was defined as low quality of life. Relations between depression, anxiety, and sleeping disorders and socioeconomic/lifestyle factors were tested by logistic regression analyses. RESULTS: Women reported significantly higher prevalence of depression, anxiety and/or sleeping disorders than men: 68.7% and 32.3%, respectively. Depression, anxiety, sleeping disorders and low quality of life were positively associated with self-evaluation of nutrition as "poor", low consumption of food, and with low-paid professional status. Depression and sleeping disorders were associated with smoking, hazardous level of alcohol drinking and alcohol dependence. Anxiety and low quality of life were associated with alcohol dependence. Depression, anxiety, sleeping disorders and low quality of life had a strong positive association with circulatory diseases and gastrointestinal diseases, the association remained significant after adjustment for smoking and alcohol variables. CONCLUSIONS: A considerable part of the examined Russian population experienced depression, anxiety, and sleeping disorders that were strongly positively associated with poor nutrition, low socioeconomic status and adverse health behaviors (alcohol use disorders, smoking).

Structure-NMR chemical shift relationships for novel functionalized derivatives of quinoxalines.

(1)H, (13)C and (15)N NMR chemical shifts for a variety of novel quinoxalines were determined by different 2D methods and were calculated using the GIAO DFT approach. Comparison with experimental data shows good correlations in the case of (1)H, (13)C and (15)N chemical shifts. Different combinations of basis sets were tested. In non-polar solvents quinoxalines exist as dimers owing to strong hydrogen bonding. Calculations for dimers improve the correlation between experiment and theory. Additive empirical methods for estimating chemical shifts have drawbacks and have to be used with a great care for this type of compound.

Alcohol consumption and its relation to risk factors for cardiovascular disease in the north-west of Russia: the Arkhangelsk study.

BACKGROUND: To explore indicators and levels of alcohol consumption in a Russian population, and to elaborate these in relation to risk factors for cardiovascular disease. METHODS: A total of 1963 men and 1734 women, aged 18-75 years, consecutively recruited at their compulsory annual medical check-up at the Semashko outpatient clinic, Arkhangelsk, participated in a cross-sectional health survey. The survey comprised a physical examination, a six-page questionnaire on health and lifestyle, and blood tests. RESULTS: Gamma-glutamyltransferase (GGT) levels in both sexes were more than twice as high as found in comparable studies. Elevated GGT-levels were 4-5 times more frequent than found in Norwegian studies. Alcohol Use Disorder Identification Test (AUDIT) identified up to 75% of male workers and 47% of female workers as hazardous or harmful alcohol drinkers. The traditional risk factors for cardiovascular disease were significantly higher in subjects with a high level of GGT. CONCLUSION: The findings indicate an extremely high level of alcohol consumption in this population. Elevation in GGT was significantly associated with increased risk for cardiovascular disease.

Factors behind the increase in cardiovascular mortality in Russia: apolipoprotein AI and B distribution in the Arkhangelsk study 2000.

BACKGROUND: Cardiovascular mortality is markedly higher in Russia than in Western Europe and the US. Little is known about indicators of atherosclerotic risk in the Russian population. To our knowledge, this is the first study of apolipoprotein (apo) AI and B in Russia based on the WHO-IFCC standard. METHODS: We measured apo AI and B by immunoturbidimetric assay in 3694 men and women from Arkhangelsk, Russia, in 1999-2000. RESULTS: The age-related distribution of apo B was similar to that in other countries, whereas the apo AI profile was different. For men > or = 20 years, apo AI was considerably higher than in studies from other countries. Women had also relatively high apo AI concentrations, although the difference was not as pronounced as in men. The apo AI concentration was positively associated with age and lifestyle variables such as alcohol consumption and physical activity, and negatively associated with body mass index and self-reported myocardial infarction. gamma-Glutamyltransferase was positively associated with apo AI in both sexes. CONCLUSIONS: The apparently favorable apolipoprotein profiles contrast with official death statistics indicating high cardiovascular mortality in Russia. High apo AI might indicate excessive alcohol consumption.

High cardiovascular mortality in Russia cannot be explained by the classical risk factors. The Arkhangelsk Study 2000.

Since the beginning of the 1990s the public health situation in Russia has been characterized by an extremely high mortality and a significant reduction in life expectancy. Cardiovascular diseases remained the major cause of death. Only a few large population studies were conducted in Russia during this period. A total of 1968 men and 1737 women aged 18-75 years participated in a health survey in Arkhangelsk, Russia, over the period 1999-2000. Investigation included assessment of classic cardiovascular risk factors (family history, smoking, blood pressure, and blood lipids) along with general health variables. The paper presents sex specific data on risk factors for coronary heart disease. Though the cardiovascular mortality is high in Russia, the calculated risk for coronary heart disease (the Framingham risk score and the Norwegian risk score) was lower in all age groups of men and women in Arkhangelsk compared with studies from the Western Europe and USA. Our data suggest that high cardiovascular mortality in Russia may be driven not only by the classic risk factors for coronary heart disease.