TMTHSI, a superior 7-membered ring alkyne containing reagent for strain-promoted azide-alkyne cycloaddition reactions.

We describe the development of TMTH-ulfoxmine (TMTH) as a superior click reagent. This reagent combines a great reactivity, with small size and low hydrophobicity and compares outstandingly with existing click reagents. TMTHSI can be conveniently functionalized with a variety of linkers allowing attachment of a diversity of small molecules and (peptide, nucleic acid) biologics.

Water and heat transport in boreal soils: implications for soil response to climate change.

Soil water content strongly affects permafrost dynamics by changing the soil thermal properties. However, the movement of liquid water, which plays an important role in the heat transport of temperate soils, has been under-represented in boreal studies. Two different heat transport models with and without convective heat transport were compared to measurements of soil temperatures in four boreal sites with different stand ages and drainage classes.

Complications of the intrauterine device in nulliparous and parous women.

Objectives: The intrauterine device (IUD) is still related to pelvic inflammatory disease (PID), pregnancy, expulsion, perforation and menstrual problems, particularly in nulliparous women. We aimed to study the complications and symptoms of the intrauterine device in general practice, particularly in nulliparous women.

Methods: We used a retrospective cohort study in four general practices participating in the Nijmegen Continuous Morbidity Registration.

Intrauterine contraception: the role of general practitioners in four Dutch general practices.

The intrauterine device (IUD) use in the Netherlands and the United States is limited to a small group of women, though the risk of infection and pregnancy is small. Therefore, it was of interest to investigate the characteristics of women who choose an IUD as contraceptive method and the influence of general practitioners concerning IUD insertion. The aim of this retrospective cohort study was to assess differences between general practices and to investigate the characteristics of IUD users.

Rearrangement of O-cinnamoyltaxicin I to a novel C-13 spiro-taxane.

During the large-scale synthesis of an O-cinnamoyltaxicin I acetonide, an intermediate for the semisynthesis of 7-deoxypaclitaxel derivatives, side-product 3 was formed via a vinylogous retro-aldol reaction and a long-range hydride shift from O-cinnamoyltaxicin I (1) under alkaline reaction conditions. Compound 3 has two hemi-acetal bridges at C-1,C-9 and C-10,C-13. Compound 4 was formed from side-product 3 under acidic reaction conditions and is the first C-13 spiro-taxane described in the literature.