Ultracold collisions between Cs atoms and Cs2 dimers in the electronic ground state are observed in an optically trapped gas of atoms and molecules. The Cs2 molecules are formed in the triplet ground state by cw photoassociation through the outer well of the 0-(g) (P3/2) excited electronic state. Inelastic atom-molecule collisions converting internal excitation into kinetic energy lead to a los...

Malaria in pregnancy is associated with placental accumulation of Plasmodium falciparum-infected erythrocytes (IE) that adhere to chondroitin sulfate A (CSA). Adhesion is mediated by P. falciparum erythrocyte membrane protein 1 (PfEMP1), a variant parasite protein expressed on the surface of IE and encoded by var genes. Rabbit antiserum was generated against the CSA-adherent P. falciparum line ...

A water-soluble, highly polar, heat-stable, small molecule has been isolated from cell-free extracts of the halotolerant green alga Dunaliella salina. This compound, soluble inhibitory factor (SIF), when added to in vivo light-activated, thylakoid membrane-bound preparations of the D. salina coupling factor 1 (CF1), causes a rapid inactivation of the ATPase activity. SIF must be in its oxidized...

Recent activities in the field of time and frequency metrology pursued at PTB are reviewed. Quasi-continuous operation of the cesium fountain frequency standard CSF1 enabled us to assess the performance of the older primary clocks CS1 and CS2 much better than previously possible. On average, the CSF1 and CS2 frequencies deviated by less than 5 parts in 10 during more than 2 years, which is well...

The mammary pheromone promotes the acquisition of novel odorants (CS1) in newborn rabbits. Here, experiments pinpoint that CS1 becomes able to support neonatal learning of other odorants (CS2). We therefore evaluated whether these first- and second-order memories remained dependent after reactivation. Amnesia induced after CS2 recall selectively blocked this memory, when recall and amnesia of C...

Silica aerogels are among the most easily produced types of aerogels due to the availability of required materials, the cheapness of required materials such as carbon dioxide, ethanol, and tetraethyl orthosilicate, and the relatively simple sol-gel chemistry. Using silica aerogels as skeletons, nanomaterials were easily and effectively structured in three dimensions. The aerogels were doped wit...

The key event in prion diseases seems to be the conversion of the prion protein PrP from its normal cellular isoform (PrP(C)) to an aberrant "scrapie" isoform (PrP(Sc)). Earlier studies have detected no covalent modification in the scrapie isoform and have concluded that the PrP(C) --> PrP(Sc) conversion is a purely conformational transition involving no chemical reactions. However, a reexamina...

The title compound, C(8)H(8)N(2)S, was prepared by the condensation of N-methyl-1,2-phenyl-enediamine and carbon disulfide. The crystal structure is stabilized by a C-H⋯π inter-action between a benzene H atom and the benzene ring of a neighbouring mol-ecule, and by inter-molecular N-H⋯S inter-actions.

The components of electrocardiograms (ECG) of 253 workers exposed to carbon disulfide (CDS) and those of 99 controls were quantitatively measured and evaluated. ECG of the exposed workers showed a statistically significant higher prevalence of ECG pathological changes, higher P amplitude and Macruz index, longer P duration, longer both crude and corrected Q-T intervals and R-R intervals and sho...

The hydrolysis mechanism of CS(2) was studied using density functional theory. By analyzing the structures of the reactant, transition states, intermediates, and products, it can be concluded that the hydrolysis of CS(2) occurs via two mechanisms, one of which is a two-step mechanism (CS(2) first reacts with an H(2)O, leading to the formation of the intermediate COS, then COS reacts with anothe...