Interstellar dust laser explorer: a new instrument for elemental and isotopic analysis and imaging of interstellar and interplanetary dust

We present the performance characteristics of a time-of-flight secondary ion mass spectrometer designed for 157 nm laser postionization of sputtered neutrals for high sensitivity elemental and isotopic analyses. The instrument was built with the aim of analyzing rare element abundances in micron to submicron samples such as interstellar grains and cometary dust. Relative sensitivity factors have been determined for secondary ion mass spectrometry which show an exponential dependency against the first ionization potential. This allows elemental abundances to be measured with errors below 25% for most major elements. The accuracy for isotope ratios, where isotopes can be resolved from isobaric interferences, is usually limited only by counting statistics. In laser secondary neutral mass spectrometry, the spatial and temporal overlaps between the laser and sputtered neutral atoms are modeled and predictions of total detection efficiency and isotopic and elemental fractionation are compared with experimental data. Relative sensitivity factors for laser-ionized secondary neutrals from a stainless steel standard are found to vary less than 3% above saturation laser pulse energy enabling more accurate quantification.     

Gastroschisis in the partially extraamniotic fetus: experimental study

The short, thick, matted bowel, often found in gastroschisis, has been attributed to a variety of factors. We designed an original animal model in order to isolate the effect of amniotic fluid on the fetal bowel. We created experimental gastroschisis in fetal rabbits. Extruded bowel was kept out of the amniotic sac in half of the operated fetuses. At term, 7 days after surgery, 21 surviving fetuses (12 intraamniotic gastroschisis [IAG] and 9 extraamniotic gastroschisis [EAG]) and 16 control littermates were collected for study. Five parameters were measured in each animal: body weight, intestinal weight, intestinal length, bowel diameter, and bowel wall thickness. Fetal mortality due to the extraamniotic fixation technique was 25%. We found no statistically significant difference in body weight, intestinal weight, or bowel wall thickness. An enormous difference was found in intestinal length (P < .0001 among the three groups). Bowel diameter was significantly different (P = .02) in the extreme groups (IAG and controls), with the intestine being more dilated in IAG than in EAG and controls. Gastroschisis in the absence of amniotic fluid was not as damaging to the fetal intestine as "natural" intraamniotic gastroschisis.     

Development of Advance Extraction Methods for the Extraction of Myristicin from <Emphasis Type="Italic">Myristica fragrans</Emphasis>

Myristicin in a psychoactive, hallucinogenic substance and as a constituent of nutmeg and mace (Myristica fragrans nut and its aril, respectively) is widely available for people seeking so-called legal highs of natural origin. In this work, we present three methods for determination of myristicin from plant material. The methods consist of optimized extraction procedures: microwave-assisted extraction, ultrasound-assisted extraction utilizing ultrasound bath or sonotrode and gas chromatography-mass spectrometry (GC-MS) analysis method. The methods were validated: repeatability and intermediate were below 10 % and recovery ranged from 97 to 109 %. The developed methods were then used for determination of myristicin in commercially available nutmeg and mace samples. The concentration ranged from 0.58 to 12.94 μg mg^?1, and the highest concentration of myristicin was observed in samples of those producers, which are often recommended by individuals experimenting with nutmeg. The microwave-assisted extraction (MAE) method has been proven to be the most effective one for the extraction of myristicin from plant material, as it also generates deeper changes in sample structure than UAE techniques. The MAE/GC-MS method was successfully used for nutmeg residue analysis, allowing identification of five characteristic violate constituents of nutmeg.     

Evaluation of the impact of multivalent metal ions on the permeation behavior of Dolutegravir sodium

Interactions between active pharmaceutical ingredients (APIs) and polyvalent cations are an important factor within drug absorption in the gastrointestinal tract. Dolutegravir sodium, as a second-generation integrase stand transfer inhibitor for the treatment of HIV was investigated regarding chelation with Al³⁺, Ca²⁺, Fe³⁺, Mg²⁺ and Zn²⁺ ions at three different molar ratios. Furthermore, the influence of drug–ion chelates on the permeability of the drug across two intestinal membrane models was analyzed. For this purpose, Caco-2 monolayer model and Ussing chamber technique utilizing freshly excited rat intestinal mucosa were chosen and a buffer system without additional Mg²⁺ and Ca²⁺ ions was tested regarding cell detachment. The addition of polyvalent cations in an equal molar ratio to the drug solution decreased the dissolved drug by at least 11%. An increased multivalent cation concentration in a ratio of 1:10 afforded an API drop in the solution of at least 88% with the exception of Mg²⁺. In particular, Dolutegravir sodium was chelated with iron ions to nearly 100%. Overall, the higher the amount of metal ions in the solution, the lower was the detected amount of the drug. The permeation experiments across the Caco-2 monolayer and the rat intestinal mucosa pointed out that the addition of AlCl₃, CaCl₂ and ZnCl₂ in a molar ratio of 10:1 to the drug led to significantly decreased drug permeation. According to these results the co-administration of Al³⁺, Ca²⁺ or Zn²⁺ as well as of supplementary medications containing these polyvalent ions is in case of oral Dolutegravir delivery not recommended.     

Conjugated Linoleic Acid Isomers, t10c12 and c9t11, are Differentially Incorporated into Adipose Tissue and Skeletal Muscle in Humans

Conjugated linoleic acid (CLA) is a popular supplement believed to enhance immune function, body composition and insulin sensitivity, but results of scientific studies investigating its effects are conflicting. The isomer- and tissue-specific effects of CLA may explain these conflicting results. Therefore, this study quantified the incorporation of the c9t11 and t10c12 CLA isomers into adipose tissue and skeletal muscle in response to supplementation in healthy, regularly-exercising, non-obese persons. The CLA group (n = 14) ingested 3.9 g per day CLA (50:50 t9c11:c10t12) and the placebo group (n = 11) 3.9 g per day high-oleic-acid sunflower oil for 12 weeks. Following supplementation, the t10c12 isomer was incorporated into adipose tissue triacylglycerol (P < 0.001), and the c9t11 isomer tended to increase in skeletal muscle phospholipids (P = 0.056). Therefore, human adipose tissue and skeletal muscle are enriched with CLA in an isomer-specific manner.