Towards matter-wave experiments with biomolecules : generation and detection of neutral biomolecular beams

The thesis aimed to identify chemical modifications for biomolecules such as peptides and proteins to make these amenable for matter‐wave interference experiments. Crucial for matter‐wave interference experiments are charge neutral biomolecular beams, which had previously only been successfully formed for small peptides in a limited number of studies. Accordingly, a main focus of the thesis was set on the formation of such beams in close collaboration with M. Arndt's group in Vienna. A second difficulty arises from the fact that neutral molecules are not detectable with common mass spectrometer detectors, i.e. electron multipliers. Consequently the ionization of neutral protein beams in high vacuum was a second central point of the presented studies. Various methods and approaches were investigated whereby the contribution of the author was concentrated on the design, synthesis and expression of the constructs for interrogation in matterwave experiments

Auguste Ghiesbreght’s natural history explorations in Oaxaca and other parts of Mexico until 1854

The authors review the zoological and botanical collections by Auguste Ghiesbreght from “Oaxaca” and other areas between 1838 and 1854. Taxonomically relevant are, for instance, the holotype of the Racer Coryphodon oaxaca Jan (Coluber constrictor L.), one of various amphibian and reptile species (coll. Ghiesbreght) not on record for Oaxaca, or a number of birds from southern Mexico implicitly attributed to Ghiesbreght but in fact gathered by other collectors. Zoological items and a plethora of plants from “Oaxaca” (coll. 1841–1854) encompassing many type specimens were obtained elsewhere, in particular the inland Gulf region between Hidalgo and the Orizaba Range. These results entail consequences regarding type localities or distribution, and possibly systematics, in different animal groups and botanical fields.Los autores revisan las colecciones de historia natural hechas por Auguste Ghiesbreght de “Oaxaca” y otras áreas entre 1838 y 1854. Especímenes de relevancia taxonómica son por ejemplo el holotipo de la ‘corredora’ Coryphodon oaxaca Jan (Coluber constrictor L.), una entre varias especies de anfibios y reptiles (col. Ghiesbreght) no registradas en el Estado de Oaxaca, o bien algunas aves de México meridional atribuidas implícitamente a Ghiesbreght pero en realidad recolectadas por otros naturalistas. Material zoológico y una multitud de plantas de “Oaxaca” (col. 1841–1854) incluyendo muchos especímenes tipo provienen de otras partes y particularmente de las regiones interiores del Golfo de México desde Hidalgo hasta el área del Pico de Orizaba. Estos resultados tienen consecuencias respecto a localidades tipo, distribución y posiblemente la sistemática en diferentes grupos de animales y campos de la botánica

Polarization determination for the studies of the eta meson production

The dynamics of $\eta$ meson production and the interaction of $\eta$ mesons with nucleons can be studied using the $\vec{p}p\rightarrow pp\eta$ reaction via measurements of the analyzing power $A_{y}$. To this end, we have performed a measurement of the $\vec{p}p\rightarrow pp\eta$ reaction using the large acceptance and $\varphi$ symmetric WASA-at-COSY detector, for beam momenta of 2026 MeV/c and 2188 MeV/c

Studies of systematic uncertainties of polarization estimation for experiments with the WASA detector at COSY

In November 2010, the azimuthally symmetric WASA detector and the polarized proton beam of COSY have been used to collect a high statistics sample of $\vec{p}p \rightarrow pp\eta$ reactions in order to determine the analyzing power as a function of the invariant mass spectra of the two-particle subsystems. Here, we show studies of the influence of the beam and target characteristics such as location and direction on the determination of degree of the polarization

Winterzwiebeln: Anbau IP oder Bio

Bei der Sorte Radar führt das Stecken von «grossen» Steckzwiebeln zu einem höheren Ertrag in beiden Anbausystemen, IP und Bio. Auch wird der Anteil an grossen und Metzgerzwiebeln gesteigert, besonders ausgeprägt unter IP-Bedingungen. Dies ging einher mit einer leichten Zunahme (<6%) der Schossneigung bei «grossen» Steckzwiebeln und frühem Stecktermin

Enzyme repurposing of a hydrolase as an emergent peroxidase upon metal binding

As an alternative to Darwinian evolution relying on catalytic promiscuity, a protein may acquire auxiliary function upon metal binding, thus providing it with a novel catalytic machinery. Here we show that addition of cupric ions to a 6-phosphogluconolactonase 6-PGLac bearing a putative metal binding site leads to the emergence of peroxidase activity (kcat7.8 × 10−2 s−1, KM 1.1 × 10−5 M). Both X-ray crystallographic and EPR data of the copper-loaded enzyme Cu·6-PGLacreveal a bis-histidine coordination site, located within a shallow binding pocket capable of accommodating the o-dianisidine substrate

Matter-wave interference and deflection of tripeptides decorated with fluorinated alkyl chains

Studies of neutral biomolecules in the gas phase allow for the study of molecular properties in the absence of solvent and charge effects, thus complementing spectroscopic and analytical methods in solution or in ion traps. Some properties, such as the static electronic susceptibility, are best accessed in experiments that act on the motion of the neutral molecules in an electric field. Here, we screen seven peptides for their thermal stability and electron impact ionizability. We identify two tripeptides as sufficiently volatile and thermostable to be evaporated and interfered in the long-baseline universal matter-wave interferometer. Monitoring the deflection of the interferometric molecular nanopattern in a tailored external electric field allows us to measure the static molecular susceptibility of Ala-Trp-Ala and Ala-Ala-Trp bearing fluorinated alkyl chains at C- and N-termini. The respective values are; 4; π; ε; 0; ×; 330; ±; 150; Å; 3; and; 4; π; ε; 0; ×; 270; ±; 80; Å; 3;

A prospective observational study comparing a non-operator dependent automatic PWV analyser to pulse pressure, in assessing arterial stiffness in hemodialysis.

BACKGROUND: Chronic kidney disease (CKD) accelerates vascular stiffening related to age. Arterial stiffness may be evaluated measuring the carotid-femoral pulse wave velocity (PWV) or more simply, as recommended by KDOQI, monitoring pulse pressure (PP). Both correlate to survival and incidence of cardiovascular disease. PWV can also be estimated on the brachial artery using a Mobil-O-Graph; a non-operator dependent automatic device. The aim was to analyse whether, in a dialysis population, PWV obtained by Mobil-O-Graph (MogPWV) is more sensitive for vascular aging than PP. METHODS: A cohort of 143 patients from 4 dialysis units has been followed measuring MogPWV and PP every 3 to 6 months and compared to a control group with the same risk factors but an eGFR &gt; 30 ml/min. RESULTS: MogPWV contrarily to PP did discriminate the dialysis population from the control group. The mean difference translated in age between the two populations was 8.4 years. The increase in MogPWV, as a function of age, was more rapid in the dialysis group. 13.3% of the dialysis patients but only 3.0% of the control group were outliers for MogPWV. The mortality rate (16 out of 143) was similar in outliers and inliers (7.4 and 8.0%/year). Stratifying patients according to MogPWV, a significant difference in survival was seen. A high parathormone (PTH) and to be dialysed for a hypertensive nephropathy were associated to a higher baseline MogPWV. CONCLUSIONS: Assessing PWV on the brachial artery using a Mobil-O-Graph is a valid and simple alternative, which, in the dialysis population, is more sensitive for vascular aging than PP. As demonstrated in previous studies PWV correlates to mortality. Among specific CKD risk factors only PTH is associated with a higher baseline PWV. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02327962