Challenges and opportunities in crowdsourced delivery planning and operations

4OR - How to best deliver goods to consumers has been a logistics question since time immemorial. However, almost all traditional delivery models involved a form of company employees, whether...     

Electrochemical sensing of trypanosome- and flavivirus-related neglected tropical diseases

Virus infections and parasitic diseases that are often found in tropical countries represent a large burden on societies in those regions but are unfortunately rarely studied by electrochemistry. These neglected tropical diseases (NTDs) are a concerning issue, especially in developing nations because a challenged healthcare system often negatively affects the economy. Besides the exploration of new treatment strategies, the development of early diagnostic methods is crucial to attenuate negative impacts related to NTDs. This review highlights the most recent developments of electrochemical biosensing efforts for five NTDs, Chagas disease, leishmaniasis, sleeping sickness, dengue fever and Zika virus infection, which affect a number of Latin American, African, and Asian countries. Special focus is placed on the design and fabrication of genosensors and immunosensors, designed as innovative and promising diagnostic tools with the potential of being integrated into portable systems to advance the development of point-of-care devices.     

A Novel Penning‐Trap Design for the High‐Precision Measurement of the 3He2 + Nuclear Magnetic Moment

A new experiment is constructed aiming at the first direct high‐precision measurement of the helium‐3 nuclear magnetic moment with a relative precision of parts‐per‐billion or better. Methods similar to those used in proton and antiproton magnetic moment measurements are applied. As those techniques rely on the challenging detection of single spin‐flips, a novel Penning trap design optimized for nuclear spin‐flip detection is developed.     

Thermionic emission from the fullerenes

Delayed ionisation of the fullerenes is reported over a timescale of up to 16 µs and compared to the Klots' model for thermionic emission [1]. The laser fluence dependence of the observed time constants for ionisation and the measured dependence on cluster size are in good agreement with model predictions giving strong evidence for the thermionic nature of the ionisation process.     

Zur Zustandsdichte der Übergangsmetalle

X-ray bremsstrahlung isochromats of the hcp metals Sc, Ti, Y, Zr, Lu, Hf and of the fcc metals La, Ce have been measured with high resolution under comparable conditions. The isochromats show, that the width of the conduction band (d-band) grows from the 3d-to the 5d-row of the periodic table; within each row a rigid-band-model seems to be valid. In the 5d-row only Lu fits well into this general trend of the transition metals: an X-ray spectroscopic argument, that Lu, but not La, should be placed below Sc and Y in the periodic table. Long range, low frequency spin fluctuations, which appear in Sc, Y, Lu, are not visible in the observed isochromat curves.     

Energieverteilungen in thermisch ausgelösten Elektronenstrahlen

In contrast with the original Maxwellian distribution of thermionically emitted electrons, there appear in electron beams so-called anomalous shiftings and broadenings as well as symmetrizations of the energy distribution (Boersch 1954). These anomalies are ascribed to a phenomenon of relaxation with the energy distribution changing to a new equilibrium. A relation is given to connect beginning relaxation with cathode temperature, accelerating voltage and beam current densityj _s. The relative energy broadening is found to be proportional toj _s ^1/3 . This is verified experimentally. It is shown that strong relaxation is already acting in the accelerating region. The influence of source geometry, especially source aperture, is discussed. The mechanism of relaxation is derived from general principles. Therefore it could turn out to be of importance for other corpuscular beams also.     

The effects of dissolved oxygen upon amide proton relaxation and chemical shift in a perdeuterated protein

The effects of dissolved molecular oxygen upon amide proton ((1)H(N)) longitudinal and transverse relaxation rates and chemical shifts were studied for a small protein domain, the second type 2 module of fibronectin ((2)F2)-isotopically enriched to 99% (2)H, 98% (15)N. Longitudinal relaxation rate enhancements, R(O(2))((1)H(N)), of individual backbone (1)H(N) nuclei varied up to 14 fold between a degassed and oxygenated (1 bar) solution, indicating that the oxygen distribution within the protein is inhomogeneous. On average, smaller relaxation rate enhancements were observed for (1)H(N) nuclei associated with the core of the protein compared to (1)H(N) nuclei closer to the surface, suggesting restricted oxygen accessibility to some regions. In agreement with an O(2)-(1)H(N) hyperfine interaction in the extreme narrowing limit, the (1)H(N) transverse relaxation rates showed no significant change, up to an oxygen pressure of 9.5 bar (the maximum pressure used in this study). For most (1)H(N) resonances, small deltadelta(O(2))((1)H(N)) hyperfine chemical shifts could be detected between oxygen pressures of 1 bar and 9.5 bar.