Production of organic seeds: Status, Challenges and Prospects

General article on the requirements of organic agriculture for seed production. Beside this the organic agricultural system has other demands for organic seed since it does not use chemical control measures and uses natural fertilizers instead of chemical fertilizers. Research can offer an important contribution in the production of seed without diseases

Quantitative methods for differentiation of vegetable and animal proteins in foods II

Op verzoek van de Nederlandse delegatie van het Codex Committee on vegetable proteins (CXVP) is een tweede "working paper" over de differentiatie van plantaardige en dierlijke eiwitten in voedingsmiddelen samengesteld. Deze "working paper" is een vervolg op de eerste van november 1981 over hetzelfde onderwerp (RIKILT- verslag 82.43). Ze beschrijft welke vooruitgang het kwantitatieve onderzoek van eiwitten van plantaardige en dierlijke oorsprong gedurende de afgelopen twee jaar heeft gemaakt

Trajectories of imaging markers in brain aging: the Rotterdam Study

With aging, the brain undergoes several structural changes. These changes reflect the normal aging process and are therefore not necessarily pathologic. In fact, better understanding of these normal changes is an important cornerstone to also disentangle pathologic changes. Several studies have investigated normal brain aging, both cross-sectional and longitudinal, and focused on a broad range of magnetic resonance imaging (MRI) markers. This study aims to comprise the different aspects in brain aging, by performing

Extreme hydrogen plasma densities achieved in a linear plasma generator

A magnetized hydrogen plasma beam was generated with a cascaded arc, expanding in a vacuum vessel at an axial magnetic field of up to 1.6 T. Its characteristics were measured at a distance of 4 cm from the nozzle: up to a 2 cm beam diameter, 7.5×1020 m-3 electron density, ~2 eV electron and ion temperatures, and 3.5 km/s axial plasma velocity. This gives a 2.6×1024 H+ m-2 s-1 peak ion flux density, which is unprecedented in linear plasma generators. The high efficiency of the source is obtained by the combined action of the magnetic field and an optimized nozzle geometry. This is interpreted as a cross-field return current that leads to power dissipation in the beam just outside the source

Structural identification and biological activity of 7-methyl-10,11-ethylenedioxy-20(S)-camptothecin, a photodegradant of lurtotecan

An additional chromatographic peak was observed in plasma samples of patients receiving NX 211, a liposomal formulation of the topoisomerase I inhibitor lurtotecan. We have isolated and purified this product by sequential solid-phase extractions, and we report its structure and cytotoxicity relative to lurtotecan and related agents. Nuclear magnetic resonance data indicate that cleavage of the piperazino moiety occurred at the N-C bond of the B-ring, yielding 7-methyl-10,11-ethylenedioxy-20(S)-camptothecin (MEC). Tests of the growth inhibition potential of MEC in seven human tumor cell lines showed that the compound was approximately 2-18-fold more cytotoxic than lurtotecan, topotecan, and 7-ethyl-10-hydroxy-20(S)-camptothecin (SN-38). Subsequently, we found that MEC was the product of rapid photolysis of lurtotecan, with the rate of degradation inversely proportional to NX 211 concentrations, and greatly depends on light intensity. Furthermore, MEC concentrations were found to increase significantly in plasma samples exposed to laboratory light but not in blood. MEC was not produced from NX 211 in the presence of human liver microsomes, suggesting that it is not a product of cytochrome P-450 metabolism. Using a validated analytical method, trace levels of MEC were quantitated in blood samples of two patients. These observations confirm that the precautions for protection from light currently specified for preparation and administration of NX 211 dose solutions are critical. Procedures to minimize formation of MEC, by the use of amber vials for NX 211 and by preparation of dilutions immediately before clinical use in a fashion completely protected from light, are now being routinely implemented

Retinal-Based Proton Pumping in the Near Infrared

Solid state NMR/Biophysical Organic Chemistr

Twitch and tetanic tension during culture of mature Xenopus laevis single muscle fibres

Investigation of the mechanisms of muscle adaptation requires independent control of the regulating factors. The aim of the present study was to develop a serum-free medium to culture mature single muscle fibres of Xenopus laevis. As an example, we used the culture system to study adaptation of twitch and tetanic force characteristics, number of sarcomeres in series and fibre cross-section. Fibres dissected from m. iliofibularis (n = 10) were kept in culture at a fibre mean sarcomere length of 2.3 µm in a culture medium without serum. Twitch and tetanic tension were determined daily. Before and after culture the number of sarcomeres was determined by laser diffraction and fibre cross-sectional area (CSA) was determined by microscopy. For five fibres twitch tension increased during culture and tetanic tension was stable for periods varying from 8 to 14 days (‘stable fibres’), after which fibres were removed from culture for analysis. Fibre CSA and the number of sarcomeres in series remained constant during culture. Five other fibres showed a substantial reduction in twitch and tetanic tension within the first five days of culture (‘unstable fibres’). After 7–9 days of culture, three of these fibres died. For two of the unstable fibres, after the substantial force reduction, twitch and tetanic tension increased again. Finally at day 14 and 18 of culture, respectively, the tensions attained values higher than their original values. For stable fibres, twitch contraction time, twitch half-relaxation time and tetanus 10%-relaxation time increased during culture. For unstable fibres these parameters fluctuated. For all fibres the stimulus threshold fluctuated during the first two days, and then remained constant, even for the fibres that were cultured for at least two weeks. It is concluded that the present culture system for mature muscle fibres allows long-term studies within a well-defined medium. Unfortunately, initial tetanic and twitch force are poor predictors of the long-term behaviour of the fibres

Transport of high fluxes of hydrogen plasma in a linear plasma generator

A study was made to quantify the losses during the convective hydrogen plasma transport in the linear plasma generator Pilot-PSI due to volume recombination. A transport efficiency of 35% was achieved at neutral background pressures below ~7 Pa in a magnetic field of 1.2 T. This efficiency decreased to essentially zero at higher pressures. At 1.6 T, the measured downstream plasma density was up to double the upstream density. Apparently plasma pumping and recycling at the target start to play a role under these increased confinement conditions. Feeding the plasma column at this field strength with a net current did not change the downstream density. This indicates that recycling sets the local plasma conditions

Rehabilitation:mobility, exercise & sports; a critical position stand on current and future research perspectives

Background Human movement, rehabilitation, and allied sciences have embraced their ambitions within the cycle of “RehabMove” congresses over the past 30 years. This combination of disciplines and collaborations in the Netherlands has tried to provide answers to questions in the fields of rehabilitation and adapted sports, while simultaneously generating new questions and challenges. These research questions help us to further deepen our understanding of (impaired) human movement and functioning, with and without supportive technologies, and stress the importance of continued multidisciplinary (inter)national collaboration. Methods This position stand provides answers that were conceived by the authors in a creative process underlining the preparation of the 6th RehabMove Congress. Results The take-home message of the RehabMove2018 Congress is a plea for continued multidisciplinary research in the fields of rehabilitation and adapted sports. This should be aimed at more individualized notions of human functioning, practice, and training, but also of performance, improved supportive technology, and appropriate “human and technology asset management” at both individual and organization levels and over the lifespan. Conclusions With this, we anticipate to support the development of rehabilitation sciences and technology and to stimulate the use of rehabilitation notions in general health care. We also hope to help ensure a stronger embodiment of preventive and lifestyle medicine in rehabilitation practice. Indeed, general health care and rehabilitation practice require a healthy and active lifestyle management and research agenda in the context of primary, secondary, and tertiary prevention. IMPLICATIONS FOR REHABILITATION Continued multidisciplinary (international) collaboration will stimulate the development of rehabilitation and human movement sciences. Notions from “human and technology asset management and ergonomics” are fundamental to rehabilitation practice and research. The rehabilitation concept will further merge into general health care and the quality there-off