Amyloid-beta peptide degradation in cell cultures by mycoplasma contaminants

<p>Abstract</p> <p>Background</p> <p>Cell cultures have become an indispensable tool in Alzheimer's disease research for studying amyloid-β (Aβ) metabolism. It is estimated that up to 35% of cell cultures in current use are infected with various mycoplasma species. In contrast with common bacterial and fungal infections, contaminations of cell cultures with mycoplasmas represent a challenging issue in terms of detectability and prevention. Mycoplasmas are the smallest and simplest self-replicating bacteria and the consequences of an infection for the host cells are variable, ranging from no apparent effect to induction of apoptosis.</p> <p>Findings</p> <p>Here we present evidence that mycoplasmas from a cell culture contamination are able to efficiently and rapidly degrade extracellular Aβ. As a result, we observed no accumulation of Aβ in the conditioned medium of mycoplasma-positive cells stably transfected with the amyloid-β precursor protein (APP). Importantly, eradication of the mycoplasma contaminant – identified as <it>M. hyorhinis </it>– by treatments with a quinolone-based antibiotic, restored extracellular Aβ accumulation in the APP-transfected cells.</p> <p>Conclusion</p> <p>These data show that mycoplasmas degrade Aβ and thus may represent a significant source of variability when comparing extracellular Aβ levels in different cell lines. On the basis of these results, we recommend assessment of mycoplasma contaminations prior to extracellular Aβ level measurements in cultured cells.</p

Improving Video Colorization by Test-Time Tuning

With the advancements in deep learning, video colorization by propagating color information from a colorized reference frame to a monochrome video sequence has been well explored. However, the existing approaches often suffer from overfitting the training dataset and sequentially lead to suboptimal performance on colorizing testing samples. To address this issue, we propose an effective method, which aims to enhance video colorization through test-time tuning. By exploiting the reference to construct additional training samples during testing, our approach achieves a performance boost of 1~3 dB in PSNR on average compared to the baseline. Code is available at: https://github.com/IndigoPurple/T3Comment: 5 pages, 4 figure

Therapeutic potential of resveratrol in Alzheimer's disease

Several epidemiological studies indicate that moderate consumption of red wine is associated with a lower incidence of dementia and Alzheimer's disease. Red wine is enriched in antioxidant polyphenols with potential neuroprotective activities. Despite scepticism concerning the bioavailability of these polyphenols, in vivo data have clearly demonstrated the neuroprotective properties of the naturally occurring polyphenol resveratrol in rodent models for stress and diseases. Furthermore, recent work in cell cultures and animal models has shed light on the molecular mechanisms potentially involved in the beneficial effects of resveratrol intake against the neurodegenerative process in Alzheimer's disease

Supercurrent, Multiple Andreev Reflections and Shapiro Steps in InAs Nanosheet Josephson Junctions

High-quality free-standing InAs nanosheets are emerging layered semiconductor materials with potentials in designing planar Josephson junction devices for novel physics studies due to their unique properties including strong spin-orbit couplings, large Land\'e g-factors and the two dimensional nature. Here, we report an experimental study of proximity induced superconductivity in planar Josephson junction devices made from free-standing InAs nanosheets. The nanosheets are grown by molecular beam epitaxy and the Josephson junction devices are fabricated by directly contacting the nanosheets with superconductor Al electrodes. The fabricated devices are explored by low-temperature carrier transport measurements. The measurements show that the devices exhibit a gate-tunable supercurrent, multiple Andreev reflections, and a good quality superconductor-semiconductor interface. The superconducting characteristics of the Josephson junctions are investigated at different magnetic fields and temperatures, and are analyzed based on the Bardeen-Cooper-Schrieffer (BCS) theory. The measurements of ac Josephson effect are also conducted under microwave radiations with different radiation powers and frequencies, and integer Shapiro steps are observed. Our work demonstrates that InAs nanosheet based hybrid devices are desired systems for investigating forefront physics, such as the two-dimensional topological superconductivity

O2ATH: An OpenMP Offloading Toolkit for the Sunway Heterogeneous Manycore Platform

The next generation Sunway supercomputer employs the SW26010pro processor, which features a specialized on-chip heterogeneous architecture. Applications with significant hotspots can benefit from the great computation capacity improvement of Sunway many-core architectures by carefully making intensive manual many-core parallelization efforts. However, some legacy projects with large codebases, such as CESM, ROMS and WRF, contain numerous lines of code and do not have significant hotspots. The cost of manually porting such applications to the Sunway architecture is almost unaffordable. To overcome such a challenge, we have developed a toolkit named O2ATH. O2ATH forwards GNU OpenMP runtime library calls to Sunway's Athread library, which greatly simplifies the parallelization work on the Sunway architecture.O2ATH enables users to write both MPE and CPE code in a single file, and parallelization can be achieved by utilizing OpenMP directives and attributes. In practice, O2ATH has helped us to port two large projects, CESM and ROMS, to the CPEs of the next generation Sunway supercomputers via the OpenMP offload method. In the experiments, kernel speedups range from 3 to 15 times, resulting in 3 to 6 times whole application speedups.Furthermore, O2ATH requires significantly fewer code modifications compared to manually crafting CPE functions.This indicates that O2ATH can greatly enhance development efficiency when porting or optimizing large software projects on Sunway supercomputers.Comment: 15 pages, 6 figures, 5 tables

Evaluating the importation of yellow fever cases into China in 2016 and strategies used to prevent and control the spread of the disease

During the yellow fever epidemic in Angola in 2016, cases of yellow fever were reported in China for the first time. The 11 cases, all Chinese nationals returning from Angola, were identified in March and April 2016, one to two weeks after the peak of the Angolan epidemic. One patient died; the other 10 cases recovered after treatment. This paper reviews the epidemiological characteristics of the 11 yellow fever cases imported into China. It examines case detection and disease control and surveillance, and presents recommendations for further action to prevent additional importation of yellow fever into China

Protective Effect of Anthocyanin from Lonicera Caerulea var. Edulis on Radiation-Induced Damage in Mice

The radioprotective effect of anthocyanin extracted from Lonicera caerulea var. edulis (ALC), was studied in ICR mice. Different doses of ALC were intragastrically administered to mice once a day, prior to radiation. After two weeks, the mice received a one-time 5 Gy whole body 60Coγ radiation. The spleen index, thymus index, activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), malondialdehyde (MDA) content, and glutathione (GSH) content in liver tissue were measured. Compared with the radiation control group, the levels of MDA in all ALC treated groups decreased significantly (p < 0.05). Moreover, the GSH content, activities of SOD and GSH-Px in liver tissue were enhanced significantly (p < 0.05) in all ALC groups. These results demonstrate that ALC may be a potential radioprotector, and a further study of the molecular mechanism is needed for further application