Design and evaluation of a Facebook game for self-directed e-learning

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Immunogenetics in SARS: a case-control study.

Key Messages: 1. Human leukocyte antigen (HLA) genotypes from 102 SARS patients (susceptible) and 108 SARS contacts (resistant) were obtained. 2. Allelic frequencies of the Class I (HLA-A, -B, and -Cw) and Class II (HLA-DR and -DQ) genes from these genetically unrelated subjects were compared. 3. A significantly higher frequency of DRB4*01010101 was found in the SARS-susceptible than SARS-resistant group. In contrast, significantly higher frequencies of HLA-B*1502 and HLADRB3*030101 were found in the SARS-resistant than SARSsusceptible group. However, none of these associations was significant after Bonferroni correction. Further, analysis of 10/36 genetically related families did not reveal any HLA alleles associated with SARS susceptibility or resistance. 4. We could not confirm previous findings of an HLA association with susceptibility or resistance to SARS. The significance of these associations needs to be validated by further independent studies.published_or_final_versio

Selectively tunable optical Stark effect of anisotropic excitons in atomically thin ReS2

The optical Stark effect is a coherent light-matter interaction describing the modification of quantum states by non-resonant light illumination in atoms, solids and nanostructures. Researchers have strived to utilize this effect to control exciton states, aiming to realize ultra-high-speed optical switches and modulators. However, most studies have focused on the optical Stark effect of only the lowest exciton state due to lack of energy selectivity, resulting in low degree-of-freedom devices. Here, by applying a linearly polarized laser pulse to few-layer ReS2, where reduced symmetry leads to strong in-plane anisotropy of excitons, we control the optical Stark shift of two energetically separated exciton states. Especially, we selectively tune the Stark effect of an individual state with varying light polarization. This is possible because each state has a completely distinct dependence on light polarization due to different excitonic transition dipole moments. Our finding provides a methodology for energy-selective control of exciton states.111612Ysciescopu

1s-intraexcitonic dynamics in monolayer MoS2 probed by ultrafast mid-infrared spectroscopy

The 1s exciton-the ground state of a bound electron-hole pair-is central to understanding the photoresponse of monolayer transition metal dichalcogenides. Above the 1s exciton, recent visible and near-infrared investigations have revealed that the excited excitons are much richer, exhibiting a series of Rydberg-like states. A natural question is then how the internal excitonic transitions are interrelated on photoexcitation. Accessing these intraexcitonic transitions, however, demands a fundamentally different experimental tool capable of probing optical transitions from 1s 'bright' to np 'dark' states. Here we employ ultrafast midinfrared spectroscopy to explore the 1s intraexcitonic transitions in monolayer MoS2. We observed twofold 1s-3p intraexcitonic transitions within the A and B excitons and 1s-2p transition between the A and B excitons. Our results revealed that it takes about 0.7 ps for the 1s A exciton to reach quasi-equilibrium; a characteristic time that is associated with a rapid population transfer from the 1s B exciton, providing rich characteristics of many-body exciton dynamics in two-dimensional materials.112412Ysciescopu

Highly photoresponsive and wavelength-selective circularly-polarized-light detector based on metal-oxides hetero-chiral thin film

A highly efficient circularly-polarized-light detector with excellent wavelength selectivity is demonstrated with an elegant and simple microelectronics-compatible way. The circularly-polarized-light detector based on a proper combination of the geometry-controlled TiO2-SnO2 hetero-chiral thin film as an effective chiroptical filter and the Si active layer shows excellent chiroptical response with external quantum efficiency as high as 30% and high helicity selectivity of similar to 15.8% in an intended wavelength range. Furthermore, we demonstrated the ability of manipulating both bandwidth and responsivity of the detector simultaneously in whole visible wavelength range by a precise control over the geometry and materials constituting hetero-chiral thin film. The high efficiency, wavelength selectivity and compatibility with conventional microelectronics processes enabled by the proposed device can result in remarkable developments in highly integrated photonic platforms utilizing chiroptical responses.1166Ysciescopu

Thermoelectric materials by using two-dimensional materials with negative correlation between electrical and thermal conductivity

In general, in thermoelectric materials the electrical conductivity sigma and thermal conductivity kappa are related and thus cannot be controlled independently. Previously, to maximize the thermoelectric figure of merit in state-of-the-art materials, differences in relative scaling between sigma and kappa as dimensions are reduced to approach the nanoscale were utilized. Here we present an approach to thermoelectric materials using tin disulfide, SnS2, nanosheets that demonstrated a negative correlation between sigma and kappa. In other words, as the thickness of SnS2 decreased, sigma increased whereas kappa decreased. This approach leads to a thermoelectric figure of merit increase to 0.13 at 300 K, a factor similar to 1,000 times greater than previously reported bulk single-crystal SnS2. The Seebeck coefficient obtained for our two-dimensional SnS2 nanosheets was 34.7mVK(-1) for 16-nm-thick samples at 300 K.114330Ysciescopu

Oral immunization of haemaggulutinin H5 expressed in plant endoplasmic reticulum with adjuvant saponin protects mice against highly pathogenic avian influenza A virus infection

Pandemics in poultry caused by the highly pathogenic avian influenza (HPAI) A virus occur too frequently globally, and there is growing concern about the HPAI A virus due to the possibility of a pandemic among humans. Thus, it is important to develop a vaccine against HPAI suitable for both humans and animals. Various approaches are underway to develop such vaccines. In particular, an edible vaccine would be a convenient way to vaccinate poultry because of the behaviour of the animals. However, an edible vaccine is still not available. In this study, we developed a strategy of effective vaccination of mice by the oral administration of transgenic Arabidopsis plants (HA-TG) expressing haemagglutinin (HA) in the endoplasmic reticulum (ER). Expression of HA in the ER resulted in its high-level accumulation, N-glycosylation, protection from proteolytic degradation and long-term stability. Oral administration of HA-TG with saponin elicited high levels of HA-specific systemic IgG and mucosal IgA responses in mice, which resulted in protection against a lethal influenza virus infection with attenuated inflammatory symptoms. Based on these results, we propose that oral administration of freeze-dried leaf powders from transgenic plants expressing HA in the ER together with saponin is an attractive strategy for vaccination against influenza A virus.X111411Ysciescopu

The highly rearranged mitochondrial genomes of the crabs Maja crispata and Maja squinado (Majidae) and gene order evolution in Brachyura

Abstract We sequenced the mitochondrial genomes of the spider crabs Maja crispata and Maja squinado (Majidae, Brachyura). Both genomes contain the whole set of 37 genes characteristic of Bilaterian genomes, encoded on both \u3b1- and \u3b2-strands. Both species exhibit the same gene order, which is unique among known animal genomes. In particular, all the genes located on the \u3b2-strand form a single block. This gene order was analysed together with the other nine gene orders known for the Brachyura. Our study confirms that the most widespread gene order (BraGO) represents the plesiomorphic condition for Brachyura and was established at the onset of this clade. All other gene orders are the result of transformational pathways originating from BraGO. The different gene orders exhibit variable levels of genes rearrangements, which involve only tRNAs or all types of genes. Local homoplastic arrangements were identified, while complete gene orders remain unique and represent signatures that can have a diagnostic value. Brachyura appear to be a hot-spot of gene order diversity within the phylum Arthropoda. Our analysis, allowed to track, for the first time, the fully evolutionary pathways producing the Brachyuran gene orders. This goal was achieved by coupling sophisticated bioinformatic tools with phylogenetic analysis

A commensal symbiotic interrelationship for the growth of Symbiobacterium toebii with its partner bacterium, Geobacillus toebii

<p>Abstract</p> <p>Background</p> <p><it>Symbiobacterium toebii </it>is a commensal symbiotic thermophile that absolutely requires its partner bacterium <it>Geobacillus toebii </it>for growth. Despite development of an independent cultivation method using cell-free extracts, the growth of <it>Symbiobacterium </it>remains unknown due to our poor understanding of the symbiotic relationship with its partner bacterium. Here, we investigated the interrelationship between these two bacteria for growth of <it>S. toebii </it>using different cell-free extracts of <it>G. toebii</it>.</p> <p>Results</p> <p><it>Symbiobacterium toebii </it>growth-supporting factors were constitutively produced through almost all growth phases and under different oxygen tensions in <it>G. toebii</it>, indicating that the factor may be essential components for growth of <it>G. toebii </it>as well as <it>S. toebii</it>. The growing conditions of <it>G. toebii </it>under different oxygen tension dramatically affected to the initial growth of <it>S. toebii </it>and the retarded lag phase was completely shortened by reducing agent, L-cysteine indicating an evidence of commensal interaction of microaerobic and anaerobic bacterium <it>S. toebii </it>with a facultative aerobic bacterium <it>G. toebii</it>. In addition, the growth curve of <it>S. toebii </it>showed a dependency on the protein concentration of cell-free extracts of <it>G. toebii</it>, demonstrating that the <it>G. toebii</it>-derived factors have nutrient-like characters but not quorum-sensing characters.</p> <p>Conclusions</p> <p>Not only the consistent existence of the factor in <it>G. toebii </it>during all growth stages and under different oxygen tensions but also the concentration dependency of the factor for proliferation and optimal growth of <it>S. toebii</it>, suggests that an important biosynthetic machinery lacks in <it>S. toebii </it>during evolution. The commensal symbiotic bacterium, <it>S. toebii </it>uptakes certain ubiquitous and essential compound for its growth from environment or neighboring bacteria that shares the equivalent compounds. Moreover, <it>G. toebii </it>grown under aerobic condition shortened the lag phase of <it>S. toebii </it>under anaerobic and microaerobic conditions, suggests a possible commensal interaction that <it>G. toebii </it>scavengers ROS/RNS species and helps the initial growth of <it>S. toebii</it>.</p

Gender differences in predictors of colorectal cancer screening uptake: A national cross sectional study based on the health belief model

10.1186/1471-2458-13-677BMC Public Health131