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Ferroelectric field-effect transistors employ a ferroelectric material as a gate insulator, the polarization state of which can be detected using the channel conductance of the device. As a result, the devices are of potential to use in non-volatile memory technology, but suffer from short retention times, which limits their wider application. Here we report a ferroelectric semiconductor field-effect transistor in which a two-dimensional ferroelectric semiconductor, indium selenide ({\alpha}-In2Se3), is used as the channel material in the device. {\alpha}-In2Se3 was chosen due to its appropriate bandgap, room temperature ferroelectricity, ability to maintain ferroelectricity down to a few atomic layers, and potential for large-area growth. A passivation method based on the atomic-layer deposition of aluminum oxide (Al2O3) was developed to protect and enhance the performance of the transistors. With 15-nm-thick hafnium oxide (HfO2) as a scaled gate dielectric, the resulting devices offer high performance with a large memory window, a high on/off ratio of over 108, a maximum on-current of 862 {\mu}A {\mu}m-1, and a low supply voltage., Comment: 44 pages, 16 figures

The combination of mixed-dimensional semiconducting materials can provide additional freedom to construct integrated nanoscale electronic and optoelectronic devices with diverse functionalities. In this work, we report a high-performance dual-channel phototransistor based on one-dimensional (1D)/two-dimensional (2D) trigonal selenium (t-Se)/ReS2 heterostructures grown by chemical vapor deposition. The injection and separation efficiency of photogenerated electron–hole pairs can be greatly improved due to the high-quality interfacial contact between t-Se nanobelts and ReS2 films. Compared with bare ReS2 film devices, the dual-channel phototransistor based on t-Se/ReS2 heterostructure exhibits considerable enhancement with the responsivity (R) and detectivity (D*) up to 98 A·W–1 and 6 × 1010 Jones at 400 nm illumination with an intensity of 1.7 mW·cm−2, respectively. Besides, the response time can also be reduced by three times of magnitude to less than 50 ms due to the type-II band alignment at the interface. This study opens up a promising avenue for high-performance photodetectors by constructing mixed-dimensional heterostructures.

We report on progress to improve the free space coupling and Purcell enhancement of a diamond microdisk resonator using eigenfrequency modal analysis and robust topology optimization.

We propose and optimize a vertically-loaded diamond microdisk resonator (VLDMoRt) coupled to a nitrogen-vacancy (NV) center in diamond for efficient collection of zero-phonon-line emission into low numerical aperture ($\text{NA}$) free-space modes. The VLDMoRt achieves a Purcell enhancement of 172 with $39\%$ of the emitted light collected within a $\text{NA}$ of 0.6, leading to a total external spin-photon collection efficiency of 0.33. As the design is compatible with established nanofabrication techniques and couples to low-NA modes accessible by cryogenic free-space optical systems, it is a promising platform for efficient spin-photon interfaces based on diamond quantum emitters.

We design and fabricate a vertically loaded diamond microdisk resonator (VLDMoRt) that enhances spin-photon entanglement generation and free-space fiber- matched coupling rate from quantum emitters.

As humans and climate change continue to alter the landscape, novel disease risk scenarios have emerged. Sever fever with thrombocytopenia syndrome (SFTS), an emerging tick-borne infectious disease first discovered in rural areas of central China in 2009, is caused by a novel bunyavirus (SFTSV). The potential for SFTS to spread to other countries in combination with its high fatality rate, possible human-to-human transmission, and extensive prevalence among residents and domesticated animals in endemic regions make the disease a severe threat to public health. Because of the lack of preventive vaccines or useful antiviral drugs, diagnosis of SFTS is the key to prevention and control of the SFTSV infection. The development of serological detection methods will greatly improve our understanding of SFTSV ecology and host tropism. We describe a highly sensitive protein detection method based on gold nanoparticles (AuNPs) and enzyme-linked immunosorbent assay (ELISA)&mdash, AuNP-based ELISA. The optical sensitivity enhancement of this method is due to the high loading efficiency of AuNPs to McAb. This enhances the concentration of the HRP enzyme in each immune sandwich structure. The detection limit of this method to the nucleocapsid protein (NP) of SFTSV was 0.9 pg mL&minus, 1 with good specificity and reproducibility. The sensitivity of AuNP-based ELISA was higher than that of traditional ELISA and was comparable to real-time quantitative polymerase chain reaction (qRT-PCR). The probes are stable for 120 days at 4 &deg, C. This can be applied to diagnosis and hopefully can be developed into a commercial ELISA kit. The ultrasensitive detection of SFTSV will increase our understanding of the distribution and spread of SFTSV, thus helping to monitor the changes in tick-borne pathogen SFTSV risk in the environment.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging hemorrhagic fever disease caused by SFTSV, a newly discovered phlebovirus that is named after the disease. Currently, no effective vaccines or drugs are available for use against SFTSV infection, as our understanding of the viral pathogenesis is limited. Bortezomib (PS-341), a dipeptide-boronic acid analog, is the first clinically approved proteasome inhibitor for use in humans. In this study, the antiviral efficacy of PS-341 against SFTSV infection was tested in human embryonic kidney HEK293T (293T) cells. We employed four different assays to analyze the antiviral ability of PS-341 and determined that PS-341 inhibited the proliferation of SFTSV in 293T cells under various treatment conditions. Although PS-341 did not affect the virus absorption, PS-341 treatment within a non-toxic concentration range resulted in a significant reduction of progeny viral titers in infected cells. Dual-luciferase reporter assays and Western blot analysis revealed that PS-341 could reverse the SFTSV-encoded non-structural protein (NS) mediated degradation of retinoic acid-inducible gene-1 (RIG-I), thereby antagonizing the inhibitory effect of NSs on interferons and blocking virus replication. In addition, we observed that inhibition of apoptosis promotes virus replication. These results indicate that targeting of cellular interferon pathways and apoptosis during acute infection might serve as the bases of future therapeutics for the treatment of SFTSV infections. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s12250-019-00162-9) contains supplementary material, which is available to authorized users.

This Research Category Full Paper explores the relationship between the demographic characteristics of students and their participation in an online forum. Online discussion forums have become widely used in undergraduate classrooms. They extend the learning space beyond the classroom and provide asynchronous opportunities for peer-to-peer collaborations. Past studies have suggested that online posting behavior plays a role in students’ learning outcomes; however, the study of the demographic characteristics of students who do or do not participate in online discussions is limited. We address this research question here. We chose our demographic variables based on prior studies of students’ general online behaviors, and therefore we compare gender, race/ethnicity and international status, as well as declared majors, with engagement in the online forum. The discussion forum provided a platform for the students to ask or answer their peers’ questions about the course material and homework assignments. The setting for this study was a sophomore-level dynamics and vibrations class that incorporated active, blended, and collaborative learning strategies. We tracked an individual’s posting behavior throughout a semester. Study participants were grouped by whether they posted to the discussion forum at least once, and the Chi-squared test of independence was used to determine the statistical significance of demographic differences across the participation groups. The data show that female students were significantly more likely to be involved in online discussions than their male counterparts. Also, White and Asian American students were overrepresented, and international and Hispanic students were underrepresented in the engaged group. Interestingly, students who were required to take this specific course as a graduation requirement do not show more engagement than those who took this class for general engineering credits. This work extends our knowledge of who uses online collaboration tools, and in the future, we will analyze the content of the engagement (posts and comments) and explore the influence of forum participation on the students’ grades.

We demonstrate room-temperature ferroelectric field-effect transistors (Fe-FETs) with MoS

The distribution of haptoglobin (HP) types was examined in six different Chinese ethnic groups. The gene frequencies were compared among these groups and to those reported in other Chinese Han populations. The effects of sex and age on the distribution of HP types are also discussed.