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Heterostructures of quantum dots (QDs) and two-dimensional (2D) materials show promising potential for photodetection applications owing to their combination of high optical absorption and good in-plane carrier mobility. In this work, the performance of QD-2D photodetectors is tuned by band engineering. Devices are fabricated by coating MoS2 nanosheets with InP QDs, type-I core-shell InP/ZnS QDs, and type-II core-shell InP/CdS QDs. Comparative spectroscopic and photoelectric studies of different hybrids show that the energy band alignment and shell thickness can influence the efficiency of charge transfer (CT), energy transfer (ET), and defect-related processes between QDs and MoS2. Benefiting from efficient CT between the QDs and MoS2, a significant enhancement of responsivity and detectivity is observed in thick-shell InP/CdS QD-MoS2 devices. Our results demonstrate the feasibility of using core-shell QDs for regulating the ET and CT efficiency in heterostructures and highlight the importance of interface band design in QD-2D and other low-dimensional photodetectors.

The aim of this study is to systematically examine the variety of viruses maintained in ticks from Shandong Province. A total of 2522 ticks were sampled from five cities of Shandong Province and divided into 264 pools according to location and species. Viral megagenomic analysis revealed the sequences of two viruses, Dabieshan tick virus and SFTSV. Then qRT-PCR and nested PCR were performed to confirm the presence of corresponding pathogens, which showed positive results for Dabieshan tick virus and SFTSV, with a minimum infection rate of 0.67% (17/2522) and 2.5% (63/2522), respectively. Phylogenetic analysis showed that Dabieshan tick virus formed a monophyletic cluster with the Yongjia tick virus and Uukuniemi virus from China, and SFTSV shared over 95% identity with human and animal derived isolates. These findings are the first time to demonstrate molecular evidence of Dabieshan tick virus in unrecognized endemic regions and indicate the need for further investigation.

Heterostructures of quantum dots (QDs) and two-dimensional (2D) materials show promising potential for photodetection applications owing to their combination of high optical absorption and good in-plane carrier mobility. In this work, the performance of QD-2D photodetectors is tuned by band engineering. Devices are fabricated by coating MoS

Charge transfer at the interface is important for the optoelectronic and photochemical applications of quantum dot-two-dimensional material (QD-2D) hybrids. In this work, Raman spectroscopy was exp...

Dabieshan tick virus (DTV) was first identified in Haemaphysalis longicornis from Hubei Province, China in 2015. However, its pathogenic potential to animals and human remains to be further explored. In this study, the presence of DTV in ticks and sheep samples was investigated. A total of 170 engorged ticks were collected from May to September 2019 from Taian and Yantai city, Shandong Province and were pooled individually to screening for DTV. The results of of qRT-PCR revealed the positive rate of 13.6% (3/22) in serum of sheep and 8.2% (14/170) in attached ticks, respectively. Phylogenetic analysis demonstrated a close evolutionary relationship among those DTV isolates from animal and ticks, and DTV was relatively conservative in evolution. These findings are the first to demonstrate molecular evidence of DTV in domestic animals. Nonetheless, whether or not could cause disease in sheep and other animals, DTV deserves further investigation.

Ultrasound segmentation models provide powerful tools for the diagnosis process of ultrasound examinations. However, developing such models for ultrasound videos requires densely annotated segmentation masks of all frames in a dataset, which is unpractical and unaffordable. Therefore, we propose a weakly-supervised learning (WSL) approach to accomplish the goal of video-based ultrasound segmentation. By only annotating the location of the start and end frames of the lesions, we obtain frame-level binary labels for WSL. We design Video Co-Attention Network to learn the correspondence between frames, where CAM and co-CAM will be obtained to perform lesion localization. Moreover, we find that the essential factor to the success of extracting video-level information is applying our proposed consistency regularization between CAM and co-CAM. Our method achieves an mIoU score of 45.43% in the breast ultrasound dataset, which significantly outperforms the baseline methods. The codes of our models will be released.

For semiconductor nanocrystals (NCs), the precise knowledge of phonons in the presence of free carriers is important for understanding their electronic and photonic properties in device applications. With Raman spectroscopy, this study investigates the effects of free charge carriers on optical phonon behaviors of NCs. The adoption of the photocharging method allows us to introduce free charge carriers into NCs without inducing other side effects. In the photocharged ZnO NCs, lower longitudinal optical (LO) phonon frequencies and weaker LO overtones relative to the fundamentals were found, which was explained by the screening and band-filling effects caused by the induced free carriers. The free carrier effects on optical phonon behaviors of NCs, usually neglected in previous studies, should be taken into consideration when discussing the electronic and photonic properties of NC-based devices.