Scalable Production of Highly Conductive 2D NbSe2 Monolayers with Superior Electromagnetic Interference Shielding Performance.

Thin, flexible, and electrically conductive films are in demand for electromagnetic interference (EMI) shielding. Two-dimensional NbSe2 monolayers have an electrical conductivity comparable to those of metals (106-107 S m-1) but are challenging for high-quality and scalable production. Here, we show that electrochemical exfoliation of flake NbSe2 powder produces monolayers on a large scale (tens of grams), at a high yield (>75%, monolayer), and with a large average lateral size (>20 µm). The as-exfoliated NbSe2 monolayer flakes are easily dispersed in diverse organic solvents and solution-processed into various macroscopic structures (e.g., free-standing films, coatings, patterns, etc.). Thermal annealing of the free-standing NbSe2 films reduces the interlayer distance of restacked NbSe2 from 1.18 to 0.65 nm and consequently enhances the electrical conductivity to 1.16 × 106 S m-1, which is superior to those of MXenes and reduced graphene oxide. The optimized NbSe2 film shows an EMI shielding effectiveness (SE) of 65 dB at a thickness of 5 µm (>110 dB for a 48-µm-thick film), among the highest in materials of similar thicknesses. Moreover, a laminate of two layers of the NbSe2 film (2 µm thick) with an insulating interlayer shows a high SE of 85 dB, surpassing that of the 20-µm-thick NbSe2 film (83 dB). A two-layer theoretical model is proposed, and it agrees with the experimental EMI SE of the laminated NbSe2 films. The ability to produce NbSe2 monolayers on a tens of grams scale will enable their diverse applications beyond EMI shielding.

A virus-borne DNA damage signaling pathway controls the lysogeny-induction switch in a group of temperate pleolipoviruses.

Many prokaryotic viruses are temperate and their reactivation is tightly regulated. However, except for a few bacterial model systems, the regulatory circuits underlying the exit from lysogeny are poorly understood, especially in archaea. Here, we report a three-gene module which regulates the switch between lysogeny and replicative cycle in a haloarchaeal virus SNJ2 (family Pleolipoviridae). The SNJ2 orf4 encodes a winged helix-turn-helix DNA binding protein which maintains lysogeny through repressing the expression of the viral integrase gene intSNJ2. To switch to the induced state, two other SNJ2-encoded proteins, Orf7 and Orf8, are required. Orf8 is a homolog of cellular AAA+ ATPase Orc1/Cdc6, which is activated upon mitomycin C-induced DNA damage, possibly through posttranslational modification. Activated Orf8 initiates the expression of Orf7 which, in turn, antagonizes the function of Orf4, leading to the transcription of intSNJ2, thereby switching SNJ2 to the induced state. Comparative genomics analysis revealed that the SNJ2-like Orc1/Cdc6-centered three-gene module is common in haloarchaeal genomes, always present in the context of integrated proviruses. Collectively, our results uncover the first DNA damage signaling pathway encoded by a temperate archaeal virus and reveal an unexpected role of the widely distributed virus-encoded Orc1/Cdc6 homologs.

Integration of CRISPR/Cas12a and Multiplexed RPA for Fast Detection of Gene Doping.

Fast and on-site detection is important for an effective antigene-doping strategy. However, the current gene doping (GD) evaluation methods require sophisticated instruments and laborious procedures, limiting their field applications. This study proposes a CRISPR/Cas12a-based detection platform (termed CasGDP) combining CRISPR/Cas12a and multiplexed Recombinase Polymerase Amplification (RPA) for rapid evaluation of GD. CasGDP showed high specificity for identifying the putative target genes such as EPO, IGF-1, and GH-1. By using fluorescence as the readout, the method achieved a limit-of-detection of 0.1 nM and 1 aM for unamplified and amplified target plasmids, respectively. Additionally, an in vitro GD cell model was successfully established with the human EPO gene (hEPO). The results indicated that the hEPO gene transfection promoted the hEPO protein expression. Furthermore, trace amounts of EPO transgene spiked in human serum were efficiently measured by CasGDP with fluorescence- and lateral flow device (LFD)-based readouts in 40 min. Finally, we designed a multiplexed microfluidic device and realized simultaneous detection of the three transgenes via LFD embedded in the device. To our knowledge, this is the first work that combines the CRISPR-based system and multiplexed RPA for GD detection. We anticipate CasGDP to be widely used as a rapid, sensitive, and robust tool for GD evaluation.

Global Evolution of Skeletal Muscle Tissue Engineering: A Scientometric Research.

Skeletal muscle tissue engineering (SMTE) is of great significance in the study of skeletal muscle physiology and pathology, which could be used in skeletal muscle graft. The scientometric analysis of SMTE can help researchers to quickly understand the evolutive history, status, novelties, and trend of this field. In this study, we performed a scientometric study that can be used to construct and visualize networks of SMTE using VOSviewer. A total of 1384 documents published between 1994 and 2020 were retrieved and analyzed. Our results showed that number of publications in SMTE has increased slowly from 1994 to 2014 and has increased rapidly from 2015 to 2020. The geographical distribution of publications in terms of total publications about SMTE is concentrated in Europe and the United States. The most productive institution was University of Michigan, while Harvard University and the University of Pittsburgh were ranked the second and third places. SMTE influenced a wide spectrum of disciplines, including Biology and Medicine and Physical Sciences. In addition, the research hotspot of SMTE was expanding from seed cells to the combination with advanced strategies (electrostatic spinning, bioprinting, and materials) for emulating the highly bionic engineered skeletal muscle tissues. This study provided a unique perspective for understanding the history and trends of SMTE, which could help to promote the rapid development of the field. Impact statement Skeletal muscle tissue engineering (SMTE), which acts as an important branch of tissue engineering, hold a great promise in the study of skeletal muscle physiology and pathology. The field of SMTE has developed rapidly in recent decades while still lacking studies based on scientometric methods. This article provided the first scientometric study of SMTE from development trends and evolution of the field. The results indicated that the field of SMTE was experiencing rapid growth and had a significant impact on multiple fields, particularly in Biology and Medicine and Physical Sciences.

[Recent advances in emerging three-dimensional in vitro models for sport-related traumatic brain injury].

Sports-related traumatic brain injury (srTBI) is a traumatic brain injury (TBI) caused by sports, which can result in cognitive and motor dysfunction. Currently, research on the molecular mechanism of srTBI and related drug development mainly relies on monolayer culture models and animal models. However, many differences exist in cell populations and inflammatory responses between these models and human pathophysiological processes. Most of the researches derived from the models can't effectively conducted translational research. Emerging three-dimensional (3D) in vitro models bridge the limitations of traditional models in simulating the pathophysiological processes of human srTBI and provide new means to understand srTBI. A literature has reported the research progress of emerging 3D in vitro models in neurological diseases, but there is a lack of systematic summary of the mentioned models in srTBI studies. Here, we review the research progress of emerging 3D in vitro models of srTBI, discuss the advantages and limitations of existing models, and further prospect the future trend of srTBI models. This paper aims to provide a new research perspective for researchers in tissue engineering and sports medicine to study the molecular mechanisms of srTBI and develop neuroprotective drugs.