Development and application of ubiquitin-based chemical probes.

Protein ubiquitination regulates almost every process in eukaryotic cells. The study of the many enzymes involved in the ubiquitination system and the development of ubiquitination-associated therapeutics are important areas of current research. Synthetic tools such as ubiquitin-based chemical probes have been making an increasing contribution to deciphering various biochemical components involved in ubiquitin conjugation, recruitment, signaling, and deconjugation.

Diazaphosphinyl radical-catalyzed deoxygenation of α-carboxy ketones: a new protocol for chemo-selective C-O bond scission mechanism regulation.

C-O bond cleavage is often a key process in defunctionalization of organic compounds as well as in degradation of natural polymers. However, it seldom occurs regioselectively for different types of C-O bonds under metal-free mild conditions. Here we report a facile chemo-selective cleavage of the α-C-O bonds in α-carboxy ketones by commercially available pinacolborane under the catalysis of diazaphosphinane based on a mechanism switch strategy.

Chemical synthesis and biological activity of peptides incorporating an ether bridge as a surrogate for a disulfide bond.

Disulfide bridges contribute to the definition and rigidity of polypeptides, but they are inherently unstable in reducing environments and in the presence of isomerases and nucleophiles. Strategies to address these deficiencies, ideally without significantly perturbing the structure of the polypeptide, would be of great interest. One possible surrogate for the disulfide bridge is a simple thioether, but these are susceptible to oxidation.

Manganese vacancy-confined single-atom Ag in cryptomelane nanorods for efficient Wacker oxidation of styrene derivatives.

Single-atom catalysts provide a pathway to elucidate the nature of catalytically active sites. However, keeping them stabilized during operation proves to be challenging. Herein, we employ cryptomelane-type octahedral molecular sieve nanorods featuring abundant manganese vacancy defects as a support, to periodically anchor single-atom Ag.

Bandgap-Coupled Template Autocatalysis toward the Growth of High-Purity sp Nanocarbons.

Extraordinary properties and great application potentials of carbon nanotubes (CNT) and graphene fundamentally rely on their large-scale perfect sp structure. Particularly for high-end applications, ultralow defect density and ultrahigh selectivity are prerequisites, for which metal-catalyzed chemical vapor deposition (CVD) is the most promising approach. Due to their structure and peculiarity, CNTs and graphene can themselves provide growth templates and nonlocal dual conductance, serving as template autocatalysts with tunable bandgap during the CVD.

On-Chip Optical Detection of Viruses: A Review.

The current outbreak of the coronavirus disease-19 (COVID-19) pandemic worldwide has caused millions of fatalities and imposed a severe impact on our daily lives. Thus, the global healthcare system urgently calls for rapid, affordable, and reliable detection toolkits. Although the gold-standard nucleic acid amplification tests have been widely accepted and utilized, they are time-consuming and labor-intensive, which exceedingly hinder the mass detection in low-income populations, especially in developing countries.

Insight into single-element nobel metal anisotropic silver nanoparticle shape-dependent selective ROS generation and quantification.

The biocidal action mechanism of single element noble metal anisotropic nanoparticles has remained a perplexing challenge. Herein, we investigated the photogenerated anisotropic AgNP ROS production kinetics and each ROS species' direct impact on Gram-negative and Gram-positive bacteria. Three shapes (Triangular, Cubes, Rods) of AgNP with excellent morphology were fabricated plasmon mediated synthesis.

Microfluidic synthesis of quantum dots and their applications in bio-sensing and bio-imaging.

Bio-sensing and bio-imaging of organisms or molecules can provide key information for the study of physiological processes or the diagnosis of diseases. Quantum dots (QDs) stand out to be promising optical detectors because of their excellent optical properties such as high brightness, stability, and multiplexing ability. Diverse approaches have been developed to generate QDs, while microfluidic technology is one promising path for their industrial production.

Recent progress in two-dimensional materials for terahertz protection.

With the wide applications of terahertz (THz) devices in future communication technology, THz protection materials are essential to overcome potential threats. Recently, THz metamaterials (MMs) based on two-dimensional (2D) materials (, graphene, MXenes) have been extensively investigated due to their unique THz response properties. In this review, THz protection theories are briefly presented first, including reflection loss and shielding mechanisms.

Optical visualization and imaging of nanomaterials.

Direct visualization and imaging of nanomaterials under ambient conditions is of great significance for their characterization and application. In most cases, the observation of individual nanomaterials usually requires high-resolution electron microscopes under high vacuum. In comparison, an optical microscope is much more convenient due to its facile operation and open space.

Hydrated negative air ions generated by air-water collision with TiO photocatalytic materials.

Photocatalytic materials are often used in the field of electrolysis of water for its competitive performance and low cost. This study describes the use of TiO for providing free electrons to prepare hydrated negative air ions together with the Lenard effect caused by air-water collision. The lifetime of HNAIs increased by 47.

High-Uniformity Threshold Switching HfO-Based Selectors with Patterned Ag Nanodots.

High-performance selector devices are essential for emerging nonvolatile memories to implement high-density memory storage and large-scale neuromorphic computing. Device uniformity is one of the key challenges which limit the practical applications of threshold switching selectors. Here, high-uniformity threshold switching HfO-based selectors are fabricated by using e-beam lithography to pattern controllable Ag nanodots (NDs) with high order and uniform size in the cross-point region.

Self-Healing of Electrical Damage in Polymers.

Polymers are widely used as dielectric components and electrical insulations in modern electronic devices and power systems in the industrial sector, transportation, and large appliances, among others, where electrical damage of the materials is one of the major factors threatening the reliability and service lifetime. Self-healing dielectric polymers, an emerging category of materials capable of recovering dielectric and insulating properties after electrical damage, are of promise to address this issue. This paper aims at summarizing the recent progress in the design and synthesis of self-healing dielectric polymers.

Carbon Microtube Textile with MoS Nanosheets Grown on Both Outer and Inner Walls as Multifunctional Interlayer for Lithium-Sulfur Batteries.

The shuttle effect of soluble lithium polysulfides during the charge/discharge process is the key bottleneck hindering the practical application of lithium-sulfur batteries. Herein, a multifunctional interlayer is developed by growing metallic molybdenum disulfide nanosheets on both outer and inner walls of cotton cloth derived carbon microtube textile (MoS@CMT). The hollow structure of CMT provides channels to favor electrolyte penetration, Li diffusion and restrains polysulfides via physical confinement.

From "S" to "O": experimental and theoretical insights into the atmospheric degradation mechanism of dithiophosphinic acids.

Dithiophosphinic acids (DPAHs, expressed as RRPSSH) are a type of sulfur-donor ligand that have been vastly applied in hydrometallurgy. In particular, DPAHs have shown great potential in highly efficient trivalent actinide/lanthanide separation, which is one of the most challenging tasks in separation science and is of great importance for the development of an advanced fuel cycle in nuclear industry. However, DPAHs have been found liable to undergo oxidative degradation in the air, leading to significant reduction in the selectivity of actinide/lanthanide separation.

Portable environment-signal detection biosensors with cell-free synthetic biosystems.

By embedding regulated genetic circuits and cell-free systems onto a paper, the portable biosensing platform showed the possibility of detecting environmental pollutants, namely arsenic ions and bacterial quorum-sensing signal AHLs (-acyl homoserine lactones). This platform has a great potential for practical environmental management and diagnosis.

Predicting the Real-Valued Inter-Residue Distances for Proteins.

Predicting protein structure from the amino acid sequence has been a challenge with theoretical and practical significance in biophysics. Despite the recent progresses elicited by improved inter-residue contact prediction, contact-based structure prediction has gradually reached the performance ceiling. New methods have been proposed to predict the inter-residue distance, but unanimously by simplifying the real-valued distance prediction into a multiclass classification problem.

Flexible Quasi-van der Waals Ferroelectric Hafnium-Based Oxide for Integrated High-Performance Nonvolatile Memory.

Ferroelectric memories with ultralow-power-consumption are attracting a great deal of interest with the ever-increasing demand for information storage in wearable electronics. However, sufficient scalability, semiconducting compatibility, and robust flexibility of the ferroelectric memories remain great challenges, e.g.

kinetics predictions for the role of pre-reaction complexes in hydrogen abstraction from 2-butanone by OH radicals.

The existence of pre- and post-reaction complexes has been proposed to influence hydrogen abstraction reaction kinetics, but the significance still remains controversial. A theoretical study is presented to discuss the effects of complexes on hydrogen abstraction from 2-butanone by OH radicals based on the detailed PESs at the DLPNO-CCSD(T)/aug-cc-pVTZ//M06-2x-D3/may-cc-pVTZ level with five pre-reaction complexes at the entrance of the channels and four post-reaction complexes at the exit. The hydrogen bond interactions, steric effects, and contributions to the bonding orbital of the OH radical species and 2-butanone species in the complex structures were visualized and investigated by wavefunction analyses.

Bioorthogonal Ligations and Cleavages in Chemical Biology.

Bioorthogonal reactions including the bioorthogonal ligations and cleavages have become an active field of research in chemical biology, and they play important roles in chemical modification and functional regulation of biomolecules. This review summarizes the developments and applications of the representative bioorthogonal reactions including the Staudinger reactions, the metal-mediated bioorthogonal reactions, the strain-promoted cycloadditions, the inverse electron demand Diels-Alder reactions, the light-triggered bioorthogonal reactions, and the reactions of chloroquinoxalines and -dithiophenols.

Cell-free biology using remote-controlled digital microfluidics for individual droplet control.

Cell-free biology for diverse protein expression and biodetection has developed rapidly in recent years because of its more open and controllable reaction environment. However, complex liquid handling schemes are troublesome, especially when scaling up to perform multiple different reactions simultaneously. Digital microfluidic (DMF) technology can operate a single droplet by controlling its movement, mixing, separation, and some other actions, and is a suitable scaffold for cell-free reactions with higher efficiency.

Trajectory and Functional Analysis of PD-1 CD4CD8 T Cells in Hepatocellular Carcinoma by Single-Cell Cytometry and Transcriptome Sequencing.

The spatial heterogeneity of immune microenvironment in hepatocellular carcinoma (HCC) remains elusive. Here, a single-cell study involving 17 432 600 immune cells of 39 matched HCC (T), nontumor (N), and leading-edge (L) specimens by mass cytometry is conducted. The tumor-associated CD4/CD8 double-positive T (DPT) cells are found enriched in L regions with synergetic expression of PD-1/HLA-DR/ICOS/CD45RO and exhibit a higher level of IFN-, TNF-, and PD-1 upon stimulation.

High thermal conductivity driven by the unusual phonon relaxation time platform in 2D monolayer boron arsenide.

The cubic boron arsenide (BAs) crystal has received extensive research attention because of its ultra-high thermal conductivity comparable to that of diamond. In this work, we performed a comprehensive study on the diffusive thermal properties of its two-dimensional (2D) counterpart, the monolayer honeycomb BAs (h-BAs), through solving the phonon Boltzmann transport equation combined with first-principles calculation. We found that unlike the pronounced contribution from out-of-plane acoustic phonons (ZA) in graphene, the high thermal conductivity (181 W m K at 300 K) of h-BAs is mainly contributed by in-plane phonon modes, instead of the ZA mode.