Probing structural superlubricity of two-dimensional water transport with atomic resolution.

Low-dimensional water transport can be drastically enhanced under atomic-scale confinement. However, its microscopic origin is still under debate. In this work, we directly imaged the atomic structure and transport of two-dimensional water islands on graphene and hexagonal boron nitride surfaces using qPlus-based atomic force microscopy.

Identification of Human Body Fluid Stains and Non-Biological Stains by Three-Dimensional Fluorescence Spectroscopy.

Objectives: To establish a rapid and nondestructive identification method for human body fluid stains and non-biological stains using three-dimensional fluorescence spectroscopy.

Methods: The collected three-dimensional fluorescence spectrum data of human saliva, 3% blood, coffee and Fanta stains were processed with dimensionality reduction. After wavelet transform, spectral denoising and feature extraction, the classification formula was established.

Application of transcriptome in time analysis and donor characterization in blood samples.

As an effective supplement to the current forensic DNA typing and one of the research hotpots in forensic science, the in-depth mining and characterization of biological evidence can provide rich and reliable clues for case investigation. In this study, the time-dependent variations of transcriptome were confirmed in blood samples within 0-168 days and a random forest model was established to realize the classification of blood samples with different TSD (time since deposition). Meanwhile, significant differences were observed in the transcripts of blood samples with different smoking habits and genders within a certain time period.

Synthesis of β-Deuterated Amino Acids via Palladium-Catalyzed H/D Exchange.

Despite several synthetic approaches that have been developed for α-deuterated amino acids, the synthesis of β-deuterated amino acids has remained a challenge. Herein, we disclose a palladium catalyzed H/D exchange protocol for a β-deuterated N-protected amino amide, which can be converted to a β-deuterated amino acid simply by removal of protecting groups. This protocol is highly efficient, simply manipulated, and appliable for deuterium-labeling of many amino amides.

Silver salt enabled H/D exchange at the β-position of thiophene rings: synthesis of fully deuterated thiophene derivatives.

We disclose a silver catalyzed H/D exchange reaction, which can introduce the deuterium atom at the β position of thiophene rings without the assistance of any coordinating groups. The advantages of this reaction include operation in open air, usage of DO as the deuterium source, good tolerance to a range of functional groups and obtaining high atom% deuterium incorporation. In addition, this H/D exchange reaction is employed for direct deuteration of a thiophene based monomer, which is usually prepared by multistep synthesis from expensive deuterated starting materials.

C-H Bond Functionalization of (Hetero)aryl Bromide Enabled Synthesis of Brominated Biaryl Compounds.

Aryl bromide is one of the most important compounds in organic chemistry, because it is widely used as synthetic building blocks enabling quick access to a wide array of bioactive molecules, organic materials, and polymers via the versatile cutting-edge transformations of C-Br bond. Direct C-H bond functionalization of aryl bromide is considered to be an efficient way to prepare functionalized aryl bromides; however, it is rarely explored possibly due to the relatively low reactivity of aryl bromide toward C-H bond activation. We herein report a palladium-catalyzed coupling reaction between aryl iodide and aryl bromide for preparing brominated biaryl compounds via a silver-mediated C-H bond activation pathway.

Synthesis of Multideuterated (Hetero)aryl Bromides by Ag(I)-Catalyzed H/D Exchange.

Deterium-labeled (hetero)aryl bromide is one of the most widespread applicable motifs to achieve important deuterated architectures for various scientific applications. Traditionally, these deterium-labeled (hetero)aryl bromides are commonly prepared via multistep syntheses. Herein, we disclose a direct H/D exchange protocol for deuteration of (hetero)aryl bromides using AgCO as catalyst and DO as deuterium source.

Moiré Phonons in Twisted Bilayer MoS.

The material choice, layer thickness, and twist angle widely enrich the family of van der Waals heterostructures (vdWHs), providing multiple degrees of freedom to engineer their optical and electronic properties. The moiré patterns in vdWHs create a periodic potential for electrons and excitons to yield many interesting phenomena, such as Hofstadter butterfly spectrum and moiré excitons. Here, in the as-grown/transferred twisted bilayer MoS (tBLMs), one of the simplest prototypes of vdWHs, we show that the periodic potentials of moiré patterns also modify the properties of phonons of its monolayer MoS constituent to generate Raman modes related to moiré phonons.

Unexpected fungal communities in the Rehai thermal springs of Tengchong influenced by abiotic factors.

Fungal communities represent an indispensable part of the geothermal spring ecosystem; however, studies on fungal community within hot springs are still scant. Here, we used Illumina HiSeq 2500 sequencing to detect fungal community diversity in extremely acidic hot springs (pH < 4) and neutral and alkaline springs (pH > 6) of Tengchong-indicated by the presence of over 0.75 million valid reads.

Morphological and Transcriptomic Analysis Reveals the Osmoadaptive Response of Endophytic Fungus ZYD4 to High Salt Stress.

Halophilic fungi have evolved unique osmoadaptive strategies, enabling them to thrive in hypersaline habitats. Here, we conduct morphological and transcriptomic response of endophytic fungus ( ZYD4) in both the presence and absence of salt stress. Under salt stress, the colony morphology of the ZYD4 changed drastically and exhibited decreased colony pigmentation.

Quantification of light-enhanced ionic transport in lead iodide perovskite thin films and its solar cell applications.

Ionic transport in organometal halide perovskites is of vital importance because it dominates anomalous phenomena in perovskite solar cells, from hysteresis to switchable photovoltaic effects. However, excited state ionic transport under illumination has remained elusive, although it is essential for understanding the unusual light-induced effects (light-induced self-poling, photo-induced halide segregation and slow photoconductivity response) in organometal halide perovskites for optoelectronic applications. Here, we quantitatively demonstrate light-enhanced ionic transport in CHNHPbI over a wide temperature range of 17-295 K, which reveals a reduction in ionic transport activation energy by approximately a factor of five (from 0.

[The application of three methods combined for extracting DNA from human epithelium].

Objective: To improve DNA extraction from human epithelium.

Methods: Chelex-100, Chelex-100 organic combined and Chelex-100 magnetism pearl combined methods were adopted according to the situation of each case.

Results: With the stepwise extracting protocol, the trace amount of DNA was analyzed most efficiently and the success rate of DNA extracting was better improved.