227 results match your criteria: "Tsinghua University Beijing 100084 China.[Affiliation]"

Understanding the adsorption behavior of intermediates at interfaces is crucial for various heterogeneous systems, but less attention has been paid to metal species. This study investigates the manipulation of Co spin states in ZnCoO spinel oxides and establishes their impact on metal ion adsorption. Using electrochemical sensing as a metric, we reveal a quasi-linear relationship between the adsorption affinity of metal ions and the high-spin state fraction of Co sites.

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Chemical modulation and defect engineering in high-performance GeTe-based thermoelectrics.

Chem Sci

January 2025

State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University Beijing 100084 China

Thermoelectric technology plays an important role in developing sustainable clean energy and reducing carbon emissions, offering new opportunities to alleviate current energy and environmental crises. Nowadays, GeTe has emerged as a highly promising thermoelectric candidate for mid-temperature applications, due to its remarkable thermoelectric figure of merit () of 2.7.

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Molecule-electrode interactions are critical for determining transport mechanisms and device functionalities in both single-molecule electrochemistry and electronics. Crucial factors such as anchoring groups and local fields have been studied, but the role of electrolytes and interfacial charge distribution remains largely underexplored. The present research focuses on how the interfacial charge distribution in the electric double layer (EDL) controls single-molecule junctions anchored by azulene.

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Pd/NHC sequentially catalyzed atroposelective synthesis of planar-chiral macrocycles.

Chem Sci

November 2024

School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology, Ministry of Education, Tsinghua University Beijing 100084 China

Planar-chiral macrocycles play a pivotal role in host-guest chemistry and drug discovery. However, compared with the synthesis of other types of chiral compounds, the asymmetric construction of planar-chiral macrocycles still remains a forbidding challenge. Herein, we report a sequential palladium and N-heterocyclic carbene catalysis to build planar-chiral macrocycles.

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We summarized the unique challenges that China faced in digital health due to its large population, regional disparities, and uneven distribution of medical resources. Under the guidance of the Global Initiative on Digital Health (GIDH) released by WHO, we proposed corresponding solutions that address infrastructure, data, terminology, technology and security.

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A smart dendritic cell (DC)-derived whole cell cytokine (DWC) nano-regulator of TCPs was developed for tumor cytokine-immunotherapy. The DWCs were purified from activated DC-cultured media and applied as a nano-dosage form. It was found that TCPs could remodel extracellular matrices the elimination of fibronectin and type I collagen (Col-I) in tumor tissues, as well as the inhibition of α-SMA expression in cancer associated fibroblasts (CAFs).

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Carbon nanotubes (CNTs) are typical one-dimensional nanomaterials which have been widely studied for more than three decades since 1991 because of their excellent mechanical, electrical, thermal, and optical properties. Among various types of CNTs, the ultralong CNTs which have lengths over centimeters and defect-free structures exhibit superior advantages for fabricating superstrong CNT fibers, CNT-based chips, transparent conductive films, and high-performance cables. The length, orientation, alignment, defects, cleanliness, and other microscopic characteristics of CNTs have significant impacts on their fundamental physical properties.

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Molecular generation stands at the forefront of AI-driven technologies, playing a crucial role in accelerating the development of small molecule drugs. The intricate nature of practical drug discovery necessitates the development of a versatile molecular generation framework that can tackle diverse drug design challenges. However, existing methodologies often struggle to encompass all aspects of small molecule drug design, particularly those rooted in language models, especially in tasks like linker design, due to the autoregressive nature of large language model-based approaches.

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C-H functionalization of 2-alkyl tryptamines: direct assembly of azepino[4,5-]indoles and total synthesis of ngouniensines.

Chem Sci

August 2024

School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Beijing Frontier Research Center for Biological Structure, Tsinghua University Beijing 100084 China

The Pictet-Spengler type condensation of tryptamine derivatives and aldehydes or ketones is a classic reaction, and has been previously applied to assemble indole-annulated 5-, 6- and 8-membered heterocyclic rings. In this work, we further expand the synthetic scope of this reaction to the 7-membered azepino[4,5-]indole skeleton through the direct C-H functionalization of 2-alkyl tryptamines, in which the non-activated methylene group participates in a 7-membered ring formation with aldehydes. By combining this unprecedented ring-forming process with a second C-H olefination at the same carbon, the concise total synthesis of natural products ngouniensines is achieved, demonstrating the synthetic potential of the developed chemistry in simplifying retrosynthetic disconnections.

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There has been a recent upsurge in research aimed at synthesizing inherently chiral molecules devoid of point, axial, planar and helical chiralities. We present herein our design and enantioselective synthesis of a series of inherently chiral macrocycles. These compounds, termed nor-heteracalixaromatics, feature a biaryl bond that replaces one of the aryl-heteroatom-aryl linkages found in classic heteracalix[4]aromatics.

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Article Synopsis
  • Noble metal-based nanoalloys (NAs) have potential in energy and catalysis, but their synthesis is challenging due to the need for small-sized alloys with controllable shapes.
  • A new synthesis method, combining cation exchange and spatial confinement (CESC), was developed, creating a library of 21 NAs that can be controlled by adjusting non-precious metals.
  • The framed PtCu/HCN NA showed impressive electrocatalytic performance for both the methanol oxidation reaction and hydrogen evolution reaction, outperforming commercial catalysts in activity and stability.
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Homogeneous gold catalysis has attracted much recent attention due to diverse activation modes of gold(i) towards unsaturated organic groups. Because of attractive aurophilic interaction, structural transformations of metalated species into high nuclear clusters are often proposed in gold catalysis, while to date little is known about their assembly behaviors and catalytic activity. In this work, based on stoichiometric Au(i)-mediated enyne cyclization reactions, we achieve a discrete vicinal dicarbanion-centered Au intermediate and three assembled Au, Au, and Au clusters held together by several aryl dicarbanions.

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Often, H is produced photocatalytically at the expense of sacrificial agents. When a sacrificial agent is selectively oxidized, this allows coupling of H production with synthesis of value-added organic compounds. Herein, it is argued that the conversion of bioethanol into 1,1-diethoxyethane with simultaneous H production increases the economic viability of photocatalysis and suggests a semiconductor material that is the most relevant for this purpose.

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Nanopore technology, re-fueled by two-dimensional (2D) materials such as graphene and MoS, controls mass transport by allowing certain species while denying others at the nanoscale and has a wide application range in DNA sequencing, nano-power generation, and others. With their low transmembrane transport resistance and high permeability stemming from their ultrathin nature, crystalline 2D materials do not possess nanoscale holes naturally, thus requiring additional fabrication to create nanopores. Herein, we demonstrate that nanopores exist in amorphous monolayer carbon (AMC) grown at low temperatures.

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Accelerating protein aggregation and amyloid fibrillation for rapid inhibitor screening.

Chem Sci

May 2024

State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University Beijing 100084 China

The accumulation and deposition of amyloid fibrils, also known as amyloidosis, in tissues and organs of patients has been found to be linked to numerous devastating neurodegenerative diseases. The aggregation of proteins to form amyloid fibrils, however, is a slow pathogenic process, and is a major issue for the evaluation of the effectiveness of inhibitors in new drug discovery and screening. Here, we used microdroplet reaction technology to accelerate the amyloid fibrillation process, monitored the process to shed light on the fundamental mechanism of amyloid self-assembly, and demonstrated the value of the technology in the rapid screening of potential inhibitor drugs.

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Single-cell mass spectrometry (MS) is an essential technology for sensitive and multiplexed analysis of metabolites and lipids for cell phenotyping and pathway studies. However, the structural elucidation of lipids from single cells remains a challenge, especially in the high-throughput scenario. Technically, there is a contradiction between the inadequate sample amount ( a single cell, 0.

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Plastic waste has imposed significant burdens on the environment. Chemical recycling allows for repeated regeneration of plastics without deterioration in quality, but often requires harsh reaction conditions, thus being environmentally unfriendly. Enzymatic catalysis offers a promising solution for recycling under mild conditions, but it faces inherent limitations such as poor stability, high cost, and narrow substrate applicability.

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Electrochemical CO reduction reaction (CORR) provides a promising route to converting CO into value-added chemicals and to neutralizing the greenhouse gas emission. For the industrial application of CORR, high-performance electrocatalysts featuring high activities and selectivities are essential. It has been demonstrated that customizing the catalyst surface/interface structures allows for high-precision control over the microenvironment for catalysis as well as the adsorption/desorption behaviors of key reaction intermediates in CORR, thereby elevating the activity, selectivity and stability of the electrocatalysts.

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AI-assisted mass spectrometry imaging with image segmentation for subcellular metabolomics analysis.

Chem Sci

March 2024

State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China

Subcellular metabolomics analysis is crucial for understanding intracellular heterogeneity and accurate drug-cell interactions. Unfortunately, the ultra-small size and complex microenvironment inside the cell pose a great challenge to achieving this goal. To address this challenge, we propose an artificial intelligence-assisted subcellular mass spectrometry imaging (AI-SMSI) strategy with image segmentation.

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We report herein the synthesis of highly enantiopure inherently chiral N,O-calix[2]arene[2]triazines from enantioselective macrocyclization enabled by chiral phosphoric acid-catalyzed intramolecular nucleophilic aromatic substitution reaction. In contrast to documented examples, the inherent chirality of the acquired compounds arises from one heteroatom difference in the linking positions of heteracalix[4](het)arenes.

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Ordered MZn intermetallic phases with structurally isolated atom sites offer unique electronic and geometric structures for catalytic applications, but lack reliable industrial synthesis methods that avoid forming a disordered alloy with ill-defined composition. We developed a facile strategy for preparing well-defined MZn intermetallic nanoparticle (i-NP) catalysts from physical mixtures of monometallic M/SiO (M = Rh, Pd, Pt) and ZnO. The RhZn i-NPs with structurally isolated Rh atom sites had a high intrinsic selectivity to ethylene (91%) with extremely low C and oligomer formation, outperforming the reported intermetallic and alloy catalysts in acetylene semihydrogenation.

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The expertise accumulated in deep neural network-based structure prediction has been widely transferred to the field of protein-ligand binding pose prediction, thus leading to the emergence of a variety of deep learning-guided docking models for predicting protein-ligand binding poses without relying on heavy sampling. However, their prediction accuracy and applicability are still far from satisfactory, partially due to the lack of protein-ligand binding complex data. To this end, we create a large-scale complex dataset containing ∼9 M protein-ligand docking complexes for pre-training, and propose CarsiDock, the first deep learning-guided docking approach that leverages pre-training of millions of predicted protein-ligand complexes.

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Membrane proteins play essential roles in a number of biological processes, and their structures are important in elucidating such processes at the molecular level and also for rational drug design and development. Membrane protein structure determination is notoriously challenging compared to that of soluble proteins, due largely to the inherent instability of their structures in non-lipid environments. Micelles formed by conventional detergents have been widely used for membrane protein manipulation, but they are suboptimal for long-term stability of membrane proteins, making downstream characterization difficult.

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The improvement in the overall efficiency of thin-film composite (TFC) reverse osmosis (RO) membranes is limited by their low permeability and sensitivity to degradation by chlorine. In the present study, polypiperazine (PIP), the commonly used amine monomer in preparing commercial TFC nanofiltration (NF) membranes, was used to regulate the -phenylenediamine (MPD) based interfacial polymerization (IP) process. The results showed that addition of PIP optimized the micro-structure and surface properties of the polyamide (PA) layer.

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Stapled peptides are regarded as the promising next-generation therapeutics because of their improved secondary structure, membrane permeability and metabolic stability as compared with the prototype linear peptides. Usually, stapled peptides are obtained by a hydrocarbon stapling technique, anchoring from paired olefin-terminated unnatural amino acids and the consequent ring-closing metathesis (RCM). To investigate the adaptability of the rigid cyclobutane structure in RCM and expand the chemical diversity of hydrocarbon peptide stapling, we herein described the rational design and efficient synthesis of cyclobutane-based conformationally constrained amino acids, termed ()-1-amino-3-(but-3-en-1-yl)cyclobutane-1-carboxylic acid (E) and ()-1-amino-3-(but-3-en-1-yl)cyclobutane-1-carboxylic acid (Z).

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