Tandem Protocol for Diversified Deuteration of Secondary Aliphatic Amines under Mild Conditions.

Deuteration of amine compounds has been widely of concern because of its practical role in organic reaction mechanisms and drug research; however, only limited deuteration label methods are accessible with D2O as a deuterium source. Herein, we propose a convenient deuteration protocol, including preparing D2 by the AlGa activation method, using PtRu nanowires as catalysts, and utilizing the elementary step in the couple reaction involving an imine unit, to realize the rapid preparation of a secondary amine with a diversified deuteration label. The self-coupling between nitriles not only provides a symmetric secondary amine with four α-D atoms but also produces high-valued ND3 in an atomic-economic way.

Engineered E. coli for Long-Term Oral Enzyme Delivery.

Intestinal flora shows excellent affinity in the gut, and the adhesive property is borrowed for oral drug delivery. A facile strategy for bacteria engineering has been successfully developed by introducing metal-organic framework (MOF) mineralization. The MOF exoskeleton serves as an extendable platform for accommodating various cargoes with good Escherichia coli morphology maintained. The artificial exoskeleton surrounding E. coli is employed for encapsulating macromolecules as a therapeutic cargo, maintaining good bioactivity with high immobilization efficiency (60%) after systematic optimization of the MOF precursor. Leveraging the natural affinity of E. coli in the gut, the in-vivo tracking of MOF-engineered E. coli in the gastrointestinal tract confirmed excellent adhesion to the GI mucosa and a 17.9-fold increase in the gut retention half-time, demonstrating significant advantages in retention capability. In comparison, the control group without E. coli equipment resulted in quick gut passage. Furthermore, the artificially engineered E. coli serves as an effective carrier for macromolecules without notable oral toxicity, as evidenced by biocompatibility evaluations in cells and animals. Overall, the MOF-engineered E. coli provides an extendable platform for loading on-demand cargoes in versatile therapeutic functions with promising clinical transnationality for long-term applications.

Lab on the Microneedles: A Wearable Metal-organic Frameworks-Based Sensor for Visual Monitoring of Stress Hormone.

Abnormal secretion and dysrhythmias of cortisol (CORT) are associated with various diseases such as sleep disorders, depression, and chronic fatigue. Wearable devices are a cutting-edge technology for point-of-care detection and dynamic monitoring of CORT with inspiring convenience. Herein, we developed a minimally invasive skin-worn device with the advanced integration of both interstitial fluid (ISF) sampling and target molecule sensing for simultaneous detection of CORT via a microneedle-based sensor with high sensitivity, excellent efficiency, and outstanding reproducibility. In the microneedle patch, swellable hydrogel was employed as the adsorption matrix for ISF extraction. Meanwhile, europium metal-organic frameworks (Eu-MOF) wrapped in the matrix played a vital role in CORT recognition and quantitative analysis. The wearable and label-free Eu-MOF-loaded microneedle patch exhibited high sensitivity in CORT detection with the detection limit reaching 10-9 M and excellent selectivity. Molecular dynamics simulation-driven mechanism exploration revealed that the strong interface interaction promoted fluorescence quenching of Eu-MOF. Moreover, in vitro and in vivo investigation confirmed the feasibility and reliability of the sensing method, and excellent biocompatibility was validated. Overall, a sensitive approach based on the wearable Eu-MOF microneedle (MN) patch was established for the simultaneous detection of CORT via visible fluorescence quenching with exciting clinical-translational ability.

In Situ Simultaneous Cavitation-Doping Approach for Constructing Bimetallic Metal-Organic Framework Hollow Nanospheres with Enhanced Electrocatalytic Hydrogen Production.

This Communication demonstrates a novel and in situ simultaneous cavitation-doping (SCD) approach to construct bimetallic metal-doped cobalt metal-organic framework hollow nanospheres (CoM-MOF HNSs, with M = Ru or Fe). The key point of the SCD approach is the careful balance between the kinetics of Co-MOF being etched and the coordinative growth of a more stable CoM-MOF shell induced by Lewis acid (MCl3, with M = Ru or Fe). Our work provides a new method to synthesize bimetallic hollow MOFs and benefits the development of electrocatalysts.

Route to the Structure-Controlled Synthesis of Fe Nanobelts and Their Oxygen Evolution Reaction Application.

Belt-shaped metal-organic frameworks (MOFs) have received extensive attention because of their unique structure. In this Communication, Fe-MOF nanobelts were synthesized by a solvothermal method with Fe2+ as the metal source and could not be obtained by using Fe3+ as the metal source. The final result shows that Fe2+ played a transitional role in the process of achieving belt-shaped and cubelike structural changes. Our work provides an idea for the synthesis of belt-shaped MOFs and promotes the development of electrocatalysts.

Highly discriminant rate of Dianhong black tea grades based on fluorescent probes combined with chemometric methods.

We established a novel Dianhong black tea grades discriminant analytic technique based on a fluorescence image along with carbon quantum dots (CDs) as fluorescent probes. Different grades of Dianhong black tea contain different various amounts of tea polyphenols. Tea polyphenols can quench the fluorescent intensity of CDs, resulting in different fluorescent peaks; Dianhong black tea grades can then be discriminated through the use of principal component analysis and Bayesian analysis. Compared with the additional data processing required in other methods, the advantage of our method is that the fluorescence curve can be used directly, and it achieves satisfactory results. We firstly used CDs combined with chemometrics to identify eight grades of Dianhong black tea, and we also provide a new method that improves the identification rate using nanotechnology to avoid performing complex data processing.

Robust Support Matrix Machine for Single Trial EEG Classification.

Electroencephalogram (EEG) signals are of complex structure and can be naturally represented as matrices. Classification is one of the most important steps for EEG signal processing. Newly developed classifiers can handle these matrix-form data by adding low-rank constraint to leverage the correlation within each data. However, classification of EEG signals is still challenging, because EEG signals are always contaminated by measurement artifacts, outliers, and non-standard noise sources. As a result, existing matrix classifiers may suffer from performance degradation, because they typically assume that the input EEG signals are clean. In this paper, to account for intra-sample outliers, we propose a novel classifier called a robust support matrix machine (RSMM), for single trial EEG data in matrix form. Inspired by the fact that empirical EEG signals contain strong correlation information, we assume that each EEG matrix can be decomposed into a latent low-rank clean matrix plus a sparse noise matrix. We simultaneously perform signal recovery and train the classifier based on the clean EEG matrices. We formulate our RSMM in a unified framework and present an effective solver based on the alternating direction method of multipliers. To evaluate the proposed method, we conduct extensive classification experiments on real binary EEG signals. The experimental results show that our method has outperformed the state-of-the-art matrix classifiers. This paper may lead to the development of robust brain-computer interfaces (BCIs) with intuitive motor imagery and thus promote the broad use of the noninvasive BCIs technology.