Intestinal Barrier Impairment Induced by Gut Microbiome and Its Metabolites in School-Age Children with Zinc Deficiency.

Zinc deficiency affects the physical and intellectual development of school-age children, while studies on the effects on intestinal microbes and metabolites in school-age children have not been reported. School-age children were enrolled to conduct anthropometric measurements and serum zinc and serum inflammatory factors detection, and children were divided into a zinc deficiency group (ZD) and control group (CK) based on the results of serum zinc. Stool samples were collected to conduct metagenome, metabolome, and diversity analysis, and species composition analysis, functional annotation, and correlation analysis were conducted to further explore the function and composition of the gut flora and metabolites of children with zinc deficiency. Beta-diversity analysis revealed a significantly different gut microbial community composition between ZD and CK groups. For instance, the relative abundances of Phocaeicola vulgatus, Alistipes putredinis, Bacteroides uniformis, Phocaeicola sp000434735, and Coprococcus eutactus were more enriched in the ZD group, while probiotic bacteria Bifidobacterium kashiwanohense showed the reverse trend. The functional profile of intestinal flora was also under the influence of zinc deficiency, as reflected by higher levels of various glycoside hydrolases in the ZD group. In addition, saccharin, the pro-inflammatory metabolites, and taurocholic acid, the potential factor inducing intestinal leakage, were higher in the ZD group. In conclusion, zinc deficiency may disturb the gut microbiome community and metabolic function profile of school-age children, potentially affecting human health.

The on-and-off dynamics of thiophene on a nickel cluster enables efficient hydrodesulfurization and excellent stability at high temperatures.

Despite significant advances in the synthesis and structural determination of atomically precise metal clusters, few studies have explored their catalytic applications in industrially important reactions. Here, we report a thiolate-stabilized Ni cluster for the efficient hydrodesulfurization of thiophene under relatively harsh reaction conditions while maintaining its atomic structure, which was enabled by the on-and-off dynamic state of thiophene on the cluster. Through a combined experimental and theoretical approach, we elucidate the activated structure and the catalytic mechanism. The study highlights the great potential of structurally precise clusters for practical industrial applications.

Coordinated histone modifications and chromatin reorganization in a single cell revealed by FRET biosensors.

The dramatic reorganization of chromatin during mitosis is perhaps one of the most fundamental of all cell processes. It remains unclear how epigenetic histone modifications, despite their crucial roles in regulating chromatin architectures, are dynamically coordinated with chromatin reorganization in controlling this process. We have developed and characterized biosensors with high sensitivity and specificity based on fluorescence resonance energy transfer (FRET). These biosensors were incorporated into nucleosomes to visualize histone H3 Lys-9 trimethylation (H3K9me3) and histone H3 Ser-10 phosphorylation (H3S10p) simultaneously in the same live cell. We observed an anticorrelated coupling in time between H3K9me3 and H3S10p in a single live cell during mitosis. A transient increase of H3S10p during mitosis is accompanied by a decrease of H3K9me3 that recovers before the restoration of H3S10p upon mitotic exit. We further showed that H3S10p is causatively critical for the decrease of H3K9me3 and the consequent reduction of heterochromatin structure, leading to the subsequent global chromatin reorganization and nuclear envelope dissolution as a cell enters mitosis. These results suggest a tight coupling of H3S10p and H3K9me3 dynamics in the regulation of heterochromatin dissolution before a global chromatin reorganization during mitosis.

Suppressing the active site-blocking impact of ligands of Ni6(SR)12 clusters with the assistance of NH3 on catalytic hydrogenation of nitriles.

Atomically precise metal clusters stabilized by organic ligands have attracted extensive interest, and these monodisperse clusters have particular potential for providing insights into puzzling areas of heterogeneous catalysis such as inherent size polydispersity. In many traditional catalytic reactions, however, the reactivity of metal clusters is frequently found to be passivated, where the active sites on the surface metal atoms are blocked by the ligand molecules. Therefore, of particular interest are studies that involve triggering the catalytic ability of metal clusters, with no need to remove any ligands, via thermal treatments that usually destroy their atomically precise structures. Herein, with the determination of the structure of Ni6(SR)12 (where SR denotes thiolate), where Ni atoms are fully coordinated with the thiolate molecules, the catalytic activity of Ni6(SR)12 for nitriles hydrogenation toward primary amines could be significantly enhanced with the assistance of NH3 molecules that positively suppress the ligand-shielding effect.

Central Doping of a Foreign Atom into the Silver Cluster for Catalytic Conversion of CO2 toward C-C Bond Formation.

Clusters with an exact number of atoms are of particular interest in catalysis. Their catalytic behaviors can be potentially altered with the addition or removal of a single atom. Now the effects of doping with a single foreign atom (Au, Pd, and Pt) into the core of an Ag cluster with 25 atoms on the catalytic properties are explored, where the foreign atom is protected by 24 Ag atoms (Au@Ag24 , Pd@Ag24 , and Pt@Ag24 ). The central doping of a single atom into the Ag25 cluster has a substantial influence on the catalytic performance in the carboxylation reaction of CO2 with terminal alkyne through C-C bond formation to produce propiolic acid. These studies reveal that the catalytic properties of the cluster catalysts can be dramatically changed with the subtle alteration by a single atom away from the active sites.

The Fourth Alloying Mode by Way of Anti-Galvanic Reaction.

Anti-galvanic reaction (AGR) not only defies classic galvanic theory but is a promising method for tuning the compositions, structures, and properties of noble-metal nanoparticles. Employing AGR for the preparation of alloy nanoparticles has recently received great interest. Herein, we report an unprecedented alloying mode by way of AGR, in which foreign atoms induce structural transformation of the mother nanoparticles and enter the nanoparticles in a non-replacement fashion. A novel, active-metal-doped, gold nanoparticle was synthesized by this alloying mode, and its structure resolved. A CdSH motif was found in the protecting staples of the bimetal nanoparticle. DFT calculations revealed that the Au20 Cd4 (SH)(SR)19 nanoparticle is a 8e superatom cluster. Furthermore, although the Cd-doping does not essentially alter the absorption spectrum of the mother nanocluster, it distinctly enhances the stability and catalytic selectivity of the mother nanoclusters.

Deep learning-based subdivision approach for large scale macromolecules structure recovery from electron cryo tomograms.

MOTIVATION: Cellular Electron CryoTomography (CECT) enables 3D visualization of cellular organization at near-native state and in sub-molecular resolution, making it a powerful tool for analyzing structures of macromolecular complexes and their spatial organizations inside single cells. However, high degree of structural complexity together with practical imaging limitations makes the systematic de novo discovery of structures within cells challenging. It would likely require averaging and classifying millions of subtomograms potentially containing hundreds of highly heterogeneous structural classes. Although it is no longer difficult to acquire CECT data containing such amount of subtomograms due to advances in data acquisition automation, existing computational approaches have very limited scalability or discrimination ability, making them incapable of processing such amount of data. RESULTS: To complement existing approaches, in this article we propose a new approach for subdividing subtomograms into smaller but relatively homogeneous subsets. The structures in these subsets can then be separately recovered using existing computation intensive methods. Our approach is based on supervised structural feature extraction using deep learning, in combination with unsupervised clustering and reference-free classification. Our experiments show that, compared with existing unsupervised rotation invariant feature and pose-normalization based approaches, our new approach achieves significant improvements in both discrimination ability and scalability. More importantly, our new approach is able to discover new structural classes and recover structures that do not exist in training data. AVAILABILITY AND IMPLEMENTATION: Source code freely available at http://www.cs.cmu.edu/∼mxu1/software . CONTACT: mxu1@cs.cmu.edu. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Preparation of La-modified magnetic composite for enhanced adsorptive removal of tetracycline.

Composite adsorbents usually outperform single component adsorbents as they could combine the properties and advantages of each component. In this research, rare earth element Lanthanum was introduced into magnetic substrate by a method of chemical co-precipitation to enhance its adsorption capability. It was found that the La-modified magnetic composite with a presumed La and Fe3O4 molar ratio at 1:50 had a better adsorption performance for tetracycline than the magnetic adsorbents at other molar ratios. The La-modified magnetic composite was characterized by scanning electron microscope, X-ray diffractometer, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The results showed that the magnetic adsorbent was nano-sized, and the introduction of La did not change the crystal structure of magnetic substrate. The adsorptive removal of tetracycline was favorable at neutral pH conditions. Kinetic experiments indicated that most of the uptake occurred within the initial 120 min. Chemisorption occurred in the process while rate-determining step might be diffusive in nature. An empirical model (Langmuir model) was applied in this paper, and fitting result indicates that the q max value of the magnetic composite reached as much as 145.9 mg/g for the uptake of tetracycline at 298 K. The above indicates that method of La doping could significantly enhance the adsorption capability of an intentionally designed composite adsorbent.