Zr modulated N doping composites for CO2 conversion into carbonates.

Acidic and basic sites of catalysts are essential for CO2 capture and activation. In this work, Zr, N-ZnO/ZnAl-LDH-IL composites in ionic liquid and methanol systems were fabricated, and applied to catalyze the synthesis of ethylene carbonate (EC) from ethylene glycol (EG) and CO2 with about 4.76 mmolEC gCat.-1 h-1. The composites showed more strong basic sites due to the effective induction of reactive groups on the catalyst surface by Zr doping, resulting in an increase of pyridinic-N groups from 5.48% to 22.25%. More C atoms adjacent to pyridinic-N as strong basic sites was conducive to the activation of CO2 and EG. In addition, the possible catalytic pathway and mechanism of the composites for synthesizing EC as well as the doping of La, Fe, Ce, and Cu were also investigated, which provides an effective strategy for regulating the acid-base centers on the catalyst surface through ionic liquids and methanol solvents.

Glycomacropeptide as an Efficient Agent to Fight Pathophysiological Mechanisms of Metabolic Syndrome.

There is currently a growing interest in the use of nutraceuticals as a means of preventing the development of complex diseases. Given the considerable health potential of milk-derived peptides, the aim of this study was to investigate the protective effects of glycomacropeptide (GMP) on metabolic syndrome. Particular emphasis was placed on the potential mechanisms mitigating cardiometabolic disorders in high-fat, high-fructose diet-fed mice in the presence of GMP or Bipro, an isocaloric control. The administration of GMP for 12 weeks reduced obesity, hyperglycemia and hyperinsulinemia caused by a high-fat, high-fructose diet, resulting in a decline in insulin resistance. GMP also lessened systemic inflammation, as indicated by decreased circulating inflammatory cytokines. In the intestinal and hepatic tissues, GMP improved homeostasis by increasing insulin sensitivity and attenuating high-fat, high-fructose-induced inflammation, oxidative stress and endoplasmic reticulum stress. Biochemical and histological analyses revealed improved hepatic steatosis and fatty acid composition in the livers of high-fat, high-fructose diet-fed mice treated with GMP compared to Bipro. A trend toward a decrease in bile acids without any marked changes in intestinal microbiota composition characterized GMP-treated animals compared to those administered Bipro. GMP offers considerable potential for fighting metabolic syndrome-related components and complications given its beneficial effects on risk factors such as inflammation, oxidative stress and endoplasmic reticulum stress without involving the intestinal microbiota.

Facilitate the preparation of naturally modified and self-healing superhydrophobic/superoleophilic biochar-based foams for efficient oil-water separation.

Oil spills are sudden, complex, and long-term hazardous, and the existing adsorption materials still have the disadvantages of small selective adsorption capacity, easy secondary contamination, and difficult to repair after breakage in practical applications. Herein, melamine foam (MF) coated by ball milled biochar (BMBC) and natural beeswax (Wax@BMBC@MF) was prepared by a bio-inspired functionalization method and further added with self-healing function (SH-Wax@BMBC@MF) to cope with complex environments, and applied to oil-water separation for oil adsorption. SEM and FTIR results showed that BMBC and natural beeswax nanoparticles successfully encapsulated the smooth surface of the melamine foam skeleton. The loading of natural beeswax increased the foam's ability to absorb oil and organic solvents from 0.6108-1.134 g to 0.850-1.391 g, and the oil-absorbing capacity of the foam remained at 0. 758-1.263 g after being cut by a knife and self-healing. The oil-absorbing capacity of SH-Wax@BMBC@MF remained in the range of 0.936-1.336 g under acid/alkali environment (pH =1-13). The surface functional groups of BMBC improved the surface roughness of the material and strengthen the MF skeleton to adsorb oils and organic solvents by capillary action. The generation of the di-coordinated structure by Fe3+ and catechol group contributed the restoration of SH-Wax@BMBC@MF structure and oil absorption capacity. SH-Wax@BMBC@MF has superiority of superhydrophobic, superoleophilic, self-healing after damage, and environmental friendliness, which provides a promising solution for the treatment of oil spills at sea.

MetaPep: A core peptide database for faster human gut metaproteomics database searches.

Metaproteomics has increasingly been applied to study functional changes in the human gut microbiome. Peptide identification is an important step in metaproteomics research, with sequence database search (SDS) and spectral library search (SLS) as the two main methods to identify peptides. However, the large search space in metaproteomics studies causes significant challenges for both identification methods. Moreover, with the development of mass spectrometry, it is now feasible to perform metaproteomic projects involving 100-1000 individual microbiomes. These large-scale projects create a conundrum for searching large databases. In this study, we constructed MetaPep, a core peptide database (including both collections of peptide sequences and tandem MS spectra) greatly accelerating the peptide identifications. Raw files from fifteen metaproteomics projects were re-analyzed and the identified peptide-spectrum matches (PSMs) were used to construct the MetaPep database. The constructed MetaPep database achieved rapid and accurate identification of peptides for human gut metaproteomics. MetaPep has a large collection of peptides and spectra that have been identified in published human gut metaproteomics datasets. MetaPep database can be used as an important resource in the current stage of human gut metaproteomics research. This study showed the possibility of applying a core peptide database as a generic metaproteomics workflow. MetaPep could also be an important resource for future human gut metaproteomics research, such as DIA (data-independent acquisition) analysis.

Magnesium lithospermate B ameliorates diabetic nephropathy by suppressing the uremic toxin formation mediated by gut microbiota.

Diabetic nephropathy (DN) is a major cause of renal failure and urgently necessitates new therapeutic strategies. Magnesium lithospermate B (MLB) showed a good protective effect on kidney injure by oral administration, despite its extremely low bioavailability. The current study aimed to investigate its gut microbiota-targeted mechanism to explain the paradoxical properties of pharmacodynamics and pharmacokinetics. Here we show that MLB alleviated DN by recovering the dysfunction of gut microbiota and their associated metabolites in colon content, such as short-chain fatty acids and amino acids. Moreover, MLB significantly decreased uremic toxin levels in plasma, especially the p-cresyl sulfate. We further discovered that MLB could affect the metabolism of p-cresyl sulfate by suppressing the formation of its intestinal precursors, i.e. the microbiota-mediated conversion from 4-hydroxyphenylacetate to p-cresol. In addition, the inhibition effects of MLB were confirmed. MLB and its metabolite danshensu exhibited inhibitory effects on p-cresol formation mediated by three strains belonging to the genus Clostridium, Bifidobacterium, and Fusobacterium, respectively. Meanwhile, MLB decreased the levels of p-cresyl sulfate in plasma and p-cresol in feces caused by rectal administration of tyrosine in mice. To summarize, the results indicated that MLB ameliorated DN through modulating gut microbiota-associated p-cresyl sulfate metabolism. Together, this study provides new insights on the microbiota-targeted mechanism of MLB in intervening DN and a new strategy in lowering plasma uremic toxins by blocking the formation of their precursors in intestine.

An emerging field: Post-translational modification in microbiome.

Post-translational modifications (PTMs) play an essential role in most biological processes. PTMs on human proteins have been extensively studied. Studies on bacterial PTMs are emerging, which demonstrate that bacterial PTMs are different from human PTMs in their types, mechanisms and functions. Few PTM studies have been done on the microbiome. Here, we reviewed several studied PTMs in bacteria including phosphorylation, acetylation, succinylation, glycosylation, and proteases. We discussed the enzymes responsible for each PTM and their functions. We also summarized the current methods used to study microbiome PTMs and the observations demonstrating the roles of PTM in the microbe-microbe interactions within the microbiome and their interactions with the environment or host. Although new methods and tools for PTM studies are still needed, the existing technologies have made great progress enabling a deeper understanding of the functional regulation of the microbiome. Large-scale application of these microbiome-wide PTM studies will provide a better understanding of the microbiome and its roles in the development of human diseases.

Assessing the Dark Field of Metaproteome.

The human gut microbiome is a complex system composed of hundreds of species, and metaproteomics can be used to explore their expressed functions. However, many lower abundance species are not detected by current metaproteomic techniques and represent the dark field of metaproteomics. We do not know the minimal abundance of a bacterium in a microbiome(depth) that can be detected by shotgun metaproteomics. In this study, we spiked 15N-labeled E. coli peptides at different percentages into peptides mixture derived from the human gut microbiome to evaluate the depth that can be achieved by shotgun metaproteomics. We observed that the number of identified peptides and peptide intensity from 15N-labeled E. coli were linearly correlated with the spike-in levels even when 15N-labeled E. coli was down to 0.5% of the biomass. Below that level, it was not detected. Interestingly, the match-between-run strategy significantly increased the number of quantified peptides even when 15N-labeled E. coli peptides were at low abundance. This is indicative that in metaproteomics of complex gut microbiomes many peptides from low abundant species are likely observable in MS1 but are not selected for MS2 by standard shotgun strategies.

Template Guiding for the Encapsulation of Uniformly Subnanometric Platinum Clusters in Beta-Zeolites Enabling High Catalytic Activity and Stability.

Subnanometric metal clusters have attracted extensive attention because of their unique properties as heterogeneous catalysts. However, it is challenging to obtain uniformly distributed metal clusters under synthesis and reaction conditions. Herein, we report a template-guidance protocol to synthesize subnanometric metal clusters uniformly encapsulated in beta-zeolite, with the metal ions anchored to the internal channels of the zeolite template via electrostatic interactions. Pt metal clusters with a narrow size range of 0.89 to 1.22 nm have been obtained on the intersectional sites of beta-zeolite (Pt@beta) with a broad range of Si/Al molar ratios (15-200). The uniformly distributed Pt clusters in Pt@H-beta are subject to strong electron withdrawal by the zeolite, which promotes transfer of active hydrogen, providing excellent activity and stability in hydrodeoxygenation reactions. A general strategy is thus proposed for the encapsulation of subnanometric metal clusters in zeolites with high thermal stability.

Robotics Dexterous Grasping: The Methods Based on Point Cloud and Deep Learning.

Dexterous manipulation, especially dexterous grasping, is a primitive and crucial ability of robots that allows the implementation of performing human-like behaviors. Deploying the ability on robots enables them to assist and substitute human to accomplish more complex tasks in daily life and industrial production. A comprehensive review of the methods based on point cloud and deep learning for robotics dexterous grasping from three perspectives is given in this paper. As a new category schemes of the mainstream methods, the proposed generation-evaluation framework is the core concept of the classification. The other two classifications based on learning modes and applications are also briefly described afterwards. This review aims to afford a guideline for robotics dexterous grasping researchers and developers.

Superhydrophobic-superoleophilic biochar-based foam for high-efficiency and repeatable oil-water separation.

Leakage accidents occurring during oil production and transportation are currently one of the most serious environmental problems worldwide. Developing efficient and environmentally friendly oil-water separation methods is the key to solve this problem. In this work, a facile method to fabricate a high-performance oil absorbent through the loading of ball-milled biochar (BMBC) and octadecylamine on the skeleton of melamine foam (MF) is reported. The resulting ball-milled biochar-based MF (BMBC@MF) displayed a complex three-dimensional porous structure. The BM biochar on the surface of BMBC@MF forms nano/µm-scale folds, which reduced the surface energy of BMBC@MF after grafted octadecylamine. These structures resulted in the conversion of the hydrophilic surface of MF to hydrophobic surface. These characteristics made the modified foam an excellent oil absorbent with a high oil absorption capacity (43-155 times its own weight) and extraordinary recyclability. Furthermore, the BMBC@MF could maintain high hydrophobicity and adsorption stability in a wide pH range (from 1 to 11). More importantly, BM biochar is a cheap and readily available material to make BMBC@MF possible for large-scale production. Therefore, this work provides an effective way for low-cost, environmentally friendly, and large-scale production of superhydrophobic adsorbents for oil-water separation.

Diagnostic performance of combined use of automated breast volume scanning & hand-held ultrasound for breast lesions.

Background & objectives: Breast cancer being one of the most common malignant tumours among women, diagnostic modalities for early detection of the same become of paramount importance. In this context, the hand-held ultrasound (HHUS) and automated breast volume scanner (ABVS) could provide valuable information for clinicians to diagnose breast diseases. This study aimed to compare and evaluate the diagnostic performance of combined use of HHUS and ABVS for the differentiation of benign and malignant breast lesions. Methods: A total of 361 female patients, who underwent both HHUS and ABVS examinations were included in this study. ABVS and HHUS images were interpreted using the American College of Radiology Breast Imaging-Reporting and Data System (BI-RADS). The distributions of the BI-RADS categories and pathology results were shown as specific numbers. Kappa coefficients test (κ) was calculated to compare the diagnostic results amongst the ABVS, HHUS and ABVS combined with HHUS. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of the three diagnostic methods were calculated and their respective diagnostic performance was analyzed by receiver operator characteristic curve. Results: Of a total of 431 lesions, 153 (35.5%) were malignant and 278 (64.5%) were benign. With respect to the pathology results, the value of κ was 0.713 (P<0.001) for HHUS, κ=0.765 (P<0.001) for ABVS and κ=0.815 (P<0.001) for HHUS+ABVS. The sensitivity, specificity, accuracy, PPV and NPV for HHUS combined with ABVS were 96.08 (147/153), 88.49 (246/278), 91.18 (393/431), 82.12 (147/179) and 97.62 per cent (246/252) respectively. For HHUS, these were 90.20 (138/153), 84.17 (234/278), 86.31 (372/431), 75.82 (138/182) and 93.98 per cent (234/249) respectively; and for ABVS these were 92.16 (141/153), 87.05 (242/278), 88.86 (383/431), 79.66 (141/177) and 95.28 per cent (242/254), respectively. There was no significant difference amongst these three methods, but the diagnostic performance of HHUS combined with ABVS was better than, or at least equal to, that of HHUS or ABVS alone. Interpretation & conclusions: The results of this study suggest that ABVS is a promising and advantageous modality for breast cancer detection. Furthermore, the combination of HHUS and ABVS showed a more comparable diagnostic performance than HHUS or ABVS alone for distinguishing between benign and malignant breast lesions.

Effects of Crystallite Sizes of Pt/HZSM-5 Zeolite Catalysts on the Hydrodeoxygenation of Guaiacol.

Herein, Pt/HZSM-5 zeolite catalysts with different crystallite sizes ranging from nanosheet (~2 nm) to bulk crystals (~1.5 µm) have been prepared for the hydrodeoxygenation of guaiacol, and their effects on the reaction pathway and product selectivity were explored. HZSM-5 zeolites prepared by seeding (Pt/Z-40: ~40 nm) or templating (Pt/NS-2: ~2 nm) fabricated intra-crystalline mesopores and thus enhanced the reaction rate by promoting the diffusion of various molecules, especially the bulky ones such as guaiacol and 2-methoxycyclohexanol, leading to a higher cyclohexane selectivity of up to 80 wt % (both for Pt/Z-40 and Pt/NS-2) compared to 70 wt % for bulky HZSM-5 (Pt/CZ: ~1.5 µm) at 250 °C and 120 min. Furthermore, decreased crystallite sizes more effectively promoted the dispersion of Pt particles than bulky HZSM-5 (Pt/Z-400: ~400 nm and Pt/CZ). The relatively low distance between Pt and acidic sites on the Pt/Z-40 catalyst enhanced the metal/support interaction and induced the reaction between the guaiacol molecules adsorbed on the acidic sites and the metal-activated hydrogen species, which was found more favorable for deoxygenation than for hydrogenation of oxygen-containing molecules. In addition, Pt/NS-2 catalyst with a highly exposed surface facilitated more diverse reaction pathways such as alkyl transfer and isomerization.

Differential distribution of characteristic constituents in root, stem and leaf tissues of Salvia miltiorrhiza using MALDI mass spectrometry imaging.

Segmentation-quantification is the most commonly used method for studying the tissue distribution of bioactive constituents in plant, but this method would bring uncontrollable pollution, compound migration and denaturation. Mass spectrometry imaging (MSI), as a new method developed in the past 20 years, has high sensitivity, high spatial resolution, high degree of visualization, and low risk of contamination and degeneration when studying tissue distribution of compounds. For the first time we applied matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) to tissue distribution of characteristic constituents of the medicinal plant Salvia miltiorrhiza. From the collected data, we found the regional differences in root, stem, and leaf tissues, and the ion information with differential distribution characteristics. We also identified 18 bioactive constituents in S. miltiorrhiza with their spatial distribution information. In addition, the plant was divided into five parts, and the identified compounds were analyzed for differences between tissues using LC-MS, which results verified those found from the MSI. It is figured out that MALDI-MSI can be reliably applied to the differential distribution of salvianolic acids and tanshinones.

Quantification of microbiota-related phenols and aromatic acids in mouse feces of a diabetic nephropathy model by simultaneous BDAPE derivatization using ultra-performance liquid chromatography-tandem mass spectrometry.

In the intestine, several phenols and aromatic acids are generated by microbiota and are highly related to the formation of uremic toxins. Herein, we developed a new derivatization reagent, 2-bromo-1-[4-(dimethylamino)phenyl] ethyl ketone (BDAPE), that reacted simultaneously with phenols and aromatic acids. Following a reaction within 2 h at 60 °C in the presence of 200 mM potassium carbonate (K2CO3), the obtained BDAPE derivatives were separated on a reversed-phase C18 column and quantified by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) in positive electrospray ionization mode. This method allowed a lower limit of quantification (LLOQ) of 0.090 µΜ for 3-indolepropionic acid (3IPA), indole-3-acetic acid (3IAA), p-cresol (PC), benzoic acid (BA), and phenol (PN); 0.30 µΜ for phenylacetic acid (PAA); 0.45 µΜ for 4-hydroxyphenylacetic acid (4HPAA); and 0.60 µΜ for 3-phenylpropionic acid (PPA). Methodological validation further demonstrated acceptable accuracy (%RE < 16.1) and precision (%RSD < 16.2), suggesting that this is a sensitive and robust method for simultaneous quantification of phenols and aromatic acids. The method was successfully applied to analyze these microbiota-related analytes in mouse feces of a diabetic nephropathy model. Graphical abstract.

A rapid and convenient derivatization method for quantitation of short-chain fatty acids in human feces by ultra-performance liquid chromatography/tandem mass spectrometry.

RATIONALE: Short-chain fatty acids (SCFAs) are associated with intestinal microbiota and diseases in humans. SCFAs have a low response in mass spectrometry, and in order to increase sensitivity, reduce sample consumption, shorten analysis time, and simplify sample preparation steps, a derivatization method was developed. METHODS: We converted seven SCFAs into amide derivatives with 4-aminomethylquinoline. The reaction occurred for 20 min at room temperature. The analytes were separated on a reversed-phase C18 column and quantitated in the positive ion electrospray ionization mode using multiple reaction monitoring. Acetic acid-d4 was used as the stable-isotope-labeled surrogate analyte for acetic acid in the working solutions, while the other stable-isotope-labeled standards were used as internal standards (ISs). RESULTS: Method validation showed that the intra-day and inter-day precision of quantitation for the seven SCFAs over the whole concentration range was ≤3.8% (n = 6). The quantitation accuracy ranged from 85.5% to 104.3% (n = 6). Most important, the collected feces were vortexed immediately with ethanol. CONCLUSIONS: This study provides a new derivatization method for a precise, accurate, and rapid quantitation of SCFAs in human feces using ultra-performance liquid chromatography/tandem mass spectrometry. This method successfully determined the concentration of SCFAs in human feces and could assist in the exploration of intestinal microbiota and diseases.