An optimized culturomics strategy for isolation of human milk microbiota.

Viable microorganisms and a diverse microbial ecosystem found in human milk play a crucial role in promoting healthy immune system and shaping the microbial community in the infant's gut. Culturomics is a method to obtain a comprehensive repertoire of human milk microbiota. However, culturomics is an onerous procedure, and needs expertise, making it difficult to be widely implemented. Currently, there is no efficient and feasible culturomics method specifically designed for human milk microbiota yet. Therefore, the aim of this study was to develop a more efficient and feasible culturomics method specifically designed for human milk microbiota. We obtained fresh samples of human milk from healthy Chinese mothers and conducted a 27-day enrichment process using blood culture bottles. Bacterial isolates were harvested at different time intervals and cultured on four different types of media. Using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis, we identified a total of 6601 colonies and successfully obtained 865 strains, representing 4 phyla, 21 genera, and 54 species. By combining CBA and MRS media, we were able to cultivate over 94.4% of bacterial species with high diversity, including species-specific microorganisms. Prolonged pre-incubation in blood culture bottles significantly increased the number of bacterial species by about 33% and improved the isolation efficiency of beneficial bacteria with low abundance in human milk. After optimization, we reduced the pre-incubation time in blood culture bottles and selected optimal picking time-points (0, 3, and 6 days) at 37°C. By testing 6601 colonies using MALDI-TOF MS, we estimated that this new protocol could obtain more than 90% of bacterial species, reducing the workload by 57.0%. In conclusion, our new culturomics strategy, which involves the combination of CBA and MRS media, extended pre-incubation enrichment, and optimized picking time-points, is a feasible method for studying the human milk microbiota. This protocol significantly improves the efficiency of culturomics and allows for the establishment of a comprehensive repertoire of bacterial species and strains in human milk.

In Situ Fabrication of SnO2 Nanowalls for Robust Acetylene Sensing at Low Temperature.

Acetylene (C2 H2 ) monitoring in real time and online is essential for erasing transformer risks and guaranteeing normal equipment operation and operator safety. This study examines the direct fabrication of ultrathin SnO2 nanowalls on Ag-Pd substrates using a simple solvothermal method that doesn't demand the use of any additional motivators or templates. The thickness and shape of the nanowalls can be controlled by varying the cetyl trimethyl ammonium bromide (CTAB) concentration in the solvent. As observed, the gas sensor (SnO2 -3) fabricated by 2.4 g CTAB exhibits superior gas-sensing features. This is primarily due to the hollow structure constructed by the arrangement of nanowalls, which delivers not only enough gas diffusion pathways but also enough reaction sites during the gas sensing processes. The findings suggest that low-cost SnO2 nanowalls created using a straightforward procedure could be taken into consideration as prospective candidates for use in industrial C2 H2 sensing applications.

Fast and Sensitive Detection of CO by Bi-MOF-Derived Porous In2O3/Fe2O3 Core-Shell Nanotubes.

In2O3 is an optimal material for sensitive detection of carbon monoxide (CO) gas due to its low resistivity and high catalytic activity. Yet, the gas response dynamics between the CO gas molecules and the surface of In2O3 is limited by its solid structure, resulting in a weak gas response value and sluggish electron transport. Herein, we report a strategy to synthesize porous In2O3/Fe2O3 core-shell nanotubes derived from In/Fe bimetallic organic frameworks. The fabricated porous In2O3/Fe2O3-4 core-shell nanotubes present outstanding gas sensitivities, including a response value 3.8 times (33.7 to 200 ppm CO at 260 °C) higher than that of monometallic-derived In2O3 (8.7), ultrashort response and recovery times (23/76 s) to 200 ppm CO, low detection limit (1 ppm), promising selectivity, and long-term stability. The enhanced sensing mechanisms are clarified by the combination of experiment and first-principles calculations, showing that the synergetic strategy of higher adsorption energy, increased electrical conductivity, higher electron transfer numbers, and larger specific surface area of porous core-shell structures promotes the surface activity and charge transfer efficiency. The present work paves a way to tune gas-sensing materials with special morphologies for the development of high-performance CO sensors.

A hard mask process and alignment device aims to achieve high consistency and mass-scale production of gas sensors based on spraying hydrothermal gas sensing material.

The material synthesized through the hydrothermal method has received extensive and in-depth study in recent years, with a large number of literature reporting their excellent performance in the fields of catalysis or gas sensitivity. In order to combine the hydrothermal material with micro-electro-mechanical system processes to achieve large-scale manufacturing of hydrothermal synthesized materials at the wafer-level, this paper proposes a series of processes for hard mask patterned electro-atomization spraying of hydrothermal materials and designs and manufactures an alignment device that achieves the alignment of silicon hard mask and electrode wafers based on the vacuum clamping principle. Through experiments, it has been verified that this device can achieve micrometer-level alignment between the hard mask and the electrode wafer. By conducting electro-atomization spraying, hard mask patterning, optical microscopy, and confocal laser scanning microscope measurements, as well as gas sensitivity testing on a CeO2/TiO2 hydrothermal composite material published in our previous research, it was further verified that this process has good film formation consistency (Sa and Sq are both less than 3 µm and the average film thickness deviation is less than 5 µm), excellent and consistent gas sensitivity performance, and good long-term working stability. This article provides a promising process method for the large-scale production of hydrothermal synthesis materials at the wafer-level.

Template Based Synthesis of Porous Graphdiyne Nanosheet for Reversible and Fast NO2 Detection by UV Irradiation.

Two-dimensional graphdiyne (GDY) formed by sp and sp2 hybridized carbon has been found to be an efficient toxic gas sensing material by density functional theory (DFT). However, little experimental research concerning its gas sensing capability has been reported owing to the complex preparation process and harsh experimental conditions. Herein, porous GDY nanosheets are successfully synthesized through a facile solvothermal synthesis technique by using CuO microspheres (MSs) as both template and source of catalyst. The porous GDY nanosheets exhibit a broadband optical absorption, rendering it suitable for the light-driven optoelectronic gas sensing applications. The GDY-based gas sensor was demonstrated to have excellent reversible to NO2 behaviors at 25 °C for the first time. More importantly, higher response value and faster response-recovery time once exposed to NO2 gas molecules are achieved by the illumination of UV light. In this way, our work paves the way for the exploration of GDY-based gas detection experimentally.

Understanding the Catalytic Kinetics of Polysulfide Redox Reactions on Transition Metal Compounds in Li-S Batteries.

Because of their high energy density, low cost, and environmental friendliness, lithium-sulfur (Li-S) batteries are one of the potential candidates for the next-generation energy-storage devices. However, they have been troubled by sluggish reaction kinetics for the insoluble Li2S product and capacity degradation because of the severe shuttle effect of polysulfides. These problems have been overcome by introducing transition metal compounds (TMCs) as catalysts into the interlayer of modified separator or sulfur host. This review first introduces the mechanism of sulfur redox reactions. The methods for studying TMC catalysts in Li-S batteries are provided. Then, the recent advances of TMCs (such as metal oxides, metal sulfides, metal selenides, metal nitrides, metal phosphides, metal carbides, metal borides, and heterostructures) as catalysts and some helpful design and modulation strategies in Li-S batteries are highlighted and summarized. At last, future opportunities toward TMC catalysts in Li-S batteries are presented.

A 3D FeOOH nanotube array: an efficient catalyst for ammonia electrosynthesis by nitrite reduction.

Nitrite (NO2-) is a detrimental pollutant widely existing in groundwater sources, threatening public health. Electrocatalytic NO2- reduction settles the demand for removal of NO2- and is also promising for generating ammonia (NH3) at room temperature. A nanotube array directly grown on a current collector not only has a large surface area, but also exhibits improved structural stability and accelerated electron transport. Herein, a self-standing FeOOH nanotube array on carbon cloth (FeOOH NTA/CC) is proposed as a highly active electrocatalyst for NO2--to-NH3 conversion. As a 3D catalyst, the FeOOH NTA/CC is able to attain a surprising faradaic efficiency of 94.7% and a large NH3 yield of 11937 µg h-1 cm-2 in 0.1 M PBS (pH = 7.0) with 0.1 M NO2-. Furthermore, this catalyst also displays excellent durability in cyclic and long-term electrolysis tests.

High-Performance Electrochemical Nitrate Reduction to Ammonia under Ambient Conditions Using a FeOOH Nanorod Catalyst.

Electrocatalytic nitrate reduction is promising as an environmentally friendly process to produce high value-added ammonia with simultaneous removal of nitrate, a widespread nitrogen pollutant, for water treatment; however, efficient electrocatalysts with high selectivity are required for ammonia formation. In this work, FeOOH nanorod with intrinsic oxygen vacancy supported on carbon paper (FeOOH/CP) is proposed as a high-performance electrocatalyst for converting nitrate to ammonia at room temperature. When operated in a 0.1 M phosphate-buffered saline (PBS) solution with 0.1 M NaNO3, FeOOH/CP is able to obtain a large NH3 yield of 2419 µg h-1 cm-2 and a surprisingly high Faradic efficiency of 92% with excellent stability. Density functional theory calculation demonstrates that the potential-determining step for nitrate reduction over FeOOH (200) is *NO2H + H+ + e- → *NO + H2O.

Ultrasensitive Pressure Sensor Sponge Using Liquid Metal Modulated Nitrogen-Doped Graphene Nanosheets.

Wearable pressure sensors are crucial for real-time monitoring of human activities and biomimetic robot status. Here, the ultrasensitive pressure sensor sponge is prepared by a facile method, realizing ultrasensitive pressure sensing for wearable health monitoring. Since the liquid metal in the sponge-skeleton structure under pressure is conducive to adjust the contact area with nitrogen-doped graphene nanosheets and thus facilitates the charge transfer at the interface, such sensors exhibit a fast response and recovery speed with the response/recovery time 0.41/0.12 s and a comprehensive response range with a sensitivity of up to 476 KPa-1. Notably, the liquid metal-based spongy pressure sensor can accurately monitor the human body's pulse, the pressure on the skin, throat swallowing, and other activities in real time, demonstrating a broad application prospect. Those results provide a convenient and low-cost way to fabricate easily perceptible pressure sensors, expanded the application potential of liquid metal-based composites for future electronic skin development.

Tunable NH4F-Assisted Synthesis of 3D Porous In2O3 Microcubes for Outstanding NO2 Gas-Sensing Performance: Fast Equilibrium at High Temperature and Resistant to Humidity at Room Temperature.

NO2 gas sensors based on metal oxides under wild conditions are highly demanded yet an incomplete surface reaction and humidity interference on the gas-sensing performance limit their applications. Herein, we report three-dimensional (3D) porous In2O3 microcubes via a simple hydrothermal strategy to produce outstanding NO2 gas-sensing performance: fast equilibrium of the surface reaction at 150 °C and negligible humidity dependence on the NO2 gas sensing at room temperature. The 3D porous In2O3 microcubes with high surface areas, suitable pore sizes, rich oxygen vacancies, and high conductivity are testified. The underlying structural transformation mechanism for 3D porous In2O3 is investigated in detail. The as-made 3D porous In2O3 microcubic gas sensors present excellent gas-sensing performance to 50 ppm NO2 at 150 °C, including a high response value (2329), fast response/recovery time (10/9 s), a low detection limit (10 ppb), long-term stability (60 days), and strong selectivity. Furthermore, they exhibit relatively stable NO2 gas response under humidity variation (20-80%). The NO2 gas mechanism under the interference of water is also clarified.

Light and Heat Triggering Modulation of the Electronic Performance of a Graphdiyne-Based Thin Film Transistor.

Graphdiyne-based field effect thin film transistors (GTFTs) with a clean, efficient, nondestructive, continuous, and reversible modulation strategy have been developed for the first time. We have determined that efficient electronic modulation utilizing light and heat results in a significant improvement in GTFT performance. Heat can increase the switching ratio of the device to 103, while light regulation can induce a higher switching ratio of >104 by efficient charge injection with an improved conductivity of 1.5 × 104 S/m. Via the adjustment of the visible light wavelength and power density, tunable charge injection has been realized. These results not only highlight the excellent intrinsic properties and modulation method of GTFTs but also promote the application of such films composed of two-dimensional graphdiyne material in integrated devices, such as logic devices and flexible devices.

Nucleation density and pore size tunable growth of ZnO nanowalls by a facile solution approach: growth mechanism and NO2 gas sensing properties.

Nanowalls are novel nanostructures whose 3D porous network morphology holds great potential for applications as gas sensors. The realization of such a nanowall-based gas sensor depends directly on the comprehensive understanding of the growth mechanism of the nanowalls. We induced nucleation density and pore size evolution by increasing the dipping and growth times. The investigation indicates that the 3D porous ZnO nanowalls consist of a seed layer of ZnO nanoparticles and a growth layer of the vertically grown ZnO nanosheets. The seed layer nucleation density dominance is driven by the dipping time. The pore size and the height of the as-grown ZnO nanowalls are determined by varying the growth time. Possible growth mechanisms governing the physical characteristics of the synthesized ZnO nanostructures in the solution process are proposed and discussed. The gas sensor that was fabricated from the ZnO nanowall structure exhibited strong dependence on the microstructure, which was mainly determined by the preparation conditions.

Overexpression of calpain­1 predicts poor outcome in patients with colorectal cancer and promotes tumor cell progression associated with downregulation of FLNA.

Several studies have demonstrated that calpain­1 is involved in a variety of pathophysiological processes, including tumorigenesis. However, the clinical relevance and role of calpain­1 in colorectal cancer (CRC) are unclear. Filamin A (FLNA) is an actin­binding protein that participates in cancer progression and can be cleaved by calpain­1. In the present study, the protein expression levels of calpain­1 and FLNA were detected by immunohistochemistry in 467 matched cancerous and paracancerous tissues from patients with CRC. The staining results and the clinicopathological characteristics of the patients were comprehensively analyzed. A high expression level of calpain­1 was strongly associated with age, metastasis, Dukes stage and survival time but not with sex, histologic grade, tumour location or tumor size. By contrast, a low expression level of FLNA was significantly associated with tumor size, histological grade, metastasis, Dukes stage and survival time, but not with age, sex, or tumor location. Kaplan­Meier survival analysis demonstrated that patients with calpain­1 overexpression had a shorter mean overall survival (OS) than patients with lower levels of calpain­1 expression. Unlike high levels of calpain­1, high levels of FLNA were associated with longer OS than lower levels of FLNA expression. Furthermore, calpain­1 expression was inversely correlated with FLNA expression. The relationship between calpain­1 and FLNA was further confirmed using CRC cell lines in vitro. When calpain­1 expression decreased in CRC cells, FLNA expression increased. Furthermore, calpain­1 knockdown in CRC cells resulted in decreased proliferation, colony formation, migration and invasion. The present findings suggest that calpain­1 overexpression predicted a poor outcome in patients with CRC and promoted tumor progression, possibly via FLNA downregulation.

Molecule-based water-oxidation catalysts (WOCs): cluster-size-dependent dye-sensitized polyoxometalates for visible-light-driven O2 evolution.

From atomic level to understand the cluster-size-dependant behavior of dye-sensitized photocatalysts is very important and helpful to design new photocatalytic materials. Although the relationship between the photocatalytic behaviors and particles' size/shape has been widely investigated by theoretical scientists, the experimental evidences are much less. In this manuscript, we successfully synthesized three new ruthenium dye-sensitized polyoxometalates (POM-n, n relate to different size clusters) with different-sized POM clusters. Under visible-light illumination, all three complexes show the stable O2 evolution with the efficient order POM-3 > POM-2 > POM-1. This cluster-size-dependent catalytic behavior could be explained by the different numbers of M = Ot (terminal oxygen) bonds in each individual cluster because it is well-known that Mo = Ot groups are the catalytically active sites for photooxidation reaction. The proposed mechanism of water oxidation for the dye-sensitized POMs is radical reaction process. This research could open up new perspectives for developing new POM-based WOCs.