Anchoring Pt Particles onto Mesoporousized ZnO Holey Cubes for Triethylamine Detection with Multifaceted Superiorities.

Designing sensing materials with integrating unique spatial structures, functional units, and surface activity is vital to achieve high-performance gas sensor toward triethylamine (TEA) detection. Herein, a simple spontaneous dissolution is used with subsequent thermal decomposition strategy to fabricate mesoporousized ZnO holey cubes. The squaric acid is crucial to coordinate Zn2+ to form a cubic shape (ZnO-0) and then tailor the inner part to open a holey cube with simultaneously mesoporousizing the left cubic body (ZnO-72). To enhance the sensing performance, the mesoporous ZnO holey cubes have been functionalized with catalytic Pt nanoparticles, which deliver superior performances including high response, low detection limit, and fast response and recovery time. Notably, the response of Pt/ZnO-72 towards 200 ppm TEA is up to 535, which is much higher than those of 43 and 224 for pristine ZnO-0 and ZnO-72. A synergistic mechanism combining the intrinsic merits of ZnO, its unique mesoporous holey cubic structure, the oxygen vacancies, and the catalytic sensitization effect of Pt has been proposed for the significant enhancement in TEA sensing. Our work provides an effective facile approach to fabricate an advanced micro-nano architecture with manipulating its spatial structure, functional units, and active mesoporous surface for promising TEA gas sensors.

Polypyrrole/Schiff Base Composite as Electromagnetic Absorbing Material with High and Tunable Absorption Performance.

In recent years, Schiff base-related conjugated systems have received extensive attention, but little research has been done in the field of electromagnetic materials. In this work, an organic conjugated system based on polypyrrole/hydrazone Schiff base (PPy/HSB) composites was constructed via a Schiff base synthetic route and their electromagnetic behavior was investigated. The electromagnetic response of PPy/HSB complexes demonstrates fine electromagnetic absorption performance. When the filler loading is 30 wt% in a paraffin matrix, an absorption peak of -43.1 dB was achieved and its effective absorption bandwidth (EAB) was located in the range of 10.88-18.0 GHz. The electromagnetic response behavior of PPy/HSB complexes is explained by models involving electronic structure, multi-polarization and conductive network. The mechanisms of PPy/HSB complexes formation and HSB crystallization are also discussed through the compatibility of PPy/HSB and the structure of HSB. Moreover, the morphology transformation of HSB in the PPy/HSB systems has been studied. This study opens the exploration of organic-dielectric conjugated systems in the field of electromagnetic materials, and significantly broadens the application range of organic-dielectric-dielectric composites.

A nickel foam modified with electrodeposited cobalt and phosphor for amperometric determination of dopamine.

Considering the importance of dopamine (DA) detection for neuroscience and disease diagnosis, herein, an electrochemical sensor for dopamine is described. It is based on the use of a Ni-Co-P nanostructure fabricated on nickel foam via electrode position from cobalt chloride and ammonium phosphate for 10 min. Time-dependent experiments show the transformation of Ni-Co-P nanoparticles to spheres. The resulting electrode display excellent electrochemical response to DA. Figures of merit include (a) a working potential of 0.55 V (vs. Ag/AgCl); (b) an electrochemical sensitivity of 5262 µA mM-1 cm-2; (c) a wide linear range (from 0.5 to 2350 µM), and (d) a 1 µM detection limit. The outstanding electrochemical performance is explained by the synergistic effects of large surface area, improved electron transfer, presence of free binders, and the presence of three active components (nickel, cobalt and phosphonium ion). Graphical abstract A Ni-Co-P nanostructure was electrodeposited on nickel foam to obtain an electrochemical sensor for amperometric determination of dopamine with outstanding performance.

Lightweight, breathable and self-cleaning polypyrrole-modified multifunctional cotton fabric for flexible electromagnetic interference shielding.

The thriving of wearable electronics and the emerging new requirements for electromagnetic interference (EMI) shielding have driven the innovation of EMI shielding materials towards lightweight, wearability and multifunctionality. Herein, the hierarchical polypyrrole nanotubes (PNTs)/PDMS structures are rationally constructed on the textile for obtaining multifunctional and flexible EMI shielding textiles by in-situ polymerization and surface coating. The modified cotton fabric possesses a conductivity of about 2715.8 S/m and an SET of 28.2 dB in the X band when the thickness is only 0.5 mm. After ultrasonic treatment, cyclic bending and washing, the conductivity and EMI shielding performance remain stable and exhibit long-term durability. Importantly, the textile's inherent lightweight, breathable and soft properties have been completely retained after modification. This work shows application potentiality in the field of EMI pollution protection and affords a novel path for the construction of multifunctionally wearable and durable EMI shielding materials.

Differences of bacterioplankton communities between the source and upstream regions of the Yangtze River: microbial structure, co-occurrence pattern, and environmental influencing factors.

The source area of the Yangtze River is located in the hinterland of the Qinghai-Tibet Plateau, which is known as the "Earth's third pole." It is the water conservation area and the natural barrier of the ecosystem of the Yangtze River basin. It is also the most sensitive area of the natural ecosystem, and the ecological environment is very fragile. Microorganisms play key roles in the biogeochemical processes of water. In this paper, the bacterioplankton communities in the source and upstream regions of the Yangtze River were studied based on 16S rRNA high-throughput sequencing, and their environmental influencing factors were further analyzed. Results showed that the upstream region had higher richness and diversity than the source region. The predominant bacterial phyla in the source and upstream regions were Proteobacteria, Firmicutes, and Actinobacteriota. The bacterial phyla associated with municipal pollution and opportunistic pathogen, such as Firmicutes and Actinobacteriota, were more abundant in the upstream. By contrast, distinct planktonic bacterial genera associated with mining pollution, such as Acidiphilium and Acidithiobacillus, were more abundant in the source region. The co-occurrence network showed that the interaction of bacterioplankton community is more frequent in the upstream. The bacterioplankton community compositions, richness, and functional profiles were affected by the spatial heterogeneity. Moreover, variation partitioning analysis further confirmed that the amount of variation in the source region independently explained by variables of altitude was the largest, followed by water nutrient. This paper revealed the spatial distribution of planktonic bacterial communities in the source and upstream regions of the Yangtze River and its correlation with environmental factors, providing information support for ensuring the health and safety of aquatic ecosystems in the Yangtze River Basin.

High-performance Li/LiNi0.8Co0.1Mn0.1O2 batteries enabled by optimizing carbonate-based electrolyte and electrode interphases via triallylamine additive.

Lithium (Li) metal batteries (LMBs), paired with high-energy-density cathode materials, are promising to meet the ever-increasing demand for electric energy storage. Unfortunately, the inferior electrode-electrolyte interfaces and hydrogen fluoride (HF) corrosion in the state-of-art carbonate-based electrolytes lead to dendritic Li growth and unsatisfactory cyclability of LMBs. Herein, a multifunctional electrolyte additive triallylamine (TAA) is proposed to circumvent those issues. The TAA molecule exhibits strong nucleophilicity and contains three unsaturated carbon-carbon double bonds, the former for HF elimination, the later for in-situ passivation of aggressive electrodes. As evidenced theoretically and experimentally, the preferential oxidation and reduction of carbon-carbon double bonds enable the successful regulation of components and morphologies of electrode interfaces, as well as the binding affinity to HF effectively blocks HF corrosion. In particular, the TAA-derived electrode interfaces are packed with abundant lithium-containing inorganics and oligomers, which diminishes undesired parasitic reactions of electrolyte and detrimental degradation of electrode materials. When using the TAA-containing electrolyte, the cell configuration with Li anode and nickel-rich layered oxide cathode and symmetrical Li cell deliver remarkably enhanced electrochemical performance with regard to the additive-free cell. The TAA additive shows great potential in advancing the development of carbonate-based electrolytes in LMBs.

Polystyrene-Modulated Polypyrrole to Achieve Controllable Electromagnetic-Wave Absorption with Enhanced Environmental Stability.

The moderation of the dielectric properties of polymer composites and their environmental stability need to be considered comprehensively in the design of microwave-absorbing materials. In this work, polypyrrole/polystyrene (PPy/PS) composited particles were synthesized through a facile in situ bulk polymerization procedure. The PS component can be modulated conveniently by controlling the polymerization time. FTIR and Raman analyses disclosed that the PS component was immobilized in PPy via covalent bonds. The electromagnetic characterization results indicated that the dielectric properties and, thus, the microwave absorption could be controlled when the styrene polymerization was prolonged from 6 h (PPy-6) to 19 h (PPy-19). The composite PPy-19 displayed an optimal reflection loss of -51.7 dB with a matching thickness of 3.16 mm, and the effective absorption bandwidth (EAB) even reached 5.8 GHz at 2.4 mm. The PS component endowed PPy/PS composites with more robust environmental stability than homogeneous PPy. After being exposed to air for 365 days and hydrothermally treated at 100 °C for 12 h, PPy-19 still exhibited a reflection loss superior to -20 dB. The present work provides a new insight into the adjustment of the electromagnetic properties of PPy composites to fabricate high-performance microwave absorbers with superior environmental stability.

Hydrodynamics Regulate Longitudinal Plankton Community Structure in an Alpine Cascade Reservoir System.

Previous studies report significant changes on biotic communities caused by cascade reservoir construction. However, factors regulating the spatial-temporal plankton patterns in alpine cascade reservoir systems have not been fully explored. The current study explored effects of environmental factors on the longitudinal plankton patterns, through a 5-year-long study on the environmental factors and communities of phytoplankton and zooplankton in an alpine cascade reservoir system located upstream of Yellow River region. The findings showed that phytoplankton and zooplankton species numbers in the studied cascade reservoir system were mainly regulated by the hydrological regime, whereas nutrient conditions did not significantly affect the number of species. Abundance and biovolume of phytoplankton in cascade reservoirs were modulated by the hydrological regime and nutrient conditions. The drainage rate, N:P ratio, and sediment content in cascade reservoirs were negatively correlated with abundance and biovolume of phytoplankton. Abundance and biovolume of zooplankton were not significantly correlated with the hydrological regime but showed a strong positive correlation with nutrient conditions in cascade reservoirs. Shannon-Wiener index (H') and the Pielou index (J) of phytoplankton were mainly regulated by the hydrological regime factors, such as drainage rate and sediment content in cascade reservoirs. However, temperature and nutrient conditions were the main factors that regulated the Shannon-Wiener index (H') and the Pielou index (J) of zooplankton. Species number, abundance, and biovolume of phytoplankton showed a significant positive correlation with those of zooplankton. Hydrodynamics and nutrient conditions contributed differently in regulating community structure of phytoplankton or zooplankton. These findings provide an understanding of factors that modulate longitudinal plankton community patterns in cascade reservoir systems.

Composition and Functional Characteristics and Influencing Factors of Bacterioplankton Community in the Huangshui River, China.

Bacterial community plays a key role in environmental and ecological processes of river ecosystems. Given the special climatic and geographical conditions, studying the compositional characteristics of microorganisms in highland rivers and the relationship between such microorganisms and water physicochemical factors is important for an in-depth understanding of microbial ecological mechanisms. In the present study, high-throughput sequencing was used to investigate and study the bacterioplankton community of the Huangshui River in the ecotone zone of the Qinghai Plateau and Loess Plateau. The results showed that the Huangshui River had significantly lower alpha diversity than the plain rivers. Despite the similarity in their environmental conditions, the main taxonomic compositions of the bacterial communities were distinct between the Huangshui River and polar regions (the Arctic and Antarctica). Proteobacteria accounted for the largest proportion (30.79-99.98%) of all the sequences, followed by Firmicutes (0-49.38%). Acidiphilium was the most numerous genera, which accounted for 0.03-86.16% of the assigned 16S reads, followed by Acidocella (0-95.9%), both belonging to Alphaproteobacteria. The diverse taxa of potential pathogens, such as Acinetobacter, Pseudomonas, and Aeromonas, were also identified. A principal coordinates analysis, coupled with a canonical correspondence analysis, showed spatial variations in the bacterial community composition. The water physical properties (e.g., Cr6+, total phosphorus, and CODMn); altitude; and land use (e.g., urban land cover and aquaculture) determined the distribution of the bacterioplankton composition. PICRUSt2 revealed that the overall functional profiles of the bacterial communities in different samples were similar, and our results suggested the potential health risks of water sources in this area. This work provided valuable insight into the composition of the plankton bacterial community and its relationship with the environmental factors in the Huangshui River in the ecotone zone of the Qinghai Plateau and Loess Plateau and a theoretical foundation for ecological health management.

ZnO-Decorated In/Ga Oxide Nanotubes Derived from Bimetallic In/Ga MOFs for Fast Acetone Detection with High Sensitivity and Selectivity.

The development of acetone gas sensors is desirable but challenging for both air quality monitoring and medical diagnosis. Herein, starting from bimetallic In/Ga metal-organic frameworks (MOFs) (MIL-68 (In/Ga)), a facile strategy is proposed to couple with zinc ions to design In/Ga oxide (IGO)@ZnO core-shell nanotubes for efficient acetone detection. In such a heterostructure, tiny ZnO nanoparticles are closely decorated on IGO nanotubes, which is beneficial to enlarge the specific surface area and create rich oxygen vacancies and heterojunction interfaces. Benefiting from the structural merits and synergetic effects, the IGO@ZnO-based gas sensor exhibits a low detection limitation (200 ppb), a high response, good linearity relationship between the sensing responses and wide testing acetone concentrations, and fast response and recovery time (6.8/6.1 s) with good selectivity and stability. These sensing performances strongly indicate the practical application to quantitatively detect acetone.

Long-term and longitudinal nutrient stoichiometry changes in oligotrophic cascade reservoirs with trout cage aquaculture.

The potential nutrient stoichiometry changes caused by trout cage aquaculture is concerned especially in oligotrophic waters. Long-term total nitrogen (N), total phosphorus (P) and N:P ratio changes in 6 cascade reservoirs with rainbow trout cage aquaculture in the oligotrophic upstream Yellow River (UYR) were studied from 2013 to 2017 in this paper. The 5-year monitoring results showed that N, P and N:P ratio levels showed no obvious long-term changes in high-altitude oligotrophic waters with rainbow trout cage aquaculture. No obvious longitudinal N, P and N:P ratio level changes were observed in the 6 cascade reservoirs from upstream Longyangxia Reservoir (LYR) to downstream Jishixia Reservoir (JSR). The increased N and P resulting from the cage aquaculture accounted only for 1.74% and 5.2% of the natural N and P levels, respectively, with a fish production of 10,000 tonnes. The upstream Yellow River remained oligotrophic and phosphorus-limited. Results in this study proved that trout cage aquaculture do not necessarily cause nitrogen, phosphorus and N:P ratio changes even in oligotrophic waters. Phosphorus should be considered first when identifying priority nitrogen and phosphorus sources and the corresponding control measures in waters with high N:P ratio.

Tribbles-2 is a novel regulator of inflammatory activation of monocytes.

Inflammatory activation of monocytes is an essential part of both innate immune responses and the pathogenesis of conditions such as atherosclerosis. However, the mechanisms which modulate the response of monocytes to inflammatory stimuli are still poorly understood. Here, we report that tribbles-2 (trb-2) is a novel regulator of inflammatory activation of monocytes. Down-regulation of trb-2 levels potentiates LPS-induced IL-8 production via enhanced activation of the extracellular signal-regulated kinase and jun kinase mitogen-activated protein kinase (MAPK) pathways. In keeping with this, the endogenous level of trb-2 expression in human primary monocytes is inversely correlated to the cell's ability to produce IL-8. We show that trb-2 is a binding partner and a negative regulator of selected MAPKs. The potential in vivo relevance of these findings is highlighted by the observation that modified low-density lipoprotein profoundly down-regulates trb-2 expression, which may, in turn, significantly contribute to the inflammatory processes in the development of vascular disease. Taken together, our results define trb-2 as a potent novel regulator of monocyte biology, controlling the activation of these cells.

MOFs-Derived Porous NiFe2O4 Nano-Octahedrons with Hollow Interiors for an Excellent Toluene Gas Sensor.

Toluene is extensively used in many industrial products, which needs to be effectively detected by sensitive gas sensors even at low-ppm-level concentrations. Here, NiFe2O4 nano-octahedrons were calcinated from NiFe-bimetallic metal-organic framework (MOFs) octahedrons synthesized by a facile refluxing method. The co-existence of p-Phthalic acid (PTA) and 3,3-diaminobenzidine (DAB) promotes the formation of smooth NiFe-bimetallic MOFs octahedrons. After subsequent thermal treatment, a big weight loss (about 85%) transformed NiFe2O4 nanoparticles (30 nm) into NiFe2O4 porous nano-octahedrons with hollow interiors. The NiFe2O4 nano-octahedron based sensor exhibited excellent gas sensing properties for toluene with a nice stability, fast response, and recovery time (25 s/40 s to 100 ppm toluene), and a lower detection limitation (1 ppm) at 260 °C. The excellent toluene-sensing properties can not only be derived from the hollow interiors combined with porous nano-octahedrons to favor the diffusion of gas molecules, but also from the efficient catalytic activity of NiFe2O4 nanoparticles.

Biomass carbon derived from pine nut shells decorated with NiO nanoflakes for enhanced microwave absorption properties.

Electromagnetic absorption materials have gained increasing attention. In this study, we report NiO decorated biomass porous carbon derived from pine nut shells as a promising microwave absorbing material by a facile strategy. The NiO/biomass porous carbon (BPC) is thermally converted from Ni(OH)2/BPC with BPC as the base for precipitation. All products were characterized by XRD, Raman, and SEM techniques, which reveals that the NiO nanoflakes were uniformly self-assembled on the surface of the activated carbon. Compared with counterparts of pure Ni(OH)2 and Ni(OH)2/BPC, a large reflection loss peak of -33.8 dB at 16.4 GHz is achieved for the NiO/BPC composites, and the absorption bandwidth less than -10 dB can reach up to about 6.7 GHz (from 11.3 to 18.0 GHz) with a thickness of 8 mm. The enhanced microwave absorption properties originate from the electric/dielectric polarization and the unique NiO decorated BPC structures. The expanded interfaces, such as NiO-NiO, Ni-BPC and NiO-paraffin interfaces in the complicated porous composites, could boost the interfacial polarization as well as related relaxation which results in enhanced dielectric loss and electromagnetic absorbing properties. In addition, NiO/BPC nanocomposites exhibit comparatively better matching of permittivity and permeability. It is expected that our present investigation could provide a new possibility for biomass based fabrication of potential microwave absorbing materials.

Analysis of innate immune signal transduction with autocatalytic expression vectors.

Signalling pathways modulated by the family of IL-1/TLR receptors are central to innate immune responses. Novel components playing key regulatory roles in these pathways continue to be isolated. Here we describe the use of autocatalytic vectors for identifying critical components of these signalling pathways. The method was tested with a vector system where cDNA clones are expressed as EGFP fusion proteins, or in an IRES containing mRNA, combined with a transcription reporter. These constructs are placed under the control of an inducible promoter, responsive to activation of TIR receptors such as IL-1RI or TLR-4. cDNAs which activate the promoter will, when transcribed, form a positive feedback loop. We introduced TIR signalling pathway components into both types of vectors. The components tested regulated reporter (EGFP/luciferase) expression in both cases. Our data suggest that this type of system is capable of selective identification of components from signal transduction pathways once the promoter of a relevant inducible gene is identified from, for example, micro-array experiments.

LDL uptake by monocytes in response to inflammation is MAPK dependent but independent of tribbles protein expression.

Inflammatory activation of monocytes is a hallmark event in cardiovascular disease. Activated monocytes migrate into atherosclerotic lesions, differentiate into macrophages and ingest lipids to become foam cells. These, in turn, through interaction with other inflammatory cell types contribute to plaque instability and are thought to play a key role in the development of acute coronary syndromes. In the current manuscript we investigated whether inflammatory activation of monocyte THP-1 cells influences their ability to take-up chemically modified LDL. We have also studied whether tribbles proteins, which have been shown to regulate the activation of inflammatory signal processing networks, have a modulatory role in the uptake of modified LDL by monocyte. Here, we show that activation of THP-1 cells by LPS potentiates LDL uptake. The greatest effect of LPS was seen after 16 h, compared to acute stimulation. Specific MAPK pathways are involved in this potentiation. Inhibition of both the p38 and ERK pathways led to reduced LPS uptake, specifically in LPS stimulated cells. Expression of tribbles, regulators of MAPK signalling, was dynamically modulated by LPS activation. However, neither suppression of tribbles expression by transient transfection of specific siRNAs nor transient overexpression of these proteins led to changes in the capacity of THP-1 cells to take up modified LDL. Therefore, we conclude that LPS potentiation of LDL uptake of THP-1 cells is MAPK dependent but is not mediated by tribbles.

Advanced technologies for studies on protein interactomes.

One of the key challenges of biology in the post-genomic era is to assign function to the many genes revealed by large-scale sequencing programmes, since only a small fraction of gene function can be directly inferred from the coding sequence. Identifying interactions between proteins is a substantial part in understanding their function. The main technologies for investigating protein-protein interactions and assigning functions to proteins include direct detection intermolecular interactions through protein microarray, yeast two-hybrid system, mass spectrometry fluorescent techniques to visualize protein complexes or pull-down assays, as well as technologies detecting functional interactions between genes, such as RNAi knock down or functional screening of cDNA libraries. Over recent years, considerable advances have been made in the above techniques. In this review, we discuss some recent developments and their impact on the gene function annotation.

Carbon spheres@MnO2 core-shell nanocomposites with enhanced dielectric properties for electromagnetic shielding.

Carbon spheres (CS)@MnO2 core-shell nanocomposites, with MnO2 nanoflakes uniformly coating at the surface of CS cores, were successfully synthesized by a facile water-bathing method. MnO2 amounts is estimated to be 24.7 wt% in CS@MnO2 nanocomposites. A high dielectric loss value and an electromagnetic shielding effectiveness of 16‒23 dB were observed for the CS@MnO2 in the frequency range of 8‒18 GHz, which is mainly attributed to the enhanced absorption loss. The incorporation of the CS with MnO2 improves the electrical conductivity. Meanwhile, the electromagnetic impendence matching has been significantly ameliorated. Moreover, the increasing interfaces between the CS and MnO2 facilitate the microwave attenuation as well. Thus, the electromagnetic shielding performances were greatly enhanced. Our findings provide an effective methodology for the synthesis of the CS@MnO2 core-shell nanocomposite for potential electromagnetic applications.

Competition between members of the tribbles pseudokinase protein family shapes their interactions with mitogen activated protein kinase pathways.

Spatio-temporal regulation of intracellular signalling networks is key to normal cellular physiology; dysregulation of which leads to disease. The family of three mammalian tribbles proteins has emerged as an important controller of signalling via regulating the activity of mitogen activated protein kinases (MAPK), the PI3-kinase induced signalling network and E3 ubiquitin ligases. However, the importance of potential redundancy in the action of tribbles and how the differences in affinities for the various binding partners may influence signalling control is currently unclear. We report that tribbles proteins can bind to an overlapping set of MAPK-kinases (MAPKK) in live cells and dictate the localisation of the complexes. Binding studies in transfected cells reveal common regulatory mechanisms and suggest that tribbles and MAPKs may interact with MAPKKs in a competitive manner. Computational modelling of the impact of tribbles on MAPK activation suggests a high sensitivity of this system to changes in tribbles levels, highlighting that these proteins are ideally placed to control the dynamics and balance of activation of concurrent signalling pathways.

Human tribbles-1 controls proliferation and chemotaxis of smooth muscle cells via MAPK signaling pathways.

Migration and proliferation of smooth muscle cells are key to a number of physiological and pathological processes, including wound healing and the narrowing of the vessel wall. Previous work has shown links between inflammatory stimuli and vascular smooth muscle cell proliferation and migration through mitogen-activated protein kinase (MAPK) activation, although the molecular mechanisms of this process are poorly understood. Here we report that tribbles-1, a recently described modulator of MAPK activation, controls vascular smooth muscle cell proliferation and chemotaxis via the Jun kinase pathway. Our findings demonstrate that this regulation takes place via direct interactions between tribbles-1 and MKK4/SEK1, a Jun activator kinase. The activity of this kinase is dependent on tribbles-1 levels, whereas the activation and the expression of MKK4/SEK1 are not. In addition, tribbles-1 expression is elevated in human atherosclerotic arteries when compared with non-atherosclerotic controls, suggesting that this protein may play a role in disease in vivo. In summary, the data presented here suggest an important regulatory role for trb-1 in vascular smooth muscle cell biology.