Two new clades recovered at high temperatures provide novel phylogenetic and genomic insights into Candidatus Accumulibacter.

Candidatus Accumulibacter, a key genus of polyphosphate-accumulating organisms, plays key roles in lab- and full-scale enhanced biological phosphorus removal (EBPR) systems. A total of 10 high-quality Ca. Accumulibacter genomes were recovered from EBPR systems operated at high temperatures, providing significantly updated phylogenetic and genomic insights into the Ca. Accumulibacter lineage. Among these genomes, clade IIF members SCELSE-3, SCELSE-4, and SCELSE-6 represent the to-date known genomes encoding a complete denitrification pathway, suggesting that Ca. Accumulibacter alone could achieve complete denitrification. Clade IIC members SSA1, SCUT-1, SCELCE-2, and SCELSE-8 lack the entire set of denitrifying genes, representing to-date known non-denitrifying Ca. Accumulibacter. A pan-genomic analysis with other Ca. Accumulibacter members suggested that all Ca. Accumulibacter likely has the potential to use dicarboxylic amino acids. Ca. Accumulibacter aalborgensis AALB and Ca. Accumulibacter affinis BAT3C720 seemed to be the only two members capable of using glucose for EBPR. A heat shock protein Hsp20 encoding gene was found exclusively in genomes recovered at high temperatures, which was absent in clades IA, IC, IG, IIA, IIB, IID, IIG, and II-I members. High transcription of this gene in clade IIC members SCUT-2 and SCUT-3 suggested its role in surviving high temperatures for Ca. Accumulibacter. Ambiguous clade identity was observed for newly recovered genomes (SCELSE-9 and SCELSE-10). Five machine learning models were developed using orthogroups as input features. Prediction results suggested that they belong to a new clade (IIK). The phylogeny of Ca. Accumulibacter was re-evaluated based on the laterally derived polyphosphokinase 2 gene, showing improved resolution in differentiating different clades.

The dual GGDEF/EAL domain enzyme PA0285 is a Pseudomonas species housekeeping phosphodiesterase regulating early attachment and biofilm architecture.

Bacterial lifestyles depend on conditions encountered during colonization. The transition between planktonic and biofilm growth is dependent on the intracellular second messenger c-di-GMP. High c-di-GMP levels driven by diguanylate cyclases (DGCs) activity favor biofilm formation, while low levels were maintained by phosphodiesterases (PDE) encourage planktonic lifestyle. The activity of these enzymes can be modulated by stimuli-sensing domains such as Per-ARNT-Sim (PAS). In Pseudomonas aeruginosa, more than 40 PDE/DGC are involved in c-di-GMP homeostasis, including 16 dual proteins possessing both canonical DGC and PDE motifs, that is, GGDEF and EAL, respectively. It was reported that deletion of the EAL/GGDEF dual enzyme PA0285, one of five c-di-GMP-related enzymes conserved across all Pseudomonas species, impacts biofilms. PA0285 is anchored in the membrane and carries two PAS domains. Here, we confirm that its role is conserved in various P. aeruginosa strains and in Pseudomonas putida. Deletion of PA0285 impacts the early stage of colonization, and RNA-seq analysis suggests that expression of cupA fimbrial genes is involved. We demonstrate that the C-terminal portion of PA0285 encompassing the GGDEF and EAL domains binds GTP and c-di-GMP, respectively, but only exhibits PDE activity in vitro. However, both GGDEF and EAL domains are important for PA0285 PDE activity in vivo. Complementation of the PA0285 mutant strain with a copy of the gene encoding the C-terminal GGDEF/EAL portion in trans was not as effective as complementation with the full-length gene. This suggests the N-terminal transmembrane and PAS domains influence the PDE activity in vivo, through modulating the protein conformation.

Epsilon-near-zero material-based bi-layer metamaterials for selective mid-infrared radiation.

Selective mid-infrared (MIR) radiation is highly desirable in many applications. However, there are still great challenges to simultaneously achieve MIR camouflage and radiative cooling utilizing simple structure. This work theoretically and experimentally proposes a bi-layer metamaterial composed of aluminum doped zinc oxide (AZO) nanoparticles embedded in Al2O3matrix on the aluminum film. The bi-layer metamaterial exhibits high performance in MIR camouflage with radiative cooling, a low emissivity (ε3-5µm= 0.11,ε8-14µm= 0.20) in atmospheric windows and a high emissivity (ε5-8µm= 0.81) in non-atmospheric windows. The interaction of the epsilon-near-zero (ENZ) mode and localized surface plasmon resonance (LSPR) mode is responsible for the perfect emission over the wavelength range of 5-8µm. Additionally, the proposed selective MIR emitter supports large-angle incidence and has great polarization insensitivity. This demonstrates that epsilon-near-zero material-based bi-layer metamaterial is highly promising for the development of selective mid-infrared radiation.

Dipeptide-1 modified nanostructured lipid carrier-based hydrogel with enhanced skin retention and topical efficacy of curcumin.

Topical administration of curcumin (CUR), a natural polyphenol with potent anti-inflammation and analgesic activities, provides a potential approach for local skin diseases. However, the drug delivery efficiency is highly limited by skin barriers and poor bioavailability of CUR. Herein, we propose hydrogel containing CUR-encapsulated dipeptide-1-modified nanostructured lipid carriers (CUR-DP-NLCs gel) to enhance topical drug delivery, and improve the topical therapeutic effect. The prepared CUR-DP-NLCs were characterized and were suitably dispersed into the Pluronic F127 hydrogel for topical application. The optimized CUR-DP-NLCs had a particle size of 152.6 ± 3.47 nm, a zeta potential of -33.1 ± 1.46 mV, an entrapment efficiency of 99.83 ± 0.14%, and a spherical morphology. X-ray diffraction (XRD) studies confirmed that CUR was successfully entrapped by the NLCs in an amorphous form. CUR-DP-NLCs gel exhibited sustained release over 48 h and significantly increased the skin retention of CUR. In vitro skin retention of CUR with CUR-DP-NLCs gel was 2.14 and 2.85 times higher than that of unmodified NLCs gel and free CUR, respectively. Fluorescence microscopy imaging revealed the formed nanoparticles accumulated in the hair follicles with prolonged retention time to form a drug reservoir. The hematoxylin-eosin staining showed that CUR-DP-NLCs gel could change the microstructure of skin layers and disturb the skin barriers. After topical administration to mice, CUR-DP-NLCs gel showed better analgesic and anti-inflammatory activities with no potentially hazardous skin irritation. These results concluded that CUR-DP-NLCs gel is a promising strategy to increase topical drug delivery of CUR in the treatment of local skin diseases.

Development of flow battery technologies using the principles of sustainable chemistry.

Realizing decarbonization and sustainable energy supply by the integration of variable renewable energies has become an important direction for energy development. Flow batteries (FBs) are currently one of the most promising technologies for large-scale energy storage. This review aims to provide a comprehensive analysis of the state-of-the-art progress in FBs from the new perspectives of technological and environmental sustainability, thus guiding the future development of FB technologies. More importantly, we evaluate the current situation and future development of key materials with key aspects of green economy and decarbonization to promote sustainable development and improve the novel energy framework. Finally, we present an analysis of the current challenges and prospects on how to effectively construct low-carbon and sustainable FB materials in the future.

A Bioinspired Bilevel Metamaterial for Multispectral Manipulation toward Visible, Multi-Wavelength Detection Lasers and Mid-Infrared Selective Radiation.

Manipulation of the electromagnetic signature in multiple wavebands is necessary and effective in civil and industrial applications. However, the integration of multispectral requirements, particularly for the bands with comparable wavelengths, challenges the design and fabrication of current compatible metamaterials. Here, a bioinspired bilevel metamaterial is proposed for multispectral manipulation involving visible, multi-wavelength detection lasers and mid-infrared (MIR), along with radiative cooling. The metamaterial, consisting of dual-deck Pt disks and a SiO2 intermediate layer, is inspired by the broadband reflection splitting effect found in butterfly scales and achieves ultralow specular reflectance (average of 0.013) over the entire 0.8-1.6 µm with large scattering angles. Meanwhile, tunable visible reflection and selective dual absorption peaks in MIR can be simultaneously realized, providing structural color, effective radiative thermal dissipation at 5-8 µm and 10.6 µm laser absorption. The metamaterial is fabricated by a low-cost colloidal lithography method combined with two patterning processes. Multispectral manipulation performances are experimentally demonstrated and a significant apparent temperature drop (maximum of 15.7 °C) compared to the reference is observed under a thermal imager. This work achieves optical response in multiple wavebands and provides a valuable way to effectively design multifunctional metamaterials inspired by nature.

Colourful phase change material-incorporated flexible film for efficient passive radiative cooling.

Passive radiative cooling involves the emission of thermal radiation into cold space and the reflection of solar radiation, which aims to cool and lower the temperature of objects. However, currently most radiative coolers have a white appearance which restricts their potential applications. We develop a coloured bilayer radiative cooling membrane using polyvinylidene fluoride/tetraethoxysilane (PVDF/TEOS) fibres, with incorporation of phase change materials (PCMs) and active dyes through a simple and large-area electrospinning process. In comparison to traditional emitters, PCM-incorporated colourful coolers provide energy storage capacity and colourful appearances. Our phase-transition-based colourful flexible film (PCFF) achieves a total solar reflectance of 0.81 and a mid-infrared (8-13µm) emissivity of 0.85 with superior mechanical strength and good hydrophobicity. We experimentally demonstrate that our PCFF can significantly reduce the temperature of objects exposed to direct sunlight, with a cooling effect of up to 9 °C compared to commercial fabrics of similar materials and colours. Our work provides a promising starting point for the design and manufacture of colourful and flexible thermal control films.

Benzidine Derivatives: A Class of High Redox Potential Molecules for Aqueous Organic Flow Batteries.

The development of water-soluble redox-active molecules with high potentials is one of the effective ways to enhance the energy density of aqueous organic flow batteries (AOFBs). Herein, a series of promising N-substituted benzidine analogues as water-soluble catholyte candidates with controllable redox potentials (0.78-1.01 V vs. standard hydrogen electrode (SHE)) were obtained by the molecular engineering of aqueous irreversible benzidines. Theoretical calculations reveal that the redox potentials of these benzidine derivatives in acidic solution are determined by their electronic structure and alkalinity. Among these benzidine derivatives, N,N,N',N'-tetraethylbenzidine(TEB) shows both high redox potential (0.82 V vs. SHE) and good solubility (1.1 M). Pairing with H4 [Si(W3 O10 )4 ] anolyte, the cell displayed discharge capacity retention of 99.4 % per cycle and a high coulombic efficiency (CE) of ∼100 % over 1200 cycles. The stable discharge capacity of 41.8 Ah L-1 was achieved at the 1.0 M TEB catholyte with a CE of 97.2 % and energy efficiency (EE) of 91.2 %, demonstrating that N-substituted benzidines could be promising for AOFBs.

Photocatalysis in Water-Soluble Supramolecular Metal Organic Complex.

As an emerging subset of organic complexes, metal complexes have garnered considerable attention owing to their outstanding structures, properties, and applications. In this content, metal-organic cages (MOCs) with defined shapes and sizes provide internal spaces to isolate water for guest molecules, which can be selectively captured, isolated, and released to achieve control over chemical reactions. Complex supramolecules are constructed by simulating the self-assembly behavior of the molecules or structures in nature. For this purpose, massive amounts of cavity-containing supramolecules, such as metal-organic cages (MOCs), have been extensively explored for a large variety of reactions with a high degree of reactivity and selectivity. Because sunlight and water are necessary for the process of photosynthesis, water-soluble metal-organic cages (WSMOCs) are ideal platforms for photo-responsive stimulation and photo-mediated transformation by simulating photosynthesis due to their defined sizes, shapes, and high modularization of metal centers and ligands. Therefore, the design and synthesis of WSMOCs with uncommon geometries embedded with functional building units is of immense importance for artificial photo-responsive stimulation and photo-mediated transformation. In this review, we introduce the general synthetic strategies of WSMOCs and their applications in this sparking field.

Bioinspired Photonic Microchip with Molecularly Imprinted Polymer for Single Recognition of c-Myc Protein in Predictive Medical Diagnostics.

Monitoring of trace c-Myc protein as the biomarker of ubiquitous cancers is critical in achieving predictive medical diagnostics. However, qualitative and quantitative detection of c-Myc protein with superior single selectivity and sensitivity is still challenging. Herein, a bioinspired photonic sensing microchip for single recognition of c-Myc protein is outlined with two synergistic aspects involving chemical and physical design criteria. Chemical design uses specific molecularly imprinted polymer (MIP) with exquisite complementarity in its chemical functions and spatial geometries to targeted c-Myc protein, leading to excellent sensitivity and selectivity for single identification. Physical design involves optical geometrical double-reflection polarization rotation and multilayer interference of the fabricated periodic photonic architecture inspired by Papilio palinurus butterfly wings to enhance the spectral diversity of reflectance. Therefore, a one-of-a-kind sensing platform integrates the advantages of MIP and bioinspired photonic structure is demonstrated to actualize distinctive signal conversion and amplification for qualitative and quantitative detection of trace c-Myc protein, accompanied with superior sensitivity (detection limit is 0.014 µg mL-1 ), selectivity, stability, anti-interference ability as well as rapid response/recovery time. This sensor microchip uniquely ventures into the territory of functionally combining bioinspired photonic structure with MIP absorbers, proven promising for prevention or diagnosis of cancers in medical field.

Exosomes from artesunate-treated bone marrow-derived mesenchymal stem cells transferring SNHG7 to promote osteogenesis via TAF15-RUNX2 pathway.

Aim: Effect of artesunate (ART)-treated bone marrow-derived mesenchymal stem cells-derived exosomes (BMSC-Exos) on osteogenesis and its underlying mechanisms were investigated. Materials & methods: Proliferation, alkaline phosphatase activity and calcified nodule formation of osteoblasts were determined. A mouse model of osteoporosis was established by ovariectomy. Results: SNHG7 was upregulated in BMSC-Exos by twofold, which was further enhanced in ART-BMSC-Exos by about twofold. ART intensified BMSC-Exos-induced proliferation, alkaline phosphatase activity by about fourfold, calcified nodule formation by about threefold and upregulation of osteogenesis related molecules RUNX2 (by 50%), BMP2 (by 30%) and ATF4 (by 40%) via delivering SNHG7. Mechanistically, SNHG7 recruited TAF15 to facilitate RUNX2 stability. Conclusion: ART-BMSC-Exos facilitated osteogenesis via delivering SNHG7 by modulating TAF15/RUNX2 axis.

Osteoporosis is the most common and complex skeletal disorder worldwide. Exosomes derived from bone marrow-derived mesenchymal stem cells (BMSC-Exos) have been recognized as an ideal seed source for bone tissue regeneration. We aimed to explore the effect of artesunate (ART)-BMSC-Exos on osteogenesis and its underlying mechanisms. The results showed that ART-BMSC derived exosomal SNHG7 facilitated osteoblast activity and attenuated osteogenesis in mice by modulating TAF15/RUNX2 pathway. Our findings contribute to a better understanding of the therapeutic mechanisms of ART-BMSCs-Exos for osteoporosis and suggest ART-BMSC-Exos as a novel therapeutic option for osteoporosis.

Dynamic probability integration for electroencephalography-based rapid serial visual presentation performance enhancement: Application in nighttime vehicle detection.

Background: Rapid serial visual presentation (RSVP) has become a popular target detection method by decoding electroencephalography (EEG) signals, owing to its sensitivity and effectiveness. Most current research on EEG-based RSVP tasks focused on feature extraction algorithms developed to deal with the non-stationarity and low signal-to-noise ratio (SNR) of EEG signals. However, these algorithms cannot handle the problem of no event-related potentials (ERP) component or miniature ERP components caused by the attention lapses of human vision in abnormal conditions. The fusion of human-computer vision can obtain complementary information, making it a promising way to become an efficient and general way to detect objects, especially in attention lapses. Methods: Dynamic probability integration (DPI) was proposed in this study to fuse human vision and computer vision. A novel basic probability assignment (BPA) method was included, which can fully consider the classification capabilities of different heterogeneous information sources for targets and non-targets and constructs the detection performance model for the weight generation based on classification capabilities. Furthermore, a spatial-temporal hybrid common spatial pattern-principal component analysis (STHCP) algorithm was designed to decode EEG signals in the RSVP task. It is a simple and effective method of distinguishing target and non-target using spatial-temporal features. Results: A nighttime vehicle detection based on the RSVP task was performed to evaluate the performance of DPI and STHCP, which is one of the conditions of attention lapses because of its decrease in visual information. The average AUC of DPI was 0.912 ± 0.041 and increased by 11.5, 5.2, 3.4, and 1.7% compared with human vision, computer vision, naive Bayesian fusion, and dynamic belief fusion (DBF), respectively. A higher average balanced accuracy of 0.845 ± 0.052 was also achieved using DPI, representing that DPI has the balanced detection capacity of target and non-target. Moreover, STHCP obtained the highest AUC of 0.818 ± 0.06 compared with the other two baseline methods and increased by 15.4 and 23.4%. Conclusion: Experimental results indicated that the average AUC and balanced accuracy of the proposed fusion method were higher than individual detection methods used for fusion, as well as two excellent fusion methods. It is a promising way to improve detection performance in RSVP tasks, even in abnormal conditions.

Hyaluronic Acid Micelles for Promoting the Skin Permeation and Deposition of Curcumin.

Background: The poor skin permeation and deposition of topical therapeutic drugs is a major issue in topical drug delivery, improving this issue is conducive to improving the topical therapeutic effect of drugs. Methods: In this study, octadecylamine modified hyaluronic acid (OHA) copolymer was synthesized by amide reaction technique to prepare curcumin (CUR)-loaded micelles (CUR-M) for topical transdermal administration. CUR-M was successfully prepared by dialysis, and the formulation was evaluated for particle size, zeta potential, surface morphology, entrapment effciency (EE%), drug loading (DL), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and the in vitro drug release. Additionally, in vitro skin permeation and retention, in vivo topical analgesic and anti-inflammatory activity, and skin irritation were assessed. Results: The mean drug loading (DL), drug entrapment efficiency (EE), hydrodynamic diameter and zeta potential of CUR-M were 8.26%, 90.86%, 165.64 nm and -26.85 mV, respectively. CUR-M was characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), it was found that there was an interaction between CUR and OHA, and CUR existed in CUR-M in an amorphous form. CUR-M exhibited sustained release in 48 h and good stability at 4 °C for 21days. CUR-M could significantly increase the skin penetration and retention of CUR and had better analgesic and anti-inflammatory activities in vivo when compared with CUR solution. Hematoxylin-eosin staining results revealed that the transdermal penetration mechanism of CUR-M might be related to the hydration of stratum corneum by HA. In addition, CUR-M showed no skin irritation to mouse skin. Conclusion: CUR-M might be a promising and safe drug delivery system for the treatment of topical diseases.

Widely targeted metabolomics reveals stamen petaloid tissue of Paeonia lactiflora Pall. being a potential pharmacological resource.

Paeonia lactiflflora Pall. has a long edible and medicinal history because of the very high content of biologically active compounds. However, little information is available about the metabolic basis of pharmacological values of P. lactiflora flowers. In this study, we investigated metabolites in the different parts of P. lactiflora flowers, including petal, stamen petaloid tissue and stamen, by widely targeted metabolomics approach. A total of 1102 metabolites were identified, among which 313 and 410 metabolites showed differential accumulation in comparison groups of petal vs. stamen petaloid tissue and stamen vs. stamen petaloid tissue. Differential accumulated metabolites analysis and KEGG pathway analysis showed that the flavonoids were the most critical differential metabolites. Furthermore, difference accumulation of flavonoids, phenolic acids, tannins and alkaloids might lead to the differences in antioxidant activities and tyrosinase inhibition effects. Indeed, stamen petaloid tissue displayed better antioxidant and anti-melanin production activities than petal and stamen through experimental verification. These results not only expand our understanding of metabolites in P. lactiflora flowers, but also reveal that the stamen petaloid tissues of P. lactiflora hold the great potential as promising ingredients for pharmaceuticals, functional foods and skincare products.

Phenotypic and integrated analysis of a comprehensive Pseudomonas aeruginosa PAO1 library of mutants lacking cyclic-di-GMP-related genes.

Pseudomonas aeruginosa is a Gram-negative bacterium that is able to survive and adapt in a multitude of niches as well as thrive within many different hosts. This versatility lies within its large genome of ca. 6 Mbp and a tight control in the expression of thousands of genes. Among the regulatory mechanisms widespread in bacteria, cyclic-di-GMP signaling is one which influences all levels of control. c-di-GMP is made by diguanylate cyclases and degraded by phosphodiesterases, while the intracellular level of this molecule drives phenotypic responses. Signaling involves the modification of enzymes' or proteins' function upon c-di-GMP binding, including modifying the activity of regulators which in turn will impact the transcriptome. In P. aeruginosa, there are ca. 40 genes encoding putative DGCs or PDEs. The combined activity of those enzymes should reflect the overall c-di-GMP concentration, while specific phenotypic outputs could be correlated to a given set of dgc/pde. This notion of specificity has been addressed in several studies and different strains of P. aeruginosa. Here, we engineered a mutant library for the 41 individual dgc/pde genes in P. aeruginosa PAO1. In most cases, we observed a significant to slight variation in the global c-di-GMP pool of cells grown planktonically, while several mutants display a phenotypic impact on biofilm including initial attachment and maturation. If this observation of minor changes in c-di-GMP level correlating with significant phenotypic impact appears to be true, it further supports the idea of a local vs global c-di-GMP pool. In contrast, there was little to no effect on motility, which differs from previous studies. Our RNA-seq analysis indicated that all PAO1 dgc/pde genes were expressed in both planktonic and biofilm growth conditions and our work suggests that c-di-GMP networks need to be reconstructed for each strain separately and cannot be extrapolated from one to another.

Pentapeptide modified ethosomes for enhanced skin retention and topical efficacy activity of indomethacin.

Challenges associated with topical analgesics and anti-inflammatory drugs include poor drug penetration and retention at the desired lesion site. Therefore, improving these challenges would help to reduce the toxic and side effects caused by drug absorption into the systemic circulation and improve the therapeutic efficacy of topical therapeutic drugs. Pentapeptide (KTTKS) is a signal peptide in skin tissue, it can be recognized and bound by signal recognition particles. In the current study, we successfully prepared novel indomethacin (IMC) loaded KTTKS-modified ethosomes (IMC-KTTKS-Es), and the physicochemical properties and topical efficacy were investigated. Results showed that the prepared IMC-KTTKS-Es displayed a particle size of about 244 nm, a negative charge, good deformability, and encapsulation efficiency (EE) exceeding 80% for IMC, with a sustained release pattern. In vitro percutaneous permeation studies revealed that the skin retention was increased after the drug was loaded in the IMC-KTTKS-Es. Confocal laser scanning microscopy also showed improved skin retention of IMC-KTTKS-Es. In addition, IMC-KTTKS-Es showed improved topical analgesic and anti-inflammatory activity with no potentially hazardous skin irritation. This study suggested that the IMC-KTTKS-Es might be an effective drug carrier for topical skin therapy with a good safety profile.

Global warming readiness: Feasibility of enhanced biological phosphorus removal at 35 °C.

Recent research has shown enhanced biological phosphorus removal (EBPR) from municipal wastewater at warmer temperatures around 30 °C to be achievable in both laboratory-scale reactors and full-scale treatment plants. In the context of a changing climate, the feasibility of EBPR at even higher temperatures is of interest. We operated two lab-scale EBPR sequencing batch reactors for > 300 days at 30 °C and 35 °C, respectively, and followed the dynamics of the communities of polyphosphate accumulating organisms (PAOs) and competing glycogen accumulating organisms (GAOs) using a combination of 16S rRNA gene metabarcoding, quantitative PCR and fluorescence in situ hybridization analyses. Stable and nearly complete phosphorus (P) removal was achieved at 30 °C; similarly, long term P removal was stable at 35 °C with effluent PO43-_P concentrations < 0.5 mg/L on half of all monitored days. Diverse and abundant Candidatus Accumulibacter amplicon sequence variants were closely related to those found in temperate environments, suggesting that EBPR at this temperature does not require a highly specialized PAO community. A slow-feeding strategy effectively limited the carbon uptake rates of GAOs, allowing PAOs to outcompete GAOs at both temperatures. Candidatus Competibacter was the main GAO, along with cluster III Defluviicoccus members. These organisms withstood the slow-feeding regime, suggesting that their bioenergetic characteristics of carbon uptake differ from those of their tetrad-forming relatives. Comparative cycle studies revealed higher carbon and P cycling activity of Ca. Accumulibacter when the temperature was increased from 30 °C to 35 °C, implying that the lowered P removal performance at 35 °C was not a direct effect of temperature, but a result of higher metabolic rates of carbon (and/or P) utilization of PAOs and GAOs, the resultant carbon deficiency, and escalated community competition. An increase in the TOC-to-PO43--P ratio (from 25:1 to 40:1) effectively eased the carbon deficiency and benefited PAOs. In general, a slow-feeding strategy and sufficiently high carbon input benefited a high and stable EBPR at 35 °C, representing basic conditions suitable for full-scale treatment plants experiencing higher water temperatures.

Profiling of widely targeted metabolomics for the identification of chemical composition in epidermis, xylem and pith of Gleditsiae Spina.

Gleditsiae Spina, the thorn of Gleditsia sinensis Lam., has a long history of being used as a traditional medicine in East Asian countries. However, only a few biologically active substances have been identified from it. In this study, the epidermis, xylem and pith of Gleditsiae Spina, respectively Gs-E, Gs-X and Gs-P, were studied. We used a widely targeted metabolomics method to investigate the chemical composition of Gs-E, Gs-X and Gs-P. A total of 728 putative metabolites were identified from Gleditsiae Spina, including 211 primary metabolites and 517 secondary metabolites. These primary and secondary metabolites could be categorized into more than 10 different classes. Flavonoids, phenolic acids, lipids, amino acids and derivatives, and organic acids constituted the main metabolite groups. Multivariate statistical analysis showed that the Gs-E, Gs-X and Gs-P samples could be clearly separated. Differential accumulated metabolite (DAM) analysis revealed that more than half of the DAMs exhibited the highest relative concentrations in Gs-E, and most of the DAMs showed the lowest relative concentrations in Gs-X. Moreover, 11 common differential primary metabolites and 79 common differential secondary metabolites were detected in all comparison groups. These results further our understanding of chemical composition and metabolite accumulation of Gleditsiae Spina.

Direct synthesis of p-methyl benzaldehyde from acetaldehyde via an organic amine-catalyzed dehydrogenation mechanism.

p-Methyl benzaldehyde (p-MBA) is a class of key chemical intermediates of pharmaceuticals. Conventional industrial processes for p-MBA production involve the consecutive photochlorination, amination, and acid hydrolysis of petroleum-derived p-xylene, while producing vast pollutants and waste water. Herein, we report a direct, green route for selective synthesis of p-MBA from acetaldehyde using a diphenyl prolinol trimethylsilyl ether catalyst. The optimized p-MBA selectivity is up to 90% at an acetaldehyde conversion as high as 99.8%. Intermediate structure and 18O-isotope data revealed that the conversion of acetaldehyde to p-methylcyclohexadienal intermediates proceeds in an enamine-iminium intermediate mechanism. Then, controlled experiments and D-isotope results indicated that the dehydrogenation of p-methylcyclohexadienal to p-MBA and H2 is catalyzed by the same amines through an iminium intermediate. This is an example that metal-free amines catalyze the dehydrogenation (releasing H2), rather than using metals or stoichiometric oxidants.

Biomimetic approach to the catalytic enantioselective synthesis of tetracyclic isochroman.

Polyketide oligomers containing the structure of tetracyclic isochroman comprise a large class of natural products with diverse activity. However, a general and stereoselective method towards the rapid construction of this structure remains challenging due to the inherent instability and complex stereochemistry of polyketide. By mimicking the biosynthetic pathway of this structurally diverse set of natural products, we herein develop an asymmetric hetero-Diels-Alder reaction of in-situ generated isochromene and ortho-quinonemethide. A broad range of tetracyclic isochroman frameworks are prepared in good yields and excellent stereoinduction (up to 95% ee) from readily available α-propargyl benzyl alcohols and 2-(hydroxylmethyl) phenols under mild conditions. This direct enantioselective cascade reaction is achieved by a Au(I)/chiral Sc(III) bimetallic catalytic system. Experimental studies indicate that the key hetero-Diels-Alder reaction involves a stepwise pathway, and the steric hindrance between in-situ generated isochromene and t-Bu group of Sc(III)/N,N'-dioxide complex is responsible for the enantioselectivity in the hetero-Diels-Alder reaction step.