Metal Variance in Multivariate Metal-Organic Frameworks for Boosting Catalytic Conversion of CO2.

Developing efficient, low-cost, MOF catalysts for CO2 conversion at low CO2 concentrations under mild conditions is particularly interesting but remains highly challenging. Herein, we prepared an isostructural series of two-dimensional (2D) multivariate metal-organic frameworks (MTV-MOFs) containing copper- and/or silver-based cyclic trinuclear complexes (Cu-CTC and Ag-CTC). These MTV-MOFs can be used as efficient and reusable heterogeneous catalysts for the cyclization of propargylamine with CO2. The catalytic performance of these MTV-MOFs can be engineered by fine-tuning the Ag/Cu ratio in the framework. Interestingly, the induction of 10% Ag remarkably improved the catalytic efficiency with a turnover frequency (TOF) of 243 h-1, which is 20-fold higher than that of 100% Cu-based MOF (i.e., TOF = 10.8 h-1). More impressively, such a bimetallic MOF still exhibited high catalytic activity even for simulated flue gas with 10% CO2 concentration. Furthermore, the reaction mechanism has been examined through the employment of NMR monitoring experiments and DFT calculations.

Molecular Engineering of Metal-Organic Frameworks for Boosting Photocatalytic Hydrogen Peroxide Production.

The development of novel metal-organic frameworks (MOFs) as efficient photocatalysts for hydrogen peroxide production from water and oxygen is particularly interesting, yet remains a challenge. Herein, we have prepared four cyclic trinuclear units (CTUs) based MOFs, exhibiting good light absorption ability and suitable bandgaps for photosynthesis of H2O2. However, Cu-CTU-based MOFs are not able to photocatalyzed the formation of H2O2, while the alteration of metal nodes from Cu-CTU to Ag-CTU dramatically enhances the photocatalytic performance for H2O2production and the production rates can reach as high as 17476 µmol g-1 h-1 with an apparent quantum yield of 9.51%, at 420 nm, which is much higher than most reported MOFs. The photocatalytic mechanism is comprehensively studied by combining the isotope labeling experiments and DFT calculation. This study provides new insights into the preparation of MOF photocatalysts with high activity for H2O2 production through molecular engineering.

Multifunctional Metal-Organic Frameworks as Catalysts for Tandem Reactions.

Owing to well-defined structure as well as easy synthesis and modification, metal-organic frameworks (MOFs) have emerged as promising catalysts for tandem reactions. In this article, we aim to summarize the development of multifunctional MOFs, including mixed metal MOFs, MOFs that are synergistically catalyzed by metal nodes and organic linkers, MOFs loaded with metal nanoparticles, etc, as heterogenous catalysts for tandem reactions over the past five years. This concept briefly discusses on present challenges, future trends, and prospects of multifunctional MOFs catalysts in tandem reactions.

Identification of two new species and a new host record of Distoseptispora (Distoseptisporaceae, Distoseptisporales, Sordariomycetes) from terrestrial and freshwater habitats in Southern China.

During our investigation of saprophytic fungi in Guizhou and Hainan provinces, China, three hyphomycetes were collected from terrestrial and freshwater habitats. Based on morphological characteristics and phylogenetic analyses of combined ITS, LSU, tef1-α, and rpb2 sequence data, two new species are introduced: Distoseptisporahainanensis and D.lanceolatispora. Additionally, one known species, D.tectonae, previously unreported from Edgeworthiachrysantha, is newly reported. Detailed descriptions, illustrations, and a phylogenetic tree to show the two new species and the new host record of Distoseptispora are provided. In addition, a checklist of Distoseptispora species with their locations, lifestyles, habitats, and hosts is provided.

Reversible modulation of interlayer stacking in 2D copper-organic frameworks for tailoring porosity and photocatalytic activity.

The properties of two-dimensional covalent organic frameworks (2D COFs), including porosity, catalytic activity as well as electronic and optical properties, are greatly affected by their interlayer stacking structures. However, the precise control of their interlayer stacking mode, especially in a reversible fashion, is a long-standing and challenging pursuit. Herein, we prepare three 2D copper-organic frameworks, namely JNM-n (n = 7, 8, and 9). Interestingly, the reversible interlayer sliding between eclipsed AA stacking (i.e., JNM-7-AA and JNM-8-AA) and staggered ABC stacking (i.e., JNM-7-ABC and JNM-8-ABC) can be achieved through environmental stimulation, which endows reversible encapsulation and release of lipase. Importantly, JNM-7-AA and JNM-8-AA exhibit a broader light absorption range, higher charge-separation efficiency, and higher photocatalytic activity for sensitizing O2 to 1O2 and O2•- than their ABC stacking isostructures. Consequently, JNM-8-AA deliver significantly enhanced photocatalytic activities for oxidative cross-coupling reactions compared to JNM-8-ABC and other reported homogeneous and heterogeneous catalysts.

A Highly NIR Emissive Cu16Pd1 Nanocluster.

The construction of stable copper nanoclusters (Cu-NCs) with near-infrared (NIR) emission that can be used for catalysis is highly desired, yet remains a challenge. Herein, an atomically precise bimetallic Cu/Pd NC with a molecular formula of Cu16Pd1L10(PPh3)2(Pz)6 (Pz = 3,5-(CF3)2Pyrazolate, L = 4-CH3OPhC≡C-), abbreviated as Cu16Pd1, is synthesized. Single-crystal X-ray crystallographic analysis of Cu16Pd1 reveals a Cu10Pd1 kernel with pseudo-gyroelongated square bipyramid confirmation surrounded by other 6 Cu(I) ions and protected ligands. Interestingly, it exhibits strong NIR emission with the highest photoluminescence quantum yield (PLQY) among all the Cu NCs/Cu alloys (λem > 800 nm) in the solid-state, and also displays NIR emission in solution. Experimental results and theoretical calculations suggest that the impressive NIR emission is attributed to abundant supramolecular interactions in the solid-state, including intramolecular metal-metal and intermolecular interactions. Of note, the bimetallic Cu16Pd1 can catalyze the reduction of 4-nitrophenol. This work provides a novel method for synthesizing Cu/Pd NCs and reminds that the less studied Cu/Pd NC can serve as outstanding luminescent material, which is seldom noticed in atomically precise nanoclusters.

Morphological and multi-gene phylogenetic analyses reveal five new hyphomycetes from freshwater habitats.

During the survey on freshwater hyphomycetes in Guangxi, Guizhou and Hainan Provinces, China, five fresh collections were encountered. Based on their morphology, these five isolates were identified as belonging to Hermatomyces, Kirschsteiniothelia, Paramonodictys, Pleopunctum and Sparticola. Multi-gene phylogenetic analyses were performed for each genus, which resulted in the identification of five new species, namely Hermatomyces hainanensis, Kirschsteiniothelia ramus, Paramonodictys globosa, Pleopunctum guizhouense, and Sparticola irregularis. Detailed descriptions and illustrations of the morphological characteristics of these new taxa were provided. This research enriches the biodiversity of freshwater dematiaceous hyphomycetes.

Tuning the Catalytic Activity of Covalent Metal-Organic Frameworks for CO2 Cycloaddition Reactions.

The development of efficient, recyclable and low-cost heterogeneous catalysts for conversion of carbon dioxide (CO2 ) into epoxides is highly desired, yet remain a challenge. Herein, we have prepared three two-dimensional (2D) copper(I) cyclic trinuclear units (Cu(I)-CTUs) based covalent metal-organic frameworks (CMOFs), namely JNM-13, JNM-14, and JNM-15, via a one-pot reaction by combination of coordination and dynamic covalent chemistry. Among them, JNM-15 contained the highest density of copper catalytic sites, and exhibited the highest capacity for adsorption of CO2 . More interestingly, JNM-15 delivered the highest catalytic activity for cycloaddition of CO2 to epoxides with good yields (up to 99 %), good substrate compatibility (11 examples) and reusability (four catalytic cycles) under mild condition.

A Self-Assembled Capsule for Propylene/Propane Separation.

The development of energy-saving technology for the efficient separation of olefin and paraffin is highly important for the chemical industry. Herein, we report a self-assembled Fe4 L6 capsule containing a hydrophobic cavity, which can be used to encapsulate and separate propylene/propane. The successful encapsulation of propylene and propane by the Fe4 L6 cage in a water solution was documented by NMR spectroscopy. The binding constants K for the Fe4 L6 cage toward propylene and propane were determined to be (5.0±0.1)×103  M-1 and (2.1±0.7)×104  M-1 in D2 O at 25 °C, respectively. Experiments and theoretical studies revealed that the cage exhibited multiple weak interactions with propylene and propane. The polymer-grade propylene (>99.5 %) can be obtained from a mixture of propylene and propane by using the Fe4 L6 cage as a separation material in a U-shaped glass tube. This work provides a new strategy for the separation of olefin/paraffin.

Gold(I)-Organic Frameworks as Catalysts for Carboxylation of Alkynes with CO2.

Construction of gold-based metal-organic frameworks (Au-MOFs) would bring the merits of gold chemistry into MOFs. However, it still remains challenging because gold cations are easily reduced to metallic gold under solvothermal conditions. Herein, we present the first example of Au-MOFs prepared from the networking of cyclic trinuclear gold(I) complexes by formal transimination reaction in a rapid (<15 min) and scalable (up to 1 g) fashion under ambient condition. The Au-MOFs feature uniform porosity, high crystallinity, and superior chemical stability toward base (i.e., 20 M NaOH). With open Au(I) sites in the skeleton, the Au-MOFs as heterogeneous catalysts delivered good performance and substrate tolerance for the carboxylation reactions of alkynes with CO2. This work demonstrates a facile approach to reticularly synthesize Au-MOFs by combining the coordination and dynamic covalent chemistry.

Morphological and phylogenetic analyses reveal three new species and one new record of Tubeufia (Tubeufiales, Tubeufiaceae) from southern China.

During an investigation of helicosporous fungi in China, a total of seven helicosporous hyphomycetes were obtained from decaying wood in the southern region of the country. Based on phylogenetic analyses using a combined LSU, ITS, tef1α, and rpb2 sequence matrix, in conjunction with morphological comparisons, these taxa were classified within Tubeufia (Tubeufiaceae, Tubeufiales) and were recognized as three new species, viz. Tubeufiaguttulata, T.hainanensis, and T.muriformis, as well as one new distribution record, viz. T.cocois. Evidence for these new taxa and the new record, descriptions, illustrations, notes, and phylogenetic evidence are provided for the newly collected helicosporous species.

Morphological and Multi-Gene Phylogenetic Analyses Reveal Pseudotubeufia gen. nov. and Two New Species in Tubeufiaceae from China.

Three helicosporous hyphomycete collections representing two species were obtained from rotting wood found in freshwater and terrestrial habitats in the Guizhou and Guangxi Provinces, China. A new genus Pseudotubeufia (Tubeufiaceae, Tubeufiales), comprising Ps. hyalospora sp. nov. and Ps. laxispora sp. nov., was introduced with morphological characteristic and molecular data. In addition, the molecular evidence showed that Helicomyces sp. (G.M. 2020-09-19.1), H. roseus (CBS: 102.76), and the new genus Pseudotubeufia clustered together with high support based on a multi-gene (LSU, ITS, tef1α, and rpb2) phylogenetic analysis. Detailed descriptions, illustrations, and notes of the three new collections are provided.

Additions to the Genus Helicosporium (Tubeufiaceae, Tubeufiales) from China with an Identification Key for Helicosporium Taxa.

Helicosporous hyphomycetes is a group of filamentous fungi that shows promising application prospects in metabolizing bioactive natural compounds. During a study of helicosporous fungi in China, six new helicosporous taxa were collected and isolated from decaying wood in Guangxi Zhuang Autonomous Region, China. Morphological comparisons with multi-gene phylogenetic analyses revealed that these six taxa belong to Helicosporium (Tubeufiaceae, Tubeufiales), and they were recognized as three novel species and were named Helicosporium liuzhouense, H. multidentatum, and H. nanningense. Detailed descriptions and illustrations of the newly discovered taxa and comparisons with similar fungi are provided. In addition, a list and a key to accepted Helicosporium species are provided.

A Photosensitizing Metal-Organic Framework as a Tandem Reaction Catalyst for Primary Alcohols from Terminal Alkenes and Alkynes.

Owing to the wide and growing demand for primary alcohols, the development of efficient catalysts with high regioselectivity remains a worthwhile pursuit. However, according to Markovnikov's rule, it is a challenge to obtain primary alcohols with high yields and regioselectivity from terminal alkenes or alkynes. Herein, we report the synthesis of a photosensitizing two-dimensional (2D) metal-organic framework (MOF) from cyclic trinuclear copper(I) units (Cu-CTUs) and a boron dipyrro-methene (Bodipy) ligand. The MOF features broadband light absorption, excellent photoinduced charge separation efficiency, and photochemical properties. By integrating the copper-catalyzed hydroboration and photocatalyzed aerobic oxidation, it can catalyze terminal alkenes and alkynes to produce primary alcohols via a one-pot tandem reaction with excellent regioselectivity, good overall yields in two-step reactions (up to 85 %), broad substrate compatibility (32 examples) and good reusability under mild conditions.

Taxonomy and Phylogeny of Hyphomycetous Muriform Conidial Taxa from the Tibetan Plateau, China.

During the investigation of lignicolous freshwater fungi in the Tibetan Plateau habitat, fifteen collections were isolated from submerged decaying wood. Fungal characteristics are commonly found as punctiform or powdery colonies with dark pigmented and muriform conidia. Multigene phylogenetic analyses of combined ITS, LSU, SSU and TEF DNA sequences showed that they belong to three families in Pleosporales. Among them, Paramonodictys dispersa, Pleopunctum megalosporum, Pl. multicellularum and Pl. rotundatum are established as new species. Paradictyoarthrinium hydei, Pleopunctum ellipsoideum and Pl. pseudoellipsoideum are reported as new records on the freshwater habitats in Tibetan Plateau, China. The morphological descriptions and illustrations of the new collections are provided.

A BODIPY-Based 1D Covalent Organic Framework for Photocatalytic Aerobic Oxidation.

Covalent organic frameworks (COFs) as metal-free photocatalysts have attracted extensive interest. However, the organic transformations photocatalyzed by COFs under mild conditions remain a challenge. Herein, a boron-dipyrromethene (BODIPY) based 1D COF, namely JNM-12, was facilely constructed by Schiff-base condensation reaction. JNM-12 exhibited strong visible-light harvesting abilities and suitable photocatalysis energy potentials, enabling the activation of O2 to superoxide anions (O2 ⋅- ) and singlet oxygen (1 O2 ) under visible light irradiation. Benefiting from these properties, JNM-12 delivered excellent photocatalytic activity in the O2 ⋅- -mediated oxidative coupling of amines and 1 O2 -engaged aerobic oxidation of enamines. Our work paves a new way for synthesis of COFs as efficient, economical, and green photocatalysts for organic synthesis.

Comparison of CT Values between Thrombus and Postmortem Clot Based on Cadaveric Pulmonary Angiography.

OBJECTIVES: To explore the difference in CT values between pulmonary thromboembolism and postmortem clot in postmortem CT pulmonary angiography (CTPA) to further improve the application value of virtual autopsy. METHODS: Postmortem CTPA data with the definite cause of death from 2016 to 2019 were collected and divided into pulmonary thromboembolism group (n=4), postmortem clot group (n=5), and control group (n=5). CT values of pulmonary trunk and left and right pulmonary artery contents in each group were measured and analyzed statistically. RESULTS: The average CT value in the pulmonary thromboembolism group and postmortem clot group were (168.4±53.8) Hu and (282.7±78.0) Hu, respectively, which were lower than those of the control group (1 193.0±82.9) Hu (P<0.05). The average CT value of the postmortem clot group was higher than that of the pulmonary thromboembolism group (P<0.05). CONCLUSIONS: CT value is reliable and feasible as a relatively objective quantitative index to distinguish pulmonary thromboembolism and postmortem clot in postmortem CTPA. At the same time, it can provide a scientific basis to a certain extent for ruling out pulmonary thromboembolism deaths.

Nitrous oxide emissions from tea plantations: A review.

Tea plantations are an important N2O source. Fertilizer-induced N2O emission factors of tea plantations are much higher than other upland agricultural ecosystems. According to the basic information on characteristics and knowledge of N2O emissions from tea plantations around the world, we comprehensively reviewed N2O emission characteristics, production process, influencing factors, and reduction measures from tea plantations. The global means of ambient N2O emission and N2O emission stimulated by nitrogen fertilizer application from tea plantations were (2.68±2.92) kg N·hm-2 and (11.29±9.45) kg N·hm-2, respectively. The fertilizer-induced N2O emission factor in tea plantations (2.2%±2.1%) was much higher than the IPCC-estimated N2O emission factor for agricultural land (1%). N2O emission from tea plantation soil (a typical acid soil) were mainly produced during nitrification and denitrification, with denitrification being dominant. N2O emission from tea plantations were significantly related to the amount of fertilizer application. Other factors, such as fertilizer type, could also affect soil N2O emissions in tea plantations. The main reduction methods of N2O emission from tea plantations included optimizing the amount and type of fertilizer, amending biochar, and rationally using nitrification inhibitors. In future, we should strengthen in-situ observations of soil N2O emission from tea plantations at both temporal and spatial scales, combine lab incubation and field studies to elucidate the mechanisms underling tea plantation soil N2O emissions, and use a data-model fusion approach to reduce uncertainties in the estimation of global N2O emission. These would provide theoretical support and practical guidance for reasonable N2O emission reduction in tea plantations.

Detection of multiple biomarkers associated with satellite cell fate in the contused skeletal muscle of rats for wound age estimation.

From the perspective of forensic wound age estimation, experiments related to skeletal muscle regeneration after injury have rarely been reported. Here, we examined the time-dependent expression patterns of multiple biomarkers associated with satellite cell fate, including the transcription factor paired box 7 (Pax7), myoblast determination protein (MyoD), myogenin, and insulin-like growth factor (IGF-1), using immunohistochemistry, western blotting, and quantitative real-time PCR in contused skeletal muscle. An animal model of skeletal muscle contusion was established in 30 Sprague-Dawley male rats, and another five rats were employed as non-contused controls. Morphometrically, the data obtained from the numbers of Pax7 + , MyoD + , and myogenin + cells were highly correlated with the wound age. Pax7, MyoD, myogenin, and IGF-1 expression patterns were upregulated after injury at both the mRNA and protein levels. Pax7, MyoD, and myogenin protein expression levels confirmed the results of the morphometrical analysis. Additionally, the relative quantity of IGF-1 protein > 0.92 suggested a wound age of 3 to 7 days. The relative quantity of Pax7 mRNA > 2.44 also suggested a wound age of 3 to 7 days. Relative quantities of Myod1, Myog, and Igf1 mRNA expression > 2.78, > 7.80, or > 3.13, respectively, indicated a wound age of approximately 3 days. In conclusion, the expression levels of Pax7, MyoD, myogenin, and IGF-1 were upregulated in a time-dependent manner during skeletal muscle wound healing, suggesting the potential for using them as candidate biomarkers for wound age estimation in skeletal muscle.

An Atomically Precise Pyrazolate-Protected Copper Nanocluster Exhibiting Exceptional Stability and Catalytic Activity.

The synthesis of atomically precise copper nanoclusters (Cu-NCs) with high chemical stability is a prerequisite for practical applications, yet still remains a long-standing challenge. Herein, we have prepared a pyrazolate-protected Cu-NC (Cu8), which exhibited exceptional chemical stability either in solid-state or in solution. The crystals of Cu8 are still suitable for single crystal X-ray diffraction analysis even after being treated with boiling water, 8 wt % H2 O2 , high concentrated acid (1 M HCl) or saturated base (≈20 M KOH), respectively. More importantly, the structure of Cu8 in solution also remained intact toward oxygen, organic acid (100 eq. HOAc) or base (400 eq. dibutylamine) confirmed by 1 H NMR and UV/Vis analysis. Taking advantage of high alkali-resistant, Cu8 illustrates excellent catalytic activity for the synthesis of indolizines, and it can be reused for at least 10 cycles without losing catalytic performance.