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2D covalent organic frameworks with Kagome (kgm) topology are a promising class of crystalline frameworks that possess both triangular and hexagonal pores. These dual-pore structures enable kgm COFs to exhibit unique advantages in selective separation, mass transfer, and targeted drug release. However, the synthesis of 2D kgm COFs has been hindered by the reliance on empirical methods. This review systematically summarizes the conventional macrocycle-to-framework strategy, typical [4+2] co-polymerization synthetic strategy, and bifunctional molecules self-condensation approach for constructing 2D kgm COFs. Factors influencing the formation of kgm lattice are surveyed, such as monomer type, solvent polarity, substrate concentration, etc., and highlight the representative examples on targeted synthesis. Additionally, applications of 2D kgm COFs and relationships between structure and performances are summarized. Finally, key fundamental perspectives are proposed to accelerate the further development of this intriguing material., (© 2023 Wiley-VCH GmbH.)

Targeted synthesis of kagome (kgm) topologic 2D covalent organic frameworks remains challenging, presumably due to the severe dependence on building units and synthetic conditions. Herein, two isomeric "two-in-one" monomers with different lengths of substituted arms based on naphthalene core (p-Naph and m-Naph) are elaborately designed and utilized for the defined synthesis of isomeric kgm Naph-COFs. The two isomeric frameworks exhibit splendid crystallinity and showcase the same chemical composition and topologic structure with, however, different pore channels. Interestingly, C 60 is able to uniformly be encapsulated into the triangle channels of m-Naph-COF via in situ incorporation method, while not the isomeric p-Naph-COF, likely due to the different pore structures of the two isomeric COFs. The resulting stable C 60 @m-Naph-COF composite exhibits much higher photoconductivity than the m-Naph-COF owing to charge transfer between the conjugated skeletons and C 60 guests., (© 2023 Wiley-VCH GmbH.)

Microbial communities in coastal waters are diverse and dynamic and play important roles in ecosystem functions and services. Despite the ecological impact of bacterioplankton or pathogens, little is known about whether bacterioplankton and pathogen communities exhibit similar patterns. Here, using 16S RNA gene amplicon sequencing, the geographic patterns and assembly processes of bacterioplankton and pathogen communities in 30 subtropical estuaries were studied. Results showed that the estuarine bacterioplankton communities mainly consisted of Proteobacteria (49.06%), Actinobacteria (17.62%), and Bacteroidetes (16.33%), among which 31 pathogen genera (186 amplicon sequence variants [ASVs]) were identified. Under the influence of salinity, bacterioplankton and pathogens showed similar biogeographic patterns. Redundancy and correlation analyses indicated that the bacterioplankton communities were strongly correlated with estuarine environmental factors, but potential pathogens were less influenced. Co-occurrence network analysis revealed a close relationship between bacterioplankton and potential pathogens, with two pathogens identified as connectors (i.e., ASV340 [Clostridium perfringens] and ASV1624 [Brevundimonas diminuta]), implying potential impacts of pathogens on structure, function, and stability of estuarine bacterioplankton communities. Null-model analysis revealed that deterministic processes (heterogeneous selection) dominated bacterioplankton community assembly, while stochastic processes (undominated effect) shaped the potential pathogen community. Our findings illustrate the biogeographic patterns and community assembly mechanisms of bacterioplankton and pathogens in estuaries, which should provide guidance and a reference for the control of potential pathogenic bacteria. IMPORTANCE Bacterioplankton play an important role in estuarine ecosystem functions and services; however, potentially pathogenic bacteria may exhibit infectivity and pose a serious threat to environmental and human health. In this study, geographic patterns and assembly processes of bacterioplankton communities in 30 subtropical estuaries were explored, and potential pathogenic bacteria in the estuaries were detected and profiled. Our results demonstrate here that bacterioplankton and pathogens show similar biogeographic patterns under the influence of salinity. Interestingly, heterogeneous selection dominated bacterioplankton assembly, while stochasticity dominated pathogen assembly. This study provides important information for future risk assessment of potential pathogenic bacteria as well as management in estuarine ecosystems.

Tobacco bacterial wilt is a serious disease caused by the soil-borne bacterium Ralstonia solanacearum ( R. solanacearum ). Herein, a rapid and purification-free α-hemolysin (α-HL) nanopore-sensing strategy based on polymerase chain reaction (PCR) and lambda exonuclease digestion was established to detect R. solanacearum . A 198-nucleotide-long single-stranded DNA was obtained via asymmetric PCR or the lambda exonuclease-mediated digestion of the PCR product. The DNA fragment produced unique long-lived, current-blocking signals when it passed through the α-HL nanopore. This sensing approach can allow for the determination of R. solanacearum in tobacco samples and can be conveniently extended to other DNA monitoring because of the extremely wide range of PCR applications.

A rapid, simple, and sensitive fluorescent detection method for brown spot of tobacco is established by lambda exonuclease-induced Mg 2+ -dependent DNAzyme amplification. It contains hybridization of the Alternaria alternata genome and HP1, digestion of the 5'-phosphorylated strand of the hybrid dsDNA by lambda exonuclease, acquisition of complete Mg 2+ -dependent DNAzyme, cleavage of the substrate modified with FAM and BHQ-1, and fluorescent detection. The proposed assay exhibits good sensitivity (10 pg L -1 ), selectivity and reproducibility. The method does not require pure DNA and expensive instruments, and can be performed within 2.5 hours. To the best of our knowledge, this is the first report of fluorescent detection of Alternaria alternata and its tobacco field samples. This method can be applied to the rapid and sensitive detection of Alternaria alternata in tobacco and its seedlings, and is particularly important for the green prevention and control of tobacco brown spot disease., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Covalent organic frameworks (COFs) with donor-acceptor (D-A) units are credible photocatalysts for their per-designed structure, inherent porosity, large surface area, splendid stability and so forth. Developing COFs with an excellent photocatalytic efficiency for hydrogen evolution is of a great significance in alleviating the energy crisis. Herein, a D-A type imine-linked crystalline Zn-Por-TT COF was fabricated successfully via the co-polymerization of electron-deficient Zinc (II) 5,10,15,20-tetrakis(para-aminophenyl) porphyrin (Zn-TAPP), and electron-rich thieno[3,2-b]thiophene-2,5-dicarbaldehyde (TT). Profiting from the D-A complex structure, the obtained Zn-Por-TT COF showcases an excellent photocatalytic activity with a hydrogen evolution rate of 8200 μmol/g/h, while the Zn-TAPP monomer presents practically no capacity for the generation of hydrogen under identical conditions. In addition, the counterparts Por-TT COF and COF-366-Zn were employed to illustrate the enhancement of the photocatalytic performance by metal catalytic sites and D-A structures. In addition, the counterparts Por-TT COF and COF-366-Zn were employed to illustrate the enhancement of metal catalytic sites and D-A structures for the photocatalytic performance.

The main protease (M pro ), which is highly conserved and plays a critical role in the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a natural biomarker for SARS-CoV-2. Accurate assessment of the M pro activity is crucial for the detection of SARS-CoV-2. Herein, we report a nanopore-based sensing strategy that uses an enzyme-catalyzed cleavage reaction of a peptide substrate to measure the M pro activity. The peptide was specifically cleaved by the M pro , thereby releasing the output products that, when translocated through aerolysin, quantitatively produced the signature current events. The proposed method exhibited high sensitivity, allowing the detection of M pro concentrations as low as 1 nM without the use of any signal amplification techniques. This simple, convenient, and label-free nanopore assay may expand the diagnostic tools for viruses., (© 2022 Wiley-VCH GmbH.)

A new species, Neodontobutis lani (Odontobutidae) is described from the Zuojiang River, a tributary of the Xijiang River of the Pearl River basin, at Longzhou Town, Guangxi Zhuang Autonomous Region, Southern China. This species can be distinguished from other Neodontobutis species by following characters: anterior head flat, with interorbital width / eye diameter = 1.41.9 (vs. less than 1.4); several rows (vs. single row) of transforming ctenii on posterior edges of body scales; sensory papilla on lower jaw arranged in two oblong clusters (vs. two single lines). It can be distinguished from Odontobutis species by: separated right and left gill membrane (vs. joined); barbel-like projection present on sensory papillae. Molecular phylogenetic analysis of 2,076 nuclear coding loci indicates that N. lani is a sister species of N. hainanensis, the only Neodontobutis species that has been described from China.

Single-molecule junctions (SMJs) offer a novel strategy for miniaturization of electronic devices. In this work, we realize a graphene-porphyrin-graphene SMJ driven by electric field and proton transfer in two configurations. In the transistor configuration with ionic liquid gating, an unprecedented field-effect performance is achieved with a maximum on/off ratio of ~4800 and a gate efficiency as high as ~179 mV/decade in consistence with the theoretical prediction. In the other configuration, controllable proton transfer, tautomerization switching, is directly observed with bias dependence. Room temperature proton transfer leads to a two-state conductance switching, and more precise tautomerization is detected, showing a four-state conductance switching at high bias voltages and low temperatures. Such an SMJ in two configurations provides new insights into not only building multifunctional molecular nanocircuits toward real applications but also deciphering the intrinsic properties of matters at the molecular scale.

The development of new linkages is one of the most efficient strategies to enrich the diversity of covalent organic frameworks (COFs). Particularly, functional linkages can endow COFs with additional tailored properties besides the building units, which further diversify COFs with desirable functions. Herein, we have developed a new arylamine linkage for the construction of COFs. Two new arylamine-linked COFs (AAm-TPB and AAm-Py) were prepared by condensing cost-effective dimethyl succinyl succinate (DMSS) with corresponding multitopic amines (TPB-NH 2 and Py-NH 2 ). Due to the abundant electroactive diphenylamine moieties in the COF skeletons resembling that of polyaniline (PANI), a state-of-the-art conductive polymer, the pseudocapacitive energy storage performance of AAm-TPB was further investigated. Remarkably, the AAm-TPB electrode exhibits a high capacitance of 271 F g -1 with a three-electrode setup at a discharge rate of 1 A g -1 , which represents one of the highest capacitances among the reported COF-based electrode materials., (© 2021 Wiley-VCH GmbH.)

Three isostructural covalent organic frameworks (COFs) with either methoxyl, hydroxyl, or both groups on the channel wall, are synthesized and served as metal-free heterogeneous catalysts for chemical fixation of CO 2 . Among them, the COF decorated with both hydroxyl and methoxyl groups named OMe-OH-TPBP-COF exhibits the highest catalytic activity and efficiency for CO 2 cycloaddition under mild conditions., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

An A2B2 type monomer, 1,6-bis(4-formylphenyl)-3,8-bis(4-aminophenyl)pyrene (BFBAPy), was employed for the fabrication of continuous and highly crystalline 2D imine-linked covalent organic framework (COF) films with tunable thickness via interfacial self-polymerization. These films served as stable acidichromism sensors with rapid response, low detection limit and good repeatability.

2D conductive metal-organic frameworks (2D c-MOFs) feature promising applications as chemiresistive sensors, electrode materials, electrocatalysts, and electronic devices. However, exploration of the spin-polarized transport in this emerging materials and development of the relevant spintronics have not yet been implemented. In this work, layer-by-layer assembly was applied to fabricate highly crystalline and oriented thin films of a 2D c-MOF, Cu 3 (HHTP) 2 , (HHTP: 2,3,6,7,10,11-hexahydroxytriphenylene), with tunable thicknesses on the La 0.67 Sr 0.33 MnO 3 (LSMO) ferromagnetic electrode. The magnetoresistance (MR) of the LSMO/Cu 3 (HHTP) 2 /Co organic spin valves (OSVs) reaches up to 25 % at 10 K. The MR can be retained with good film thickness adaptability varied from 30 to 100 nm and also at high temperatures (up to 200 K). This work demonstrates the first potential applications of 2D c-MOFs in spintronics., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Invariant natural killer T (iNKT) cells are innate T lymphocytes that express T cell receptors binding to exogenous and endogenous glycosphingolpid antigens presented by a nonpolymorphic, non-MHC antigen presenting molecule, CD1d. The endogenous glycosphingolipid metabolite, isoglobotrihexosylceramide (iGb3), is the first known natural ligand for both human and mouse iNKT cells, whose activity has been confirmed in a variety of iNKT cell clones generated by different investigators, representing the majority of the iNKT cell population. The signaling pathway mediated by T cell receptor is largely influenced by the structural variation of glycosphingolpid antigens, leading to multiple and varied biological functions of iNKT cells. In order to investigate the structural requirements behind iGb3 triggered iNKT cell activation, the structure-activity relationship (SAR) of iGb3 needs to be characterized. In this study, iGb3 analogues containing 2' '', 3' '', 4' '' and 6' '' deoxy terminal galactose were synthesized for probing the SAR between iGb3 and TCR. The biological assays on the synthetic iGb3 analogues were performed with use of the murine iNKT cell hybridoma DN32.D3. The results showed that the 2' '' and 3' '' hydroxyl groups of terminal galactose play more important roles for the recognition of iGb3 by TCR; while 4' '' and 6' '' hydroxyl groups were not as crucial for this recognition. These studies might help to understand the general structural requirements for natural endogenous ligands recognized by iNKT cells.

Objective: To evaluate the clinical effect of non-penetrating trabecular surgery (NPTS) with mitomycin C (MMC) in primary open-angle glaucoma (POAG)., Methods: Twenty-five eyes of 18 patients with POAG underwent NPTS with MMC during the operation. The mean follow-up was 16.6 months (6 - 28 months)., Results: The mean preoperative intraocular pressure (IOP) was (27.93 +/- 7.62) mm Hg (1 mm Hg = 0.133 kPa) which decreased to a mean postoperative IOP of (14.62 +/- 3.53) mm Hg (P < 0.001). After operation, there was an obvious diffuse bleb in each eye, in the 3 months after operation, there were functional blebs in 21 eyes, and the successful filtration was ceased in 4 eyes. The anterior chamber reaction was mild. Hyphema occurred in 1 eye after operation. Intra-operatively, in 4 eyes microperforations occurred in the trabecular meshwork without iris prolapse, and after operation, under the gonioscope, the perforation could be observed in these eyes. In another 2 eyes, there was no intra-operative perforation, but a small fissure was seen by gonioscopy., Conclusions: NPTS with application of MMC can lower the IOP effectively in this group of patients. The recovery of vision after operation is quick. A few complications occurred after operation. It is a promising technique to treat POAG.