Two-Dimensional Metal-Organic Framework Nanosheets

Two-dimensional (2D) metal–organic framework (MOF) nanosheets are attracting increasing research interest due to their unique properties originating from their ultrathin thickness and large surface area with highly accessible active sites. Here, the aim is to provide recent advances in the synthesis of 2D MOF nanosheets by using the top-down and bottom-up methods, including sonication exfoliation, interfacial synthesis, three-layer synthesis, and surfactant-assisted synthesis methods. In addition, the recent progress in 2D-MOF-nanosheet-based nanocomposites is also introduced. The synthesis of 2D MOF nanosheets should lead to new kinds of functional nanomaterials for a wide range of applications.MOE (Min. of Education, S’pore

The Function of the PRRSV–Host Interactions and Their Effects on Viral Replication and Propagation in Antiviral Strategies

Porcine reproductive and respiratory syndrome virus (PRRSV) affects the global swine industry and causes disastrous economic losses each year. The genome of PRRSV is an enveloped single-stranded positive-sense RNA of approximately 15 kb. The PRRSV replicates primarily in alveolar macrophages of pig lungs and lymphatic organs and causes reproductive problems in sows and respiratory symptoms in piglets. To date, studies on how PRRSV survives in the host, the host immune response against viral infections, and pathogenesis, have been reported. PRRSV vaccines have been developed, including inactive virus, modified live virus, attenuated live vaccine, DNA vaccine, and immune adjuvant vaccines. However, there are certain problems with the durability and effectiveness of the licensed vaccines. Moreover, the high variability and fast-evolving populations of this RNA virus challenge the design of PRRSV vaccines, and thus effective vaccines against PRRSV have not been developed successfully. As is well known, viruses interact with the host to escape the host’s immune response and then replicate and propagate in the host, which is the key to virus survival. Here, we review the complex network and the mechanism of PRRSV–host interactions in the processes of virus infection. It is critical to develop novel antiviral strategies against PRRSV by studying these host–virus interactions and structures to better understand the molecular mechanisms of PRRSV immune escape

Effects of Land Use Change on Soil Aggregate Stability and Erodibility in the Karst Region of Southwest China

Differences in land use type and chronological age affect soil properties and plant community characteristics, which may influence soil structural stability and erodibility. However, knowledge on the effects of soil physicochemical properties on soil aggregate stability and erodibility at different land use years is limited. This study selected five land use types: corn field (Year 38th-y), corn intercropped with cabbage field (Year 38th-y + b), fruit and meridian forest (Year 6th-jgl), naturally restored vegetation (Year 6th-zr), and artificial forest (Year 7th-rgl) in the karst landscape of the Chishui River Basin in Yunnan Province. We aimed to identify the influencing factors of soil stability and erodibility under different land use time series. The results indicated that the mean weight diameter (MWD), the geometric mean diameter (GMD), and soil structural stability index (SSI values) were highest in Y6th-zr and lowest in Y7th-rgl. Conversely, the erodibility K value was lowest in Y6th-zr, suggesting that the soil structure in Y6th-zr exhibited greater stability, whereas soil stability in Y7th-rgl was lower. Redundancy and throughput analyses revealed that organic carbon and water-stable aggregates > 2.0 mm content had higher vector values. Soil bulk density, total nitrogen, organic carbon, and soil texture content were the main factors contributing to soil stability variation (0.338–0.646). Additionally, total nitrogen, organic carbon, total phosphorus, and soil texture content drove the variation in K values (0.15–1.311). Natural vegetation restoration measures can enhance soil structure to a certain extent. These findings highlight changes in soil aggregate stability and erodibility over different land use durations. The research results have important theoretical and practical significance for understanding the differences in soil erosion and soil restoration under different land use patterns in the karst landscapes of southwest China

The Impacts of Chlorine and Disinfection Byproducts on Antibiotic-Resistant Bacteria (ARB) and Their Conjugative Transfer

Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are emerging contaminants leading to severe worldwide health problems. Chlorination, a widely used procedure, was extensively explored as one of the main methods to remove ARB and ARGs in recent years. In this study, to enrich the analyses of chlorination, several comprehensive effects of the chlorine disinfection system on ARB and their conjugative transfer ability were explored. The results presented that the low dose of chlorine (3-log inactivation rate) triggered cell membrane changes, with little influence on the bacteria in terms of their antibiotic resistance. However, their capacity for conjugative transfer sharply decreased. Minor consumption of chloramphenicol was achieved with the chlorine dose applied in the disinfection system. Monochloroacetonitrile (MCAN) had limited effects on the frequency of conjugative transfer, indicating that the existence of MCAN would not aggravate the dissemination of ARGs by conjugative transfer. The overall impacts of the chlorine disinfection system with different containments on antibiotic resistance need further investigation

A Low-Latency Fair-Arbiter Architecture for Network-on-Chip Switches

As semiconductor technology evolves, computing platforms attempt to integrate hundreds of processing cores and associated interconnects into a single chip. Network-on-chip (NoC) technology has been widely used for data exchange centers in recent years. As the core element of the NoC, the round-robin arbiter provides fair and fast arbitration, which is essential to ensure the high performance of each module on the chip. In this paper, we propose a low-latency fair switch arbiter (FSA) architecture based on the tree structure search algorithm. The FSA uses a feedback-based parallel priority update mechanism to complete the arbitration within the leaf nodes and a lock-based round-robin search algorithm to guarantee global fairness. To reduce latency, the FSA keeps the lock structure only at the leaf node so that the complexity of the critical path does not increase. Meanwhile, the FSA achieves a critical path with only O(log4N) delay by using four input nodes in parallel. The latency of the proposed circuit is on average 22.2% better than the existing fair structures and 8.1% better than the fastest arbiter, according to the synthesis results. The proposed architecture is well suited for high-speed network-on-chip switches and has better scalability for switches with large numbers of ports

The effect of exercise on cerebral blood flow and executive function among young adults: a double-blinded randomized controlled trial

Abstract Studies have demonstrated that exercise benefits executive function. However, it remains unclear which type of exercise is optimal for preserving executive function among young adults and the cerebral blood flow (CBF) mechanisms that underlie exercise-induced cognitive benefits. Therefore, this study aims to compare the intervention effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on executive function and the CBF mechanism. This was a double-blinded, randomized, controlled trial study conducted between October 2020 and January 2021 (ClinicalTrials.gov identifier: NCT04830059). Ninety-three healthy young adults (25.23 ± 2.18 years old; 49.82% male) were randomized into the HIIT (N = 33), MICT (N = 32), and control (N = 28) groups. Participants in exercise groups were guided to perform 40 min of HIIT and MICT three times a week for 12 weeks, while the control group received health education for the same period. The primary outcomes, changes in executive function assessed by the trail-making test (TMT), and CBF measured by transcranial Doppler flow analyzer (EMS-9WA), were evaluated before and after the interventions. The time taken to complete the TMT task improved significantly in the MICT group compared to the control group [β = −10.175, 95%, confidence interval (CI) =  −20.320, −0.031]. Additionally, the MICT group showed significant improvements in the pulsatility index (PI) (β = 0.120, 95% CI = 0.018, 0.222), resistance index (RI) (β = 0.043, 95% CI = 0.005, 0.082), and peak-systolic/end-diastolic velocity (S/D) (β = 0.277, 95% CI = 0.048, 0.507) of CBF compared to the control group. The time taken to complete the TMT was associated with the velocity of peak-systolic (F = 5.414, P = 0.022), PI (F = 4.973, P = 0.012), and RI (F = 5.845, P = 0.006). Furthermore, the accuracy of TMT was associated with PI (F = 4.797, P = 0.036), RI (F = 5.394, P = 0.024), and S/D (F = 4.312, P = 0.05) of CBF. A 12-week MICT intervention improved CBF and executive function more effectively than HIIT among young adults. Furthermore, the findings suggest that CBF was one of the potential mechanisms underlying the cognitive benefits of exercise in young people. These results provide practical evidence supporting the promotion of regular exercise to maintain executive function and improve brain health

Sequence-controlled polymers constructed by alkyne-based polymerizations

Synthesizing polymers with precise sequence structures is of great significance but is still a great challenge in polymer science. The exploration of alkyne-based polymerizations recently has attracted considerable attention due to their great potential to construct polymers with diverse structures and versatile functions, especially those with precise sequence structures. In this review, we summarized recent advances in the preparation of sequence-controlled polymers by alkyne-base polymerizations. Representative examples of each method were selected to illustrate the essential construction principles and implementation approaches, which are expected to provide guidance for the development of sequence-controlled polymers. In addition, we also systematically introduce the diverse and appealing properties and applications of the obtained sequence-controlled polymers, hoping to promote the development of polymeric materials with more superior and innovative properties and applications

Structures of MPND Reveal the Molecular Recognition of Nucleosomes

Adenine N6 methylation in DNA (6mA) is a well-known epigenetic modification in bacteria, phages, and eukaryotes. Recent research has identified the Mpr1/Pad1 N-terminal (MPN) domain-containing protein (MPND) as a sensor protein that may recognize DNA 6mA modification in eukaryotes. However, the structural details of MPND and the molecular mechanism of their interaction remain unknown. Herein, we report the first crystal structures of the apo–MPND and MPND–DNA complex at resolutions of 2.06 Å and 2.47 Å, respectively. In solution, the assemblies of both apo–MPND and MPND–DNA are dynamic. In addition, MPND was found to possess the ability to bind directly to histones, no matter the N-terminal restriction enzyme-adenine methylase-associated domain or the C-terminal MPN domain. Moreover, the DNA and the two acidic regions of MPND synergistically enhance the interaction between MPND and histones. Therefore, our findings provide the first structural information regarding the MPND–DNA complex and also provide evidence of MPND–nucleosome interactions, thereby laying the foundation for further studies on gene control and transcriptional regulation

Table_1_Reference genes identification for qRT-PCR normalization of gene expression analysis in Cucumis sativus under Meloidogyne incognita infection and Pseudomonas treatment.docx

qRT-PCR is a common and key technical means to study gene expression in biological research. However, reliability and accuracy of quantification by qRT-PCR is entirely dependent on the identification of appropriate reference genes. Cucumber as an economical vegetable is widely cultivated worldwide and is subject to serious nematode infection, especially from M. incognita. Plant could employ beneficial soil bacteria in the rhizosphere to enhance plant adaptability to various stresses. In this study, the optimal reference genes in cucumber under M. incognita stress and Pseudomonas treatment were calculated and confirmed. A total of thirteen candidate reference genes were identified across three different treatments. Of these, geNorm, NormFinder and BestKeeper programs combined RefFinder software identified EF1 and UBI are the most suitable reference gene in the root knot and whole root of cucumber infected M. incognita, respectively, and CACS is the most suitable reference gene in the whole root of cucumber treated by Pseudomonas. The work first validated the most suitable reference genes for the normalization gene expression in cucumber by nematode infected or Pseudomonas inoculated, and these results would facilitate the further research on M. incognita or Pseudomonas soil rhizosphere microbe interaction with cucumber.</p

MOF‐Based Hierarchical Structures for Solar‐Thermal Clean Water Production

Solar-thermal water evaporation, as a promising method for clean water production, has attracted increasing attention. However, solar water evaporators that exhibit both high water vapor generation ability and anti-oil-fouling ability have not been reported. Here, a unique metal-organic-framework-based hierarchical structure, referred to as MOF-based hierarchical structure (MHS), is rationally designed and prepared, which simultaneously displays a high solar absorption and a superhydrophilic and underwater superoleophobic surface property. As a proof-of-concept application, a device prepared from the MHS can achieve a high solar-thermal water evaporation rate of 1.50 kg m-2 h-1 under 1 sun illumination. Importantly, the MHS also possesses an excellent anti-oil-fouling property, ensuring its superior water evaporation performance even in oil-contaminated water. The high solar-thermal water evaporation rate and anti-oil-fouling property make the MHS a promising material for the solar-thermal water production.Ministry of Education (MOE)Nanyang Technological UniversityNational Research Foundation (NRF)This work was supported by MOE under AcRF Tier 2 (MOE2015-T2-2-057; MOE2016-T2-2-103; MOE2017-T2-1-162) and AcRF Tier 1 (2016-T1-001-147; 2016-T1-002-051; 2017-T1-001-150; 2017-T1-002-119), NTU under Start-Up Grant (M4081296.070.500000), and the NOL Fellowship Programme Research Grant in Singapore. This research was supported by the National Research Foundation, Prime Minister’s Office, Singapore under its Campus for Research Excellence and Technological Enterprise (CREATE) programme. The authors would like to acknowledge the Facility for Analysis, Characterization, Testing and Simulation, Nanyang Technological University, Singapore, for use of their electron microscopy (and/or X-ray) facilities