Summary
Rice grain filling rate contributes largely to grain productivity and accumulation of nutrients. MicroRNAs (miRNAs) are key regulators of development and physiology in plants and become a ...novel key target for engineering grain size and crop yield. However, there is little studies, so far, showing the miRNA regulation of grain filling and rice yield, in consequence. Here, we show that suppressed expression of rice miR1432 (STTM1432) significantly improves grain weight by enhancing grain filling rate and leads to an increase in overall grain yield up to 17.14% in a field trial. Molecular analysis identified rice Acyl‐CoA thioesterase (OsACOT), which is conserved with ACOT13 in other species, as a major target of miR1432 by cleavage. Moreover, overexpression of miR1432‐resistant form of OsACOT (OXmACOT) resembled the STTM1432 plants, that is, a large margin of an increase in grain weight up to 46.69% through improving the grain filling rate. Further study indicated that OsACOT was involved in biosynthesis of medium‐chain fatty acids. In addition, RNA‐seq based transcriptomic analyses of transgenic plants with altered expression of miR1432 demonstrated that downstream genes of miR1432‐regulated network are involved in fatty acid metabolism and phytohormones biosynthesis and also overlap with the enrichment analysis of co‐expressed genes of OsACOT, which is consistent with the increased levels of auxin and abscisic acid in STTM1432 and OXmACOT plants. Overall, miR1432‐OsACOT module plays an important role in grain filling in rice, illustrating its capacity for engineering yield improvement in crops.
Herein, we report a Rh(III)‐catalyzed 1,3‐dienylation of isoquinolin‐1(2H)‐ones through C−H activation. The present reaction enables the preparation of 3‐(buta‐1,3‐dien‐2‐yl)isoquinolin‐1(2H)‐ones ...through the direct cross‐coupling reaction of readily available isoquinolin‐1(2H)‐ones with methylenecyclopropanes, while tolerating many sensitive functional groups. Therefore, this method provides an efficient and convenient approach for modification of interesting molecules.
With the development of artificial intelligence, machine learning has a wide range of applications in the field of materials. The sparsity of data on the mechanical properties of high-entropy alloys ...makes it difficult to balance between the generalizability and interpretability in data-driven predictive models of material properties. A machine learning model was established based on the HEA hardness data of the Al-Co-Cr-Cu-Fe-Ni system, and several modeling features were screened out through a three-step parallel approach. Model ensemble was performed for RandomForest, XGBoost, LightGBM and CatBoost using the stacking ensemble algorithm, and the coefficient of determination(R2) of the model reached 0.93 after a ten-fold cross-validation. The ensemble learning is stable and accurate for predicting HEA hardness value, and is experimentally verified. The model and selected features can also be applied to different HEA systems as well as low hardness CrFeNi MEA. In addition, we further explained the large prediction deviation of MEA in the high hardness region. Further, the effects of HEA composition and phase formation on the hardness of HEA were qualitatively analyzed based on interpretable tools like SHAP values as well as PDP/ICE plots, respectively. Finally, the model not only has the generalization of ensemble learning, but also has certain interpretability.
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•Establishing an ensemble learning combining classification and Stacking regression.•Transferable for various HEA and ternary CrFeNi MEA material systems.•Interpretable machine learning approach to analyze the hardening mechanism.
Herein, we report a Palladium(0)‐catalyzed C4 site‐selective C−H difluoroalkylation of isoquinolin‐1(2H)‐ones through a radical pathway. The present reaction enables the preparation of ...2,2‐difluoro‐2‐(1‐oxo‐1,2‐dihydroisoquinolin‐4‐yl)acetates/acetamides through the direct cross‐coupling reaction of readily available isoquinolin‐1(2H)‐ones with 2‐bromo‐2,2‐difluoroacetates or 2‐bromo‐2,2‐difluoroacetamides. Therefore, this method provides an efficient and convenient approach to install a difluoroacetate or a difluoroacetamide moiety into bioactive molecules. Bioassay results showed that introduction of these difluorinated groups at C4 position was beneficial to improve their antiviral activity and compound 5 ab was found to exhibit similar antiviral activity with commercial Ningnanmycin.
The development of functionally distinct catalysts for enantioselective synthesis is a prominent yet challenging goal of synthetic chemistry. In this work, we report a family of chiral
N
...-heterocyclic carbene (NHC)–ligated boryl radicals as catalysts that enable catalytic asymmetric radical cycloisomerization reactions. The radical catalysts can be generated from easily prepared NHC-borane complexes, and the broad availability of the chiral NHC component provides substantial benefits for stereochemical control. Mechanistic studies support a catalytic cycle comprising a sequence of boryl radical addition, hydrogen atom transfer, cyclization, and elimination of the boryl radical catalyst, wherein the chiral NHC subunit determines the enantioselectivity of the radical cyclization. This catalysis allows asymmetric construction of valuable chiral heterocyclic products from simple starting materials.
Editor’s summary
A good catalyst must bind tightly enough to reactants to bias their reactivity but then loosen its grip sufficiently to release the products. Radical catalysts with unpaired electrons are rare, in large part because the release step is too unfavorable. C.-L. Wang
et al
. now report that boron radicals, generated in situ from boranes bound to chiral carbene ligands, can achieve this balancing act as effective asymmetric catalysts for the cyclization of alkyne compounds, forming a variety of nitrogen heterocycles of interest in medicinal chemistry research. —Jake S. Yeston
In situ generated boryl radicals with chiral N-heterocyclic carbene ligands catalyze asymmetric cycloisomerization reactions
Despite regional brain structural changes having been reported in patients with chronic low back pain (CLBP), the topological properties of structural covariance networks (SCNs), which refer to the ...organization of the SCNs, remain unclear. This study applied graph theoretical analysis to explore the alterations of the topological properties of SCNs, aiming to comprehend the integration and separation of SCNs in patients with CLBP.
A total of 38 patients with CLBP and 38 healthy controls (HCs), balanced for age and sex, were scanned using three-dimensional T1-weighted magnetic resonance imaging. The cortical thickness was extracted from 68 brain regions, according to the Desikan–Killiany atlas, and used to reconstruct the SCNs. Subsequently, graph theoretical analysis was employed to evaluate the alterations of the topological properties in the SCNs of patients with CLBP.
In comparison to HCs, patients with CLBP had less cortical thickness in the left superior frontal cortex. Additionally, the cortical thickness of the left superior frontal cortex was negatively correlated with the Visual Analogue Scale scores of patients with CLBP. Furthermore, patients with CLBP, relative to HCs, exhibited lower global efficiency and small-worldness, as well as a longer characteristic path length. This indicates a decline in the brain's capacity to transmit and process information, potentially impacting the processing of pain signals in patients with CLBP and contributing to the development of CLBP. In contrast, there were no significant differences in the clustering coefficient, local efficiency, nodal efficiency, nodal betweenness centrality, or nodal degree between the two groups.
From the regional cortical thickness to the complex brain network level, our study demonstrated changes in the cortical thickness and topological properties of the SCNs in patients with CLBP, thus aiding in a better understanding of the pathophysiological mechanisms of CLBP.
•Investigating the topological properties of structural covariance network in CLBP.•Thinner cortical thickness of the left superior frontal in CLBP.•The left superior frontal related to the severity of pain of CLBP.•Decreases in the global efficiency and small-worldness, as well as an increase in the characteristic path length in CLBP.
Au-Fe
3
O
4
multifunctional nanoparticles (NPs) were synthesized and integrated with lateral flow immunoassay (LFIA) for dual-mode detection of
Salmonella typhimurium
. The Au-Fe
3
O
4
NPs not only ...combined excellent local surface plasmon resonance characteristics and superparamagnetic properties, but also exhibited good photothermal effect. In the detection, antibody-conjugated Au-Fe
3
O
4
NPs first captured
S. typhimurium
from complex matrix, which was then loaded on the LFIA strip and trapped by the T-line. By observing the color bands with the naked eyes, qualitative detection was performed free of instrument. By measuring the photothermal signal, quantification was achieved with a portable infrared thermal camera. The introduction of magnetic separation achieved the enrichment and purification of target bacteria, thus enhancing the detection sensitivity and reducing interference. This dual-mode LFIA achieved a visual detection limit of 5 × 10
5
CFU/mL and a photothermal detection limit of 5 × 10
4
CFU/mL. Compared with traditional Au-based LFIA, this dual-mode LFIA increased the detection sensitivity by 2 orders of magnitude and could be directly applied to unprocessed milk sample. Besides, this dual-mode LFIA showed good reproducibility and specificity. The intra-assay and inter-assay variation coefficients were 3.0% and 7.9%, and with this dual-mode LFIA, other bacteria hardly produced distinguishable signals. Thus, the Au-Fe
3
O
4
NPs-based LFIA has potential to increase the efficiency of pandemic prevention and control.
Graphical Abstract
Au-Fe
3
O
4
nanoparticle proved to be a promising alternative reporter for LFIA, achieving multifunctions: target purification, target enrichment, visual qualitation, and instrumental quantification, which improved the limitations of traditional LFIA.
The electrochemical transformation of biomass to high value‐added products is attractive. Herein, Cu sulfide‐mediated in‐situ synthesis of Cu oxide was achieved for efficient electro‐oxidation of ...biomass derived 5‐hydroxymethylfurfural (HMF) to 2,5‐furandicarboxylic acid (FDCA). The copper foam‐supported Cu sulfide (Cu−S/CF) was in‐situ converted to Cu oxide during the electro‐oxidation process. The in‐situ formed Cu oxide presented high HMF conversion, FDCA yield, and faradaic efficiency in 1 m KOH with HMF concentration up to 100 mm. The oxidation of HMF on Cu oxide started with the formation of high‐valence Cu species with the assistance of OH−, which then oxidized HMF spontaneously. An anion exchange membrane (AEM) electrolyzer with Cu−S/CF as the anode was assembled to continuously produce FDCA with H2 generation at the cathode. The AEM electrolyzer ran stably for 60 h with FDCA content higher than 85 % at a cell voltage between 1.50 and 1.60 V.
Biomass electrochemical oxidation: Copper foam‐supported Cu sulfide (Cu−S/CF) is in‐situ converted to Cu oxide during electrochemical oxidation of 5‐hydroxymethylfurfural. The anion exchange membrane electrolyzer with Cu−S/CF as the anode can work stably for at least 60 h, and the 2,5‐furandicarboxylic acid content in the product can be higher than 90 %.
Dietary fibre plays an important role in controlling postprandial glycemic and insulin response in diabetic patients. The intake of dietary fibre has been shown to delay the gastric emptying in ...healthy subjects. The relationship between gastric emptying and postprandial blood glucose in diabetic patients with fibre-load liquids needs to be investigated. To investigate the impact of soluble dietary fibre (SDF) on gastric emptying, postprandial glycemic and insulin response in patients with type 2 diabetes. 30 patients with type 2 diabetes (DM) and 10 healthy subjects (HS) matched for gender and age were randomized to receive SDF-free liquid (500 mL, 500 Kcal) and isoenergetic SDF liquid (oat β-glucan 7.5 g, 500 mL, 500 Kcal) on two separate days based on a cross-over with 6-day wash-out period. Gastric emptying was monitored by ultrasonography at intervals of 30 min for 2 hours. Fasting and postprandial blood was collected at intervals of 30-60 min for 180 min to determine plasma glucose and insulin. Proximal gastric emptying was delayed by SDF-treatment both in DM (p=0.001) and HS (p=0.037). SDF resulted in less output volume in the distal stomach in DM (p<0.05). SDF decreased postprandial glucose (p=0.001) and insulin (p=0.001) in DM subjects. Postprandial glucose (r=-0.547, p=0.047) and insulin (r=-0.566, p=0.004) were negatively correlated with distal emptying of SDF in DM subjects. Distal gastric emptying was delayed significantly in DM subjects with HbA1c levels ≥6.5% (p=0.021) or with complications (p=0.011) by SDF, respectively. SDF improved postprandial glycaemia which was related to slowing of gastric emptying.
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