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Comprehensive Summary: The alkenylzincation of internal alkynes is an effective method for the synthesis of multi‐substituted conjugated dienes; however, the current catalytic systems for this reaction are limited in terms of substrate scope and selectivity control, which restricts its practical applications. Herein, we report the first iron‐catalyzed alkenylzincation of internal alkynes, which features mild conditions, simple operation, broad substrate scope (including aryl/alkyl, diaryl, and dialkyl acetylenes), excellent functional group tolerance (tolerating highly active functional groups such as ester, methylthio, amide, sulfonyl, cyano, etc.), and high activity (with a turnover number of up to 11500, the highest record for carbometallation reactions). Notably, the catalytic system described in this article also realized the highly selective vinylzincation of unfunctionalized internal alkynes as well as the alkenylzincation of unsymmetrical diarylacetylenes and dialkyl acetylenes, which have not been achieved with other catalytic systems reported in the literatures. The current study provides a highly selective access to synthetically important multi‐substituted conjugated dienes. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The alkenylzincation of internal alkynes is an effective method for the synthesis of multi‐substituted conjugated dienes; however, the current catalytic systems for this reaction are limited in terms of substrate scope and selectivity control, which restricts its practical applications. Herein, we report the first iron‐catalyzed alkenylzincation of internal alkynes, which features mild conditions, simple operation, broad substrate scope (including aryl/alkyl, diaryl, and dialkyl acetylenes), excellent functional group tolerance (tolerating highly active functional groups such as ester, methylthio, amide, sulfonyl, cyano, etc.), and high activity (with a turnover number of up to 11500, the highest record for carbometallation reactions). Notably, the catalytic system described in this article also realized the highly selective vinylzincation of unfunctionalized internal alkynes as well as the alkenylzincation of unsymmetrical diarylacetylenes and dialkyl acetylenes, which have not been achieved with other catalytic systems reported in the literatures. The current study provides a highly selective access to synthetically important multi‐substituted conjugated dienes. [ABSTRACT FROM AUTHOR]

Here, we demonstrate the first example of natural product harmaline and its derivatives serving as useful N–C synthons in formal [3+2] cycloadditions with isothiocyanates for the construction of a library of spiropolycyclic harmaline-based hybrids containing two adjacent quaternary stereocentres. These products were smoothly afforded in up to 90% yield, 20 : 1 dr with Et3N as the catalyst under mild conditions. To the best of our knowledge, this also represents the first example of the synthesis of natural product harmaline-based spiropolycyclic scaffolds, and expands the chemical space of biologically significant harmaline derivative species. The newly synthesized structurally diverse compounds were evaluated for their in vitro anticancer activities. These studies indicate that some compounds displayed good anticancer activity against three tumor cells (A549, K562, and PC-3). Among them, compound 3cb displayed the best activity when applied to A549, which is similar to that of cisplatin. Preliminary mechanistic studies indicate that compound 3cb induces apoptosis in A549 cells through a caspase-dependent pathway. These results show that compound 3cb can be prepared as a good lead for drug development. [ABSTRACT FROM AUTHOR]

The first example of ring-opening and recyclization reaction of 3-vinyl oxindole-chromones 1 as versatile synthons, which can react with ammonia or primary aliphatic amines as binucleophiles is developed, serving as a fruitful strategy for the eco-friendly and atom-economic synthesis of a new family of skeletally diverse 2-hydroxy benzoyl pyridones 3 with high to excellent yields (70–92%). The advantages of this methodology, including the use of easily available raw materials and the catalyst-free, wide functional group tolerance, and gram-scale synthesis, make the developed methodology a practical way to access important biologically active 2-hydroxy benzoyl pyridone molecules. [ABSTRACT FROM AUTHOR]

Transcription factor Broad Complex (BR‐C) is an ecdysone primary response gene in insects and participates in the regulation of insect growth and development. In this study, we performed a genome‐wide identification of BR‐C target genes in silkworm (Bombyx mori) using chromatin immunoprecipitation followed by high‐throughput sequencing (ChIP‐seq). As a result, a total of 1006 BR‐C ChIP peaks were identified, and 15% of peaks were located in the promoter regions of 133 protein‐coding genes. Functional annotation revealed that these ChIP peak‐associated genes, as potential BR‐C targets, were enriched in pathways related to biosynthetic process, metabolic process, and development. Transcriptome analysis and quantitative real‐time polymerase chain reaction (PCR) examination revealed that developmental changes in expression patterns of a portion of potential BR‐C targets, including HR96 and GC‐α1, were similar to those of BR‐C. ChIP‐PCR examination confirmed that BR‐C could directly bind to the promoters of potential targets. Further, dual luciferase assays demonstrated that HR96 promoter activity was significantly upregulated following BR‐C overexpression, and this upregulation was abolished when the binding motif in the promoter was truncated. This study will be helpful for deciphering the regulatory roles of BR‐C during insect growth and development. [ABSTRACT FROM AUTHOR]

The pursuit of high energy densities propels the design of next‐generation nickel‐based layered oxide cathodes. The utilization of low‐cobalt, ultrahigh‐nickel layered oxide cathodes, and the extension of operating voltages promise enhanced energy density. However, stability and safety face challenges associated with nickel content, including structural degradation, lattice oxygen evolution, and thermal instability. In this study, a promising strategy of Al and Nb dual‐bulk‐doping is presented in high‐Ni cathode materials of LiNi0.96Co0.04O2 (NC) to stabilize the bulk structure, suppress oxygen release, and attain superior electrochemical performance at high voltages. The introduction of Al and Nb effectively raises the migration energy of Ni2+ into Li sites and stabilizes lattice oxygen through strengthened Al─O and Nb─O bonds. Furthermore, the substitution of high‐valence Nb ions reduces the charge depletion of lattice oxygen and induces an ordered microstructure. The Al and Nb dual‐bulk‐doping strategy mitigates strain and stress associated with the H2↔H3 phase transition, reducing the generation and propagation of microcracks. The resulting Li(Ni0.96Co0.04)0.985Al0.01Nb0.005O2 (NCAN) cathode exhibits superior cycling stability, with a capacity retention of 77.8% after 300 cycles, even when operating at a high‐voltage of 4.4 V, outperforming the NC (48.5%). This work provides a promising perspective for developing high‐voltage and high‐Ni cathode materials. [ABSTRACT FROM AUTHOR]

A novel turn-on fluorescent probe containing a benzoxazole fluorophore has been synthesised and its response to different metal ions has been investigated by spectrometry. The probe was highly selective and sensitive to Zn2+and showed a complexation ratio towards Zn2+of 1:1. It also exhibited a linear response range for Zn2+from 0.3 to 4.8 μmol L–1 with a detection limit of 0.36 μmol L–1. [ABSTRACT FROM AUTHOR]

The Pacific white shrimp ( Litopenaeus vannamei), as an economically important species, has been reared in low-salinity water during the last decade. To investigate how juvenile L. vannamei shrimp fed with fructose-enriched Artemia respond to acute low-salinity stress, the shrimp were randomly divided into four treatment groups, three groups were fed with Artemia enriched with either 100, 200 and 300 mg L−1 of fructose and a control group fed with Artemia with no enrichment for 10 days. The results showed that the 300 mg L−1 fructose group demonstrated the maximum survival rate and glycogen content. Additionally, the 300 mg L−1 fructose group showed significantly higher Na+/K+- ATPase activity, total antioxidant capacity, and expression levels of Na+/K+- ATPase α-subunit, V-H ATPase α-subunit, hexokinase, phosphofructokinase, antioxidants ( SOD, CAT, GPX) and Hsp70 mRNA when compared with the control group. Furthermore, after exposure to low salinity, the mRNA levels of phosphofructokinase, V-H ATPase α-subunit, GPX, p38, JNK and Rac1 stayed constant in shrimp fed with fructose-enriched Artemia but changed significantly in the control group. Thus, a diet of fructose-enriched Artemia can improve the osmoregulation and survival of juvenile L. vannamei shrimp exposed to low salinities. [ABSTRACT FROM AUTHOR]

PTEN is a key tumor suppressor gene that can play a regulatory role in the cellular proliferation, survival and apoptosis. In this study, the full-length PTEN (EcPTEN) was obtained, containing a 5′UTR of 745 bp, an ORF of 1269 bp and a 3′UTR of 106 bp. The EcPTEN gene encoded a polypeptide of 422 amino acids with an estimated molecular mass of 49.14 KDa and a predicted isoelectric point (pI) of 6.34. The deduced amino acid sequence analysis showed that EcPTEN comprised the conserved residues and the characteristic domains known to the critical functionality of PTEN. qRT-PCR analysis revealed that EcPTEN mRNA was broadly expressed in all the examined tissues, while the highest expression level was observed in liver, followed by the expression in blood, kidney, spleen, heart, gill, muscle and intestine. The groupers challenged with Vibrio alginolyticus showed a sharp increase of EcPTEN mRNA expression in immune tissues. In addition, western blotting analysis confirmed that the up-regulation of EcPTEN protein expression was steadily induced in liver. Subcellular localization analysis indicated that EcPTEN was localized in both nucleus and cytoplasm. Overexpression of EcPTEN can activate the apoptotic cascade and abrogate NF-kB, AP-1, Stat3 and Myc promoter activity in Hela cells. These results indicated that EcPTEN harboring highly-conserved domains with a close sequence similarity to those of PTP superfamily may disrupt the mammalian signalings and play a regulatory role in the apoptotic process. [ABSTRACT FROM AUTHOR]

A novel turn-off fluorescent probe bearing a benzoxazole fluorophore has been synthesised and characterised. Its recognition properties towards different metal ions have been researched by spectrometry. The probe was highly selective and sensitive to Hg2+ and showed a complexation ratio towards Hg2+ of 1:1. Its fluorescence intensity varied almost linearly with the concentration of Hg2+ (1.6∼8.6 μmol L-1), and the detection limit of Hg2+ was estimated to be 0.68 μmol L-1. [ABSTRACT FROM AUTHOR]

The small GTPase Rac1 acts as a molecular switch for signal transduction that regulates various cellular functions. However, its functions in crustaceans remain unclear. In this study, a cDNA encoding a RAS GTPase ( Lv Rac1) in the Pacific white shrimp ( L. vannamei ) was identified and characterized. A recombinant variant of this GTPase, r Lv Rac1, was expressed in the model organism P. pastoris and its expression was confirmed by mass spectrometry. Biochemical assays indicated that the recombinant protein retained GTPase activity and was expressed in all of the organism's tested tissues. Injection of the bacterium V. alginolyticus into L. vannamei induced hepatopancreatic upregulation of Lv Rac1 expression. Moreover, knocking down Lv Rac1 in vivo significantly reduced the expression of the L. vannamei p53 and Cu/Zn superoxide dismutase genes ( Lv p53 and Lv Cu/Zn SOD, respectively) while increasing that of the galectin gene ( Lv gal). Hemolymph samples from control and Lv Rac1-silenced L. vannamei individuals were analyzed by flow cytometry, revealing that the latter exhibited significantly reduced respiratory burst activity and total hemocyte counts. Cumulative mortality in shrimp lacking Lv Rac1 was significantly greater than in control groups following V. alginolyticus challenge. The silencing of Lv Rac1 by double-stranded RNA injection thus increased the V. alginolyticus challenge sensitivity of L. vannamei and weakened its bacterial clearance ability in vivo . Suppressing Lv Rac1 also promoted the upregulation of Lv p53, Lv Cu/ZnSOD, and Lv gal following V. alginolyticus injection. Taken together, these results suggest that Lv Rac1 is important in the innate immune response of shrimp to V. alginolyticus infection. [ABSTRACT FROM AUTHOR]