Synthesis of Benzyl Esters via Functionalization of Multiple C–H Bonds by Palladium Catalysis

A highly efficient, selective synthesis of benzyl esters by palladium catalysis is developed through the bidentate directing group assisted functionalization of multiple C­(sp³)–H bonds

Direct <i>ortho</i>-Thiolation of Arenes and Alkenes by Nickel Catalysis

The direct thiolation of arenes and alkenes with diaryl disulfides was developed by nickel catalysis. The reaction displayed exceptional compatibility with a wide range of functional groups to regioselectively give the diaryl sulfides and alkenyl sulfides in high yields

Self-Nucleation and Self-Assembly of Highly Fluorescent Au₅ Nanoclusters for Bioimaging

Fluorescent Au nanoclusters (NCs) are new excellent nanomaterials for biomedical applications but plagued by the problems of limited emission efficiency, unclear emission mechanism, and poor biological application ability. Herein, a novel strategy was developed to facilely synthesize poly­(amidoamine) (PAMAM) dendrimer-hosted Au₅ NCs (poly-Au₅) with a high fluorescence quantum yield of 25%. Most importantly, a two-stage growth process of poly-Au₅ was demonstrated through in situ time-course experiments. Stage I was a simultaneous self-nucleation and self-assembly with a rapid rate of fluorescence increase; stage II was a sole self-assembly after the end of reduction with a relatively slower rate of fluorescence increase but contributed 30% to the overall emission intensity of end products. In both stages, enhanced aurophilic interactions promoted the excited state relaxation dynamics; enhanced rigid structures reduced the level of nonradiative relaxition of excited states, and these two factors ensured high emission efficiency of poly-Au₅. To further evidence the inference above, we successfully used PAMAM to realize the self-assembly of presynthesized, separated, and red-emitting Au-GSH NCs through electrostatic interaction between negative charges of carboxylic groups in Au-GSH NCs and positive charges of amine groups in PAMAM. As expected, the emission efficiency of Au-GSH NCs was obviously enhanced by PAMAM-mediated self-assembly. Moreover, the as-synthesized poly-Au₅ assemblies exhibited excellent cell permeability and great biostability against various metal ions, high REDOX stress, and complex intracellular environments. By virtue of MnO₄^– as an intermediary agent, poly-Au₅ was successfully used for sensitive and stable intracellular fluorescent imaging of endogenous GSH. This study lights up the emission origin of dendrimer-hosted Au NCs with strong emission and implies their huge applications in biomedical sensing and imaging

DataSheet_2_Revealing genetic diversity, population structure, and selection signatures of the Pacific oyster in Dalian by whole-genome resequencing.xlsx

IntroductionThe Pacific oyster (Crassostrea gigas), one of the major aquaculture shellfish worldwide, has strong environmental adaptability. However, genetic diversity and population structure of the Pacific oysters in Dalian Sea, the major natural and farming area of the species in China, has not been systematically investigated, especially at genome-wide level, limiting the conservation and management of the species. MethodsIn this study, whole-genome resequencing of 105 individuals from seven Pacific oyster populations, including five wild and one cultured populations in Dalian and one wild population in Qingdao relatively distant from others, were first performed.ResultsA total of 2,363,318 single nucleotide polymorphisms (SNPs) were identified. Based on all these SNPs, similar but relatively low genetic diversity (0.2352~0.2527) was found in the seven populations. The principal component analysis (PCA), phylogenetic and population structure analysis consistently revealed weak differentiation among the seven populations. Frequent migration events were detected among the studied populations by TreeMix, which probably led to a high genetic similarity of these populations. Rapid linkage disequilibrium (LD) decay was observed in the genome of the Pacific oyster. Investigation of genome-wide selection signatures of these populations identified many selected genes involved in the biological processes related to DNA metabolism and stability, shell formation, and environmental stress response, which may be critical for oysters to adapt to the stressful environments.DiscussionThis study laid theoretical basis for the subsequent germplasm conservation, management and genetic breeding of the indigenous Pacific oysters, and provided novel insights for the adaptive evolutionary mechanism of oysters.</p

DataSheet_1_Revealing genetic diversity, population structure, and selection signatures of the Pacific oyster in Dalian by whole-genome resequencing.pdf

IntroductionThe Pacific oyster (Crassostrea gigas), one of the major aquaculture shellfish worldwide, has strong environmental adaptability. However, genetic diversity and population structure of the Pacific oysters in Dalian Sea, the major natural and farming area of the species in China, has not been systematically investigated, especially at genome-wide level, limiting the conservation and management of the species. MethodsIn this study, whole-genome resequencing of 105 individuals from seven Pacific oyster populations, including five wild and one cultured populations in Dalian and one wild population in Qingdao relatively distant from others, were first performed.ResultsA total of 2,363,318 single nucleotide polymorphisms (SNPs) were identified. Based on all these SNPs, similar but relatively low genetic diversity (0.2352~0.2527) was found in the seven populations. The principal component analysis (PCA), phylogenetic and population structure analysis consistently revealed weak differentiation among the seven populations. Frequent migration events were detected among the studied populations by TreeMix, which probably led to a high genetic similarity of these populations. Rapid linkage disequilibrium (LD) decay was observed in the genome of the Pacific oyster. Investigation of genome-wide selection signatures of these populations identified many selected genes involved in the biological processes related to DNA metabolism and stability, shell formation, and environmental stress response, which may be critical for oysters to adapt to the stressful environments.DiscussionThis study laid theoretical basis for the subsequent germplasm conservation, management and genetic breeding of the indigenous Pacific oysters, and provided novel insights for the adaptive evolutionary mechanism of oysters.</p

Dimethyl Sulfoxide Involved One-Pot Synthesis of Quinoxaline Derivatives

An efficient, green, and novel method for the synthesis of N-heterocycle-fused quinoxalines is reported herein. Dimethyl sulfoxide was used as both a reactant and a solvent in this reaction. A wide range of products in moderate to excellent yields were obtained, including pyrrolo­[1,2-<i>a</i>]­quinoxalines, indolo­[1,2-<i>a</i>]­quinoxalines, 1<i>H</i>-pyrrolo­[3,2-<i>c</i>]­quinolines, and benzo­[4,5]­imidazo­[1,2-<i>c</i>]­quinazolines

Solution Conformation of Polymer Brushes Determines Their Interactions with DNA and Transfection Efficiency

Polymer brush-functionalized nanomaterials offer interesting features for the design of gene delivery vectors as their physicochemical and structural properties can be designed independently of the chemistry, size and shape of the nanomaterial core. However, little is known of the parameters regulating the adsorption and infiltration of DNA molecules at the surface of positively charged polymer brushes, despite the importance of such processes for gene delivery. Here we investigate the role of the molecular environment (e.g., pH, type of buffer, concentration) on the interactions between plasmid DNA and positively charged poly­(dimethylaminoethyl methacrylate) (PDMAEMA) brushes using a combination of light scattering, electrophoretic light scattering, in situ ellipsometry, and surface plasmon resonance. We show that the conformation of swollen PDMAEMA brushes is modulated by the surrounding buffer and that this impacts strongly on the ability of such brushes and nanomaterials based on these coatings to complex DNA molecules. In turn, the levels of transfection efficiency measured correlate with changes in brush conformation and DNA binding. Therefore, this work demonstrates the importance of molecular design of polymer brushes to control DNA complexation and release in order to optimize the performance of polymer brush-functionalized nanomaterials for gene delivery applications

Table_2_MOF negatively regulates estrogen receptor α signaling via CUL4B-mediated protein degradation in breast cancer.xlsx

Estrogen receptor α (ERα) is the dominant tumorigenesis driver in breast cancer (BC), and ERα-positive BC (ERα+ BC) accounts for more than two-thirds of BC cases. MOF (males absent on the first) is a highly conserved histone acetyltransferase that acetylates lysine 16 of histone H4 (H4K16) and several non-histone proteins. Unbalanced expression of MOF has been identified, and high MOF expression predicted a favorable prognosis in BC. However, the association of MOF with ERα and the regulatory mechanisms of MOF in ERα signaling remain elusive. Our study revealed that the expression of MOF is negatively correlated with that of ERα in BC. In ERα+ BC cells, MOF overexpression downregulated the protein abundance of ERα in both cytoplasm and nucleus, thus attenuating ERα-mediated transactivation as well as cellular proliferation and in vivo tumorigenicity of BC cells. MOF promoted ERα protein degradation through CUL4B-mediated ubiquitin–proteasome pathway and induced HSP90 hyperacetylation that led to the loss of chaperone protection of HSP90 to ERα. We also revealed that suppression of MOF restored ERα expression and increased the sensitivity of ERα-negative BC cells to tamoxifen treatment. These results provide a new insight into the tumor-suppressive role of MOF in BC via negatively regulating ERα action, suggesting that MOF might be a potential therapeutic target for BC.</p

DataSheet_3_Study on the seasonal variations of dimethyl sulfide, its precursors and their impact factors in the Bohai Sea and North Yellow Sea.zip

Dimethyl sulfide (DMS) is one of the most important volatile biogenic sulfur compounds and plays a significant role in global climate change. Studying the seasonal variations and the environmental factors that affect the concentration of DMS would aid in understanding the biogeochemical cycle of sulfur compounds. Using benzene-assisted photoionization positive ion mobility spectrometry (BAPI-PIMS), the seasonal distribution and the key impact factors of DMS and dimethylsulfoniopropionate (DMSP) in the Bohai Sea and North Yellow Sea were investigated in the summer and autumn of 2019. The concentrations of DMS and its precursors, DMSPp and DMSPd, in the surface seawater were 0.11–23.90, 0.67–41.38, and 0.03–12.28 nmol/L, respectively, in summer, and 0.10–20.79, 0.39–13.51, and 0.18–20.58 nmol/L, respectively, in autumn. The air-to-sea exchange flux of DMS was 43.05 ± 44.52 and 34.06 ± 63.38 μmol/(m·d), respectively, in summer and autumn. The results demonstrated that the temperature was the most dominant environmental factor, and the abundance of dinoflagellates was the most dominant biological factor that affected the distribution of DMS and DMSP in summer. The abundance of diatoms was the most dominant biological factor, and the levels of PO43-, NO2-, NO3-, and SiO32- were the dominant environmental factors that affected the distribution of DMS and DMSP in autumn. These results of this study would be of great significance in understanding the biochemical cycle of DMS in BS and NYS.</p

Image_1_MOF negatively regulates estrogen receptor α signaling via CUL4B-mediated protein degradation in breast cancer.jpeg

Estrogen receptor α (ERα) is the dominant tumorigenesis driver in breast cancer (BC), and ERα-positive BC (ERα+ BC) accounts for more than two-thirds of BC cases. MOF (males absent on the first) is a highly conserved histone acetyltransferase that acetylates lysine 16 of histone H4 (H4K16) and several non-histone proteins. Unbalanced expression of MOF has been identified, and high MOF expression predicted a favorable prognosis in BC. However, the association of MOF with ERα and the regulatory mechanisms of MOF in ERα signaling remain elusive. Our study revealed that the expression of MOF is negatively correlated with that of ERα in BC. In ERα+ BC cells, MOF overexpression downregulated the protein abundance of ERα in both cytoplasm and nucleus, thus attenuating ERα-mediated transactivation as well as cellular proliferation and in vivo tumorigenicity of BC cells. MOF promoted ERα protein degradation through CUL4B-mediated ubiquitin–proteasome pathway and induced HSP90 hyperacetylation that led to the loss of chaperone protection of HSP90 to ERα. We also revealed that suppression of MOF restored ERα expression and increased the sensitivity of ERα-negative BC cells to tamoxifen treatment. These results provide a new insight into the tumor-suppressive role of MOF in BC via negatively regulating ERα action, suggesting that MOF might be a potential therapeutic target for BC.</p