Catalytic asymmetric cycloadditions via transition-metal-containing dipolar intermediates are a powerful tool for synthesizing chiral heterocycles. However, within the field of palladium catalysis, ...compared with the well-developed normal electron-demand cycloadditions with electrophilic dipolarophiles, a general strategy for inverse electron-demand ones with nucleophilic dipolarophiles remains elusive, due to the inherent linear selectivity in the key palladium-catalyzed intermolecular allylations. Herein, based on the switched regioselectivity of iridium-catalyzed allylations, we achieved two asymmetric 4+2 cycloadditions of vinyl aminoalcohols with aldehydes and β,γ-unsaturated ketones through synergetic iridium and amine catalysis. The activation of vinyl aminoalcohols by iridium catalysts and carbonyls by amine catalysts provide a foundation for the subsequent asymmetric 4+2 cycloadditions of the resulting iridium-containing 1,4-dipoles and (di)enamine dipolarophiles. The former provides a straightforward route to a diverse set of enantio-enriched hydroquinolines bearing chiral quaternary stereocenters, and the later represent an enantio- and diastereodivergent synthesis of chiral hydroquinolines.
This study explores the effect of COL1A2, COL6A3, and THBS2 gene silencing on proliferation, migration, invasion, and apoptosis of gastric cancer cells through the PI3K‐Akt signaling pathway. The ...gastric cancer microarray expression data (GSE19826, GSE79973, and GSE65801) was analyzed. Gastric cancer tissues and corresponding adjacent normal tissues were extracted from patients. Positive expression rate of PI3K, Akt, and p‐Akt was measured with immunohistochemistry. Two cell lines, BGC‐823 and SGC‐7901, were transfected and cells were grouped into blank, negative control, COL1A2‐shRNA, COL6A3‐shRNA, and THBS2‐shRNA groups. Expressions of COL1A2, COL6A3, and THBS2 in gastric cancer cells transfected with corresponding silencing sequences were evaluated by RT‐qPCR and Western blot. MTT assay, Transwell, and cell scratch tests were conducted to evaluate cell proliferation, invasion, and migration capacity, respectively. Flow cytometry was used to evaluate cell cycle distribution and apoptosis. The positive expression of PI3K, Akt, and p‐Akt was higher in gastric cancer tissues compared with adjacent normal tissues, and the mRNA expression of COL1A2, COL6A3, and THBS2 was increased in gastric cancer tissues. Akt, p‐Akt, and PI3K expression drastically decreased in cells transfected with COL1A2, COL6A3, and THBS2 silencing sequences. Cells transfected with COL1A2, COL6A3, and THBS2 silencing sequences exhibited promoted apoptosis but inhibited proliferation, migration, and invasion. This study demonstrates that COL1A2, COL6A3, and THBS2 gene silencing inhibits gastric cancer cell proliferation, migration, and invasion while promoting apoptosis through the PI3K‐Akt signaling pathway.
COL1A2, COL6A3, and THBS2 gene silencing inhibits gastric cancer cell proliferation, migration, and invasion while promoting apoptosis through the PI3K‐Akt signaling pathway.
Colorectal cancer (CRC), one of the most prevalent cancers, has complex etiology. The dysbiosis of intestinal bacteria has been highlighted as an important contributor to CRC. Fusobacterium ...nucleatum, an oral anaerobic opportunistic pathogen, is enriched in both stools and tumor tissues of patients with CRC. Therefore, F. nucleatum is considered to be a risk factor for CRC. This review summarizes the biological characteristics and the mechanisms underlying the regulatory behavior of F. nucleatum in the tumorigenesis and progression of CRC. F. nucleatum as a marker for the early warning and prognostic prediction of CRC, and as a target for prevention and treatment, is also described.
Fusobacterium nucleatum has been related to genetic and epigenetic lesions, such as microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and genome mutation in colorectal cancer (CRC) tissues.F. nucleatum could promote the proliferation and metabolism, remodel the immune microenvironment, and facilitate metastasis and chemoresistance in the tumorigenesis and development of CRC.F. nucleatum could function as a biomarker for screening the high-risk population for CRC.Although further in-depth studies are warranted, several virulence- or phage-based therapeutics specific to F. nucleatum may be novel promising methods in CRC treatment.
Difficult and expensive financing has always been a problem for domestic and foreign enterprises, and how to effectively improve financing efficiency and improve the financing environment is a key ...issue to be studied. LightGBM is an advanced machine learning algorithm, which uses histogram algorithm and Leaf-wise strategy with depth limitation to improve the accuracy of the model. However, there are almost no cases of applying this method to corporate financing risk prediction. Therefore, the paper establishes the LightGBM model to predict the financing risk profile of 186 enterprises. In order to compare the prediction performance of LightGBM for enterprise financing risk, the paper conducted comparison experiments using k-nearest-neighbors algorithm, decision tree algorithm, and random forest algorithm on the same data set. The experiments show that LightGBM has better prediction results than the other three algorithms for several metrics in corporate financing risk prediction. Therefore, we believe that the LightGBM algorithm can be used as an effective tool to predict the financing risk of enterprises.
China’s traditional cultural heritage is facing serious challenges under the impact of modern culture. The somatosensory interaction gestures for cultural relics are designed using the Kinect ...somatosensory interaction model in this paper. The appearance of virtual cultural relics can be designed and realized using a three-dimensional coordinate system. Combined with the method of digital projection, the interaction projection generated by the Kinect somatic interaction model is corrected by the geometric correction method, and the edge fusion algorithm is applied to correct and fuse the edges of the corrected virtual artifact appearance. Testing the effects of cultural inheritance and promotion in the 38 regions of the application is carried out through the application of the cultural relics interaction. According to the findings, the highest score for traditional culture inheritance among the 38 regions is 28.36, and four regions have inheritance scores above 20 points. In traditional culture promotion, the highest score region is close to 12 points, and the heritage interaction experience can make users feel the inherent culture of the heritage, which has a positive effect on traditional culture inheritance and promotion.
The photogeneration of stable radicals is important but still challenging in the field of optical switching, displays, and other devices. Herein, crystalline 9-anthracene carboxylic acid (
9-AC
) and ...a mononuclear complex constructed from this ligand were for the first time discovered to show radical-induced photochromism and photomagnetism after Xe lamp light irradiation. This study finds a simple radical-actuated photochromic molecule for constructing a novel system of photochromic materials.
The crystalline 9-anthracene carboxylic acid and the constructed mononuclear complex were for the first time discovered to show radical-induced photochromism and photomagnetism after Xe lamp light irradiation.
The intermarriage of neutral and tripodal imidazole ligand, tris(4‐(1H‐imidazol‐1‐yl)phenyl)amine (TIPA), with zinc phosphite yields two hybrid phosphites, Zn2(HPO3)2(TIPA)⋅2 H2O (1) and ...Zn3(HPO3)3(TIPA)⋅6 H2O (2). Compound 1 has a hybrid sheet with neutral zinc‐phosphite chains as supramolecular building blocks (SBBs), whereas 2 exhibits a 3D hybrid architecture with other neutral zincophosphite chains as supramolecular building blocks. The structural discrepancy between 1 and 2 is mainly due to the distinct linkage modes between organic TIPA ligands and inorganic zincophosphite chains. Interestingly, compounds 1 and 2 feature fast photochromism in response to UV light irradiation under ambient conditions. The discrepancy of photochromic performance between 1 and 2 is mainly due to the different geometrical configuration of the TIPA ligand. Different to majority of reported hybrid photochromic compounds driven by photochromic active units, the photochromism in 1 and 2 is derived from the electron transfer (ET) between phosphite and non‐photochromic triimidazole‐derivative ligand TIPA. Compared with the widely explored nonphotochromic polypyridine‐derivative as electron acceptors (EAs), our work provides a new EA model for the design of hybrid photochromic materials based on the ligand‐to‐ligand ET mechanism. A multiple anti‐counterfeiting application based on 1 and 2 was investigated.
A new electron‐acceptor: We provide a new category of electron acceptors (EAs), the tri(imidazole)‐derivative moiety, for the design of crystalline hybrid photochromic materials. The new unit differs clearly from other broadly investigated photoactive units and that are being explored as EAs for nonphotoactive polypyridine‐derivative units.
Catalytic asymmetric cycloadditions of ambident Pd‐containing dipolar species with nucleophilic dipolarophiles, namely, inverse‐electron‐demand cycloadditions, are challenging and underdeveloped. ...Possibly, the inherent linear selectivity of Pd‐catalyzed intermolecular allylations and the lack of efficient chiral ligands are responsible for this limitation. Herein, two cycloadditions of such intermediates with deconjugated butenolides and azlactones were accomplished by using a novel chiral hybrid P,S‐ligand and hydrogen bonding. By doing so, highly functionalized, optically active dihydroquinol‐2‐ones were produced with generally high reaction efficiencies and selectivities. Preliminary DFT calculations were performed to explain the high enantio‐ and diastereoselectivities.
By popular demand: With the help of chiral P,S‐ligands and hydrogen‐bonding interactions, inverse‐electron‐demand asymmetric 4+2 cycloadditions were accomplished for the first time. A variety of optically active, highly functionalized hydroquinolin‐2‐ones were produced in good yields with excellent stereocontrol from readily available starting materials.
A-D-A small molecules have drawn more and more attention in solution-processed organic solar cells due to the advantages of a diversity of structures, easy control of energy levels,
etc.
Recently, a ...power conversion efficiency of nearly 10% has been achieved through careful material design and device optimization. This feature article reviews recent representative progress in the design and application of A-D-A small molecules in organic photovoltaic cells.
The recent representative progress in the design and synthesis of A-D-A small molecules for organic solar cells is summarized.
A novel copper-catalyzed decarboxylative cyclization of ethynyl benzoxazinanones with P(O)H compounds has been developed. This protocol leads to a series of 2-phosphorylmethyl indoles with high ...efficiency and selectivity (up to 99% yield) through tandem C-P/C-N bond formation under mild conditions.
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