查找使用阿拉丁产品的科研文献

Inhibitor of Growth 4 (ING4) Plays a Tumor-repressing Role in Oral Squamous Cell Carcinoma via Nuclear Factor Kappa-B (NF-kB)/DNA Methyltransferase 1 (DNMT1) Axis-mediated Regulation of Aldehyde Dehydrogenase 1A2 (ALDH1A2)

Cui Zhi,Sun Shiqun,Li Jia,Li Jianing,Sha Tong,He Jie,Zuo Linjing

Background: Inhibitor of growth 4 (ING4) level was reported to be decreased in head and neck squamous cell carcinoma (HNSC) tissue, however, it is unknown whether and how ING4 participates in regulating the development of oral squamous cell carcinoma (OSCC). Objective: This study aimed to investigate the role and mechanism of ING4 in OSCC. Methods: ING4 was forced to up- or down-regulated in two OSCC cell lines, and its effects on the malignant behavior of OSCC cells were investigated in vitro. The ubiquitination level of NF-kB p65 in ING4 upregulated cells was measured by co-immunoprecipitation. Moreover, the effects of ING4 on the methylation level of ALDH1A2 were evaluated by methylation-specific polymerase chain reaction (MSP) assay. The role of ING4 in OSCC growth in vivo was observed in nude mice. Results: Our results showed that the expression of ING4 in OSCC cell lines was lower than that in normal oral keratinocyte cells. In vitro, ING4 overexpression inhibited the proliferation, migration, and invasion of OSCC cell lines and ING4 silencing exhibited opposite results. We also demonstrated that ING4 overexpression promoted the ubiquitination and degradation of P65 and reduced DNA methyltransferase 1 (DNMT1) expression and Aldehyde dehydrogenase 1A2 (ALDH1A2) methylation. Moreover, overexpression of p65 rescued the suppression of malignant behavior, induced by ING4 overexpression. In addition, ING4 negatively regulated the growth of OSCC xenograft tumors in vivo. Conclusion: Our data evidenced that ING4 played a tumor-repressing role in OSCC in vivo and in vitro via NF-ΚB/DNMT1/ALDH1A2 axis.

Highly selective cleavage C–O ether bond of lignin model compounds over Ni/CaO–H-ZSM-5 in ethanol

Guo J.,Ma Yu L.,Yu Jia Y.,Gao Yu J.,Ma Ning X.,Wu Xiao Y.

Herein, 2-(2-methoxyphenoxy)-1-phenylethanol (β- O -4), 2-methoxyphenyl anisole (α- O -4) and 4-phenoxyphenol (4- O -5) were selected as typical lignin model compounds. Given the effectiveness of traditional acid–base catalysts for lignin depolymerisation, a novel Ni/CaO–H-ZSM-5(60) catalyst was prepared to investigate the difficulty level of C–O bond of three model compounds cleavage in ethanol. It was observed that Ni/CaO–H-ZSM-5(60) had prominent performance on the C–O bond cleavage at very mild conditions (140 °C, 1 MPa H 2 ). Among them, the C–O bond of α- O -4 and β- O -4 could be completely cleaved within 60 min. Although the C–O bond of 4- O -5 had high bond energy, 41.2% of conversion was occurred in 60 min. The introduction of CaO could regulate the acidity of H-ZSM-5 to enhance the ability to break C–O bonds. Moreover, the possible pathways of C–O ether bonds in three lignin model compounds cleavage were proposed in order to selectively obtain target products from the raw lignin degradation.

Synthesis, structure and magnetic properties of two selenites, Li2Mn2.5(SeO3)4 and Li2Co3(SeO3)4 with a one-dimensional spin-chain

Mingming Huang,Shoushuang Li,Rui Cui,Laura C.J. Pereira,Ambre Theron,Olivier Mentré,Xiedong Cheng,Feifan Li,Hui Shao,Minfeng Lü

Two transition metal selenites Li 2 Mn 2.5 (SeO 3 ) 4 and Li 2 Co 3 (SeO 3 ) 4 were synthesized using hydrothermal and solid-state reactions, respectively. Both compounds form similar three-dimensional (3D) frameworks featuring twisted one-dimensional (1D) chains, where transition metal polyhedra connect through shared corners or edges. However, Li 2 Co 3 (SeO 3 ) 4 and Li 2 Mn 2.5 (SeO 3 ) 4 exhibit distinct structural features. The former contains one type of [4 + 2] Li, two different CoO 6 octahedra, and two SeO 3 pyramids. The latter possesses one type of [5 + 1] Li, one Mn 3+ O 6 octahedron, one Mn 2+ O 5 square-pyramid, and two SeO 3 pyramids. Consequently, the lithium polyhedron undergoes unusually strong irregular distortions in the cobalt compound, but experiences strong distortions in the manganese compound. Magnetic measurements confirm that Li 2 Co 3 (SeO 3 ) 4 with a S  = 3/2 uniform spin chain structure possess a long-range antiferromagnetic ordering and field-induced spin-flip transition at 2K, where the fitting via the Bonner–Fisher model with interchain mean-field corrections yields J intra /k B  = -4.32(2) K, J inter /k B  = −0.64(10) K, g  = 2.34(3). Systematic distortion regularities in central metal cation polyhedra emerge from quantifying the ratio of SeO 3 groups to total cation polyhedra within lithium transition metal selenites.

Fabrication of poly(4-vinylpyridine)-b-polystyrene-b-poly(4-vinylpyridine) triblock copolymer particles via three-dimensional soft confined self-assembly

Lei Guo,Dingli Xia,Yaping Wang,Shipeng Ding,Junting Xu,Yutian Zhu,Binyang Du

Using cetyltrimethylammonium bromide (CTAB) as a single surfactant, a series of symmetrical poly(4-vinylpyridine)-b-polystyrene-b-poly(4-vinylpyridine) (VmS24.2kVm) triblock copolymers with various molecular weights m of P4VP blocks (m = 3.0k, 6.3k, 7.9k, 13.4k) were employed to fabricate onion-like particles, spherical particles with an inner curved cylinder, convex lens (CL)-like particles with hexagonal P4VP cylinder and tulip-like particles with alternately stacked PS and P4VP lamella via three-dimensional soft confined self-assembly (3D-SCSA). Both the external shape and internal morphology of VmS24.2kVm particles were closely related to the volume fraction of the P4VP block and the concentration of CTAB. Upon increasing the volume fraction of the P4VP block, the internal phase separation structure of VmS24.2kVm particles changed from a cylinder to a lamella. Interestingly, as the concentration of CTAB increased, VmS24.2kVm particles changed from spherical (or onion-like) particles with a P4VP outmost layer to CL-like or tulip-like particles with a neutral interface, of which PS and P4VP blocks had an analogical preference to the oil/water interface, and finally into spherical particles with a PS outmost layer. The location of P4VP domains in VmS24.2kVm particles was clearly identified by selectively loading Au nanoparticles. It was the first time to observe VSV triblock copolymer particles with a neutral interface via 3D-SCSA using a single surfactant CTAB although it exhibits a preferred affinity and selective interaction with the PS block.

Preparation of biocidal 4-ethyl-4-(hydroxymethyl)oxazolidin-2-one-based N-halamine polysiloxane for impregnation of polypropylene in supercritical CO2

Yong Chen,Qingkun He,Guoyuan Ren,Chunyan Feng,Na Li,Hao Yu,Qiuxia Han

A cyclic N -halamine precursor, 4-ethyl-4-(hydroxymethyl)oxazolidin-2-one (EHMO), was synthesized and attached to poly(methylhydrosiloxane) (PMHS) through silane alcoholysis between the O  H of EHMO and Si  H of PMHS. The alcoholysis product was chlorinated with tert -butyl hypochlorite to transfer the N  H to N  Cl and obtain an EHMO-based N -halamine polysiloxane. The N -halamine polysiloxane was impregnated into inert polypropylene (PP) fibers and formed a 72 nm coating layer using supercritical carbon dioxide (scCO 2 ) as solvent and swelling reagent at 28 MPa and 50 °C for biocidal application. The overall synthetic procedure and the impregnation process were characterized by FTIR, XPS, and SEM, respectively. The N-halamine polysiloxane layer on PP imparted potent antibacterial abilities against both Staphylococcus aureus and Escherichia coli while pristine ones did not exhibit noticeable killing activities. Stability tests showed that the N -halamine polysiloxane layer was resistant to washing cycles, storage, and UV irradiation and the rechlorination of lost chlorines was good. The strategy of using CO 2 -philic PMHS as carrier polymer and scCO 2 as working solvent for impregnation presents a general and friendly procedure to functionalize inert substrates without the need of chemical linkage and organic solvent. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46624.

Ion diffusion and electrochromic performance of poly(4,4′,4″-tris[4-(2-bithienyl)phenyl]amine) based on ionic liquid as electrolyte

Xiaojing Lv,Shuanma Yan,Yuyu Dai,Mi Ouyang,Yuan Yang,Pengfei Yu,Cheng Zhang

Ionic liquids 1-butyl-3-methyl-imidazolium tetrafluoroborate ([BMIM]BF 4 ), 1-butyl-3-methylimidazoliumhexafluorophosphate ([BMIM]PF 6 ) and conventional medium tetrabutylammonium perchlorate (TBAP) were utilized as electrolyte for the preparation of poly(4,4′,4′'-tris[4-(2-bithienyl)phenyl]amine) (PTBTPA) films and assembling of EC devices. FTIR spectra and EDX pattern demonstrate an effective doping of the anion into the PTBTPA film at the oxidation state. SEM images investigate the thickness of the polymer films and the morphologies of crimped structure at the oxidation state. The ion diffusion distance (the thickness of polymer film) plays a more critical role for the EC switching speed. According to the electrochemical impedance spectra, the improved ionic conductivity with ionic liquid [BMIM]BF 4 as the electrolyte promote ions more easily dope into the polymer film which leads to the higher optical contrast. In addition, the size of doping anion during the redox process has essential influence on the electrochemical stability.

Design, synthesis, antimicrobial activity, and mechanism of novel 3-(2,4-dichlorophenyl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivatives

Yuguo Zheng,Mei Chen,Renfeng Zhang,Wei Xue

BACKGROUND Plant pathogens cause substantial crop losses annually, posing a grave threat to global food security. Fungicides have usually been used for their control, but the rapid development of pesticide resistance renders many ineffective, therefore the search for novel and efficient green pesticides to prevent and control plant diseases has become the top priority in crop planting. RESULTS The results of bioassay studies indicated that most of the target compounds showed certain antimicrobial activity in vitro . In particular, compound X7 showed high inhibitory activity against Xanthomonas oryzae pv. oryzae ( Xoo ), with an EC 50 value of 27.47 μg mL −1 , surpassing conventional control agents such as thiazole zinc (41.55 μg mL −1 ) and thiodiazole copper (53.39 μg mL −1 ). Further studies on molecular docking showed that X7 had a strong binding affinity with 2FBW. The morphological change observed by scanning electron microscopy indicated that the surface of Xoo appears wrinkled and cracked under X7 treatment and a total of 2662 proteins were identified by label-free proteomic analysis. Three experiments have elucidated the mechanism whereby X7 induced considerable changes in the physiological and biochemical properties of Xoo , which in turn affected the reproduction and growth of bacteria. CONCLUSION This work represents a pivotal advancement, offering important reference for the research and development therapeutics in combating plant pathogens. © 2024 Society of Chemical Industry.

An environment-friendly synthesis of 4(3H)-quinazolinones

Haidong Wei,Lihong Zhou,Yue Zhou,Qingle Zeng

4-octyl itaconate ameliorates ventilator-induced lung injury

Xiudan Wang,Weijing Kong,Rui Yang,Chunyan Yang

Ventilator-induced lung injury (VILI) disturbs the disordered immune system and causes persistent inflammatory damage. 4-octyl itaconate (OI) is a synthetic cell-permeable itaconate derivative with antioxidant and anti-inflammatory effects. In this study, we assessed whether OI protects against VILI. OI was intraperitoneally injected for three days before mechanical ventilation (MV; 20 ml/kg at 70 breaths/min) for 2 h. Mouse lung vascular endothelial cells (MLVECs) were pretreated with OI (62.5, 125, and 250 μM) prior to cyclic stretch for 4 h. We found that OI attenuated VILI and inflammatory response. OI also increased superoxide dismutase, nuclear factor E2-related factor 2, and heme oxygenase-1 levels, and decreased reactive oxygen species and malondialdehyde levels. Furthermore, OI inhibited the expression of NLR family pyrin domain-containing 3 (NLRP3), caspase-1 p20, apoptosis-associated speck-like protein containing a CARD, and N-terminal fragment of gasdermin D. Therefore, OI attenuates VILI, potentially by suppressing oxidative stress and NLRP3 activation.

Thermophysical properties of 4-dimethylaminopyridine based ionic liquids

Dongren Cai,Nisakorn Saengprachum,Zhipeng Lin,Ting Qiu

In this study, a molecular simulation (Gaussian03) was used to analyze the chemical structure of 4-dimethylaminopyridine (DMAP) to investigate its use for the synthesis of ionic liquids (ILs). Based on DMAP, a series of new ILs was prepared and characterized by fourier transform infrared spectroscopy (FT-IR), 1 H nuclear magnetic resonance ( 1 H-NMR), thermogravimetric analysis (TGA), and differential scanning calorimeter (DSC). The density data of the studied ILs were measured from 328.15 K to 358.15 K, p  = 0.101 MPa. It is shown that density decreases with an increase in the temperature and the alkyl chain length of cations. And density is also affected by the anion type. Furthermore, the volume of ions, NBO charges, and the interactions of anions and cations were calculated by Gaussian03 to explain the obtained density results. The second-order polynomial equation was adopted to correlate the relationship of density and temperature. Then, an isobaric thermal expansion coefficient , molecular volume, and lattice potential energy were obtained from the density data. Viscosity was determined from 323.15 K to 368.15 K, p  = 0.101 MPa. It is determined that the viscosity of ILs decreases with an increase in the temperature but increases with an increase in the alkyl chain length of cations. The temperature dependence of viscosity was described by the Vogel-Fulcher-Tamman (VFT) model, and the activation energy of viscous flow ( E η ) was obtained. Furthermore, the decomposition temperature ( T d ), glass transition temperature ( T g ), and melting temperature ( T m ) of ILs were obtained from the results of TGA and DSC.

Synthesis, Structures and Urease Inhibition Studies of Copper(II) and Zinc(II) Complexes Derived from N’-(4-bromo-2-hydroxybenzylidene)-4-Hydroxybenzohydrazide

Wang N.,Liu Y. -M.,Qiu X. -Y.

Two new copper(II) and zinc(II) complexes [Cu 2 (bhb) 2 (CH 3 OH) 2 ] ( 1 ) and [Zn(Hbhb) 2 ]·4CH 3 OH ( 2 ), where bhb and Hbhb are the dianionic and monoanionic forms of N ’-(4-bromo-2-hydroxybenzylidene)-4-hydroxybenzohydrazide (H 2 bhb), respectively. The two complexes are characterized by elemental analysis and physico-chemical method, as well as single crystal X-ray diffraction. The Cu atom in complex  1 is in square pyramidal coordination, and the Zn atom in complex  2 is in octahedral coordination. The compounds are tested for their urease inhibitory properties. The copper complex has strong activity ( IC 50  = 1.7 ± 0.3 μM). The alternative text for this image may have been generated using AI.

The distribution of 4-hydroxy-hexenal and 4-hydroxy-nonenal in different vegetable oils and their formation from fatty acid methyl esters

Lukai Ma,Guoqin Liu,Weiwei Cheng,Xinqi Liu

Summary The formation of 4-hydroxy-hexenal (HHE) and 4-hydroxy-nonenal (HNE) in eight vegetable oils was investigated at 180 °C. HHE was only detectable in soybean (SBO), rapeseed (RO) and linseed oils (LO). HNE was measured in all tested oils, but was found mainly in corn (CO), sunflower (SO) and soybean oil (SBO). Oil-dependent formation of HHE/HNE was remarkably observed. Furthermore, different fatty acid methyl esters in tricaprylin, as model oil systems, were constructed to demonstrate their characteristic contribution to HHE/HNE formation. As expected, HHE and HNE originated from the oxidative degradation of methyl linolenate (MLN) and methyl linoleate (ML) respectively. Whereas low concentrations of MLN (<5.0%) and ML (<1.0%) produced no detectable HHE/HNE. The results suggested MLN/ML could induce both HHE/HNE formation and pro-oxidation at higher concentrations. Unexpectedly, methyl stearate and methyl oleate slightly promoted HHE/HNE formation, which might be attributed to free radical transfer mechanisms during thermal oxidation.