查找使用阿拉丁产品的科研文献

DT7 peptide-modified lecithin nanoparticles co-loaded with γ-secretase inhibitor and dexamethasone efficiently inhibit T-cell acute lymphoblastic leukemia and reduce gastrointestinal toxicity

Ying Zhou,Li Guan,Wei Li,Ruinan Jia,Lejiao Jia,Yuanyuan Zhang,Xin Wen,Sibo Meng,Daoxin Ma,Na Zhang,Min Ji,Yongjun Liu,Chunyan Ji

T-cell acute lymphoblastic leukemia (T-ALL) is a serious hematologic malignancy and glucocorticoid resistance is the main recurrent cause for a high relapsed and death rate. Here, we proposed an effective therapeutic regimen of combining gamma-secretase inhibitors (GSIs) with dexamethasone (DEX) to overcome glucocorticoid resistance. Moreover, the bone marrow targeting DT7 peptide-modified lecithin nanoparticles co-loaded with DEX and GSI (TLnp/D&G) were developed to enhance T-ALL cells recognition and endocytosis. In vitro cytotoxicity studies showed that TLnp/D&G significantly inhibited cell survival and promoted apoptosis of T-ALL cells. Mechanically, we found that GSIs promoted DEX-induced cell apoptosis by two main synergetic mechanisms: 1) GSIs significantly upregulated glucocorticoid receptor (GR) expression in T-ALL and restored the glucocorticoid-induced pro-apoptotic response. 2) Both DEX and GSI synergistically inhibited BCL2 and suppressed the survival of T-ALL cells. Furthermore, in vivo studies demonstrated that TLnp/D&G showed high bone marrow accumulation and better antileukemic efficacy both in leukemia bearing models and in systemic Notch1-induced T-ALL models, with excellent biosafety and reduced gastrointestinal toxicity. Overall, our study provides new strategies for the treatment of T-ALL and promising bone marrow targeting systems with high transformation potential.

A sensitive surface-enhanced Raman spectroscopy detection for gentamicin and tobramycin using γ-Al2O3-modified silver nanoparticles coated with bovine serum albumin as substrate

Shuyun Bi,Yue Yuan,Fengming Zhang,Yuting Wang,Jia Liu,Bin Yang,Daqian Song

Two aminoglycoside antibiotics (AGs), gentamicin (GEN) and tobramycin (TOB), have good antibacterial activity against most pseudomonas aeruginosa and staphylococcus. The molecular structure of these drugs lack chromogenic groups, which brings challenges to their detection. In this project, the detecting methods for GEN and TOB utilizing surface-enhanced Raman spectroscopy (SERS) based on γ -Al 2 O 3 -modified silver nanoparticles (AgNPs) coated with bovine serum albumin (BSA) were established. The enhancement factors (EFs) of GEN and TOB were 2.44 × 10 5 and 2.67 × 10 6 , respectively. The transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and spectrophotometric techniques were used to characterize the substrate and the combination of the substance with drugs. The pH, the addition amounts for the substrate and coagulant, as well as the mixing time were optimized. On the basis of single factor experiments, a more scientific response surface model was established. The concentrations of GEN and TOB showed good linear relationships with their Raman signals in the ranges of 6.67 × 10 −8 – 2.00 × 10 −6 and 6.67 × 10 −9 – 3.00 × 10 −7  mol L −1 respectively. The limits of detection (LODs) were 11.88 and 1.26 nmol L −1 for GEN and TOB, respectively. The methods were used successfully for the samples determination of the two AGs in commercial drugs and meat products.

Quinoa Peptides Alleviate Obesity in Mice Induced by a High-Fat Diet via Regulating of the PPAR-α/γ Signaling Pathway and Gut Microbiota

Yiju Li,Zhi Feng,Tianliang Wu,Haixi You,Wei Wang,Xuebo Liu,Long Ding

Scope The obesity epidemic continues to be a major global public health threat with limited effective treatments. Peptides are a group of promising bioactive molecules. Both in vivo and in vitro studies have demonstrated that quinoa has potential prebiotic benefits. Thus, the present study aims to investigate the influence of quinoa peptides (QP) consumption on obesity and its underlying mechanisms in high-fat diet (HFD)-induced mice. Methods and results QP (1000 mg kg −1 day −1 ) is administered to HFD mice for 8 weeks, and is found to significantly reduce the body weight, and plasma levels of triacylglycerol (TG) and total cholesterol (TC) compare to the HFD group. In addition, QP significantly decreases lipid accumulation in the liver caused by HFD. The liver transcriptome analysis shows that the alleviation of QP on obesity is related to the PPAR signaling pathway. QP upregulates the expressions of PPAR-α and its related genes and downregulates the expressions of PPAR-γ and its downstream genes. Furthermore, QP remodels the community composition of gut microbiota by lowering the ratio of Firmicutes c Bacteroidetes (F/B). Conclusion These findings suggest that QP consumption alleviates HFD-induced obesity by regulating the PPAR-α/γ signaling pathway in the liver and community structure of gut microbiota.

In-situ synthesis of single-atom Ir by utilizing metal-organic frameworks: An acid-resistant catalyst for hydrogenation of levulinic acid to γ-valerolactone

Wenxiu Cao,Lu Lin,Haifeng Qi,Qian He,Zhijie Wu,Aiqin Wang,Wenhao Luo,Tao Zhang

The hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) is a key reaction for the production of renewable chemicals and fuels, wherein acid-resistant and robust catalysts are highly desired for practical usage. Herein, an ultra-stable 0.6 wt% Ir@ZrO 2 @C single-atom catalyst was prepared via an in-situ synthesis approach during the assembly of UiO-66, followed by confined pyrolysis . The Ir@ZrO 2 @C offered not only a quantitative LA conversion and an excellent GVL selectivity (>99%), but also an unprecedented stability during recycling runs under harsh conditions (at T = 453 K, P H2  = 40 bar in pH = 3 or pH = 1 aqueous solution). By thorough spectroscopy characterizations, a well-defined structure of atomically dispersed Ir δ+ atoms onto nano-tetragonal ZrO 2 confined in the amorphous carbon was identified for the Ir@ZrO 2 @C. The strong metal-support interaction and the confinement of the amorphous carbon account for the ultra-stability of the Ir@ZrO 2 @C.

Regulating the nanoscale intimacy of metal and acidic sites in Ru/γ-Al2O3 for the selective conversions of lignin-derived phenols to jet fuels

Shanshuai Chen,Weichen Wang,Xue Li,Puxiang Yan,Wanying Han,Tian Sheng,Tiansheng Deng,Wanbin Zhu,Hongliang Wang

Catalytic hydrodeoxygenation (HDO) of biomass-derived oxy-compounds to advanced hydrocarbon fuels usually requires bifunctional catalysts containing metals and acidic sites. The appropriate tuning of metal and/or acidic active sites at interfaces of bifunctional catalysts can significantly improve catalyst activity and product selectivity. Here, 4-trifuoromethyl salicylic acid (TFMSA), as a hydrothermal stable organic acid, was employed to tailor the bifunctional interface of Ru/γ-Al 2 O 3 to enhance the catalytic performance on converting lignin-derived phenols to jet fuel range cycloalkanes. More than 80% phenol was converted into cyclohexane at 230 °C for 1 h over Ru/γ-Al 2 O 3 modified by TFMSA, which was about three times higher than that over unmodified Ru/γ-Al 2 O 3 . X-ray diffraction (XRD), Transmission electron microscope (TEM), H 2 chemisorption, and energy dispersive X-ray spectroscopy (EDS) elemental mapping results indicated that Ru nanoparticles and TFMSA were well distributed on γ-Al 2 O 3 , and a nanoscale intimacy between Ru and TFMSA was reached. Meanwhile, Fourier transform infrared spectroscopy after pyridine adsorption (Py-FT-IR) analysis proved that Brønsted acidic sites on the catalytic interfaces of TFMSA modified Ru/γ-Al 2 O 3 had been improved. Moreover, the kinetic and density functional theory (DFT) results suggested that the synergistic effects of adjacent Ru nanoparticles and acidic sites were crutial for promoting the rate-limiting conversion step of phenol HDO to cyclohexane.

Fabrication of highly dispersed Pt-based catalysts on γ-Al2O3 supported perovskite Nano islands: High durability and tolerance to coke deposition in propane dehydrogenation

Xingye Chen,Meng Ge,Yanyong Li,Yatian Liu,Jiameng Wang,Lihong Zhang

A series of novel γ -Al 2 O 3 supported Pt In bimetallic catalysts were prepared by perovskite (PTO) lattice interstitial confined reduction and compared with industrial catalyst PtIn/ γ -Al 2 O 3 in the propane dehydrogenation to propene . The physics-chemistry properties of all catalysts and precursors were characterized by BET, NH 3 -TPD, TPR, XRD , TEM , STEM-EDS, XPS , TG and O 2 -TPO techniques. The results show that the metal ions of Pt 4+ and In 3+ confined in PTO lattice interstitial sites were more easily reduced than those confined in PTO lattice. The lattice interstitial confinement was beneficial for the formation of small and highly dispersed Pt In bimetallic species on the surface of γ -Al 2 O 3 supported PTO Nano islands. It is just the confinement of PTO lattice interstitial sites for appropriate In 3+ /In 0 ratio and weak Pt In interaction and the sharing Al O bond for anchoring PTO nanoparticles and weakening the surface acid sites result in the high activity and superior stability of PtIn/LaAlO 3 / γ -Al 2 O 3 in propane dehydrogenation. The initial propane conversion of PtIn/LaAlO 3 / γ -Al 2 O 3 was 47%, and can be maintained at 25% after 16 h, while its propene selectivity only decreased from 96% to 90%.

Photocatalytic selective aerobic oxidation of amines to nitriles over Ru/γ-Al2O3: the role of the support surface and the strong imine intermediate adsorption

Pengqi Zhu,Jin Zhang,Jie Wang,Peng Kong,Yunwei Wang,Zhanfeng Zheng

Hydroxyl coordinated ruthenium dispersed on the surface of γ-Al2O3 can be applied to the selective oxidation of amines with light irradiation and an atmospheric pressure of O2 at room temperature. Sunlight is also an effective light source for the selective aerobic oxidation of primary amines to corresponding nitriles. The high photocatalytic activity and selectivity over Ru/γ-Al2O3 originate from the adsorption of amines and imine intermediates on the abundant surface OH groups of the photocatalyst and further formation of Ru–amide species by ligand exchange of adsorbed amines and imine intermediates with adjacent exposed active Ru sites. Light is introduced to the system successfully via the formation of Ru–amide species, which are used as the light absorption sites of the photocatalytic selective oxidation of amines. Primary amines are directly converted to corresponding nitriles via a two-step oxidative dehydrogenation process.

Organocatalyzed ring-opening copolymerization of α-bromo-γ-butyrolactone with ε-caprolactone for the synthesis of functional aliphatic polyesters – pre-polymers for graft copolymerization

Chen Gao,Chi-Hui Tsou,Chun-Yan Zeng,Li Yuan,Rui Peng,Xue-Mei Zhang

Poly(γ-glutamic acid) induced homogeneous mineralization of the poly(ethylene glycol)-co-2-hydroxyethyl methacrylate cryogel for potential application in bone tissue engineering

Chuntao Liu,Xin Liu,Changyun Quan,Xiaoqiong Li,Chaozhu Chen,Hua Kang,Weikang Hu,Qing Jiang,Chao Zhang

Methacrylated poly(γ-glutamic acid) (mPGA) was introduced to the spongy poly(ethylene glycol)-co-2-hydroxyethyl methacrylate (PEG-HEMA) cryogels. A suitable amount (<0.1% w/v) of poly(γ-glutamic acid) (γ-PGA) in cryogels was found to promote homogeneous mineralization, while higher concentration of γ-PGA inhibited the mineralization. The deposited minerals mainly consisted of hydroxyapatite, carbonated apatite, and calcium phosphate, and were independent on the concentration of γ-PGA. The mineralized cryogels can support adhesion, viability, and migration of rat bone marrow stromal cells (rMSCs). The γ-PGA/HEMA-PEGDA cryogels showed their great potential as promising scaffolding materials in bone tissue engineering.

Enantioseparation of dansyl amino acids and dipeptides by chiral ligand exchange capillary electrophoresis based on Zn(II)-l-hydroxyproline complexes coordinating with γ-cyclodextrins

Xiaoyu Mu,Li Qi,Juan Qiao,Xinzheng Yang,Huimin Ma

A chiral ligand exchange capillary electrophoresis (CLE-CE) method using Zn(II) as the central ion and l -4-hydroxyproline as the chiral ligand coordinating with γ-cyclodextrin (γ-CD) was developed for the enantioseparation of amino acids (AAs) and dipeptides. The effects of various separation parameters, including the pH of the running buffer, the ratio of Zn(II) to l -4-hydroxyproline, the concentration of complexes and cyclodextrins (CDs) were systematically investigated. After optimization, it has been found that eight pairs of labeled AAs and six pairs of labeled dipeptides could be baseline-separated with a running electrolyte of 100.0   mM boric acid, 5.0   mM ammonium acetate, 3.0   mM Zn(II), 6.0   mM l -hydroxyproline and 4.0   mM γ-CD at pH 8.2. The quantitation of AAs and dipeptides was conducted and good linearity ( r 2   ≥   0.997) and favorable repeatability (RSD   ≤   3.6%) were obtained. Furthermore, the proposed method was applied in determining the enantiomeric purity of AAs and dipeptides. Meanwhile, the possible enantiorecognition mechanism based on the synergistic effect of chiral metal complexes and γ-CD was explored and discussed briefly.

Highly efficient NOx reduction with superior H2O and SO2 resistance on Ce-Ti/γ-Fe2O3 dual single-atom Catalysts: Synergistic interactions and mechanistic insights

Jianping Ding,Xiaoyan Zhou,Zhengzheng Yang,Changgeng Liu,Mingchao Sun,Congling Yang,Lu Fan

In this study, a novel strategy was proposed for synthesizing dual single-atom Ce-Ti catalysts supported on γ-Fe 2 O 3 via ball milling and calcination. Compared to γ-Fe 2 O 3 and single-atom Ce/γ-Fe 2 O 3 and Ti/γ-Fe 2 O 3 catalysts, the Ce-Ti/γ-Fe 2 O 3 catalyst exhibits superior NO conversion rates and significantly enhanced tolerance to H 2 O and SO 2 at 200–240 °C. These advancements are attributed to the synergistic interactions between Ce and Ti, which enhance redox properties, increase Lewis acid site density, and facilitate the Langmuir-Hinshelwood reaction pathway. In-situ DRIFTS and density functional theory (DFT) analyses revealed the mechanistic role of surface-active oxygen species and intermediate formation in promoting the SCR reaction. The findings provide valuable mechanistic insights and establish a scalable approach for the development of high-performance, environmentally friendly catalysts for industrial NO x removal.

Facilely constructing physical-linked γ-Fe2O3/CeO2/cellulose nanofibril films for highly effective, recyclable, and multi-removal of heavy metals and dyes from wastewater

Yan Mengxing,Tan Yang,Dong Hanqi,Xu Huawei,Ling Zhe,Xiao Xiao,Huang Chen,Yong Qiang

The problems of heavy metal and dye contamination in wastewater urgently requires green, efficient, and convenient removal strategy. In this paper, a new type of γ-Fe 2 O 3 /CeO 2 /cellulose nanofibril (CNF) composite film (CNFMONP film) adsorbent based on nanocellulose was facilely prepared which is green, easy to be recycled, and has high-efficiency adsorption performance. The proposed CNFMONP films exhibited rough surface, excellent mechanical properties, and stability performance, as well as satisfying adsorption removal performance for Pb 2+ and Cu 2+ , with removal rates of 77.9% and 69.6%, respectively. In addition, a removal rate of up to 95.4% for the dye methylene blue (MB) was also achieved under UV illumination. The adsorption kinetics showed that the CNFMONP films were mainly chemisorbed for heavy metals. Besides, isotherm analysis indicated that monolayer adsorption is the adsorption behavior of the proposed film types adsorbent for heavy metals and dyes. Furthermore, the CNFMONP films still have excellent adsorption affinity after five rounds of cycles, with high adsorption efficiency of 75.0% for Pb 2+ in complex environment. Therefore, environmentally friendly CNFMONP films with excellent stabilization and adsorption properties were simply prepared, which may provide a highly efficient way for recyclable and multi adsorption of heavy metals and dyes.