查找使用阿拉丁产品的科研文献

Red emission B, N, S-co-doped carbon dots with pH-responsive functionality for colorimetric and fluorescent dual-mode detection of Ag+ ions

Du Jinyan,Xu Na,Wang Chaofeng,Shu Qin,Xu Qidi,Zhang Ping,Zhuo Shujuan,Zhu Changqing

Novel red-emitting B, N, S-co-doped carbon dots (B,N,S-CDs) were prepared via a one-step hydrothermal carbonization. The obtained B,N,S-CDs are found to be responsive to the pH changes, i.e., the fluorescence intensities obviously change with the watershed of pH 7.4, accompanied by a blue-shift of the fluorescence emission wavelengths with the pH from 1 to 13. The surface state and size of the B, N, S-CDs are responsible for the fantastic responses. Furthermore, introduction of Ag + into the B, N, S-CDs resulted in fluorescence quenching and apparent changes of extinction value, thereby the quantitative assay can be successfully realized where a linear range of 0.1–400 and 0–700 μM with a detection limit of 38 and 107 nM is obtained, respectively. The mechanism might be due to static quenching and induced electron/energy transfer (ET) resulted from the formation of non-fluorescent complex. Strikingly, Ag + can be visualized via evident color changes from red to navy blue under UV light and from maroon to dark brown under sunlight, respectively. These findings indicate that the as-obtained B, N, S-CDs possess a great potential as a dual probe of pH and Ag + ions for biosensing. Graphical Abstract The red-emitting fluorescent B, N, S-CDs with a fantastic pH-sensitive feature, as a dual-mode nanosensor via colorimetric and fluorescence outputs, were applied to detect Ag + ions with the LOD of 107 and 38 nM, respectively.

Defect engineering on VO2(B) nanoleaves/graphene oxide for the high performance of cathodes of zinc-ion batteries with a wide temperature range

Ziyan Yuan,Fuyu Xiao,Yixing Fang,Peixun Xiong,Xiaoli Sun,Xuehui Duan,Xuhui Yang,Haosen Fan,Mingdeng Wei,Qingrong Qian,Qinghua Chen,Lingxing Zeng

Designing cathodes with long service life, remarkable rate capability and all-climate workable is crucial to improve the performance of aqueous zinc-ion batteries (AZIBs). Herein, we constructed a vanadium dioxide/graphene oxide (VO 2 (B)/GO) sample that combines VO 2 with GO through hydrothermal route and can simultaneously provide rate capability. VO 2 (B)/GO is rich in oxygen vacancies , which weakens the electrostatic force , and GO prevents vanadium oxidation . Density functional theory (DFT) calculations elucidate oxygen vacancies can offer more storage sites with increased reaction kinetics. The electrode exhibited a high reversible capacity of 423 mAh g −1 at 0.5 A g −1 and preserved long-life cycling properties at 15 A g −1 . The presence of oxygen vacancies and GO can contribute to the excellent performance and prevent the structure of VO 2 from collapsing during cycling. We successfully lit up commercial light-emitting diode (LED) lights with a VO 2 (B)/GO electrode. In addition, VO 2 (B)/GO exhibits excellent performance in all-climate conditions (-15-60 °C). This combinatorial design strategy provides a broadly applicable approach for durability and all-climate workable batteries .

Determination of polymyxin B in human plasma and epithelial lining fluid using LC-MS/MS and its clinical application in therapeutic drug monitoring

Bingqing Zhang,Xueyong Li,Yiying Chen,Bo Chen,Yu Cheng,Hailing Lin,Wancai Que,Maobai Liu,Lili Zhou,Hui Zhang,Hongqiang Qiu,Chaoyang Wu

Polymyxin B (PB) is currently one of the last resort treatment options against carbapenem-resistant gram-negative bacterial pathogens. Pharmacokinetics/pharmacodynamics (PK/PD) guided therapeutic drug monitoring (TDM) of antibiotics is critical for optimizing dosage regimens to maximize efficacy, minimize toxicity, and delay the emergence of resistance. Currently, methods for determining PB in human plasma and epithelial lining fluid (ELF) are limited. In this study, we developed and validated a simple method for PB determination in human plasma and ELF using LC-MS/MS. Protein precipitation of the sample was conducted with 0.1% formic acid-acetonitrile. Polymyxin B1 and B2 were separated on a C 18 column and detected within 4 min by the mass spectrometer in the positive mode coupled with multiple reaction monitoring. The calibration curve range was 0.156–10.0 and 0.0156–1.00 μg/mL in the plasma for polymyxin B1 and B2, respectively, and was 0.0625–2.00 and 0.00625–0.200 μg/mL for polymyxin B1 and B2, respectively in bronchoalveolar lavage fluid. The accuracy of the intra- and inter-assay studies ranged from 80.6% to 114.9%, and the coefficients of variation for intra- and inter-day assays were less than 14.8%. Among a considerable number of patients, the average steady-state plasma concentration of PB was suboptimal. Moreover, the exposure to PB in patients with acute kidney injury (AKI) was considerably higher than that in patients without AKI. Meanwhile, a higher concentration of PB in ELF could be achieved than that in plasma after PB nebulization treatment. The established method was proven to be rapid, simple, and suitable for TDM of PB and PK/PD studies in human plasma and ELF.

The improvement effects of edible bird’s nest on proliferation and activation of B lymphocyte and its antagonistic effects on immunosuppression induced by cyclophosphamide

Ran Zhao,Geng Li,Xiu-juan Kong,Xiu-yan Huang,Wei Li,Yao-ying Zeng,Xiao-ping Lai

In situ bifunctional solid acids bearing B–OH and –COOH groups for efficient hydrolysis of cellulose to sugar in a pure aqueous phase

Yuhua Chen,Chengqi Feng,Chenkai Jin,Yuxin Zhu,Juncheng Huang,Haining Na,Jin Zhu

Pyruvaldehyde as a carbon source is synthesized together with boric acid to produce a carbon-based solid catalyst with in situ bifunctional groups of adsorptive boron hydroxyls and carboxyls in a single-step hydrothermal carbonization process, which is mainly utilized to induce the hydrolysis of cellulose to sugar in pure water. The obtained catalyst exhibits a strong adsorption capacity of 532 mg g−1 with cotton cellulose and possesses good water dispersibility. It can effectively break the aggregated structure of cellulose through the strong interfacial adsorption interaction to induce the hydrolysis of cellulose to sugar with high efficiency in the pure aqueous system. The cellulose conversion and the glucose yield reach 97.3% and 40.0%, respectively. Additionally, the catalyst demonstrates excellent hydrothermal stability and reusability. As a result, a high-yield, acid-free, green, and environmentally friendly hydrolytic process of cellulose to sugar in pure water is successfully established.

Fabrication, characterization and application of single-phase hollow BiFeO3 nanofibers as an efficient visible-light photocatalyst for degradation of Rhodamine B in wastewater

Zhaoyang Li,Yongshuai Xie,Yifan Wang,Ying Peng,Zhezhe Deng,Benxue Liu,Guanghui Zhang,Xinqiang Wang,Fengqing Zhang,Luyi Zhu

In this paper, we conducted a study on the structural modulation and photocatalytic performance of single-phase hollow BiFeO 3 nanofibers (SPH–BFO NFs) photocatalysts , investigated the effect of heat treatment temperature on the structure of BFO NFs and the formation mechanism of a hollow structure. The SPH-BFO NFs consist of BiFeO 3 nanocrystals without other heterogeneous phases, with diameters of 400–600 ​nm and extraordinary flexibility, allowing easy separation of the catalyst from the solution. As a result, the SPH-BFO NFs possess outstanding photocatalytic performance and higher photocatalytic efficiency compared with other forms of BiFeO 3 . In addition, the effects of different environments and water quality on RhB degradation were investigated. It was found that the vacancies (h + ) and superoxide radicals (·O 2 − ) as active substances were less environment-dependent, making the SPH-BFO NFs more resistant to environmental interference. The RhB degradation efficiency of BFO NFs was about 99% in 10 ​mg/L of RhB dye solution at pH ​= ​6. This work provides valuable insights into the application of SPH-BFO NFs in photocatalysis and the design of nanofiber photocatalysts.

A novel visible-light-induced double Z-scheme photocatalytic system: NH2-UiO-66/BiOBr/Bi2S3 for degradation of tetracycline hydrochloride and rhodamine B

Rui Zhang,Ziyin Chen,Yu Li,Chen Zhao,Lu Cai,Junrong Yu,Ze Yang,Jiacheng Jiang

The unique properties of MOFs make them the best candidates for catalytic and photocatalytic applications. In this research, the NH 2 -UiO-66 material was prepared by solvothermal method , and different content of NH 2 -UiO-66 was added before the composite growth of Bi 2 S 3 and BiOBr nanomaterials to obtain the NH 2 -UiO-66/BiOBr/Bi 2 S 3 ternary composite material. In order to investigate the relationship between the structure and properties of the catalyst, XRD , FT-IR, SEM , HRTEM , UV–vis DRS, XPS and other characterization technologies were used to analyze the structure, morphology, optical properties of the samples, showing that NH 2 -UiO-66/BiOBr/Bi 2 S 3 have been successfully synthesized. Their photocatalytic performance was evaluated based on the photocatalytic degradation of tetracycline hydrochloride and rhodamine B under visible light . The results show that 2% NH 2 -UiO-66/BiOBr/Bi 2 S 3 has better photocatalytic activity than other materials. Moreover, NH 2 -UiO-66/BiOBr/Bi 2 S 3 also demonstrated good photocatalytic reusability and stability. The formation of Bi 2 S 3 and BiOBr heterojunctions and the introduction of NH 2 -UiO-66 with more active sites increase the carrier performance and separation efficiency. Then the valence band and conduction band values of the semiconductor material are calculated through the M-S curve, combined with the forbidden bandwidth deduced by UV–vis DRS and the experimental results of radical trapping, a double Z-type electron transfer mechanism suitable for this system is inferred. Finally, taking RhB as an example, the degradation path of dye pollutants was studied.

Quantifying H2O2 by ratiometric fluorescence sensor platform of N-GQDs/rhodamine B in the presence of thioglycolic acid under the catalysis of Fe3+

Xin Zhan,Xiaoxiao Yu,Benmengyang Li,Rui Zhou,Qingyu Fang,Yiwei Wu

In the presence of thioglycolic acid (TGA) and under the catalysis of Fe 3+ , a simple, rapid, sensitive, selective and effective ratiometric fluorescence sensor platform based on the mixed physically blue nitrogen-doped graphene quantum dots (N-GQDs) as probe signals and orange rhodamine B as internal standard signals has been constructed for analysis of H 2 O 2 in human serum. TGA is the key factor for fluorescence response toward H 2 O 2 by N-GQDs and the mechanism is H 2 O 2 reacts speedily with TGA under the catalysis of Fe 3+ , and produces intermediate of superoxide anions ( O 2 − ), which accepts electrons from N-GQDs, and generates graphene oxide, causing the fluorescence quench of N-GQDs. Compared with N-GQDs probe, the sensitivity of the ratiometric fluorescence sensor platform of N-GQDs/rhodamine B for analysis of H 2 O 2 has been improved by nearly 5-folds. Under the optimum conditions, F λ=580nm / F λ=440nm has a good linear relationship with the concentration of H 2 O 2 and the detection limit of H 2 O 2 is 0.46 μmol/L with 3.5% RSD. The established sensor platform has been successfully used for probing H 2 O 2 in human serum with satisfactory results. The superior performance of the probe lies in its high selectivity and can be directly employed in detecting H 2 O 2 in serum samples without any sample pretreatment procedures.

Synthesis of chitosan/SnO2 nanocomposites by chemical precipitation for enhanced visible light photocatalytic degradation efficiency of congo red and rhodamine-B dye molecules

Muthuchamy Maruthupandy,Thillaichidambaram Muneeswaran,Gnanasekaran Chackaravarthi,Thirumalaiswamy Vennila,Muthusamy Anand,Wan-Seob Cho,Franck Quero

Tin oxide (SnO 2 ) nanoparticles (NPs) as well as SnO 2 /chitosan(CS) nanocomposites (NCs) were successfully synthesized by a simple chemical precipitation technique and their photocatalytic degradation ability against congo red (CR) and Rhodamine-B (Rh-B) were subsequently evaluated. The crystallinity and surface morphology of the materials were evaluated using X-ray diffraction analysis and transmission electron microscopy (TEM), respectively. The TEM images revealed that nanosized SnO 2 NPs were successfully obtained and were homogeneously distributed within the CS matrix. The CS/SnO 2 NCs were exposed to Rh-B dye molecules, resulting in 95% degradation within 60 min, which was significantly higher than for SnO 2 NPs. On the other hand, CS/SnO 2 NCs were found to degrade 98% of CR dye molecules within 40 min of visible light irradiation, which was also significantly shorter than for SnO 2 NPs. The CR dye molecules experienced significantly better levels of photodegradation parameters than Rh-B. The present study demonstrates the potential of CS/SnO 2 NCs in the area of environmental remediation of organic dye-based water pollutants.

Glytabastan B, a coumestan isolated from Glycine tabacina, alleviated synovial inflammation, osteoclastogenesis and collagen-induced arthritis through inhibiting MAPK and PI3K/AKT pathways

Yanbei Tu,Lihua Tan,Tao Lu,Kai Wang,Haiyong Wang,Bing Han,Yuxin Zhao,Hanbin Chen,Yanfang Li,Haixia Chen,Meiwan Chen,Chengwei He

The roots of Glycine tabacina are used to treat rheumatoid arthritis (RA) and joint infection in folk medicine. Glytabastan B (GlyB), a newly reported coumestan isolated from this species, was found to significantly attenuate IL-1β-induced inflammation in SW982 human synovial cells at 3 and 6 μM, as evidenced by the decreased levels of pro-inflammatory mediators and matrix metalloproteinases (MMPs). GlyB also suppressed RANKL-induced osteoclastogenesis, decreased the expression of osteoclastogenic markers (NFATc1, CTSK , MMP-9) and osteoclast-mediated bone resorption. Further, GlyB administration (12.5 and 25 mg/kg) significantly inhibited inflammation, osteoclast formation and disease progression in collagen-induced arthritis (CIA) mice. Integration of network pharmacology , quantitative phosphoproteomic and experimental pharmacology results revealed that these beneficial actions were closely associated with the blockade of GlyB on the activation of MAPK , PI3K/AKT and their downstream signals including NF-κB and GSK3β/NFATc1. Drug affinity responsive target stability (DARTS) assay, cellular thermal shift (CETSA) assay and molecular docking analysis confirmed that there were direct interactions between GlyB and its target proteins ERK2 , JNK1 and class Ⅰ PI3K catalytic subunit p110 (α, β, δ and γ), which significantly contributed to the inhibition of activation of MAPK and PI3K/AKT pathways. In conclusion, these results strongly suggest GlyB is a promising multiple-target candidate for the development of agents for the prevention and treatment of RA.

METTL3 inhibition ameliorates liver damage in mouse with hepatitis B virus-associated acute-on-chronic liver failure by regulating miR-146a-5p maturation

Da Cheng,Cichun Wu,Ying Li,Yao Liu,Juan Mo,Lei Fu,Shifang Peng

Hepatitis B virus (HBV)-associated acute-on-chronic liver failure (ACLF) is a clinical syndrome of severe liver damage. HBV infection is affected by N6-methyladenosine (m 6 A) RNA modification. Here, we investigated whether methyltransferase-like 3 (METTL3)-mediated m 6 A methylation can affect ACLF. Human hepatic cells (THLE-2) were treated with lipopolysaccharide (LPS) to induce cell damage. Proliferation, apoptosis and m 6 A modification were measured by MTT assay , flow cytometry and Dot blot assay. Our results showed that HBV infection significantly enhanced the levels of m 6 A modification and elevated the expression of METTL3 and mature-miR-146a-5p in THLE-2 cells, which was repressed by cycloleucine (m 6 A inhibitor). METTL3 overexpression enhanced m 6 A modification and promoted mature-miR-146a-5p expression. METTL3 overexpression promoted HBV replication and apoptosis, enhanced the levels of pro-inflammatory cytokines, hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg), and repressed cell proliferation in THLE-2 cells, which attributed to repress miR-146a-5p maturation. Moreover, a severe liver failure mouse model was established by HBV infection to verify the impact of METTL3 knockdown on liver damage in vivo . HBV-infection led to a severe liver damage and increase of apoptosis in hepatic tissues of mice, which was abolished by METTL3 knockdown. METTL3 knockdown reduced METTL3 expression and impeded miR-146a-5p maturation in HBV-infected mice. In conclusion, this work demonstrates that METTL3 inhibition ameliorates liver damage in mouse with HBV-associated ACLF, which contributes to repress miR-146a-5p maturation. Thus, this article suggests a novel therapeutic avenue to prevent and treat HBV-associated ACLF.

Enhanced Fenton-like degradation of Rhodamine B and Congo red by benzene and K+ co-doped carbon nitride with in situ-generated H2O2

Yanfang Chen,Xuemei Yan,Haifeng Lin,Chao Wang,Jixiang Xu

Background Fe 2+ /H 2 O 2 -based photo-Fenton process is often used in pollutions removal. But, Fe-species related low activity at neutral condition hinders their practical applications. Activation of in situ generated H 2 O 2 for Fenton-like degradation of pollutions through catalysts absences of Fe species is expected. Methods A strip-like benzene and K + co-doped g-C 3 N 4 (KBCN) was constructed by the thermal polymerization of assembly of melamine and 2-aminoterephthalic acid, then post-calcination in LiCl–KCl molten salt, which was then used to degrade Rhodamine B (RhB) and Congo red (CR) via in situ generated H 2 O 2 . Significant findings Benzene and K + co-doping were critical both in increasing charge separation and enhancing the H 2 O 2 production. The yield of H 2 O 2 for KBCN was 57.5 μM in pure water after 60 min irradiation. In the absence of Fe 2+ , the in situ generated H 2 O 2 could subsequently degrade RhB and CR with the formed ·OH. The apparent rate constants of KBCN for RhB and CR degradation were 0.0446 and 0.0497 min −1 , respectively. The advantages of degradation with in situ generated H 2 O 2 in the absence of Fe 2+ can provide a new prospective to the environmental friendly Fenton-like reaction.