RSC Advances

Feng, Yadong; Li, Yudong; Yu, Yunliang; Wang, Lianhui; Cui, Xiuling

doi: 10.1039/c8ra00524apmid: 35539849

Ir-catalysed direct sulfamidation of quinazolinones has been achieved. A series of ortho-diamided quinazolinones were obtained in up to 96% yields. This transformation could proceed smoothly with a low catalyst loading under mild conditions with nitrogen released as the sole byproduct. This approach potentially provides an environmentally benign sulfamidation process for atom/step economic syntheses of useful pharmaceutical molecules or important building blocks.

Lu, Pengwei; Xue Yang, ; Yang, Yunqing; Wang, Fang; Li, Lin; Gu, Yuanting

doi: 10.1039/c8ra00296gpmid: 35539872

The existence of drug resistance strikingly hampers the therapy of many malignancies, including breast cancer. Long non-coding RNAs (LncRNAs) have been reported to participate in the regulation of various biological processes associated with cancer progression. Whereas, the role of linc00472 in breast cancer pathogenesis and doxorubicin (ADR) resistance have not been well elucidated. In the present study, it is found that linc00472 expression was decreased in breast cancer tissues and cells. Moreover, higher linc00472 expression was positively associated with favorable disease status and prognosis for breast cancer patients. Functional analyses revealed that linc00472 overexpression suppressed proliferation and invasion, facilitated apoptosis and enhanced ADR sensitivity in breast cancer cells. Mechanistic studies discovered that linc00472 acted as a competing endogenous RNA (ceRNA) of miR-141 to sequester miR-141 from its target mRNA PDCD4 (programmed cell death 4). Furthermore, the inhibition effect of linc00472 on breast cancer cell progression and ADR resistance could be partly abrogated by miR-141 up-regulation or PDCD4 knockdown. In vivo assays also demonstrated that linc00472 hindered tumor growth by suppressing miR-141 expression and enhancing PDCD4 expression. In conclusion, linc00472 blocked breast cancer progression and induced ADR sensitivity through regulation of miR-141 and PDCD4, highlighting a potential therapeutic strategy for breast cancer patients.

Qi, Te; Ge, Bei-kang; Zhao, Liang; Ma, Yi; Li, Xiao-rong; Xu, Ping-xiang; Xue, Ming

doi: 10.1039/c7ra13295fpmid: 35539855

The promising benefits of salidroside (SAL) in alleviating high altitude sickness boost investigations on its pharmacokinetics and biological activity. However, the transportation and disposition process of SAL under hypoxic conditions has never been explored. The current study was proposed to investigate the pharmacokinetics of SAL in hypoxic rats and to explore the underlying mechanisms for the distinct metabolic fate of SAL under hypoxia. Pharmacokinetic studies on SAL was conducted in both hypoxic and normoxic rats. The transport properties of SAL were investigated on both hypoxic and normoxic Caco-2 monolayer models. Enzymes involved in SAL metabolism were identified and the effects of hypoxia on these enzymes were assessed by real-time PCR, western blotting analyses, and rat liver homogenate incubation. The renal clearance (CLr) of SAL, effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) in both hypoxic and normoxic rats were also determined for renal function assessment. It was found that the systemic exposure of SAL in hypoxic rats was remarkably higher than that in normoxic rats. The barrier function of Caco-2 monolayer was weakened under hypoxia due to the impaired brush border microvilli and decreased expression of tight junction protein. Hepatic metabolism of SAL in hypoxic rats was attenuated due to the reduced activity of cytosolic β-glucosidase (CBG). Moreover, CLr of SAL was reduced in hypoxic rats due to the suppressed ERPF. Our findings suggest the potential need for dose-adjustment of SAL or its structural analogs under hypoxic conditions.

Hamama, Wafaa S.; Ibrahim, Mona E.; Gooda, Ayaa A.; Zoorob, Hanafi H.

doi: 10.1039/c7ra11537gpmid: 35539824

This review highlights the recently cited research data in the literature on the chemistry of 2-chloroquinoline-3-carbaldehyde and related analogs and their applications over the period from 2013 to 2017. It covers: synthesis of quinoline ring systems and reactions adopted to construct fused or binary quinoline-cord heterocyclic systems. The biological evaluation and the synthetic applications of the target compounds were illustrated.

Ramalingam, G.; Saravanan, K. Venkata; Vizhi, T. Kayal; Rajkumar, M.; Baskar, Kathirvelu

doi: 10.1039/c7ra13400bpmid: 35539869

Many synthesized semiconductor QDs materials are formed using trioctylphosphine oxide (TOPO) but it requires high temperature, is very expensive and is also hydrophobic. Our study deals with selective syntheses of CdSe and core–shell CdSe/ZnS quantum dots (QDs) in aqueous solution by a simple heating and refluxing method. It is more hydrophilic, needs less temperature, is economically viable and is eco-friendly. Bio-ligands, such as thioacetamide, itaconic acid and glutathione, were used as stabilizers for the biosynthesis of QDs. A simplified aqueous route was used to improve the quality of the colloidal nanocrystals. As a result, highly monodisperse, photoluminescent and biocompatible nanoparticles were obtained. The synthesized QDs were characterized by XRD, FTIR, confocal microscopy, ultraviolet (UV) absorption and photoluminescence (PL). The size of synthesized QDs was observed as 5.74 nm and the core–shell shape was confirmed by using XRD and confocal microscopy respectively. The QD nanoparticles showed antibacterial activity against pathogenic bacteria. The QDs could be applied for biological labelling, fluorescence bio-sensing and bio-imaging etc.

Tadesse, Aschalew; RamaDevi, Dharmasoth; Hagos, Mabrahtu; Battu, GangaRao; Basavaiah, K.

doi: 10.1039/c8ra00158hpmid: 35539823

As a remedy for environmental pollution, a simple synthesis approach has been developed to prepare nitrogen doped carbon quantum dot/magnetite nanocomposites (Fe3O4@NCQDs NCs) using non-toxic and cost effective lemon juice as precursor for removal of organic dye pollutant. Fe3O4@NCQDs NCs were characterized by using UV-Vis spectroscopy, FTIR, XRD, FESEM, EDS, TEM, VSM and TGA/DTA. TEM results show spherical shaped Fe3O4@NCQDs NCs with an average particle size of 5 nm. Batch adsorption studies were done to investigate the tendency of the nanocomposites to remove representative methyl blue (MB) dye from aqueous solution. The effects of MB dye concentration, dosage of Fe3O4@NCQDs NC adsorbent, pH, contact time and temperature were optimized by varying one variable while all the other parameters were kept constant. The experiment showed rapid removal of MB dye within 20 minutes with an adsorption efficiency of over 90.84% under optimum conditions. The adsorption process fits the Freundlich isotherm model well with R2 and n values of 0.993 and 1.842, respectively, at 298 K indicating the feasibility of the adsorption process. The adsorption process is spontaneous and involves exothermic behaviour as confirmed by thermodynamic studies. From a kinetic study, it was found that the pseudo-second order model is more suitable to describe the adsorption process than the pseudo-first order model for adsorption of MB dye onto Fe3O4@NCQDs NCs.

Kabtamu, Daniel Manaye; Lin, Guan-Yi; Chang, Yu-Chung; Chen, Hsueh-Yu; Huang, Hsin-Chih; Hsu, Ning-Yih; Chou, Yi-Sin; Wei, Hwa-Jou; Wang, Chen-Hao

doi: 10.1039/c7ra12926bpmid: 35539857

In this paper, we propose a new, abundant, cost-effective, non-toxic, and environmentally benign iron–copper redox flow battery (Fe/Cu RFB), which employs Fe2+/Fe3+ and Cu+/Cu0 as the positive and negative electrolytes, respectively. The effect of graphite felt (GF) electrode modification and addition of Bi3+ into the electrolytes on the performance of the Fe/Cu RFB were investigated. It was found that the cell containing Bi3+ in the electrolytes revealed higher coulombic efficiency (89.18%) and energy efficiency (35.24%) than the cell without Bi3+ (CE = 84.10% and EE = 34.43%) at 20 mA cm−2. This is because after adding Bi3+, Cu metal precipitation was not observed on the electrode surface, which indicates that the deposition process was potentially reversible on the electrode material, thus leading to enhanced performance of the battery. Furthermore, the efficiencies of the battery are stable over 10 cycles, which demonstrates that Fe/Cu RFB exhibits good stability on the microwave heat treated GF plus one layer microwave heat treated carbon paper (HT-GF + HT-CP) electrode after adding Bi3+ into the electrolytes.

Wu, Shuaijin; Yu, Bing; Wu, Zhaohui; Fang, Sheng; Shi, Bimeng; Yang, Juanyu

doi: 10.1039/c8ra00539gpmid: 35539828

Si has been extensively examined as a potential alternative to carbonaceous negative materials, because it shows exceptional gravimetric capacity and abundance. In recent years, the strategy of using nano-structured silicon materials as building blocks to build micro-sized silicon-based materials has been widely studied. In this work, a commercialized and benchmark micro-sized silicon-based material (denoted as SiOx/C) is used as research target and three groups of materials with different particle size distributions (PSDs) were obtained by simply mechanical sieving. The effects of PSD on the electrochemical performance and electrode structure of micro-sized silicon-based negative electrodes are discussed. The optimized selection of micro-sized active material PSD presents a comprehensive way for developing and characterizing Si-based negative electrodes for practicable high-energy LIBs. In this case, the optimized SiOx/C composite electrode with a particle size of 22.7 μm and narrow PSD shows enhanced cycling stability with a high capacity retention of 84.31% over 100 cycles.

Ye, Lvyuan; Wan, Liqiang; Tang, Junkun; Li, Yujing; Huang, Farong

doi: 10.1039/c8ra00541apmid: 35539842

Novolac-based poly(1,2,3-triazolium)s with 1,2,3-triazolium side groups spaced by oligo(ethylene glycol), a new kind of poly(ionic liquid) membrane, was prepared via the well-known Click chemistry (1,3-dipolar cycloaddition reaction). The thermal properties, ionic conductivity and gas permeation performance of these self-standing membranes were investigated. The obtained membranes exhibit glass transition temperatures ranging from −1 °C to −7.5 °C, and a temperature at 10% weight loss above 330 °C. These membranes have good ionic conductivity (σDC up to 5.1 × 10−7 S cm−1 at 30 °C under anhydrous conditions) as compared with the reported 1,2,3-triazolium-based crosslinked polymers. And they could be potentially used for CO2 separation as they exhibit enhanced CO2 permeability up to 434.5 barrer at 4 atm pressure.

Li, Jingwei; Tong, Yifei; Guan, Li; Wu, Shaofeng; Li, Dongbo

doi: 10.1039/c7ra13202fpmid: 35539871

When using ultraviolet-visible spectroscopy (UV-visible spectroscopy) to detect water quality parameters, the measured absorption spectrum signal often contains a lot of interference information. Therefore, denoising is extremely important in spectrum data processing and analysis, which directly affects the subsequent quantitative analysis and information mining. Choosing an appropriate denoising method is key to improve the spectral analysis accuracy and promote the spectral analysis ability. In this paper, a new UV-visible absorption spectrum denoising method is proposed: a denoising method based on ensemble empirical mode decomposition (EEMD) and improved universal threshold filtering (EEMD-based method). The noisy UV-visible absorption spectrum signal is firstly decomposed into a finite set of band limited signals called intrinsic mode functions (IMFs) via EEMD. Spearman's rank correlation coefficient (Spearman's rho) is then used as a criterion for the IMFs dominated by noise or useful signals, and the improved universal threshold filtering method is applied to the noise dominant IMFs to eliminate the noise. Finally, the denoised UV-visible absorption spectrum signal is reconstructed. In order to discuss the effectiveness of the EEMD-based denoising method proposed in this paper, we compare it with various wavelet-based threshold denoising methods. Both methods have been implemented on synthetic signals with diverse waveforms (‘Blocks’, ‘Bumps’ and ‘Heavy sine’). It is demonstrated that the proposed method outperforms the wavelet-based methods. Then, the measured UV-visible absorption spectra with different SNR were denoised by the wavelet and proposed methods. The method proposed also performs well in the spectrum denoising experiment.