RSC Advances

Zhong, Jiyou; Zhao, Weiren; Yang, Lunwei; Shi, Peng; Liao, Zifeng; Xia, Menglong; Pu, Wenhua; Xiao, Wei; Wang, Ligen

doi: 10.1039/c8ra00844bpmid: 35542502

A series of red-emitting Ca3ZrSi2O9:Eu3+,xBi3+ phosphors was synthesized using a conventional high temperature solid-state reaction method, for the purpose of promoting the emission efficiency of Eu3+ in a Ca3ZrSi2O9 host. The site preference of Bi3+ and Eu3+ in the Ca3ZrSi2O9 host was evaluated by formation energy. The effects of Bi3+ on electronic structure, luminescent properties, and related mechanisms were investigated. The inner quantum yield of the optimized sample increased to 72.9% (x = 0.08) from 34.6% (x = 0) at 300 nm ultraviolet light excitation. The optimized sample (x = 0.08) also showed excellent thermal stability, and typically, 84.2% of the initial emission intensity was maintained when the temperature increased to 150 °C from 25 °C, which is much higher than that without Bi3+ doping (70.1%). The mechanisms of emission properties and thermal stability enhancement, as well as the redshift of the charge transfer band (CTB) induced by Bi3+ doping in the Ca3ZrSi2O9:Eu3+ phosphor, were discussed. This study elucidates the photoluminescence properties of Bi3+-doped Ca3ZrSi2O9:Eu3+ phosphor, and indicates that it is a promising luminescent material that can be used in ultraviolet light-emitting diodes.

Guo, Yinghui; Yan, Jing; Pu, Mingbo; Li, Xiong; Ma, Xiaoliang; Zhao, Zeyu; Luo, Xiangang

doi: 10.1039/c7ra11953dpmid: 35542545

Realizing effective scattering manipulation in broad operation band is a long pursuit. Here, we present an ultra-broadband metasurface to manipulate the scattering of electromagnetic waves based on spin–orbit interaction induced virtual shaping. The spin conversion efficiency is over 90% from 4.9 GHz to 22.8 GHz accompanied by a abrupt phase shift covering 0–2π, which is dependent on the orientation of the subwavelength of building blocks. Both Bessel- and triangular-type virtual profile shapes are developed for electromagnetic illusion and camouflage. Simulation and experimental results demonstrate that the significant backward RCS reduction of 10 dB is obtained from 5.5 to 22.5 GHz. The significant improvement in working bandwidth can be attributed to: the application of the dispersionless phase–shift properties of P–B phase, two-dimensional dispersion management methodology and catenary shaped local field enhancement in the metallic gap. The proposed design may have the potential applications in eletromagnetic manipulation and object detection.

Li, Quan; Chen, Hai-Feng

doi: 10.1039/c8ra01545gpmid: 35542505

Muscarinic acetylcholine receptors are GPCRs that regulate the activity of a diverse array of central and peripheral functions in the human body, including the parasympathetic actions of acetylcholine. The M2 muscarinic receptor subtype plays a key role in modulating cardiac function and many important central processes. The orthosteric agonist and allosteric modulator can bind the pocket of M2. However, the detailed relationship between orthosteric agonist and allosteric modulator of M2 is still unclear. In this study, we intend to elucidate the residue-level regulation mechanism and pathway via a combined approach of dynamical correlation network and molecular dynamics simulation. Specifically computational residue-level fluctuation correlation data was analyzed to reveal detailed dynamics signatures in the regulation process. A hypothesis of “synergistic regulation” is proposed to reveal the cooperation affection between the orthosteric agonist and allosteric modulator, which is subsequently validated by perturbation and mutation analyses. Two possible synergistic regulation pathways of 2CU-I178-Y403-W400-F396-L114-Y440-Nb9 and IXO-V111-F396-L114-Y440-Nb9 were identified by the shortest path algorithm and were confirmed by the mutation of junction node. Furthermore, the efficiency of information transfer of bound M2 is significant higher than any single binding system. Our study shows that targeting the synergistic regulation pathways may better regulate the calcium channel of M2. The knowledge gained in this study may help develop drugs for diseases of the central nervous system and metabolic disorders.

Liu, Y. C.; Huang, J. C.; Wang, X.; Tsai, M. T.; Wang, Z. K.

doi: 10.1039/c8ra00463cpmid: 35542559

In this research, nanoporous silver foams are fabricated through dealloying Ag35Al65 (as atomic percentage, at%) thin films in supercritical (SC) carbon dioxide. The supercritical CO2 is mixed with either HCl, water or H2C2O4 aqueous solution as the solute in the reaction chamber. Due to the low tension of the supercritical fluid, under the best operating conditions, the surface area of the as-dealloyed Ag35Al65 can reach 4.6 m2 g−1, and the porosity volume fraction value can reach 74%, with a smallest average pore size of around 75 nm. In an optimum supercritical CO2 environment, a lower chemical concentration can be applied and it can take less time to form a uniform nanoporous structure.

Xue, Wenjuan; Yang, Yaping; Yang, Qiaoling; Liu, Yuping; Wang, Lian; Chen, Changguo; Cheng, Renju

doi: 10.1039/c8ra01329bpmid: 35542504

Recently, solid-state electrolyte lithium lanthanum zirconium oxide garnet (Li7La3Zr2O12, LLZO) has attracted great attention due to its high room temperature conductivity of lithium ions and stability against lithium metal electrodes. The Al-doped cubic garnet Li6.4Al0.2La3Zr2O12 was synthesized by a conventional solid-state method at different sintering temperatures. The influence of the sintering process on the structure and ionic conductivity was investigated by X-ray diffraction, electrochemical impedance spectroscopy, and scanning electron microscopy. The results showed that Li vaporization and relative density were affected by the sintering process. The synergistic effects of Li concentration and relative density determined the Li+ ionic conductivity. Compared with the relative density, the Li concentration plays a more important role in determining the ionic conductivity via the solid-state method.

Kim, Mi Hye; Lee, Haesu; Yang, Woong Mo

doi: 10.1039/c7ra12531cpmid: 35542540

Angelica gigas (AG) has been used for periodontal diseases in traditional Korean medicine. However, the effects of AG on periodontitis have not been clarified yet. In this study, we investigated the ameliorative effects of AG against ligature-induced periodontitis. Sprague-Dawley rats were divided into four groups; non-ligatured (normal), ligatured and treated with vehicle (ligatured), ligatured and treated with 1 mg mL−1 AG (AG1), and ligatured and treated with 100 mg mL−1 AG (AG100). 70% ethanol extracts of AG were topically applied onto both sides of the first molar daily for 14 days. In addition, human dermal fibroblast cells were treated with 1, 10 and 100 μg mL−1 AG to characterize the expression of matrix metallopeptidase 9 (MMP-9). Topical AG treatment reduced alveolar bone resorption, as assessed by methylene blue staining. The structures of soft gingival tissues (periodontal pocket) were recovered in the AG-treated groups. The expression of MMP-9 was decreased, and that of type 1 collagen was significantly increased in AG-treated gingival tissues. In addition, AG treatment inhibited the activity of MMP-9 in LPS-treated human dermal fibroblast cells. This study reveals that topical AG treatment has the potential to ameliorate the destruction of gingival tissues by inhibiting MMP-9 activity. AG may be a candidate for the treatment of periodontitis.

Sánchez, José G.; Balderrama, Víctor S.; Garduño, Salvador I.; Osorio, Edith; Viterisi, Aurelien; Estrada, Magali; Ferré-Borrull, Josep; Pallarès, Josep; Marsal, Lluis F.

doi: 10.1039/c8ra01481gpmid: 35542512

In this paper, we demonstrate that zinc oxide (ZnO) layers deposited by inkjet printing (IJP) can be successfully applied to the low-temperature fabrication of efficient inverted polymer solar cells (i-PSCs). The effects of ZnO layers deposited by IJP as electron transport layer (ETL) on the performance of i-PSCs based on PTB7-Th:PC70BM active layers are investigated. The morphology of the ZnO-IJP layers was analysed by AFM, and compared to that of ZnO layers deposited by different techniques. The study shows that the morphology of the ZnO underlayer has a dramatic effect on the band structure and non-geminate recombination kinetics of the active layer deposited on top of it. Charge carrier and transient photovoltage measurements show that non-geminate recombination is governed by deep trap states in devices made from ZnO-IJP while trapping is less significant for other types of ZnO. The power conversion efficiency of the devices made from ZnO-IJP is mostly limited by their slightly lower JSC, resulting from non-optimum photon conversion efficiency in the visible part of the solar spectrum. Despite these minor limitations their J–V characteristics compare very favourably with that of devices made from ZnO layer deposited using different techniques.

Zhang, Jing; Zhang, Di; Hu, Xu; Liu, Ruiling; Li, Zhonghao; Luan, Yuxia

doi: 10.1039/c8ra01225cpmid: 35542498

Because of the drawbacks of cytarabine (Ara-C) such as poor lipid solubility, deamination inactivation and low oral bioavailability limiting its application by oral administration, herein we propose a novel amphiphilic low molecular weight cytarabine prodrug (PA-Ara) by conjugating palmitic acid (PA) to Ara-C, making it possible to avoid the deamination inactivation by protecting the active 4-amino, as well as improving lipid solubility. Thanks to the rational design, the oil/water partition coefficient (P) of PA-Ara was improved tremendously compared with Ara-C, and the PA-Ara conjugation was stable enough in artificial digestive juice, ensuring that most molecules could be absorbed in the form of the prodrug. Results from an MTT assay conducted to measure the cytotoxicity of Ara-C and PA-Ara to HL60 (acute myeloblastic leukemia cell line) and K562 cells (chronic granulocytic leukemia cell line) showed that PA-Ara had significantly stronger antiproliferation activities than Ara-C. Significantly, we firstly compared the bioavailability of the oral fatty acid chain modified cytarabine prodrug preparation with injection and the relative bioavailability was up to 61.77% for our PA-Ara, which was much superior to that of oral Ara-C solution (3.23%). Overall, these findings make it clear that the PA-Ara suspension has the potential to be a promising new cytarabine oral preparation for leukemia therapy.

Choi, Changsoon; Park, Jong Woo; Kim, Keon Jung; Lee, Duck Weon; de Andrade, Mônica Jung; Kim, Shi Hyeong; Gambhir, Sanjeev; Spinks, Geoffrey M.; Baughman, Ray H.; Kim, Seon Jeong

doi: 10.1039/c8ra01384epmid: 35542516

Asymmetric supercapacitors are receiving much research interests due to their wide operating potential window and high energy density. In this study, we report the fabrication of asymmetrically configured yarn based supercapacitor by using liquid-state biscrolling technology. High loading amounts of reduced graphene oxide anode guest (90.1 wt%) and MnO2 cathode guest (70 wt%) materials were successfully embedded into carbon nanotube yarn host electrodes. The resulting asymmetric yarn supercapacitor coated by gel based organic electrolyte (PVDF-HFP-TEA·BF4) exhibited wider potential window (up to 3.5 V) and resulting high energy density (43 μW h cm−2). Moreover, the yarn electrodes were mechanically strong enough to be woven into commercial textiles. The textile supercapacitor exhibited stable electrochemical energy storage performances during dynamically applied deformations.

Chevalier, Arnaud; Ouahrouch, Abdelaaziz; Arnaud, Alexandre; Gallavardin, Thibault; Franck, Xavier

doi: 10.1039/c8ra01546epmid: 35542511

Indazole derivatives are currently drawing more and more attention in medicinal chemistry as kinase inhibitors. 1H-indazole-3-carboxaldehydes are key intermediates to access to a variety of polyfunctionalized 3-substituted indazoles. We report here a general access to this motif, based on the nitrosation of indoles in a slightly acidic environment. These very mild conditions allow the conversion of both electron-rich and electron-deficient indoles into 1H-indazole-3-carboxaldehydes.