RSC Advances

Sun, Kehuan; Tao, Cheng; Long, Bohua; Zeng, Xiaobin; Wu, Zhengzhi; Zhang, Ronghua

doi: 10.1039/d3ra90061dpmid: 37435387

Expression of concern for ‘Highly stereoselective gram scale synthesis of all the four diastereoisomers of Boc-protected 4-methylproline carboxylates’ by Kehuan Sun et al., RSC Adv., 2019, 9, 32017–32020, https://doi.org/10.1039/C9RA06827A.

Sabahi, Negin; Shahroosvand, Hashem

doi: 10.1039/d3ra01304apmid: 37435383

The possible mechanisms damaging perovskite solar cells have attracted considerable attention in the photovoltaic community. This study answers specifically open problems regarding the critical role of methylammonium iodide (MAI) in investigations as well as stabilizing the perovskite cells. Surprisingly, we found that when the molar ratio between PbI2 : MAI precursor solution increased from 1 : 5 to 1 : 25, the stability of perovskite cells dramatically increased over time. The stability of perovskite in the air without any masking in the average stoichiometry was about five days, while when the amount of MAI precursor solution increased to 5, the perovskite film was unchanged for about 13 days; eventually, when the value of MAI precursor solution enhanced to 25, the perovskite film stayed intact for 20 days. The outstanding XRD results indicated that the intensity of perovskite's Miler indices increased significantly after 24 h, and the MAI's Miler indices decreased, which means that the amount of MAI was consumed to renew the perovskite crystal structure. In particular, the results suggested that the charging of MAI using the excess molar ratio of MAI reconstructs the perovskite material and stabilizes the crystal structure over time. Therefore, it is crucial that the main preparation procedure of perovskite material is optimized to 1 unit of Pb and 25 units of MAI in a two-step procedure in the literature.

Alharthi, Fahad A.; Marghany, Adel El; Abduh, Naaser A. Y.; Hasan, Imran

doi: 10.1039/d3ra02949bpmid: 37426706

A straightforward hydrothermal technique was used for the synthesis of a g-C3N4/GdVO4 (CN/GdV) heterostructure as an alternate material for energy and environmental applications. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) were used to characterize the synthesized g-C3N4 (CN), GdVO4 (GdV), and the CN/GdV heterostructure. The characterization results revealed the distribution of GdV over CN sheets. The as-fabricated materials were tested for their capacity to evolve hydrogen gas and degrade two azo dyes (Amaranth; AMR and Reactive Red2; RR2) in the presence of visible light. When compared to pure CN and GdV, the efficiency of CN/GdV toward hydrogen evolution was high, with H2 evolution of 8234, 10 838, and 16 234 μmol g−1 in 4 h, respectively. The CN/GdV heterostructure was able to degrade 96% and 93% of AMR (60 min) and RR2 (80 min), respectively. The enhanced activity with CN/GdV could be attributed to the type-II heterostructure and decreased recombination of charge carriers. The intermediate analysis of AMR and RR2 degradation was conducted using mass spectrometry (MS). The mechanism of photocatalysis was investigated and is discussed based on the optical and electrochemical characterizations. The efficient photocatalytic characteristics of CN/GdV could promote further research on metal vanadate nanocomposite materials.

Khan, Sanaullah; Khan, Javed Ali; Shah, Noor S.; Sayed, Murtaza; Ateeq, Muhammad; Ansar, Sabah; Boczkaj, Grzegorz; Farooq, Umar

doi: 10.1039/d3ra03610cpmid: 37435380

Organochlorine pesticides (OCPs) have been used extensively as insecticides and herbicides. This study investigates the occurrence of lindane in surface water from the Peshawar valley (i.e., Peshawar, Charsadda, Nowshera, Mardan and Swabi districts of Khyber Pakhtunkhwa, Pakistan). Out of 75 samples tested (i.e., 15 samples from each district), 13 samples (including 2 from Peshawar, 3 from Charsadda, 4 from Nowshera, 1 from Mardan, and 3 from Swabi) are found to be contaminated with lindane. Overall, the detection frequency is 17.3%. The maximum concentration of lindane is detected in a water sample from Nowshera and found to be 2.60 μg L−1. Furthermore, the degradation of lindane in the water sample from Nowshera, containing the maximum concentration, is investigated by simulated solar-light/TiO2 (solar/TiO2), solar/H2O2/TiO2 and solar/persulfate/TiO2 photocatalysis. The degradation of lindane by solar/TiO2 photocatalysis is 25.77% after 10 h of irradiation. The efficiency of the solar/TiO2 process is significantly increased in the presence of 500 μM H2O2 and 500 μM persulfate (PS) (separately), represented by 93.85 and 100.00% lindane removal, respectively. The degradation efficiency of lindane is lower in natural water samples as compared to Milli-Q water, attributed to water matrix effect. Moreover, the identification of degradation products (DPs) shows that lindane follows similar degradation pathways in natural water samples as the one in Milli-Q water. The results show that the occurrence of lindane in surface waters of Peshawar valley is a matter of great concern for human beings and the environment. Interestingly, H2O2 and PS assisted solar/TiO2 photocatalysis is an effective method for the removal of lindane from natural water.

Soliman, Dalia H.; Nafie, Mohamed S.

doi: 10.1039/d3ra02579apmid: 37435371

Since VEGFR-2 plays a crucial role in tumor growth, angiogenesis, and metastasis, it is a prospective target for cancer treatment. In this work, a series of 3-phenyl-4-(2-substituted phenylhydrazono)-1H-pyrazol-5(4H)-ones (3a–l) were synthesized and investigated for their cytotoxicity against the PC-3 human cancer cell line compared to Doxorubicin and Sorafenib as reference drugs. Two compounds 3a and 3i showed comparable cytotoxic activity with IC50 values of 1.22 and 1.24 μM compared to the reference drugs (IC50 = 0.932, 1.13 μM). Compound 3i was found to be the most effective VEGFR-2 inhibitor using in vitro testing of the synthesized compounds, with nearly 3-fold higher activity than Sorafenib (30 nM), with IC50 8.93 nM. Compound 3i significantly stimulated total apoptotic prostate cancer cell death 55.2-fold (34.26% compared to 0.62% for the control) arresting the cell cycle at the S-phase. The genes involved in apoptosis were also impacted, with proapoptotic genes being upregulated and antiapoptotic Bcl-2 being downregulated. These results were supported by docking studies of these two compounds within the active site of the VEGFR2 enzyme. Finally, in vivo, the study revealed the potentiality of compound 3i to inhibit tumor proliferation by 49.8% reducing the tumor weight from 234.6 mg in untreated mice to 83.2 mg. Therefore, 3i could be a promising anti-prostate cancer agent.

Tao, Jun; Wang, Xiaofeng

doi: 10.1039/d3ra02509hpmid: 37435376

In order to explore the mechanism of reaction involving Al-polytetrafluoroethylene (PTFE) mechanically activated energetic composites, a molecular dynamics simulation was carried out to predict the pyrolysis of PTFE. Then, density functional theory (DFT) was applied to calculate the mechanism of reaction between the products of PTFE pyrolysis and Al. Furthermore, the pressure and temperature obtained during the reaction of Al–PTFE were tested to study the chemical structure before and after heating. Finally, the laser-induced breakdown spectroscopy experiment was performed. According to the experimental results, the main pyrolysis products of PTFE include F, CF, CF2, CF3 and C. The path of the CF3 + Al → CF2 + AlF reaction is the easiest to achieve. AlF3, Al and Al2O3 are the main components of the pyrolysis products of PTFE with Al. Compared with Al–PTFE, the ignition temperature required by the Al–PTFE mechanically activated energetic composite is lower and its combustion reaction is faster.

Drabczyk, Anna K.; Kułaga, Damian; Zaręba, Przemysław; Tylińska, Wiktoria; Bachowski, Wojciech; Archała, Aneta; Wnorowski, Artur; Tzani, Andromachi; Detsi, Anastasia; Jaśkowska, Jolanta

doi: 10.1039/d3ra03926apmid: 37435368

New derivatives of the known antipsychotic drug olanzapine have been obtained as potential compounds with anticancer activity in two metabolically different breast cancer cell lines: MCF-7 and triple negative MDA-MB-231. The compounds were obtained under phase transfer catalysis (PTC) in the presence of microwave irradiation (MW) or ultrasound (“)))”), evaluating the effect of solvents such as dimethylformamide, water, or choline chloride/urea (natural deep eutectic solvent, NaDES). In the best option, the compounds were obtained within 2 minutes with a yield of 57–86% in MW. Two of the obtained compounds which have a naphthalimide moiety and a pentyl (7) or hexyl chain (8) show pronounced cytotoxicity. Interestingly, neither olanzapine nor desmethylolanzapine (DOLA), which was one of the substrates for the synthesis reaction, showed any significant activity in the study.

Meng, Liying; Wu, Guanzhao

doi: 10.1039/d3ra03313apmid: 37435377

Mitochondrial disorders are observed in various human diseases, including rare genetic disorders and complex acquired pathologies. Recent advances in molecular biological techniques have dramatically expanded the understanding of multiple pathomechanisms involving mitochondrial disorders. However, the therapeutic methods for mitochondrial disorders are limited. For this reason, there is increasing interest in identifying safe and effective strategies to mitigate mitochondrial impairments. Small-molecule therapies hold promise for improving mitochondrial performance. This review focuses on the latest advances in developing bioactive compounds for treating mitochondrial disease, aiming to provide a broader perspective of fundamental studies that have been carried out to evaluate the effects of small molecules in regulating mitochondrial function. Novel-designed small molecules ameliorating mitochondrial functions are urgent for further research.

Park, Yujin; Kim, Joondong; Yun, Ju-Hyung; Jang, Segeun; Kim, Sang Moon

doi: 10.1039/d3ra03017bpmid: 37435370

The pressure-driven liquid flow controller is one of the key components in diverse applications including microfluidic systems, biomedical drug injection devices, and pressurized water supply systems. Electric feedback loop based flow controllers are fine-tunable but expensive and complex. The conventional safety valves based on spring force are simple and low cost, but their diverse application is limited due to their fixed pressure range, size, and shape. Herein, we propose a simple and controllable liquid-flowing system combining a closed liquid reservoir and an oil-gated isoporous membrane (OGIM). The ultra-thin and flexible OGIM acts as an immediately responsive and precisely controlled gas valve to maintain internal pneumatic pressure as designed to induce constant liquid flow. The oil filling apertures act as a gate for gas flow depending on the applied pressure and the threshold (gating) pressure of the gate is determined by the surface tension of the oil and the gate diameter. It is confirmed that the gating pressure is precisely controlled by varying the gate diameter, which agrees with the theoretically estimated pressures. Based on stably maintained pressure due to the function of OGIM, the constant liquid flow rate is achieved even with the high gas flow rate.

Hu, Xi; Wang, Teng; Li, Faqi; Mao, Xiang

doi: 10.1039/d3ra02248jpmid: 37435384

Biomaterial implantation into the human body plays a key role in the medical field and biological applications. Increasing the life expectancy of biomaterial implants, reducing the rejection reaction inside the human body and reducing the risk of infection are the problems in this field that need to be solved urgently. The surface modification of biomaterials can change the original physical, chemical and biological properties and improve the function of materials. This review focuses on the application of surface modification techniques in various fields of biomaterials reported in the past few years. The surface modification techniques include film and coating synthesis, covalent grafting, self-assembled monolayers (SAMs), plasma surface modification and other strategies. First, a brief introduction to these surface modification techniques for biomaterials is given. Subsequently, the review focuses on how these techniques change the properties of biomaterials, and evaluates the effects of modification on the cytocompatibility, antibacterial, antifouling and surface hydrophobic properties of biomaterials. In addition, the implications for the design of biomaterials with different functions are discussed. Finally, based on this review, it is expected that the biomaterials have development prospects in the medical field.