Correction: Acridinedione as selective flouride ion chemosensor: a detailed spectroscopic and quantum mechanical investigation

Correction for ‘Acridinedione as selective flouride ion chemosensor: a detailed spectroscopic and quantum mechanical investigation’ by Nafees Iqbal et al., RSC Adv., 2018, 8, 1993–2003.

The authors regret that the interpretation of the fluorescence spectra of compound 7i published in the original article was incorrect. In the original article, it was reported that upon excitation at 380 nm, the fluorescence spectrum of compound 7i showed two emission bands at 450 nm and 770 nm (Fig. 5b of the original article). The signal at 770 nm (previously reported as an emission band), is instead a second order diffraction (an artefact of diffraction grating/spectrofluorometer monochromator), as revealed from the literature.^1,2 The authors thank a reader for highlighting this mistake.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

DFT-based study of the structural,optoelectronic, mechanical and magnetic properties of Ti3AC2 (A = P,As, Cd) for coating applications

The first-principles approach has been used while employing the Perdew–Burke–Ernzerhof exchange-correlation functional of generalized gradient approximation (PBE-GGA) along with the Hubbard parameter to study the structural, optoelectronic, mechanical and magnetic properties of titanium-based MAX materials Ti₃AC₂ (A = P, As, Cd) for the first time. As there is no band gap found between the valence and conduction bands in the considered materials, these compounds belong to the conductor family of materials. A mechanical analysis carried out at pressures of 0 GPa to 20 GPa and the calculated elastic constants C_ij reveal the stability of these materials. Elastic parameters, i.e., Young''s, shear and bulk moduli, anisotropy factor and Poisson''s ratio, have been investigated in the framework of the Voigt–Reuss–Hill approximation. The calculated values of relative stiffness are found to be greater than ½ for Ti₃PC₂ and Ti₃AsC₂, which indicates that these compounds are closer to typical ceramics, which possess low damage tolerance and fracture toughness. Optical parameters, i.e., dielectric complex function, refractive index, extinction coefficient, absorption coefficient, loss function, conductivity and reflectivity, have also been investigated. These dynamically stable antiferromagnetic materials might have potential applications in advanced electronic and magnetic devices. Their high strength and significant hardness make these materials potential candidates as hard coatings.

The first-principles approach has used the Perdew–Burke–Ernzerhof exchange-correlation functional of generalized gradient approximation along with the Hubbard parameter to study various properties of titanium-based MAX materials Ti₃AC₂ (A = P, As, Cd).     

趋化性细胞因子受体CXCR4在大肠癌的表达及其临床意义

目的:探讨趋化性细胞因子受体CXCR4在大肠癌中的表达及其与预后的关系.方法:收集67例大肠癌患者手术标本,采用免疫组织化学方法检测肿瘤组织中CXCR4蛋白的表达和微血管密度,分析CXCR4的表达水平与临床病理特征和生存的关系.结果:大肠癌组织中CXCR4蛋白表达阳性率为56.7%(38/67),与患者的性别、年龄、肿瘤部位、T分期和病理类型无相关性(P＞0.05),与淋巴结转移、临床分期、微血管密及生存相关.NO,N1和N2期CXCR4的阳性率分别为40.6%,68.2%,76.9%(P＜0.05);Ⅰ Ⅱ期和Ⅲ期CXCR4的阳性率分别为39.4%.73.5%(P＜0.05).低MVD组CXCR4的阳性率显著低于高MVD组(36.4%vs 74.3%,P＜0.01);CXCR4阳性组较CXCR4阴性组有较高的复发/转移率(47.4%vs 24.1%,P＜0.05)和较低的3a无病生存率(32.6%vs 71.3%.P＜0.05).结论:CXCR4可促进大肠癌的侵袭和转移以及血管生成并影响其预后.     

Maternal mortality and maternity care from 1990 to 2005: uneven but important gains

Maternal mortality continues to be the major cause of death among women of reproductive age in many countries. Data from published studies and Demographic and Health Surveys show that gains in reducing maternal mortality between 1990 and 2005 have been modest overall. In 2005, there were about 536,000 maternal deaths, and the maternal mortality ratio was estimated at 400 per 100,000 live births, compared to 430 in 1990. Noteworthy declines took place in east Asia (4% per year) and north Africa (3% per year). Maternal deaths and mortality ratios were highest in sub-Saharan Africa and southeast Asia and low in east Asia and Latin America/Caribbean. In 11 of 53 countries with data, fewer than 25% of women had had at least four antenatal visits. About 63% of births were attended by a skilled attendant: from 47% in Africa to 88% in Latin America/Caribbean. In 16 of 23 countries with data, less than 50% of the recommended levels of emergency obstetric care had been fulfilled. Only 61% of women who delivered in a health facility in 30 developing countries received post-partum care, and far fewer who gave birth at home. Countries with maternal mortality ratios of 750+ per 100,000 live births shared problems of high fertility and unplanned pregnancies, poor health infrastructure with limited resources and low availability of health personnel. The task ahead is enormous.     

Microbubble drug conjugate and focused ultrasound blood brain barrier delivery of AAV-2 SIRT-3

BackgroundDelivery of viral vectors as gene therapies to treat neurodegenerative diseases has been hampered by the inability to penetrate the blood brain barrier (BBB) and invasive or non-targeted delivery options prone to inducing immune responses. MR guided focused ultrasound (MR-g-FUS) and microbubbles have demonstrated safe, temporary, targeted BBB permeabilization clinically.MethodsWe developed clinically scalable, microbubble drug conjugates (MDCs) for the viral gene therapy, AAV.SIRT3-myc [adeno-associated virus expressing myc-tagged SIRT3], which has previously been shown to have disease modifying effects in animal models of Parkinson’s disease (PD). The lipid shells of the perfluorocarbon gas MDCs were covalently conjugated to antibodies with binding specificity to AAVs. Following systemic (iv) delivery of AAV.SIRT3-myc MDCs, MR-g-FUS was used to deliver SIRT3-myc to brain regions affected in PD. SIRT3-myc expression was determined post mortem, using immunohistochemistry.ResultsAn in vitro, SH-SY5Y cell culture model was used to show that the localized destruction of MDCs using ultrasound exposures within biological safety limits dissociated AAV2-GFP (green fluorescent protein) from the MDCs in the targeted area while maintaining their transduction capacity. In rats, MR-g-FUS resulted in BBB permeabilization in the striatum and substantia nigra (SNc). SIRT3-myc was expressed in the striatum, but not the SNc.ConclusionThese studies demonstrate that MDCs combined with MR-g-FUS are an effective method for delivery of viral vector gene therapies, such as AAV.SIRT3, to brain regions affected in PD. This technology may prove useful as a disease-modifying strategy in PD and other neurodegenerative disorders.     

Aortic valve neocuspidization for aortic regurgitation associated with ventricular septal defect

 Open in a separate windowOBJECTIVESDifferent methods of aortic valve repair have been described in the literature for aortic regurgitation (AR) associated with doubly committed subarterial ventricular septal defects. Our goal was to present our experience with aortic valve reconstruction of a single leaflet using the aortic valve neocuspidization technique in this subset of patients.METHODSIt is a retrospective review of 7 patients with doubly committed subarterial ventricular septal defects with significant (>moderate) AR who underwent the single-leaflet neocuspidization technique of aortic valve reconstruction from January 2016 to January 2019. Data were collected from medical records. All patients had thorough 2-dimensional echocardiographic assessment preoperatively and during the follow-up period. Primary end points were freedom from postoperative AR and freedom from reoperation and all-cause mortality within the follow-up period with secondary end points of freedom from thromboembolism and infective endocarditis.RESULTSOut of 7 patients, 6 were male and 1 was female. There were no perioperative deaths. The mean follow-up period was 2.6 ± 0.8 years. No deaths occurred during the follow-up period. At the latest follow-up examination, only 2 patients showed mild AR and were asymptomatic. There was no documented event of infective endocarditis or thromboembolism during the follow-up period.CONCLUSIONSThe aortic leaflet neocuspidization procedure for the aortic valve is a relatively new concept. Availability of a template makes it an easily reproducible valve repair in paediatric patients with a single-leaflet abnormality. This technique preserves the remaining 2 normal leaflets, thus promoting the growth potential while maintaining near normal aortic root complex dynamics.     

Acute epiploic appendagitis mimicking symptoms of urinary tract infection: A diagnostic enigma in the emergency department

The epiploic appendages (also known as appendices epiploicae) are usually located on the anti‐mesenteric surface of the colon, extending from the caecum to the rectosigmoid, and epiploic appendagitis (EA) is the inflammation of these appendages. We report a clinical image of epiploic appendagitis creating a diagnostic challenge.     

Correction: Development and in vitro evaluation of κ-carrageenan based polymeric hybrid nanocomposite scaffolds for bone tissue engineering

Correction for ‘Development and in vitro evaluation of κ-carrageenan based polymeric hybrid nanocomposite scaffolds for bone tissue engineering’ by Muhammad Umar Aslam Khan et al., RSC Adv., 2020, 10, 40529–40542. DOI: 10.1039/D0RA07446B.

The authors regret errors in Fig. 9 in the original article. The corrected Fig. 9 is shown below where all three +ive control panels and the 72 h CG-g-Aac-2 panel have been replaced.Open in a separate windowFig. 9Cell morphology of MC3T3-E1 against +ive control and all scaffold samples (CG-g-AAc1, CG-g-AAc2 and CG-g-AAc3) under standard in vitro conditions. The red arrows show thread-like morphology and the yellow arrows exhibits well-grown morphology of the cells.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Exploration of stilbenoid trimers as potential inhibitors of sirtuin1 enzyme using a molecular docking and molecular dynamics simulation approach

A combination of molecular docking and molecular dynamics simulation (250 ns) has been carried out to study the interaction of stilbenoid trimer compounds with the SIRT1 enzyme as the target protein. SIRT1 expression regulates cellular stress responses that lead to the development of cancer. Redocking showed a good native ligand pose with an RMSD value of 1.40 Å at the receptor active site''s coordinates. The molecular docking score uses a grid score functional (kcal mol⁻¹), which shows results of 1NS: 79.56, TS1: −26.83, TS2: −87.77, and TS3: −83.67. The TS2 and TS3 candidates were chosen for further analysis because they had a lower grid score than the native ligand (1NS). Furthermore, prediction of binding free energy (kcal mol⁻¹) using the Quantum Mechanics/generalized Born Surface Area (QM/MM-GBSA) method shows the results of 1NS: −31.52 ± 0.39, TS2: −58.99 ± 0.34, and TS3: −43.38 ± 0.35. These results indicate that the TS2 and TS3 compounds have good potential as inhibitors of the SIRT1 enzyme. Additionally, the amino acid residues were responsible for the inhibition mechanism through hydrogen bond interactions at the molecular level, including ASP22, PHE91, PRO11, ILE165, ASP166, and VAL230. The observations made in this study provide theoretical information for exploring the stilbenoid trimers as anticancer agents by targeting the SIRT1 enzyme.

A combination of molecular docking and molecular dynamics simulation (250 ns) has been carried out to study the interaction of stilbenoid trimer compounds with the SIRT1 enzyme as the target protein.