Correction: Porous conducting polymer and reduced graphene oxide nanocomposites for room temperature gas detection

Correction for ‘Porous conducting polymer and reduced graphene oxide nanocomposites for room temperature gas detection’ by Yajie Yang et al., RSC Adv., 2014, 4, 42546–42553.

The authors wish to draw the reader’s attention to their previous related study, published in ACS Applied Materials & Interfaces,¹ which was not cited in this RSC Advances paper. The RSC Advances paper is a valuable and necessary supplement to the publication in ACS Applied Materials & Interfaces and focused on the reduced gas sensing performance of the devices instead of film characterization and film conductive performance.The authors regret not giving correct attribution to Fig. 1–6 which duplicate data from ref. 1 and therefore should be attributed to that paper. Additionally, there are portions of overlapping text in the discussion of these figures and the Introduction and Conclusion sections of the RSC Advances paper, which should be attributed to ref. 1.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Correction: Directed evolution of mevalonate kinase in Escherichia coli by random mutagenesis for improved lycopene

Correction for ‘Directed evolution of mevalonate kinase in Escherichia coli by random mutagenesis for improved lycopene’ by Hailin Chen et al., RSC Adv., 2018, 8, 15021–15028.

The authors wish to draw the readers’ attention to their closely related paper, published in Microbial Cell Factories,¹ which should have been cited in this RSC Advances paper.The authors regret that there is unattributed overlap in text between this RSC Advances paper and ref. 1. The authors confirm that new data has been reported in this RSC Advances article.Two different rate-limiting enzymes in the lycopene synthetic pathway were studied using the same methods, mevalonate kinase (MK) in this paper and isopentenyl diphosphate isomerase (IDI) in ref. 1. In the RSC Advances paper, a directed evolution strategy was used to optimize the activity of MK to enhance the tolerance for farnesyldiphosphate (FPP) and geranylgeranyldiphosphate (GGPP), to enhance the affinity of mevalonate and MK, and to improve lycopene production. The catalytic mechanisms of both enzymes are very different; however improving their activities can improve lycopene production.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Retraction: Fabrication of hollow CoS1.097 prisms toward supercapactior performance

Retraction of ‘Fabrication of hollow CoS_1.097 prisms toward supercapactior performance’ by Ruili Zhang et al., RSC Adv., 2019, 9, 10814–10819.

We, the named authors, hereby wholly retract this RSC Advances article due to extensive overlap with the text, data and figures published in ref. 1, which means that this RSC Advances article is redundant. All the figures and tables in this RSC Advances article have been reproduced from ref. 1.The authors would like to apologise for any inconvenience to readers.Signed: Ruili Zhang and Ping Yang.Date: 8^th July 2019.We do not have current contact details for the second author of the article, Yuntao Yang, as he has graduated and therefore has not been able to comment on the retraction.Retraction endorsed by Andrew Shore, Executive Editor, RSC Advances.     

Correction: Direct electrodeposition of cationic pillar[6]arene-modified graphene oxide composite films and their host–guest inclusions for enhanced electrochemical performance

Correction for ‘Direct electrodeposition of cationic pillar[6]arene-modified graphene oxide composite films and their host–guest inclusions for enhanced electrochemical performance’ by Qunpeng Duan et al., RSC Adv., 2020, 10, 21954–21962, DOI: 10.1039/D0RA03138K.

The authors regret omitting a citation of their related paper published in Frontiers in Chemistry: ‘Facile one-step electrodeposition preparation of cationic pillar[6]arene-modified graphene films on glassy carbon electrodes for enhanced electrochemical performance’ (DOI: 10.3389/fchem.2020.00430) shown as ref. 1 here. The citation should appear as ref. 58 in the original article.¹The authors regret that it was not clear in the original article that the ErGO-CP6/GCE film had been previously reported by them in their related Frontiers in Chemistry paper¹ and therefore the sentence at the start of paragraph 3 on page 2 ‘In this work, we report for the first time preparation of CP6 functionalized graphene films on glassy carbon electrode (GCE) directly from GO-CP6 dispersions by facile one-step pulsed electrodeposition technique (Scheme 1).’ should be ‘In this work, we report the preparation of CP6 functionalized graphene films on glassy carbon electrode (GCE) directly from GO-CP6 dispersions by facile one-step pulsed electrodeposition technique (Scheme 1), which was previously reported by us.⁵⁸’.The authors also wish to clarify the differences between this RSC Advances paper and the Frontiers in Chemistry paper.¹ The papers use different guests molecules and different optimum pulse electrodeposition parameters and the RSC Advances paper reports an improvement in electrochemical performance with additional characterisation, stability studies and the analysis of real samples which are not reported in the Frontiers in Chemistry paper.¹The appropriate figure captions have been updated to reflect the data reproduced from the Frontiers in Chemistry paper.¹Scheme 1 Schematic illustration for the pulsed electrodeposition preparation of ErGO and ErGO-CP6 films on the surface of GCE and sensing the guest molecules by an electrochemical strategy. Reproduced with permission from ref. 1. Copyright 2020 Frontiers.Fig. 1 Characterization of materials. FTIR spectra (A), UV-vis absorption spectra (B), TGA curves of CP6, GO-CP6, and GO (C), and XPS survey spectra of GO and GO-CP6 (D). The data in (a, c and d) have been reproduced with permission from ref. 1. Copyright 2020 Frontiers.Fig. 4 (A) Raman spectra of GO and ErGO. (B) Raman spectra of GOCP6 and ErGO-CP6. Reproduced with permission from ref. 1. Copyright 2020 Frontiers.     

Retraction: Structural characterization of centipede oligopeptides and capability detection in human small cell lung carcinoma: inducing apoptosis

Retraction of ‘Structural characterization of centipede oligopeptides and capability detection in human small cell lung carcinoma: inducing apoptosis’ by JingQuan Zhao et al., RSC Adv., 2019, 9, 10927–10936, https://doi.org/10.1039/C8RA09018A.

The Royal Society of Chemistry hereby wholly retracts this RSC Advances article due to a significant amount of unattributed text overlap throughout the article, and particularly with ref. 1 in the Results and discussion section and ref. 2 in the Conclusion section.Jie Liu opposes the retraction. The other authors have been informed but have not responded to any correspondence regarding the retraction.Signed: Laura Fisher, Executive Editor, RSC AdvancesDate: 29^th March 2022     

Retraction: Olefin epoxidation with chiral salen Mn(iii) immobilized on ZnPS-PVPA upon alkyldiamine

Retraction of ‘Olefin epoxidation with chiral salen Mn(iii) immobilized on ZnPS-PVPA upon alkyldiamine’ by J. Huang et al., RSC Adv., 2016, 6, 19507–19514, DOI: 10.1039/C6RA00002A.

The Royal Society of Chemistry, with the agreement of the authors, hereby wholly retracts this RSC Advances article due to extensive overlap with other published articles by these authors, including the text, data and figures published in ref. 1, which was not cited in this article. Although there are sections of original work, there are significant portions of text overlap, particularly in the Results and discussion section. Fig. 1, 3, 4 and 5, Tables 1 and 2 and Schemes 1 and 2 in the RSC Advances article have also been reproduced from ref. 1.Signed: J. Huang, D. W. Qi, J. L. Cai and X. H. ChenDate: 19^th November 2020Retraction endorsed by Laura Fisher, Executive Editor, RSC Advances     

Retraction: Salvianolic acid B inhibits inflammatory response and cell apoptosis via the PI3K/Akt signaling pathway in IL-1β-induced osteoarthritis chondrocytes

Retraction of ‘Salvianolic acid B inhibits inflammatory response and cell apoptosis via the PI3K/Akt signalling pathway in IL-1β-induced osteoarthritis chondrocytes’ by Bin Zhu et al., RSC Adv., 2018, 8, 36422–36429, DOI: 10.1039/C8RA02418A.

The Royal Society of Chemistry hereby wholly retracts this RSC Advances article due to concerns with the reliability of the data.The images in the article were screened by an image integrity expert who confirmed that some of the western blots images in this paper had been duplicated in other articles. There are no common authors between the papers.The Col II band in Fig. 3B of this paper has been duplicated as the p62 band in Fig. 4A of ref. 1.One of the blots in the control band (GAPDH) in Fig. 3D has also been reused as a blot in Fig. 2C of ref. 1 and in Fig. 4A of ref. 2.The authors were asked to provide the raw data for this article but did not respond. Given the significance of the concerns about the validity of the data, and the lack of raw data, the findings presented in this paper are not reliable.The authors have been informed but have not responded to any correspondence regarding the retraction.Signed: Laura Fisher, Executive Editor, RSC AdvancesDate: 7^th January 2021     

Retraction: Enhanced electrocatalytic activity and durability of highly monodisperse Pt@PPy–PANI nanocomposites as a novel catalyst for the electro-oxidation of methanol

Retraction of ‘Enhanced electrocatalytic activity and durability of highly monodisperse Pt@PPy–PANI nanocomposites as a novel catalyst for the electro-oxidation of methanol’ by Özlem Karatepe et al., RSC Adv., 2016, 6, 50851–50857. DOI: 10.1039/C6RA06210E.

The Royal Society of Chemistry hereby wholly retracts this RSC Advances article due to concerns with the reliability of the data in the published article.The two high resolution transmission electron micrograph insets in Fig. 2 that represent Pt@PPy–PANI NPs polymer composites are identical. In addition, these insets are duplicated and scaled versions of the high-resolution transmission electron micrograph insets in Fig. 1 in an International Journal of Hydrogen Energy article,¹ and in Fig. 2 in a Journal of Cluster Science article,² by the same author group representing different nanoparticles or synthetic methods. Fig. 1 in the International Journal of Hydrogen Energy article¹ represents Pt(0)/DPA@GO NPs and Fig. 2 in the Journal of Cluster Science article² represents Pt(0) NPs. The authors claim that this was a mistake and provided replacement data for consideration. However, an expert reviewed the author’s response and concluded that it did not satisfactorily address the concerns, and that the replacement figure did not fully support the conclusions. Given the significance of the concerns about the validity of the data, the findings presented in this paper are no longer reliable.Sinan Eriş and Fatih Sen oppose this retraction. Handan Pamuk, Yunus Yıldız, Özlem Karatepe and Zeynep Dasdelen were contacted but did not respond.Signed: Laura Fisher, Executive Editor, RSC AdvancesDate: 23^rd September 2021     

Retraction: Structural characterization of ginseng oligopeptides and anti-aging potency evaluation in Caenorhabditis elegans

Retraction of ‘Structural characterization of ginseng oligopeptides and anti-aging potency evaluation in Caenorhabditis elegans’ by Qiang Luo et al., RSC Adv., 2020, 10, 39485–39494, https://doi.org/10.1039/D0RA06093C.

The Royal Society of Chemistry hereby wholly retracts this RSC Advances article due to a significant amount of unattributed text overlap with articles by different author groups that were not cited, including articles published in Phytochemistry by Shan Su et al.¹ and Journal of Functional Foods by Elena M. Vayndorf et al.²Zhigang Liu agrees to the retraction. The other authors have been informed but have not responded to any correspondence regarding the retraction.Signed: Laura Fisher, Executive Editor, RSC AdvancesDate: 25^th April 2022     

Retraction: Amino acid derived highly luminescent,heteroatom-doped carbon dots for label-free detection of Cd2+/Fe3+, cell imaging and enhanced antibacterial activity

Retraction of ‘Amino acid derived highly luminescent, heteroatom-doped carbon dots for label-free detection of Cd²⁺/Fe³⁺, cell imaging and enhanced antibacterial activity’ by Paramita Karfa et al., RSC Adv., 2015, 5, 58141–58153.

The Royal Society of Chemistry hereby wholly retracts this RSC Advances article due to concerns with the reliability of the data in the published article.A repeating pattern can be observed in the XPS spectra in Fig. 2C in the 390–396 eV range. The XPS data also duplicates data that was presented in another publication, but reported as a different material.¹The TEM image in Fig. 3A has been used in another publication, but reported as a different material.²The bacterial growth curves in Fig. 3F illustrate duplication of data, which were reported as different bacterial strains. The growth curves also duplicate data presented in other publications.^3,4The fluorescence microscopy images in Fig. 5A and B have been used in another publication, but reported as different materials.⁵The concentration stability data points in Fig. S2 have been duplicated in Fig. S3 as pH stability data points.Given the number and significance of the concerns, the validity of the data and, therefore, the conclusions presented in this paper are no longer reliable.The Royal Society of Chemistry apologises for the fact that these concerns were not identified during the peer review process.Paramita Karfa, Santanu Patra, Rashmi Madhuri and Prashant K. Sharma oppose the retraction. Ekta Roy, Sunil Kumar and Abhrajyoti Tarafdar were contacted but did not respond.Signed: Andrew Shore, Executive Editor, RSC Advances.Date: 23rd November 2018.     

Retraction: Ligustrazine attenuates renal damage by inhibiting endoplasmic reticulum stress in diabetic nephropathy by inactivating MAPK pathways

Retraction of ‘Ligustrazine attenuates renal damage by inhibiting endoplasmic reticulum stress in diabetic nephropathy by inactivating MAPK pathways’ by Hongling Yang et al., RSC Adv., 2018, 8, 21816–21822, DOI: 10.1039/C8RA01674G.

The Royal Society of Chemistry hereby wholly retracts this RSC Advances article due to concerns with the reliability of the data.The images in the article were screened by an image integrity expert who confirmed that some of the western blot images in this paper had been duplicated in other articles. There are no common authors between the papers.The control bands (GAPDH) in Fig. 3A of this paper are identical to the western blot control bands (GAPDH) presented in Fig. 1E of ref. 1.The control bands (GAPDH) in Fig. 4A of this paper are identical to the western blot control bands (GAPDH) presented in Fig. 2C and Fig. 4G of ref. 2.One of the blots in the control band (GAPDH) in Fig. 4A has also been reused as a blot in Fig. 3D of ref. 3.The authors were asked to provide the raw data for this article but did not respond. Given the significance of the concerns about the validity of the data, and the lack of raw data, the findings presented in this paper are not reliable.The authors have been informed but have not responded to any correspondence regarding the retraction.Signed: Laura Fisher, Executive Editor, RSC Advances.Date: 7^th January 2021.     

Correction: Nano N-TiO2 mediated selective photocatalytic synthesis of quinaldines from nitrobenzenes

Correction for ‘Nano N-TiO₂ mediated selective photocatalytic synthesis of quinaldines from nitrobenzenes’ by Kaliyamoorthy Selvam et al., RSC Adv., 2012, 2, 2848–2855, DOI: 10.1039/C2RA01178F.

The authors regret omitting citations of their related papers in Journal of Molecular Catalysis A: Chemical and Applied Catalysis A: General: ‘Cost effective one-pot photocatalytic synthesis of quinaldines from nitroarenes by silver loaded TiO₂’ (DOI: 10.1016/j.molcata.2011.09.014)¹ and ‘Mesoporous nitrogen doped nano titania—A green photocatalyst for the effective reductive cleavage of azoxybenzenes to amines or 2-phenyl indazoles in methanol’ (DOI: 10.1016/j.apcata.2011.11.011).² The citations should have appeared in the following places as ref. 36 (ref. 1, in the reference list here) and ref. 37 (ref. 2, in the reference list here):In the sentence starting on line 5 of paragraph 5 in the introduction:‘Photocatalytic synthesis of quinolone derivatives from nitrobenzene using TiO₂, metal doped TiO₂ and others had been reported earlier.^1,23–25’At the end of Section 3.12 with the addition of the following sentence:‘This catalyst was also found to be effective for the reductive cleavage of azoxybenzenes to amines or 2-phenyl indazoles in methanol.²’The authors regret that it was not clear in the original article that the bare TiO₂ and N-TiO₂ characterisation data had been reproduced from their related Journal of Molecular Catalysis A: Chemical, Applied Catalysis A: General and Catalysis Communications papers.^1–3 Although the Catalysis Communications article was cited as ref. 25 (ref. 3, in the reference list here) in the original article, it was not made clear that some of the data was reproduced from this article. The appropriate figure captions have been updated to reflect this.Fig. 2: Diffuse reflectance spectra of (a) bare TiO₂, (b) N-TiO₂ and (c) TiO₂-P25. The bare TiO₂ data in Fig. 2a have been reproduced with permission from ref. 1. Copyright 2011 Elsevier. The N-TiO₂ data in Fig. 2b have been reproduced with permission from ref. 2. Copyright 2012 Elsevier.Fig. 3: Photoluminescence spectra of (a) bare TiO₂, (b) TiO₂-P25 and (c) N-TiO₂. The bare TiO₂ data in Fig. 3a have been reproduced with permission from ref. 1. Copyright 2011 Elsevier. The N-TiO₂ data in Fig. 3c have been reproduced with permission from ref. 2. Copyright 2012 Elsevier.Fig. 4: HR-TEM analysis: (a and b) images at two different regions of N-TiO₂, (c) SAED pattern of N-TiO₂, (d) lattice fringes of N-TiO₂ and (e) particle size distribution of N-TiO₂. Fig. 4 has been entirely reproduced with permission from ref. 2. Copyright 2012 Elsevier.Fig. 5: X-ray photoelectron spectra of N-TiO₂: (a) survey spectrum, (b) Ti 2p peak, (c) O 1s peak, (d) N 1s peak and (e) C peak. Fig. 5 has been entirely reproduced with permission from ref. 2. Copyright 2012 Elsevier.Fig. 6: (a) N₂ adsorption–desorption isotherms of N-TiO₂ and (b) its pore size distribution. Fig. 6 has been entirely reproduced with permission from ref. 2. Copyright 2012 Elsevier.Fig. 8: GC-MS chromatograms at different reaction times for the photocatalytic conversion of nitrobenzene with N-TiO₂. Fig. 8 has been entirely reproduced with permission from ref. 3. Copyright 2011 Elsevier.The authors also wish to remove Fig. 1 from the original article due to similarities between two of the spectra and the raw data no longer being available. This does not affect the conclusions as the presence of nitrogen was confirmed by other techniques.The authors also wish to clarify the differences between this RSC Advances paper and the Journal of Molecular Catalysis A: Chemical, Applied Catalysis A: General and Catalysis Communications papers.^1–3 The Journal of Molecular Catalysis A: Chemical paper discusses the photocatalytic synthesis of quinaldines from nitroarenes by silver loaded TiO₂.¹ The Applied Catalysis A: General paper reports the reductive cleavage of azoxybenzenes to amines or 2-phenyl indazoles using mesoporous nitrogen doped nano titania.² The Catalysis Communications paper, ref. 25 in the original article, discusses the synthesis of quinaldines from nitroarenes with gold loaded TiO₂ nanoparticles.³ The original RSC Advances paper discusses the catalytic ability of N-TiO₂ in the synthesis of quinaldines from nitrobenzenes. In each paper, either a different catalyst was used or a different synthetic reaction was investigated.     

Correction: Oxidative carboxylation of olefins with CO2: environmentally benign access to five-membered cyclic carbonates

Correction for ‘Oxidative carboxylation of olefins with CO₂: environmentally benign access to five-membered cyclic carbonates’ by Liang Wang et al., RSC Adv., 2020, 10, 9103–9115.

The Royal Society of Chemistry regrets that incorrect details were given for Ref. 10b, 11b and 11c in the original article. The correct versions of Ref. 10b, 11b and 11c are given below as Ref. 1, 2a and 2b, respectively.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Retraction: Tuning the chemistry of graphene oxides by a sonochemical approach: application of adsorption properties

Retraction of ‘Tuning the chemistry of graphene oxides by a sonochemical approach: application of adsorption properties’ by Yubing Sun et al., RSC Adv., 2015, 5, 24886–24892, DOI: 10.1039/C5RA02021B.

The Royal Society of Chemistry, with the agreement of the named authors, hereby wholly retracts this RSC Advances article due to concerns with the reliability of the data in the published article.The TEM image in Fig. 1B duplicates data published in another publication by Pan et al., but presented as different materials.¹The AFM images in Fig. 1C and D illustrate duplication of data, given that these experiments were reported under different reaction conditions.The EXAFS spectra in Fig. 4 duplicate data in another publication, but reported as different materials.²Given the number and significance of the concerns about the validity of the data, the findings presented in this paper are no longer reliable.Signed: Yubing Sun, Shubin Yang, Congcong Ding and Wencai ChengDate: 27^th March 2020Zhongxiu Jin was contacted but did not respond.Retraction endorsed by Laura Fisher, Executive Editor, RSC Advances     

TEMPORAL EVOLUTION AND PREDICTORS OF SUBJECTIVE COGNITIVE COMPLAINTS UP TO 4 YEARS AFTER STROKE

ObjectiveTo examine the temporal evolution of subjective cognitive complaints in the long-term after stroke, and to identify predictors of long-term subjective cognitive complaints.MethodsProspective cohort study including 395 stroke patients. Subjective cognitive complaints were assessed at 2 months, 6 months and 4 years post-stroke, using the Checklist for Cognitive and Emotional consequences following stroke (CLCE-24). The temporal evolution of subjective cognitive complaints was described using multilevel growth modelling. Associations between CLCE-24 cognition score at 4 years post-stroke and baseline characteristics, depression, anxiety, cognitive test performance, and adaptive and maladaptive psychological factors were examined. Significant predictors were entered in a multivariate multilevel model.ResultsA significant increase in subjective cognitive complaints from 2 months up to 4 years (mean 3.7 years, standard deviation (SD) 0.6 years) post-stroke was observed (p≤0.001). Two months post-stroke, 76% of patients reported at least one cognitive complaint, 72% at 6 months, and 89% at 4 years post-stroke. A higher level of subjective cognitive complaints at 2 months and lower scores on adaptive and maladaptive psychological factors were significant independent predictors of a higher level of subjective cognitive complaints at 4 years post-stroke.ConclusionPost-stroke subjective cognitive complaints increase over time and can be predicted by the extent of subjective cognitive complaints and the presence of adaptive and maladaptive psychological factors in the early phases after stroke.LAY ABSTRACTMany people suffer a stroke in the brain leading to consequences in different areas of functioning. Complaints in the domain of thinking (memory, attention, planning and organization) are frequent post-stroke. This study investigated the occurrence and type of complaints experienced in the first years after a stroke. The study found that these complaints increase over time. Longterm complaints are found in those people who already have problems early after stroke.Key words: stroke, rehabilitation, cognition, cognitive complaints

Subjective cognitive complaints (SCC) are common after stroke, with prevalence rates varying between 28.6% (1) and 90.2%, (2), depending on stroke characteristics, time since stroke, SCC definitions and the instruments used. The most commonly reported complaints are mental slowness (in 46–80% of patients) and difficulties in concentration and memory (in 38–68% and 38–94% of patients, respectively) (3). Previous cross-sectional studies showed that SCC are present in both the early stages after stroke (1–6 months after stroke) (4–6), and in the long-term (> 1 year after stroke) (1, 7, 8). To date only a few studies have examined the temporal evolution of SCC. Tinson & Lincoln observed an increase in SCC between 1 and 7 months post-stroke (n = 95) (9). The authors used the Everyday Memory Questionnaire (10), focusing on memory-related complaints. Wilz & Barskova also found an increase in SCC over time after stroke (3 vs 15 months post-stroke, n = 81) (11). SCC were measured with the Patient Competency Rating Scale cognition subscale (12). Van Rijsbergen et al., who used the Checklist for Cognitive and Emotional consequences following stroke (CLCE-24) (13), recently found that SCC remained stable between 3 and 12 months after stroke (n = 155) (14). Long-term results on the course of post-stroke SCC are lacking. Since SCC were found to be independently related to lower quality of life in patients with mild cognitive impairment (15), and patients with subarachnoid haemorrhage (16), it is important to assess SCC after stroke. Furthermore, earlier research showed that SCC were most strongly associated with participation after stroke, compared with cognitive tests in a neuropsychological test battery, and the Montreal Cognitive Assessment (MoCA) (17, 18). Hence, in order to improve participation and integration in society after stroke, it is important to take the patients’ perspective into account, rather than only determining objective cognitive measures.The presence and severity of SCC is expected to be a direct reflection of the presence and severity of cognitive deficits. However, previous studies investigating the relationship between SCC and cognitive performance in stroke patients have shown conflicting results (1–4, 7, 8, 13, 19, 20). Other factors have shown to be related to SCC, in particular psychological factors, such as depressive symptoms (2, 4, 6, 7, 21), anxiety (21, 22), perceived stress (14), personality traits (7, 22), and coping style (23). To date, only one study on SCC used a longitudinal design (14), which prevents conclusions on the temporal evolution of SCC in stroke patients in the long term. Since more stroke patients survive, recover well and are discharged home nowadays, it is important to address predictors of SCC in the early phases after stroke, in order to identify patients who need more intensive monitoring at follow-up. Once identified, it is possible to investigate whether the patients will benefit from more focused rehabilitation programmes.The aim of this longitudinal study was to examine the temporal evolution of SCC, from 2 months until 4 years post-stroke. Furthermore, the study assessed which factors are predictive of SCC at 4 years post-stroke, taking into account demographic and stroke-related characteristics at baseline, and cognitive deficits and psychological factors measured at 2 months post-stroke.     

E–Z isomerization of 3-benzylidene-indolin-2-ones using a microfluidic photo-reactor

Here, we report controlled E–Z isomeric motion of the functionalized 3-benzylidene-indolin-2-ones under various solvents, temperature, light sources, and most importantly effective enhancement of light irradiance in microfluidic photoreactor conditions. Stabilization of the E–Z isomeric motion is failed in batch process, which might be due to the exponential decay of light intensity, variable irradiation, low mixing, low heat exchange, low photon flux etc. This photo-μ-flow light driven motion is further extended to the establishment of a photostationary state under solar light irradiation.

(E)-3-Benzylidene-indolin-2-ones were efficiently converted to their corresponding (Z) -isomers at low temperature in the presence of light.

Functionalized 3-benzylidene-indolin-2-ones are an important structural motif in organic chemistry and are embedded in many naturally occurring compounds.¹ They found wide applications in molecular-motors,² energy harvesting dyes,³ pharmaceutical chemistry (sunitinib, tenidap),⁴ protein kinase inhibitors,⁵ pesticides,⁶ flavors,⁷ and the fragrance industry.⁸ In the last few decades, numerous protocols have been developed for the synthesis of novel indolin-2-ones. For instance, palladium (Pd)-catalysed intramolecular hydroarylation of N-arylpropiolamides,⁹ Knoevenagel condensation of oxindole and aldehyde,¹⁰ two-step protocols such as Ni-catalyzed CO₂ insertion followed by coupling reaction,¹¹ Pd-catalysed C–H functionalization/intramolecular alkenylation,¹² Pd(0)/monophosphine-promoted ring–forming reaction of 2-(alkynyl)aryl isocyanates with organoboron compound, and others.¹³Knoevenagel condensation is one of the best methods for the preparation of 3-benzylidene-indolin-2-ones, but often it gives mixture of E/Z isomeric products. Otherwise, noble metal-catalysed protocols received enormous interest. However, the limited availability, high price, and toxicity of these metals diminished their usage in industrial applications. Therefore, several research groups have been engaged in search of an alternative greener and cleaner approach under metal-free conditions. To address the diastereoisomeric issue, Tacconi et al. reported a thermal (300–310 °C) isomerization reaction of 3-arylidene-1,3-dihydroindol-2-ones,¹⁴ which suffers from poor reaction efficiency and E/Z selectivity. Therefore, transformations controlling E/Z ratio of 3-benzylidene-indolin-2-ones remains a challenging task and highly desirable (Scheme 1).Open in a separate windowScheme 1Functionalized 3-benzylidene-indolin-2-ones and alkenes in bioactive compounds and the accessible methods.On the other hand, selective E/Z stereo-isomerization of alkenes has been well established using various methods in the presence of light stimuli,^15a cations,^15b halogens or elemental selenium,¹⁶ palladium-hydride catalyst,¹⁰ cobalt-catalyst,¹⁷ Ir-catalyst,¹⁸ organo-catalysts.¹⁹ Among these, light-induced photostationary E/Z stereoisomerization is very attractive, due to its close proximity towards the natural process. In recent years, several light-driven molecular motors (controlled motion at the molecular level), molecular propellers,²⁰ switches,²¹ brakes,²² turnstiles,²³ shuttles,²⁴ scissors,²⁵ elevators,²⁶ rotating modules,²⁷ muscles,²⁸ rotors,²⁹ ratchets,³⁰ and catalytic self-propelled objects have been developed.³¹ Further, equipment''s relying on molecular mechanics were rapidly developed, particularly in the area of health care.Till date, controlled photo-isomerization of functionalized 3-benzylidene-indolin-2-ones is one of the puzzling problems to the scientific community. Photochemical reactions in batch process have serious drawbacks with limited hot-spot zone due to inefficient light penetration with increasing light path distance through the absorbing media, and the situation becomes poorer when the reactor size increases.^32,33 In contrast, the capillary microreactor platform has emerged as an efficient the artificial tool with impressive advantages, such as excellent photon flux, uniform irradiation, compatibility with multi-step syntheses, excellent mass and heat transfer, which lead to significant decrease the reaction time with improved yield or selectivity over batch reactors.^33a,34 To address the aforementioned challenges, it is essential to develop a highly efficient photo-microchemical flow approach for the controlled isomerization of functionalized 3-benzylidene-indolin-2-ones in catalyst-free and an environment friendly manner.     

Retraction: Synthesis and characterization of Co/Ti layered double hydroxide and its application as a photocatalyst for degradation of aqueous Congo Red

Retraction of ‘Synthesis and characterization of Co/Ti layered double hydroxide and its application as a photocatalyst for degradation of aqueous Congo Red’ by Priyadarshi Roy Chowdhury and Krishna G. Bhattacharyya, RSC Adv., 2015, 5, 92189–92206.

The Royal Society of Chemistry hereby wholly retracts this RSC Advances article due to concerns with the reliability of the data in the published article.The XPS data in Fig. 4B, E and F have been duplicated in another publication, but reported as a different material.¹A repeating segment can be observed in the TEM image presented in Fig. 10C, which indicates that this image has been manipulated.There are unexpected similarities in the baseline of the EDX spectrum in Fig. 10F and the EDX spectra in other publications, which have all been reported as different materials.^1–3There are repeating motifs within the AFM image in Fig. 10G, which indicates that this image has been manipulated. Many of these motifs can also be observed in an AFM image in another publication, but representing a different material.²The image in Fig. 10I is unreliable as it has subsequently been reused in unpublished material to represent different materials.The FTIR data presented in Fig. 16B (blue, red and green spectra) illustrate duplication of data, given that these experiments were reported under different reaction conditions.Given the number and significance of the concerns about the validity of the data, the findings presented in this paper are no longer reliable.Priyadarshi Roy Chowdhury and Krishna G. Bhattacharyya were informed about the retraction of the article but did not respond.Signed: Laura Fisher, Executive Editor, RSC AdvancesDate: 12^th March 2020     

Retraction: Synthesis of non-toxic,biocompatible, and colloidal stable silver nanoparticle using egg-white protein as capping and reducing agents for sustainable antibacterial application

Retraction of ‘Synthesis of non-toxic, biocompatible, and colloidal stable silver nanoparticle using egg-white protein as capping and reducing agents for sustainable antibacterial application’ by Kalaiyarasan Thiyagarajan et al., RSC Adv., 2018, 8, 23213–23229, https://doi.org/10.1039/C8RA03649G.

I, the undersigned author, hereby wholly retract this RSC Advances article due to the following instances of matched/similar images that have been identified that weaken this article, which occurred due to honest human errors.Following the previous publication of a correction to replace Fig. 3D, instances of duplicating images have been identified that undermine this article.In Fig. 5, the panels E. coli MTCC No 62 6 μg ml⁻¹ and E. coli MTCC No 62 8 μg ml⁻¹ are identical. Furthermore, they are identical to panels in another article published by the authors in RSC Advances,¹ namely the panel for freshly prepared S. enterica MTCC-3219 2 μg ml⁻¹ 10⁻¹⁰ and the panel for S. typhirmurium MTCC-3224 4 μg ml⁻¹ 10⁻⁵ after one year of storage in Fig. 3 of ref. 1 and the panel 1 h treated with SBT@AgNPs in Fig. 7 of ref. 1.Thiyagarajan Kalaiyarasan and Vijay K. Bharti responded to all enquiries and submitted data related to the above concern. However, to avoid any future ambiguity to the readers, the article is retracted.Krishna Kumar and Vijay K. Bharti do not agree to the retraction. The other authors have been informed but have not responded to any correspondence regarding the retraction.Signed: Kalaiyarasan ThiyagarajanDate: 1/6/2022Retraction endorsed by Laura Fisher, Executive Editor, RSC Advances     

Preparation of Ni-microsphere and Cu-MOF using aspartic acid as coordinating ligand and study of their catalytic properties in Stille and sulfoxidation reactions

In this study, the thermal and catalytic behavior of Ni-microsphere and Cu-MOF were investigated with aspartic acid as the coordinating ligand with different morphologies. The Ni-microsphere and Cu-MOF with aspartic acid, as the coordinating ligand, were prepared via a solvothermal method. The morphology and porosity of the obtained Ni microsphere and Cu-MOF were characterized by XRD, FTIR, TGA, DSC, BET and SEM techniques. The catalytic activity of the Ni-microsphere and Cu-MOF was examined in Stille and sulfoxidation reactions. The Ni microsphere and Cu-MOF were easily isolated from the reaction mixtures by simple filtration and then recycled four times without any reduction of catalytic efficiency.

In this study, the thermal and catalytic behavior of Ni-microsphere and Cu-MOF were investigated with aspartic acid as the coordinating ligand with different morphologies.

Cross-coupling reaction is one of the most significant methods to create carbon–carbon bonds in organic synthesis. There are many approaches, including, Suzuki, Stille, and Sonogashira cross-coupling reactions, which are well recognized and highly applicable in organic synthesis. Among them, the Stille reaction, which is an increasingly versatile tool for the formation of carbon–carbon bonds, involves the coupling of aryl halides with organotin reagents.¹ However, these reactions generally require expensive transition metal catalysts such as Pd.² Therefore, it is necessary to develop a new economic, green, and efficient methodology to reduce the environmental impact of the reaction. They are also important intermediates in organic chemistry and have been widely used as ligands in catalysis. The direct oxidation of sulfides is an important method in organic chemistry. Besides, they are also valuable synthetic intermediates for the construction of chemically and biologically important molecules, which usually synthesized by transition metal complexes.³ In this regard, different transition metal complexes of mercury(ii) oxide/iodine,⁴ oxo(salen) chromium(v),⁵ rhenium(v) oxo,⁶ H₅IO₆/FeCl₃,⁷ Na₂WO₄/C₆H₅PO₃H₂,⁸ chlorites and bromites,⁹ NBS¹⁰etc. have been introduced as catalysts. However, these catalysts have several drawbacks; including, separation problems from the reaction medium, harsh reaction conditions, and generating a lot of waste. In order to solve these drawbacks, of separation and isolation of expensive homogeneous catalysts is the heterogenization of homogeneous catalysts and generation of a new heterogeneous catalytic system. Metal–organic frameworks (MOFs) are a class of porous crystalline materials, which show great advantages, i.e. their enormous structural and chemical diversity in terms of high surface area,^11,12 pore volumes,¹³ high thermal,¹⁴ and chemical stabilities,¹⁵ various pore dimensions/topologies, and capabilities to be designed and modified after preparation.¹⁶ In this sense, it is worth mentioning that these features would result in viewing these solids as suitable heterogeneous catalysts for organic transformations.^17–22 MOFs materials are prepared using metal ions (or clusters) and organic ligands in solutions (i.e. solvothermal or hydrothermal synthesis). MOF structures are affected by metal and organic ligands, leading to have more than 20 000 different MOFs with the largest pore aperture (98 Å) and lowest density (0.13 g cm⁻³).²³ Generally, surface area and pore properties of MOFs seem quite dependent on their metal and ligand type as well as synthesis conditions and the applied post-synthesis modifications. The largest surface area was measured in Al-MOF (1323.67 m² g⁻¹)^24,25 followed by ZIF-8-MOF (1039.09 m² g⁻¹),²⁶ while the lowest value was with Zn-MOF (0.86 m² g⁻¹),²⁷ followed by γ-CD-MOF (1.18 m² g⁻¹)²⁸ and Fe₃O(BDC)₃ (7.6 m² g⁻¹).²⁹ Microspheres are either microcapsule or monolithic particles, with diameters in the range (typically from 1 μm to 1000 μm),²⁹ depending on the encapsulation of active drug moieties. In this regard, there are two types of microspheres: microcapsules, defined, as spherical particles in the size range of about 50 nm to 2 mm and micro matrices.³⁰ Microsphere structures have recently attracted much attention due to their unique properties, such as large surface area,³¹ which make them suitable for tissue regenerative medicine,³²i.e. as cell culture scaffolds,³³ drug-controlled release carriers³⁴ and heterogeneous catalysis.³⁵ Many chemical synthetic methods has been developed for their synthesis, including seed swelling,³⁶ hydrothermal or solvothermal methods,³⁶ polymerization,³⁷ spray drying³⁸ and phase separation.³⁹ Among these methods, the solvothermal synthesis has been used as the most suitable methodology to prepare a variety of nanostructural materials, such as wire, rod,⁴⁰ fiber,⁴¹ mof⁴² and microsphere.⁴³ In this sense, the synthesis process involves the use of a solvent under unusual conditions of high pressure and high temperature.⁴⁴ The properties of microspheres are highly dependent on the number of pores, pore diameter and structure of pore.⁴⁵ The degree of porosity depends on various factors such as temperature, pH, stirring speed, type, and concentration of porogen, polymer, and its concentration.⁴⁶ There have been numerous studies to investigate the coordination behavior of a ligand with different metals under the same conditions.^47–49 Herein, we aim at comparing the catalytic behavior of Ni-microsphere and Cu-MOF with aspartic acid as the coordinating ligand in Stille and sulfoxidation reactions (Scheme 1).Open in a separate windowScheme 1(a) Schematic synthesis of Ni microsphere and Cu-MOF and their application as catalyst (b) topological structure of Cu-MOF (c) topological of Ni microsphere.