Simulation of Depth of Wear of Eco-Friendly Concrete Using Machine Learning Based Computational Approaches

To avoid time-consuming, costly, and laborious experimental tests that require skilled personnel, an effort has been made to formulate the depth of wear of fly-ash concrete using a comparative study of machine learning techniques, namely random forest regression (RFR) and gene expression programming (GEP). A widespread database comprising 216 experimental records was constructed from available research. The database includes depth of wear as a response parameter and nine different explanatory variables, i.e., cement content, fly ash, water content, fine and coarse aggregate, plasticizer, air-entraining agent, age of concrete, and time of testing. The performance of the models was judged via statistical metrics. The GEP model gives better performance with R² and ρ equals 0.9667 and 0.0501 respectively and meet with the external validation criterion suggested in the previous literature. The k-fold cross-validation also verifies the accurateness of the model by evaluating R², RSE, MAE, and RMSE. The sensitivity analysis of GEP equation indicated that the time of testing is the influential parameter. The results of this research can help the designers, practitioners, and researchers to quickly estimate the depth of wear of fly-ash concrete thus shortening its ecological susceptibilities that push to sustainable and faster construction from the viewpoint of environmentally friendly waste management.     

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.     

First principles study of electronic and optical properties and photocatalytic performance of GaN–SiS van der Waals heterostructure

The vertical stacking of two-dimensional materials via van der Waals (vdW) interaction is a promising technique for tailoring the physical properties and fabricating potential devices to be applied in the emerging fields of materials science and nanotechnology. The structural, electronic and optical properties and photocatalytic performance of a GaN–SiS vdW heterostructure were explored using first principles calculations. The most stable stacking configuration found energetically stable, possesses a direct staggered band gap, which is crucial for separating photogenerated charged carriers in different constituents and is efficacious for solar cells. Further, the charge transfer occurred from the SiS to GaN layer, indicating that SiS exhibits p-type doping in the GaN–SiS heterobilayer. Interestingly, a systematic red-shift was observed in the optical absorption spectra of the understudy heterobilayer system. Moreover, the conduction band edge and valence band edge of the monolayers and corresponding heterostructure were located above and below the standard redox potentials for photocatalytic water splitting, making these systems promising for water dissociation for hydrogen fuel production. The results provide a route to design the GaN–SiS vdW heterostructure for the practical realization of next-generation light detection and energy harvesting devices.

The two dimensional GaN–SiS van der Waals heterostructure is a promising candidate for optoelectronic and photocatalytic water splitting.     

Realizing high performance flexible supercapacitors by electrode modification

It is well known that the structure of an electrode material seriously affects its electrochemical performance. In this study, we prepare hybrid structured NiCo₂S₄@PPy nanoarchitectures by a hydrothermal method and subsequent electrodeposition process. The specific capacitance of the obtained sample is 1733.23 C g⁻¹ at 1 A g⁻¹. The assembled asymmetric device presents an energy density of 59.59 W h kg⁻¹ at 1404.04 W kg⁻¹. The excellent electrochemical performance can be attributed to the synergistic effect between the high theoretical specific capacitance of the NiCo₂S₄ sheets and the superior cycling stability of the PPy film. The device also shows an outstanding mechanical flexibility at different bending angles.

We prepare hybrid structured NiCo₂S₄@PPy nanoarchitectures by a hydrothermal method and subsequent electrodeposition process. The assembled asymmetric device presents an energy density of 59.59 W h kg⁻¹ at 1404.04 W kg⁻¹.     

Review of policies,data, and interventions to improve maternal nutrition in Afghanistan

Malnutrition contributes to direct and indirect causes of maternal mortality, which is particularly high in Afghanistan. Women's nutritional status before, during, and after pregnancy affects their own well‐being and mortality risk and their children's health outcomes. Though maternal nutrition interventions have documented positive impact on select child health outcomes, there are limited data regarding the effects of maternal nutrition interventions on maternal health outcomes globally. This scoping review maps policies, data, and interventions aiming to address poor maternal nutrition outcomes in Afghanistan. We used broad search categories and approaches including database and website searches, hand searches of reference lists from relevant articles, policy and programme document requests, and key informant interviews. Inclusion and exclusion criteria were developed by type of source document, such as studies with measures related to maternal nutrition, relevant policies and strategies, and programmatic research or evaluation by a third party with explicit interventions targeting maternal nutrition. We abstracted documents systematically, summarized content, and synthesized data. We included 20 policies and strategies, 29 data reports, and nine intervention evaluations. The availability of maternal nutrition intervention data and the inclusion of nutrition indicators, such as minimum dietary diversity, have increased substantially since 2013, yet few nutrition evaluations and population surveys include maternal outcomes as primary or even secondary outcomes. There is little evidence on the effectiveness of interventions that target maternal nutrition in Afghanistan. Policies and strategies more recently have shifted towards multisectoral efforts and specifically target nutrition needs of adolescent girls and women of reproductive age. This scoping review presents evidence from more than 10 years of efforts to improve the maternal nutrition status of Afghan women. We recommend a combination of investments in measuring maternal nutrition indicators and improving maternal nutrition knowledge and behaviours.     

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.