Experimental and Theoretical Study on the Corrosion Inhibition of Mild Steel by 1‑Octyl-3-methylimidazolium l‑Prolinate in Sulfuric Acid Solution

A newly amino acid ionic liquid, 1-octyl-3-methylimidazolium l-prolinate ([Omim]­Lpro), was investigated as the inhibitor for mild steel in 0.5 M H₂SO₄ solution using weight loss method, electrochemical measurements, scanning electron microscopy (SEM), and quantum chemical calculation. The obtained results revealed that [Omim]­Lpro was a mixed-type inhibitor with a predominantly cathodic action for mild steel in 0.5 M H₂SO₄ solution, and inhibition efficiency reached nearly 80% at the concentration of 10 mM, in which the Omim cation played a major role in the corrosion inhibition of [Omim]­Lpro. The adsorption of [Omim]­Lpro on the mild steel surface was found to obey the El-Awady thermodynamic-kinetic model and Flory–Huggins isotherm equations; thus the thermodynamic and kinetic parameters governing the adsorption process were calculated and discussed. Moreover, quantum chemical calculation gave further insight into the mechanism of inhibition of [Omim]­Lpro

UV-Light-Induced Morphological Transformation of Spiropyran Assemblies from Irregular Sheet-like Structures to Nanospheres

Studies on self-assembling systems with a controllable morphology responding to light stimulation are significant for revealing the process and mechanism of assembly. Here, a molecule of spiropyran derivative (SP) possessing photoresponsive assembly morphology is constructed. SP self-assembles into irregular sheet-like structures whose morphology can be significantly transformed into regular nanospheres under continuous ultraviolet light stimulation. The UV–vis absorption spectra indicate that 56% of SP are isomerized from closed-ring form (SPC) to open-ring form (SPO) with color changes from colorless to magenta. Furthermore, theoretical calculations demonstrate that SPO-SPO aggregates possess stronger van der Waals forces than do SPC–SPC aggregates and tend to form stable intermediates combined with SPO isomers. Therefore, the isomerization of SP from SPC to SPO and the differences in intermolecular interactions are important factors in the morphological transition. Our study provides an efficient strategy to modulate the assembled morphology, which holds great promise to be applied in the field of smart materials

Electrospun Microfiber Membranes Embedded with Drug-Loaded Clay Nanotubes for Sustained Antimicrobial Protection

Guided tissue regeneration/guided bone regeneration membranes with sustained drug delivery were developed by electrospinning drug-loaded halloysite clay nanotubes doped into poly(caprolactone)/gelatin microfibers. Use of 20 wt % nanotube content in fiber membranes allowed for 25 wt % metronidazole drug loading in the membrane. Nanotubes with a diameter of 50 nm and a length of 600 nm were aligned within the 400 nm diameter electrospun fibers, resulting in membranes with doubling of tensile strength along the collector rotating direction. The halloysite-doped membranes acted as barriers against cell ingrows and have good biocompatibility. The metronidazole-loaded halloysite nanotubes incorporated in the microfibers allowed for extended release of the drugs over 20 days, compared to 4 days when directly admixed into the microfibers. The sustained release of metronidazole from the membranes prevented the colonization of anaerobic Fusobacteria, while eukaryotic cells could still adhere to and proliferate on the drug-loaded composite membranes. This indicates the potential of halloysite clay nanotubes as drug containers that can be incorporated into electrospun membranes for clinical applications

Petrogenesis of Middle Triassic Mafic Enclaves and Host Granodiorite in the Eastern Kunlun Orogenic Belt, NW China: Implications for Continental Crust Growth in Syn-Collisional Setting

The mechanism of the Triassic continental crust growth in the East Kunlun Orogenic Belt (EKOB) is highly controversial. In this contribution, we present comprehensive data on the Yuegelu granodiorite and its mafic microgranular enclaves (MMEs) from the eastern segment of the EKOB, including zircon U–Pb geochronology and Hf isotope, mineral chemistry, whole-rock geochemistry and Sr–Nd isotopes, and in situ plagioclase Sr isotope, to constrain the genesis of these rocks and shed new insights on the continental crust growth. The MMEs are coeval with the host granodiorite at ∼240 Ma and display abundant quenching textures such as acicular apatites and quartz phenocrysts rimmed by amphibole. They typically exhibit low SiO2 but high TiO2, Fe2O3T, MnO, and MgO concentrations and have similar Sr–Nd–Hf isotopic compositions to the host rock. We suggest that the Yuegelu MMEs are late cognate cumulates derived from the same parental magma with the host rock as a result of pressure quenching rather than the hybrids of crustal and mantle magmas. The granodiorite is medium- to high-K calc-alkaline, metaluminous I-type granite with relatively high SiO2, but low Al2O3, CaO, and Fe2O3T contents. The granodiorite is enriched in Rb, K, and Pb but depleted in Nb, Ta, Sr, P, and Ti, resembling a bulk continental crust. However, Yuegelu granodiorite has much more depleted Sr–Nd–Hf isotopic compositions than those of the mature crustal materials, indicating a significant mantle contribution. Based on Sr–Nd isotopic modeling, the Yuegelu granodiorite could be generated by partial melting of the Paleo-Tethys Oceanic crust (∼80%) with the overlying terrigenous sediments (∼20%). The partial melting of oceanic crust fragments in the syn-collisional setting in the Middle Triassic contributed substantially to the continental crust growth in the EKOB

Morphology of cultured MSC and CM.

<p>Panel A: MSC obtained from rat bone marrow. Panel B: Quantitative real-time PCR of GATA-4 expression in MSC transduced with GATA-4 (MSC^GATA-4) or empty vector (MSC^Null). Panel C: Immunostaining of MSC^GATA-4 and MSC^Null. Panel D: CM obtained from rat neonatal ventricles. Panel E: CM were immunostained positive for α-actinin (green) and connexin 43 (red, white arrows). Myofibers were seen with clear Z-lines in sarcomeres. E1: DAPI; E2: α-actinin; E3: connexin 43; and E4: merged images of E1 to E3. ^§, p<0.05 <i>vs</i> MSC^Null.</p

Internalization of PKH-26 pre-labeled MSC-MVs (MVs-PKH26) by CM.

<p>Panel A: Time-lapse images of MVs-PKH26 recorded at one hour intervals for 8 hours after addition of these MVs to CM culture. PKH26 red fluorescence (MVs) (white arrows) appeared inside CM at hour 3 and was widely scattered in whole cell clusters at hour 8. Panel B: Immunostaining shows internalization of MVs-PKH26 (red arrows) by α-actinin positive cells after MVs were added to CM cultures for 24 hours.</p

miR-221 transferred from MSC to CM and reduced PUMA expression in CM.

<p>Panel A: <i>In situ</i> hybridization staining of miR-221 in CM co-cultured with MSC^miR-221 for 48 hours. miR-221 is shown as a purple-blue signal (red circles) which was observed in both GFP positive MSC (green arrow) and GFP negative CM (red arrow). Panel B: Western blot of PUMA and corresponding semi-quantitative data in CM co-cultured with various MSC in a dual-chamber system.</p

The morphology and characterization of MSC derived MVs (MSC-MVs).

<p>Panel A: Morphological features of MSC-MVs under electron microscope. Panel B: Western blot results show that MSC-MVs highly expressed HSP70, CD63, and CD9 compared to MSC; Panel C: The expression of miR-221 in MSC-MVs, MSC, and CM analyzed using real-time PCR.</p

ΔΨm and activity of caspase3/7 in MSCs exposed to different environments.

<p>A. JC-1 fluorescence imaging in MSCs. The green fluorescence represented the JC-1 monomer and red fluorescence represented the JC-1 aggregate image. B. JC-1 ratio of J-aggregate to monomer in MCSs exposed to hypoxia for different time. C. Effect of clusterin on JC-1 ratio of MSCs cultured under hypoxia for 72 h. D. Effect of clusterin on the activity of caspase 3/7 in MSCs cultured under hypoxia for 72 h. ^#, <i>p</i> < 0.05 <i>vs</i> normal control; *, <i>p</i> < 0.05 <i>vs</i> hypoxic control without clusterin, respectively.</p

MSC injury following exposure to hypoxia from 24 h to 120 h.

<p>A. Morphology of MSCs in normoxia culture; B. LDH release; C. MTs intake; D. Ratio of LDH to MTs.</p