Corrosion behavior of 904L austenitic stainless steel in hydrofluoric acid

Corrosion behaviors of 904L austenitic stainless steel in HF and HCl were studied and compared using electrochemical method, microscopic analysis, and phase analysis. An insoluble layer is deposited on 904L in HF due to a preferential reaction between [F⁻] and the [Ni] from the alloy. This insoluble deposited layer not only helps isolate the aggressive ions from the base metal, but also inhibits the passivation of 904L in HF, the mechanism for which was entirely different from that in HCl.

An insoluble layer is deposited on 904L in HF due to a preferential reaction between [F⁻] and the [Ni] from the alloy. This insoluble deposit layer helps isolate the aggressive ions from the base metal, while inhibits the passivation of 904L in HF.     

A carbonised sieve-like corn straw cellulose–graphene oxide composite for organophosphorus pesticide removal

The development of efficient adsorbents for the removal of organophosphorus pesticides from water is a major challenge. In this work, we prepared an activated carbon derived from sieve-like cellulose/graphene oxide composites (ACCE/G) for the removal of several organophosphorus pesticides. We employed corn straw to produce a sieve-like cellulose–graphene oxide composite (CCE/G); then, by treating CCE/G with potassium hydroxide at high temperatures, the efficient adsorbent ACCE/G was prepared. The adsorption capacity of ACCE/G is higher than those of other sorbents, including a multi-wall carbon nanotube, graphitised carbon black, activated carbon, C18, and primary secondary amine adsorbent. The ACCE/G structure has been fully characterised via scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and Brunauer–Emmett–Teller analysis. The maximum adsorption capacity of ACCE/G is 152.5 mg g⁻¹ for chlorpyrifos. The mechanism, the thermodynamic properties, and the kinetics of the adsorption process have been investigated as well. Our findings demonstrate that the adsorption mechanism depends on the electron-donating abilities of the S and P atoms. Moreover, the Langmuir model gives the best fit for the isotherm data, and the adsorption efficiency of the ACCE/G is still over 80% after eight times of recycling, making ACCE/G a valuable candidate for the removal of OPPs.

Synthesizing a reusable adsorbent from waste corn straw is a sustainable way to utilize secondary resources and purify water.     

Correction: Synthesis,and single crystal structure of fully-substituted polynitrobenzene derivatives for high-energy materials

Correction for ‘Synthesis, and single crystal structure of fully-substituted polynitrobenzene derivatives for high-energy materials’ by Wei Yang et al., RSC Adv., 2018, 8, 2203–2208.

The literature citation to molecule 1 in Scheme 1 was in error and should have been to ref. 8; the corrected Scheme 1 is attached.Open in a separate windowScheme 1Synthetic strategy of polynitrobenzene derivatives for energetic materials.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Variability of native T1 values: implication for defining regional myocardial changes using MRI

The aim of the present study was to establish T1 variation (T1v) thresholds for duplicated measurements of regional T1 values in left ventricle (LV) using magnetic resonance imaging (MRI). Eighteen healthy volunteers were recruited to undergo two consecutive cardiac MRI scans using modified Look-Locker Inversion recovery (MOLLI) with two spatial resolutions on different days to repeat T1 measurements on LV. The absolute differences (d) and standard deviations (SDs) of regional T1 values were acquired with the two scans and two readers. T1v threshold (mean difference?+?2SD), intra-class correlation coefficient (ICC) and coefficient of variation (CoV) were calculated. T1 mapping using the MOLLI sequence (with multiple spatial resolutions) was successfully performed in all 18 volunteers twice. On a per-slice basis, ICCs for intra-observer, inter-observer, inter-resolution and inter-study T1v were 0.988, 0.899, 0.763 and 0.6. CoVs were 0.72, 2.39, 3.90 and 4.28%. T1v thresholds were 22, 66, 118 and 120 ms. On a per-segment basis, ICCs for intra-observer, inter-observer, inter-resolution and inter-study T1v were 0.974, 0.859, 0.711 and 0.594. CoVs were 1.09, 3.36, 4.69 and 5.01%. T1v thresholds were 33, 94, 140 and 144 ms. Those thresholds may be useful for discriminating disease-initiated T1v from random errors of T1 measurements.     

Research advances on the mechanism of biofilm formation in Acinetobacter baumannii北大核心CSCD

[No abstract available]     

Crystal structure and luminescence properties of a novel single-phase orange-red emitting phosphor Ca9La (PO4)7:Sm3+

Ca₉La_1−x(PO₄)₇:xSm³⁺ phosphors (0.01 < x < 0.25) were synthesized via high temperature solid-state reaction. Their properties including crystal structure, decay performance, thermal stability and photoluminescence were examined in detail. Phase analysis indicated that the phosphors crystallized in a rhombohedral structure, and the emission spectra of the phosphors consisted of four peaks centered around 570, 607, 653, and 714 nm, attributed to Sm³⁺ ions transitions ⁴G_5/2 → ⁶H_J (J = 5/2, 7/2, 9/2, and 11/2, respectively). The optimal Sm³⁺ doping content was 0.12 mol and the Ca₉La(PO₄)₇:Sm³⁺ phosphor also exhibited better thermal stability compared to other phosphors. In addition, the mechanism behind the energy transfer between Sm³⁺ ions was determined to be dipole–dipole interactions as described by Dexter theory. The results indicated that as orange-red phosphors, Ca₉La (PO₄)₇:Sm³⁺ phosphors were promising candidates for being integrated into white light emitting diodes.

Ca₉La_1–x(PO₄)₇:xSm³⁺ phosphors (0.01 < x < 0.25) were successfully synthesized. Crystal structure and luminescence properties of the phosphors were discussed in detail.     

Pharmacological inhibition of fatty acid-binding protein 4 (FABP4) protects against renal ischemia-reperfusion injury

Fatty acid-binding protein 4 (FABP4) is a key mediator of endoplasmic reticulum (ER) stress and apoptosis in diabetes and atherosclerosis. Studies also confirmed that circulating FABP4 depended on renal function in chronic kidney disease (CKD) and acute kidney injury (AKI) patients. However, the function of FABP4 in AKI remains poorly understood and the aim of this study was to investigate the role of FABP4 in ischemia-reperfusion (I/R)-induced AKI. In the present study, renal I/R injury triggered the high expression of the FABP4 gene and protein in the nucleus and cytoplasm of tubular cells of mouse kidney tissue compared to that of Sham. Pretreatment with BMS309403, a highly selective inhibitor of FABP4 at a dose of 20 mg kg⁻¹ d⁻¹ for 4 d, significantly reduced serum creatinine levels to improve acute renal dysfunction and attenuated renal tubular damage in injured kidneys. Pharmacological inhibition of FABP4 also decreased the number of TdT-mediated dUTP nick-end labeling (TUNEL) positive apoptotic tubular cells, accompanied by the down-regulation of cleaved-caspase-3 expression. Furthermore, oral administration of FABP4 inhibitor resulted in a significant attenuation of ER stress indicated by its maker proteins expression of glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP), and caspase-12 in I/R injured kidneys. In vitro, the increased expression of FABP4 in the human renal proximal tubule cell line (HK-2 cell) was induced by hypoxia followed by reoxygenation (HR) and the FABP4 inhibitor resulted in a significant attenuation of cell apoptosis and ER stress in HR-induced HK-2 cells. In summary, these findings indicated that FABP4 contributed to the pathogenesis of I/R-induced AKI and suggested that the inhibition of FABP4 might be a promising therapeutic strategy for AKI treatment.

FABP4 inhibition might attenuate I/R-induced AKI through reducing ER stress and apoptosis.     

84% efficiency improvement in all-inorganic perovskite light-emitting diodes assisted by a phosphorescent material

A novel mixed perovskite emitter layer is applied to design all-inorganic cesium lead halide perovskite light-emitting diodes (PeLEDs) with high electroluminescence (EL) performance, by combining CsPbBr₃ with iridium(iii)bis[2-(4′,6′-difluorophenyl)pyridinato-N,C²′]-picolinate (FIrpic), where FIrpic is a phosphorescent material with very high internal quantum efficiency (IQE) approaching 100%. The CsPbBr₃:FIrpic PeLEDs show a maximum luminance of 5486 cd m⁻², and an external quantum efficiency of 0.47%, which are 1.84 and 1.76 times that of neat CsPbBr₃ PeLEDs, respectively. It is found that FIrpic molecules as an assistant dopant can efficiently transmit energy from the excitons of FIrpic to the excited state of the CsPbBr₃ emitter via a Förster energy transfer process, leading to enhanced EL efficiency in the CsPbBr₃:FIrpic PeLEDs.

Remarkable EL performance is achieved in CsPbBr₃:FIrpic perovskite light-emitting diodes assisted by a phosphorescent material.     

Effect of template removal using plasma treatment on the structure and catalytic performance of MCM-22

To investigate the effect of template removal methods on the structure, properties and catalytic performance of the MCM-22 zeolite, dielectric-barrier discharge (DBD) plasma treatment and thermal calcination have been comparatively studied for the removal of hexamethyleneimine (HMI) from the two-dimensional layered precursor of MCM-22 (MCM-22(P)). The materials were characterized using FT-IR, TG, XRD, N₂ adsorption at low temperature, NH₃-TPD, and ²⁷Al and ²⁹Si MAS NMR. The results revealed that the seven-membered heterocyclic compound HMI can be effectively removed from the MCM-22 zeolite, and the condensation of silanol groups on the neighboring surface of MWW nanosheets can be induced by DBD treatment. Compared with calcination, DBD treatment could preserve the structure well and decrease the formation of extra-framework aluminum. Consequently, the concentration of acidic sites over MCM-22 treated by DBD (MCM-22(DBD)) is higher than that over calcined MCM-22 (MCM-22(C)). Moreover, MCM-22(DBD) possesses a certain amount of external surface area derived from the intercrystal pores due to the inhibiting effect of the condensation of the silanol groups on the external surface of the MCM-22 crystals. The activity and product selectivity of the Fischer–Tropsch (FT) synthesis was investigated over cobalt supported on the obtained MCM-22 zeolites. Compared with Co/MCM-22(C), Co/MCM-22(DBD) shows a higher catalytic activity in the FT synthesis reaction. Moreover, Co/MCM-22(DBD) can effectively decrease CH₄ selectivity and increase C₅–C₂₀ liquid fuel selectivity.

Template removal from MCM-22 using dielectric-barrier discharge (DBD) plasma could decrease the formation of extra-framework aluminum (EFAl) and increase the concentration of the acidic sites and external surface area of MCM-22.