Steering CO2 electroreduction pathway toward ethanol via surface-bounded hydroxyl species-induced noncovalent interaction.

Selective electroreduction of carbon dioxide (CO2RR) into ethanol at an industrially relevant current density is highly desired. However, it is challenging because the competing ethylene production pathway is generally more thermodynamically favored. Herein, we achieve a selective and productive ethanol production over a porous CuO catalyst that presents a high ethanol Faradaic efficiency (FE) of 44.1 ± 1.0% and an ethanol-to-ethylene ratio of 1.2 at a large ethanol partial current density of 501.0 ± 15.0 mA cm-2, in addition to an extraordinary FE of 90.6 ± 3.4% for multicarbon products. Intriguingly, we found a volcano-shaped relationship between ethanol selectivity and nanocavity size of porous CuO catalyst in the range of 0 to 20 nm. Mechanistic studies indicate that the increased coverage of surface-bounded hydroxyl species (*OH) associated with the nanocavity size-dependent confinement effect contributes to the remarkable ethanol selectivity, which preferentially favors the *CHCOH hydrogenation to *CHCHOH (ethanol pathway) via yielding the noncovalent interaction. Our findings provide insights in favoring the ethanol formation pathway, which paves the path toward rational design of ethanol-oriented catalysts.

Ferroelastically protected reversible orthorhombic to monoclinic-like phase transition in ZrO2 nanocrystals.

Robust ferroelectricity in nanoscale fluorite oxide-based thin films enables promising applications in silicon-compatible non-volatile memories and logic devices. However, the polar orthorhombic (O) phase of fluorite oxides is a metastable phase that is prone to transforming into the ground-state non-polar monoclinic (M) phase, leading to macroscopic ferroelectric degradation. Here we investigate the reversibility of the O-M phase transition in ZrO2 nanocrystals via in situ visualization of the martensitic transformation at the atomic scale. We reveal that the reversible shear deformation pathway from the O phase to the monoclinic-like (M') state, a compressive-strained M phase, is protected by 90° ferroelectric-ferroelastic switching. Nevertheless, as the M' state gradually accumulates localized strain, a critical tensile strain can pin the ferroelastic domain, resulting in an irreversible M'-M strain relaxation and the loss of ferroelectricity. These findings demonstrate the key role of ferroelastic switching in the reversibility of phase transition and also provide a tensile-strain threshold for stabilizing the metastable ferroelectric phase in fluorite oxide thin films.

PdMo bimetallene for oxygen reduction catalysis.

The efficient interconversion of chemicals and electricity through electrocatalytic processes is central to many renewable-energy initiatives. The sluggish kinetics of the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER)1-4 has long posed one of the biggest challenges in this field, and electrocatalysts based on expensive platinum-group metals are often required to improve the activity and durability of these reactions. The use of alloying5-7, surface strain8-11 and optimized coordination environments12 has resulted in platinum-based nanocrystals that enable very high ORR activities in acidic media; however, improving the activity of this reaction in alkaline environments remains challenging because of the difficulty in achieving optimized oxygen binding strength on platinum-group metals in the presence of hydroxide. Here we show that PdMo bimetallene-a palladium-molybdenum alloy in the form of a highly curved and sub-nanometre-thick metal nanosheet-is an efficient and stable electrocatalyst for the ORR and the OER in alkaline electrolytes, and shows promising performance as a cathode in Zn-air and Li-air batteries. The thin-sheet structure of PdMo bimetallene enables a large electrochemically active surface area (138.7 square metres per gram of palladium) as well as high atomic utilization, resulting in a mass activity towards the ORR of 16.37 amperes per milligram of palladium at 0.9 volts versus the reversible hydrogen electrode in alkaline electrolytes. This mass activity is 78 times and 327 times higher than those of commercial Pt/C and Pd/C catalysts, respectively, and shows little decay after 30,000 potential cycles. Density functional theory calculations reveal that the alloying effect, the strain effect due to the curved geometry, and the quantum size effect due to the thinness of the sheets tune the electronic structure of the system for optimized oxygen binding. Given the properties and the structure-activity relationships of PdMo metallene, we suggest that other metallene materials could show great promise in energy electrocatalysis.

Structural Reversibility of Nanoscaled Sn Anodes.

Alloying-type anode materials provide high capacity for lithium-ion batteries; however, they suffer pulverization problems resulting from the volume change during cycling. Realizing the cycling reversibility of these anodes is therefore critical for sustaining their electrochemical performance. Here, we investigate the structural reversibility of Sn NPs during cycling at atomic-level resolution utilizing in situ high-resolution TEM. We observed a surprisingly near-perfect structural reversibility after a complete cycle. A three-step phase transition happens during lithiation, accompanied by the generation of a significant number of defects, grain boundaries, and up to 202% volume expansion. In subsequent delithiation, the volume, morphology, and crystallinity of the Sn NPs were restored to their initial state. Theoretical calculations show that compressive stress drives the removal of vacancies generated within the NPs during delithiation, therefore maintaining their intact morphology. This work demonstrates that removing vacancies during cycling can efficiently improve the structural reversibility of high-capacity anode materials.

Atomically Resolved Transition Pathways of Iron Redox.

The redox transition between iron and its oxides is of the utmost importance in heterogeneous catalysis, biological metabolism, and geological evolution. The structural characteristics of this reaction may vary based on surrounding environmental conditions, giving rise to diverse physical scenarios. In this study, we explore the atomic-scale transformation of nanosized Fe3O4 under ambient-pressure H2 gas using in-situ environmental transmission electron microscopy. Our results reveal that the internal solid-state reactions dominated by iron diffusion are coupled with the surface reactions involving gaseous O or H species. During reduction, we observe two competitive reduction pathways, namely Fe3O4 → FeO → Fe and Fe3O4 → Fe. An intermediate phase with vacancy ordering is observed during the disproportionation reaction of Fe2+ → Fe0 + Fe3+, which potentially alleviates stress and facilitates ion migration. As the temperature decreases, an oxidation process occurs in the presence of environmental H2O and trace amounts of O2. A direct oxidation of Fe to Fe3O4 occurs in the absence of the FeO phase, likely corresponding to a change in the water vapor content in the atmosphere. This work elucidates a full dynamical scenario of iron redox under realistic conditions, which is critical for unraveling the intricate mechanisms governing the solid-solid and solid-gas reactions.

Introducing Electron Buffers into Intermetallic Pt Alloys against Surface Polarization for High-Performing Fuel Cells.

Surface polarization under harsh electrochemical environments usually puts catalysts in a thermodynamically unstable state, which strictly hampers the thermodynamic stability of Pt-based catalysts in high-performance fuel cells. Here, we report a strategy by introducing electron buffers (variable-valence metals, M = Ti, V, Cr, and Nb) into intermetallic Pt alloy nanoparticle catalysts to suppress the surface polarization of Pt shells using the structurally ordered L10-M-PtFe as a proof of concept. Operando X-ray absorption spectra analysis suggests that with the potential increase, electron buffers, especially Cr, could facilitate an electron flow to form a electron-enriched Pt shell and thus weaken the surface polarization and tensile Pt strain. The best-performing L10-Cr-PtFe/C catalyst delivers superb oxygen reduction reaction (ORR) activity (mass activity = 1.41/1.02 A mgPt-1 at 0.9 V, rated power density = 14.0/9.2 W mgPt-1 in H2-air under a total Pt loading of 0.075/0.125 mgPt cm-2, respectively) and stability (20 mV voltage loss at 0.8 A cm-2 after 60,000 cycles of accelerated durability test) in a fuel cell cathode, representing one of the best reported ORR catalysts. Density functional theory calculations reveal that the optimized surface strain by introducing Cr on L10-PtFe/C accounts for the enhanced ORR activity, and the durability enhancement stems from the charge transfer contribution of Cr to the Pt shells and the increased kinetic energy barrier for Pt dissolution/Fe diffusion.

The role of ultraviolet radiation in the flavor formation during drying processing of Pacific saury (Cololabis saira).

BACKGROUND: Traditional sun-drying aquatic products are popular and recognized by customers, owing to their unique flavor and long-term preservation. However, the product quality and production efficiency cannot be guaranteed. Cololabis saira is rich in unsaturated fatty acids, which are susceptible to hyperoxidation during the drying process. This study aimed to make clear the role of ultraviolet (UV) radiation in flavor formation during drying processes of Cololabis saira to develop a modern drying technology. RESULTS: Lipid oxidation analysis revealed that moderate hydrolytic oxidation occurred in the UV-assisted cold-air drying group due to the combined influence of UV and cold-air circulation, resulting in the thiobarbituric acid reactive substances value being higher than that of cold-air drying group but lower than the natural drying group. Hexanal, heptanal, cis-4-heptenal, octanal, nonanal, (trans,trans)-2,4-heptadienal, (trans,trans)-2,6-nonanedial, 1-octen-3-ol, heptanol, 2,3-pentanedione, 3,5-octadien-2-one and trimethylamine were identified as the characteristic flavor odor-active compounds present in all Cololabis saira samples. Yet, during the natural drying process, sunlight promoted the lipid oxidation, resulting in the highest degree of lipid oxidation among three drying methods. Light and heat promoted lipid oxidation in Cololabis saira prepared through natural drying process, leading to a large accumulation of volatile compounds, such as 3-methylbutyraldehyde, 2,3-pentanedione, 1-propanol, and 3-pentanone. Cold air circulation inhibited lipid oxidation to some extent, resulting in a blander flavor profile. More cis-4-heptenal, cis-2-heptenal, octanal and 2-ethylfuran accumulated during the UV-assisted cold-air drying process, enriching its greasy flavor and burnt flavor. CONCLUSION: UV-assisted cold-air drying could promote moderate lipid oxidation, which is beneficial for improving product flavor. To sum up, UV radiation played a crucial role in the flavor formation during the drying process of Cololabis saira. © 2024 Society of Chemical Industry.

Integrated assessment of available water volume for sustainable sponge city construction - A case study in Xi'an, China.

To address the lack of theoretical guidance for sponge city construction (SCC) in China, this study introduces a method to evaluate the available water volume (AWV) in urban watersheds. This evaluation is based on the water balance relationship, water volume, and ecological water demand (EWD). The Xi'an urban area was selected as a case study due to its water shortage and flooding issues. Results show monthly surface and subsurface AWV ranging between 53.06 and 53.98 million m3 and between 8,701.89 and 8,898.14 million m3, respectively. By maximizing the potential for surface AWV, an annual water supply of 527.75 million m3 could be provided, surpassing the annual artificial water consumption of 394.20 million m3, effectively addressing water scarcity. During the rainy season, implementing measures such as employing permeable paving materials, establishing wetlands and rainwater gardens, and constructing lakes and reservoirs can mitigate flooding caused by rainfall exceeding 32.8 mm. While the subsurface space in Xi'an holds significant potential for subsurface AWV utilization, revitalizing the ecological environment of subsurface water is crucial. Overall, the AWV theoretical framework offers a comprehensive solution to water shortage and flooding issues in the Xi'an urban area, serving as a vital theory for SCC.

Surface Lattice Modulation Enables Stable Cycling of High-Loading All-solid-state Batteries at High Voltages.

Halide solid electrolytes, known for their high ionic conductivity at room temperature and good oxidative stability, face notable challenges in all-solid-state Li-ion batteries (ASSBs), especially with unstable cathode/solid electrolyte (SE) interface and increasing interfacial resistance during cycling. In this work, we have developed an Al3+-doped, cation-disordered epitaxial nanolayer on the LiCoO2 surface by reacting it with an artificially constructed AlPO4 nanoshell; this lithium-deficient layer featuring a rock-salt-like phase effectively suppresses oxidative decomposition of Li3InCl6 electrolyte and stabilizes the cathode/SE interface at 4.5 V. The ASSBs with the halide electrolyte Li3InCl6 and a high-loading LiCoO2 cathode demonstrated high discharge capacity and long cycling life from 3 to 4.5 V. Our findings emphasize the importance of specialized cathode surface modification in preventing SE degradation and achieving stable cycling of halide-based ASSBs at high voltages.

Engineering Structurally Ordered High-Entropy Intermetallic Nanoparticles with High-Activity Facets for Oxygen Reduction in Practical Fuel Cells.

High-entropy solid-solution alloys have generated significant interest in energy conversion technologies. However, structurally ordered high-entropy intermetallic (HEI) nanoparticles (NPs) have been rarely reported in electrocatalysis applications. Here, we demonstrate structurally ordered PtIrFeCoCu HEI (PIFCC-HEI) NPs with extremely superior performance for both oxygen reduction reaction (ORR) and H2/O2 fuel cells. The PIFCC-HEI NPs show an average diameter of 6 nm. Atomic structural characterizations including atomic-resolution energy-dispersive spectroscopy (EDS) mapping technology confirm the ordered intermetallic structure of PIFCC-HEI NPs. As an electrocatalyst for ORR, the PIFCC-HEI/C achieves an ultrahigh mass activity of 7.14 A mgnoble metals-1 at 0.85 V and extraordinary durability over 60 000 potential cycles. Moreover, the fuel cell assembled with PIFCC-HEI/C as the cathode delivers an ultrahigh peak power density of 1.73 W cm-2 at a back pressure of 1.0 bar and almost no working voltage decay after 80 h operation, certifying the top-level performance among reported fuel cells. Theoretical calculations combined with experimental results reveal that the superior performance of PIFCC-HEI/C for ORR and fuel cells is attributed to its ultrahigh-activity facets. Especially, the (001) facet affords the lowest activation barriers for the rate-limiting step, the optimal downshift of the d-band center, and more efficient regulation of electron structures for ORR. This work not only opens up a new avenue for the fabrication of high-activity facets in the catalysts but also highlights structurally ordered HEI NPs as sufficiently effective catalysts in practical fuel cells and other potential energy-related applications.

Reconstructing 3d-Metal Electrocatalysts through Anionic Evolution in Zinc-Air Batteries.

As one of the promising sustainable energy storage systems, academic research on rechargeable Zn-air batteries has recently been rejuvenated following development of various 3d-metal electrocatalysts and identification of their dynamic reconstruction toward (oxy)hydroxide, but performance disparity among catalysts remains unexplained. Here, this uncertainty is addressed through investigating the anionic contribution to regulate dynamic reconstruction and battery behavior of 3d-metal selenides. Comparing with the alloy counterpart, anionic chemistry is identified as a performance promoter and further exploited to empower Zn-air batteries. Based on theoretical modeling, Se-resolved operando spectroscopy, and advanced electron microscopy, a three-step Se evolution is established, consisting of oxidation, leaching, and recoordination. The process generates an amorphous (oxy)hydroxide with O-sharing bonded Se motifs that triggers charge redistribution at metal sites and lowers the energetic barrier of their current-driven redox. A pervasive concept of Se back-feeding is then proposed to describe the underlying chemistry for 3d-metal selenides with diversity in crystals or compositions, and the feasibility to fine-tune their behavior is also presented.

Unconventional Bilateral Compressive Strained Ni-Ir Interface Synergistically Accelerates Alkaline Hydrogen Oxidation.

The alkaline hydrogen oxidation reaction (HOR) involves the coupling of adsorbed hydrogen (Had) and hydroxyl (OHad) species and is thus orders of magnitude slower than that in acid media. According to the Sabatier principle, developing electrocatalysts with appropriate binding energy for both intermediates is vital to accelerating the HOR though it is still challenging. Herein, we propose an unconventional bilateral compressive strained Ni-Ir interface (Ni-Ir(BCS)) as efficient synergistic HOR sites. Density functional theory (DFT) simulations reveal that the bilateral compressive strain effect leads to the appropriate adsorption for both Had and OHad, enabling their coupling thermodynamically spontaneous and kinetically preferential. Such Ni-Ir(BCS) is experimentally achieved by embedding sub-nanometer Ir clusters in graphene-loaded high-density Ni nanocrystals (Ni-Ir(BCS)/G). As predicted, it exhibits a HOR mass activity of 7.95 and 2.88 times those of commercial Ir/C and Pt/C together with much enhanced CO tolerance, respectively, ranking among the most active state-of-the-art HOR catalysts. These results provide new insights into the rational design of advanced electrocatalysts involving coordinated adsorption and activation of multiple reactants.

Defective ZnIn2S4 Nanosheets for Visible-Light and Sacrificial-Agent-Free H2O2 Photosynthesis via O2/H2O Redox.

H2O2 photosynthesis has attracted great interest in harvesting and converting solar energy to chemical energy. Nevertheless, the high-efficiency process of H2O2 photosynthesis is driven by the low H2O2 productivity due to the recombination of photogenerated electron-hole pairs, especially in the absence of a sacrificial agent. In this work, we demonstrate that ultrathin ZnIn2S4 nanosheets with S vacancies (Sv-ZIS) can serve as highly efficient catalysts for H2O2 photosynthesis via O2/H2O redox. Mechanism studies confirm that Sv in ZIS can extend the lifetimes of photogenerated carriers and suppress their recombination, which triggers the O2 reduction and H2O oxidation to H2O2 through radical initiation. Theoretical calculations suggest that the formation of Sv can strongly change the coordination structure of ZIS, modulating the adsorption abilities to intermediates and avoiding the overoxidation of H2O to O2 during O2/H2O redox, synergistically promoting 2e- O2 reduction and 2e- H2O oxidation for ultrahigh H2O2 productivity. The optimal catalyst displays a H2O2 productivity of 1706.4 µmol g-1 h-1 under visible-light irradiation without a sacrificial agent, which is ∼29 times higher than that of pristine ZIS (59.4 µmol g-1 h-1) and even much higher than those of reported photocatalysts. Impressively, the apparent quantum efficiency is up to 9.9% at 420 nm, and the solar-to-chemical conversion efficiency reaches ∼0.81%, significantly higher than the value for natural synthetic plants (∼0.10%). This work provides a facile strategy to separate the photogenerated electron-hole pairs of ZIS for H2O2 photosynthesis, which may promote fundamental research on solar energy harvest and conversion.

Hot Spot Engineering in Hierarchical Plasmonic Nanostructures.

The controllable nanogap structures offer an effective way to obtain strong and tunable localized surface plasmon resonance (LSPR). A novel hierarchical plasmonic nanostructure (HPN) is created by incorporating a rotating coordinate system into colloidal lithography. In this nanostructure, the hot spot density is increased drastically by the long-range ordered morphology with discrete metal islands filled in the structural units. Based on the Volmer-Weber growth theory, the precise HPN growth model is established, which guides the hot spot engineering for improved LSPR tunability and strong field enhancement. The hot spot engineering strategy is examined by the application of HPNs as the surface-enhanced Raman spectroscopy (SERS) substrate. It is universally suitable for various SERS characterization excited at different wavelengths. Based on the HPN and hot spot engineering strategy, single-molecule level detection and long-range mapping can be realized simultaneously. In that sense, it offers a great platform and guides the future design for various LSPR applications like surface-enhanced spectra, biosensing, and photocatalysis.

MUC1 promotes glioblastoma progression and TMZ resistance by stabilizing EGFRvIII.

Epidermal growth factor receptor variant III (EGFRvIII) is a mutant isoform of EGFR with a deletion of exons 2-7 making it insensitive to EGF stimulation and downstream signal constitutive activation. However, the mechanism underlying the stability of EGFRvIII remains unclear. Based on CRISPR-Cas9 library screening, we found that mucin1 (MUC1) is essential for EGFRvIII glioma cell survival and temozolomide (TMZ) resistance. We revealed that MUC1-C was upregulated in EGFRvIII-positive cells, where it enhanced the stability of EGFRvIII. Knockdown of MUC1-C increased the colocalization of EGFRvIII and lysosomes. Upregulation of MUC1 occurred in an NF-κB dependent manner, and inhibition of the NF-κB pathway could interrupt the EGFRvIII-MUC1 feedback loop by inhibiting MUC1-C. In a previous report, we identified AC1Q3QWB (AQB), a small molecule that could inhibit the phosphorylation of NF-κB. By screening the structural analogs of AQB, we obtained EPIC-1027, which could inhibit the NF-κB pathway more effectively. EPIC-1027 disrupted the EGFRvIII-MUC1-C positive feedback loop in vitro and in vivo, inhibited glioma progression, and promoted sensitization to TMZ. In conclusion, we revealed the pivotal role of MUC1-C in stabilizing EGFRvIII in glioblastoma (GBM) and identified a small molecule, EPIC-1027, with great potential in GBM treatment.

Charge transfer effect: a new assignment of the abnormal optical absorption band of gold nanoparticles.

As a significant accompanying phenomenon of surface-enhanced Raman scattering (SERS), the addition of foreign molecules to colloidal gold or silver nanoparticles results in a new abnormal optical absorption (AOA) band, which usually appears in the long-wavelength region. The assignment of this AOA band has long been debated as an important issue that is desired to be addressed in the SERS field, which is crucial for a clear understanding of the SERS enhancement mechanism and beneficial to surface plasmonics. In this study, both the calculated and measured optical absorptions of gold nanoparticle monomers and dimers as well as their interactions with adsorbed molecules, showed that the AOA band in the long-wavelength region which was assigned to the characteristic longitudinal localized surface plasmon resonance (LSPR) effect of gold nanoparticle chain aggregates in conventional SERS electromagnetic theory, should be attributed to the charge-transfer resonance absorption from gold nanoparticles to adsorbed molecules. This was further confirmed by the corresponding SERS effects. As the excitation wavelength at 785 nm was resonant with the broad AOA band centered at 750 nm, the SERS peaks of the adsorbed pyridine molecules could be dramatically enhanced due to the charge-transfer resonance effect. In contrast, under an excitation wavelength of 532 nm, the SERS peaks appeared very weak, although the excitation wavelength was resonant with the LSPR absorption band of the individual gold nanoparticles.

Anhydrous Alum Inhibits α-MSH-Induced Melanogenesis by Down-Regulating MITF via Dual Modulation of CREB and ERK.

Melanogenesis, the intricate process of melanin synthesis, is central to skin pigmentation and photoprotection and is regulated by various signaling pathways and transcription factors. To develop potential skin-whitening agents, we used B16F1 melanoma cells to investigate the inhibitory effects of anhydrous alum on melanogenesis and its underlying molecular mechanisms. Anhydrous alum (KAl(SO4)2) with high purity (>99%), which is generated through the heat-treatment of hydrated alum (KAl(SO4)2·12H2O) at 400 °C, potentiates a significant reduction in melanin content without cytotoxicity. Anhydrous alum downregulates the master regulator of melanogenesis, microphthalmia-associated transcription factor (MITF), which targets key genes involved in melanogenesis, thereby inhibiting α-melanocyte-stimulating hormone (α-MSH)-induced melanogenesis. Phosphorylation of the cAMP response element-binding protein, which acts as a co-activator of MITF gene expression, is attenuated by anhydrous alum, resulting in compromised MITF transcription. Notably, anhydrous alum promoted extracellular signal-regulated kinase phosphorylation, leading to the impaired nuclear localization of MITF. Overall, these results demonstrated the generation and mode of action of anhydrous alum in B16F1 cells, which constitutes a promising option for cosmetic or therapeutic use.

Electrospinning micro-nanofibers immobilized aerobic denitrifying bacteria for efficient nitrogen removal in wastewater.

Electrospinning micro-nanofibers with exceptional physicochemical properties and biocompatibility are becoming popular in the medical field. These features indicate its potential application as microbial immobilized carriers in wastewater treatment. Here, aerobic denitrifying bacteria were immobilized on micro-nanofibers, which were prepared using different concentrations of polyacrylonitrile (PAN) solution (8%, 12% and 15%). The results of diameter distribution, specific surface area and average pore diameter indicated that 15% PAN micro-nanofibers with tighter surface structure were not suitable as microbial carriers. The bacterial load results showed that the cell density (OD600) and total protein of 12% PAN micro-nanofibers were 107.14% and 106.28% higher than those of 8% PAN micro-nanofibers. Subsequently, the 12% PAN micro-nanofibers were selected for aerobic denitrification under the different C/N ratios (1.5-10), and stable performance was obtained. Bacterial community analysis further manifested that the micro-nanofibers effectively immobilized bacteria and enriched bacterial structure under the high C/N ratios. Therefore, the feasibility of micro-nanofibers as microbial carriers was confirmed. This work was of great significance for promoting the application of electrospinning for microbial immobilization in wastewater treatment.

[Expression and clinical significance of plasma exosomal miR-34-5p and miR-142-3p in systemic sclerosis].

OBJECTIVE: To detect the expression of plasma exosomal microRNA (miRNA) in systemic sclerosis (SSc), and to investigate its clinical significance. METHODS: A total of 20 patients who were initially diagnosed with SSc and did not receive medication in Department of Rheumatology and Immunology of Meizhou People' s Hospital from January 2020 to January 2022 were recruited, as well as 15 healthy individuals whose gender and age matched with those of the SSc patients. Plasma exosomes were isolated using ultracentrifugation method. The expression levels of exosomal miR-34-5p, miR-92-3p and miR-142-3p were detected by quantative real-time polymerase chain reaction (qRT-PCR). Correlations between the expression levels of exosomal miRNAs and clinical characteristic were analyzed by Spearman's rank correlation coefficient test. RESULTS: The mean age of 20 patients with SSc was (52.6±12.6) years, including 7 males and 13 females. Among the 20 SSc patients, 13 cases were diagnosed as limited cutaneous systemic sclerosis (lcSSc) and 7 cases were diagnosed as diffuse cutaneous systemic sclerosis (dcSSc) according to the extent of skin involvement. According to the findings of high resolution chest CT, 7 of 20 SSc patients were diagnosed with interstitial lung disease (ILD) and 13 SSc patients were diagnosed with non-ILD. The expression levels of exosomal miR-34-5p, miR-92-3p and miR-142-3p were significantly elevated in the SSc patients compared with those in the healthy controls group (P=0.003, P=0.000 1, and P=0.016, respectively). Compared with the SSc patients without ILD, the expression levels of miR-34-5p and miR-142-3p were significantly lower in the SSc patients with ILD (P=0.037 and P=0.015, respectively). The expression levels of exosomal miR-34-5p and miR-142-3p showed negative correlation with ILD (r=-0.48, P=0.031 and r=-0.55, P=0.011, respectively), and arthritis (r=-0.46, P=0.040 and r=-0.48, P=0.032, respectively). The expression levels of exosomal miR-142-3p showed a negative correlation with erythrocyte sedimentation rate (ESR) (r=-0.55, P=0.012). CONCLUSION: Plasma exosomal miR-34-5p, miR-92-3p and miR-142-3p were dysregulated in SSc. The dyregulation of exosomal miR-34-5p and miR-142-3p showed correlation with SSc associated ILD (SSc-ILD).

An Anomalous Electron Configuration Among 3d Transition Metal Atoms.

Physical properties of materials are mainly determined by valence electron configurations, where different valence shells would induce divergent phenomena. In compounds containing Sc2+ , 3d electron occupancy is expected, the same as other transition metal atoms like Ti3+ . But this situation still awaits experimental verification in inorganic materials. Here, we selected ScS to measure the valence electron density and orbital population of Sc2+ through delicate quantitative convergent-beam electron diffraction. With the absence of 3d orbital features around Sc-atom sites and the nearly bare population of t2g orbital, the unintuitive occupation of 4s orbital in Sc2+ is concluded. It should be the first time to report such a special electron configuration in a transition metal compound, in which 4s rather than 3d orbital is preferred. Our findings reveal the distinct behavior of Sc and probable ways to modulate material properties by controlling electron orbitals.