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The energy conversion in Earth’s surface environments over geological history heavily involves the redox reactions of natural minerals. Natural Mn(III/IV) oxides and Mn2+(aq) is one of the most important redox couples that significantly dictate the electron flow in nature. Elucidating their formation and redox reactions is of critical importance for understanding numerous elemental cycles and the evolution of redox environments on Earth and other planets. Previous studies generally consider biotic processes as the dominant oxidation pathway for Mn2+(aq) in natural environments. In this study, we demonstrate rapid abiotic oxidation of Mn2+(aq) through photocatalytic reactions in the presence of natural Fe oxide minerals at rates comparable to those of currently known biotic/abiotic oxidation processes. Fe oxide minerals not only facilitate the electron transfer, but also serve as templates for the heterogeneous nucleation of tunnel structured Mn oxides. This finding highlights an important yet previously overlooked abiotic process on the formation of Mn oxides, which offers a new pathway for explaining the commonly observed co-occurrence of Fe and Mn oxide minerals in nature and the origin of diverse structures of Mn oxides.

Specific targeting of cell organelles is indispensable for bioimaging and diagnostics but remains a challenge due to the limitation of highly selective fluorescent targeting probes. Herein, we successfully designed a molecular fusion route to controllably synthesize bright orange fluorescent graphene quantum dots (GQDs). The relative nitrogen doping level of the GQDs reached 18.88 at%. The GQDs exhibited long-wavelength excitation fluorescence and photoluminescence (PL) stability. Femtosecond transient absorption spectroscopy elucidated that the sp2 cluster and the surface state's synergistic effect contributed to the PL. Furthermore, the most alluring discovery was that the GQDs had good biocompatibility and an unprecedented targeting capability for superselective nucleus imaging without staining cell organelles. Molecular dynamics simulations revealed that once the GQDs were transported across the plasma membrane, the higher the N-doping ratio of the GQDs was, and the easier the GQDs penetrated the membrane. The reason may stem from the compatibility of –NH2 with lipid molecules, which is higher than that of –OH. Enriched nitrogen doping in GQDs is beneficial for crossing the cell membrane to the target nucleus. Our findings could provide scientific theory and a technical basis to design nucleus-targeting probes in the future.

Long non‐coding RNAs (lncRNAs) contribute to disease pathogenesis and drug treatment effects. Both emodin and dexamethasone (DEX) have been used for treating severe acute pancreatitis‐associated acute lung injury (SAP‐ALI). However, lncRNA regulation networks related to SAP‐ALI pathogenesis and drug treatment are unreported. In this study, lncRNAs and mRNAs in the lung tissue of SAP‐ALI and control rats, with or without drug treatment (emodin or DEX), were assessed by RNA sequencing. Results showed both emodin and DEX were therapeutic for SAP‐ALI and that mRNA and lncRNA levels differed between untreated and treated SAP‐ALI rats. Gene expression profile relationships for emodin‐treated and control rats were higher than DEX‐treated and ‐untreated animals. By comparison of control and SAP‐ALI animals, more up‐regulated than down‐regulated mRNAs and lncRNAs were observed with emodin treatment. For DEX treatment, more down‐regulated than up‐regulated mRNAs and lncRNAs were observed. Functional analysis demonstrated both up‐regulated mRNA and co‐expressed genes with up‐regulated lncRNAs were enriched in inflammatory and immune response pathways. Further, emodin‐associated lncRNAs and mRNAs co‐expressed modules were different from those associated with DEX. Quantitative polymerase chain reaction demonstrates selected lncRNA and mRNA co‐expressed modules were different in the lung tissue of emodin‐ and DEX‐treated rats. Also, emodin had different effects compared with DEX on co‐expression network of lncRNAs Rn60_7_1164.1 and AABR07062477.2 for the blue lncRNA module and Nrp1 for the green mRNA module. In conclusion, this study provides evidence that emodin may be a suitable alternative or complementary medicine for treating SAP‐ALI.

Both electronic and ionic conductivities are of high importance to the performance of anode materials for Li-ion batteries. Many large capacity anode materials (such as Ge) do not have sufficiently high electronic and ionic conductivities required for high-rate cycling. Here, we report a novel ternary compound, copper germanium phosphide (CuGe2P3), as a high-rate anode. Being synthesized via a facile and scalable mechanochemistry method, CuGe2P3 has a cation-disordered sphalerite structure and offers higher ionic and electronic conductivities and better tolerance to volume change during cycling than Ge, as confirmed by first principles calculations and experimental characterization, including high-resolution synchrotron X-ray diffraction, HRTEM, SAED, XPS and Raman spectroscopy. Furthermore, the results suggest that CuGe2P3 has a reversible Li-storage mechanism of conversion reaction. When composited with graphite by virtue of a two-stage ball-milling process, the yolk–shell structure of the amorphous carbon-coated CuGe2P3 nanocomposite (CuGe2P3/C@Graphene) delivers a high initial coulombic efficiency (91%), a superior cycling stability (1312 mA h g−1 capacity after 600 cycles at 0.2 A g−1 and 876 mA h g−1 capacity after 1600 cycles at 2 A g−1), and an excellent rate capability (386 mA h g−1 capacity at 30 A g−1), surpassing most Ge-based anodes reported to date. Moreover, a series of cation-disordered new phases in the Cu(Zn)–Ge–P family with various cation ratios offer similar Li-storage properties, achieving high reversible capacities with high initial coulombic efficiencies and desirable redox chemistry with improved safety.

Aqueous zinc–manganese dioxide (Zn–MnO2) batteries show great promise for grid-scale energy storage but suffer from sluggish reaction kinetics and severe structural instability of the MnO2 cathode. Herein, a K+-pre-intercalated α-MnO2 cathode with oxygen defects (KMOd) is designed, guided by a new coupling engineering strategy, demonstrating boosted reaction kinetics and improved structural stability of MnO2. Closely coupled first-principles calculations and experiments reveal that the synergy effects of pre-intercalated K+ and oxygen defects are key to the high electronic conductivity, favorable H+ diffusion kinetics, enhanced H+/Zn2+ adsorption/intercalation capability, and improved structural stability of the KMOd cathode. A high energy density of 518 W h kg−1 calculated based on the mass of the cathode and outstanding long-term cycling performance of over 2500 cycles at 2.0 A g−1 with a capacity of 203 mA h g−1 and a retention of 81.3% are achieved. New insights into the structural stabilization effect by adding K2SO4 additive into the aqueous electrolyte are also revealed. A hybrid charge storage mechanism of non-diffusion controlled Zn2+ intercalation and diffusion controlled H+ intercalation is proposed.

The difference between the excited- and ground-state vibrational wavepackets remains to be fully explored when multiple vibrational modes are coherently excited simultaneously by femtosecond pulses. In this work, we present a series of one- and two-dimensional electronic spectroscopy for studying multimode wavepackets of oxazine 720 in solution. Fourier transform (FT) maps combined with time-frequency transform (TFT) are employed to unambiguously distinguish the origin of low-frequency vibrational wavepackets, that is, an excited-state vibrational wavepacket of 586 cm-1 with a dephasing time of 0.7 ps and a ground-state vibrational wavepacket of 595 cm-1 with a dephasing time of 1.3-1.7 ps. We also found the additional low-frequency vibrational wavepackets resulting from the coupling of the 595 cm-1 mode to a series of high-frequency modes centered at 1150 cm-1 via electronic transitions. The combined use of FT maps and TFT analysis allows us to reveal the potential vibrational coupling of wavepackets and offers the possibility of disentangling the coupling between the electronic and vibrational degrees of freedom in condensed-phase systems.

We report on a non-destructive, on-chip technique for determining the elastic modulus ( $E_{\mathrm {Y}}$ ) of silicon carbide (SiC) thin diaphragms by measuring their nonlinear resonances. Departing from the conventional static load-deflection techniques ( e.g. , beam bending, membrane bulging and nanoindentation), the nonlinear resonance approach enables characterizing mechanical properties without risk to the microdevices, bypassing complicated contact-mode sample preparation, and bulky, expensive apparatus. We derive the mode-dependent Duffing resonances of the diaphragms in the ‘membrane’ regime, and correlates $E_{\mathrm {Y}}$ with the Duffing ‘backbone’ curve. To verify our model, we fabricate SiC square diaphragms (1mm $\times 1$ mm $\times 2~\mu \text{m}$ ) that exhibit multimode resonances up to 500kHz and quality ( $Q$ ) factors up to 16,000. Taking the device’s (2,2) mode as an example, we obtain $E_{\mathrm {Y}} = 436\,\,\pm \,\,27$ GPa via its Duffing nonlinear response. The technique can be readily and widely extended to other thin films and MEMS/NEMS resonators. [2020-0209]

Early diagnosis of Hepatocellular Carcinoma (HCC) is an important means to raise the survival rate of patients. Multi-marker combined detection is a powerful tool of early HCC diagnosis. Traditional detection methods are not effective and accurate because it is difficult to achieve combined detection of multiple markers. In this paper, we selected Alpha Fetoprotein (AFP) and miRNA-125b as the combined detection markers to improve the simultaneously diagnostic sensitivity and specificity. The anti-AFP monoclonal antibody and the DNA probes paired with the miRNA-125b were modified on the surface of surface plasmon resonance (SPR) sensor respectively to specifically recognize AFP and miRNA-125b in serum. In order to enhance the SPR response signal and detection sensitivity, Double Antibody Sandwich Method (DASM) and S9.6 antibody enhanced method were applied to achieve low detection limit of the two markers. Experimental results showed that AFP (25–400 ng/mL) was accurately detected by DASM and the detection limit of miRNA-125b by S9.6 antibody enhanced method reached 123.044 pM. These results verified the feasibility of the multi-marker detection method in early diagnosis of HCC.

Owing to highly conductive solid ionic conductors, all-solid-state batteries attract significant attention as promising next-generation energy storage devices. A lot of research is invested in the search and optimization of solid electrolytes with higher ionic conductivity. However, a systematic study of an interlaboratory reproducibility of measured ionic conductivities and activation energies is missing, making the comparison of absolute values in literature challenging. In this study, we perform an uncertainty evaluation via a Round Robin approach using different Li-argyrodites exhibiting orders of magnitude different ionic conductivities as reference materials. Identical samples are distributed to different research laboratories and the conductivities and activation barriers are measured by impedance spectroscopy. The results show large ranges of up to 4.5 mScm-1 in the measured total ionic conductivity (1.3 – 5.8 mScm-1 for the highest conducting sample, relative standard deviation 35 – 50% across all samples) and up to 128 meV for the activation barriers (198 – 326 meV, relative standard deviation 5 – 15%, across all samples), presenting the necessity of a more rigorous methodology including further collaborations within the community and multiplicate measurements.

Mn oxides are among the most ubiquitous minerals on Earth and play critical roles in numerous elemental cycles in biotic/abiotic loops as the key redox center. Yet, it has long puzzled geochemists why the laboratory synthesis of todorokite, a tunnel-structured Mn oxide, is extremely difficult while it is the dominant form over other tunneled phases in low-temperature natural environments. This study employs a novel electrochemical method to mimic the cyclic redox reactions occurring over long geological time scales in an accelerated manner. The results revealed that the kinetics and electron flux of the cyclic redox reaction are key to the layer-to-tunnel structure transformation of Mn oxides, provided new insights for natural biotic and abiotic redox reactions, and explained the dominance of todorokite in nature.

Free vibration analyses of lattice sandwich beams with general elastic supports have rarely been discussed in this field’s literature. In this paper, a unified method is proposed to study the free vibration characteristics of lattice sandwich beams under various boundary conditions. The proposed method is to convert the three truss cores of lattice sandwich beams into an equivalent homogeneous layer and introduce two different types of constraint springs to simulate the general elastic support boundary at both ends of lattice sandwich beams. By changing the rigidity of the boundary restraint spring, various boundary conditions can be easily obtained without modifying the solving algorithm and solving process. In order to overcome all the discontinuities or jumps associated with the elastic boundary support conditions, the displacement function of lattice sandwich beams is usually obtained as an improved Fourier cosine series along with four sine terms. On this basis, the unknown series coefficients of the displacement function are treated as the generalized coordinates and solved using the Rayleigh–Ritz method. The correctness of the present method is verified through comparison with existing literature. The calculation results of the present method are highly accurate, indicating that the present method is suitable for analyzing the vibration characteristics of lattice sandwich beams with general elastic supports. In addition, the effects of beam length, panel thickness, core height, radius and truss inclination on the natural frequencies of lattice sandwich beams with arbitrary boundary conditions have been discussed in this paper.

According to specific formulas, the mixing of rubber samples occurs by two methods: open mixing and internal mixing. The effects of frequency, mixing process, carbon black (CB) content, zinc oxide (ZnO) content, and stearic acid (SA) content on the dielectric properties of rubber materials were studied. The results showed that the effects of the mixing process on the dielectric properties of the rubber samples cannot be ignored, and the appropriate mixing process should be selected when preparing the required rubber materials. The dielectric constant and loss factor of the rubber samples vary depending on the frequency. The dielectric constant had a peak and valley value, while the loss factor only had a peak. The dielectric constant and loss factor of rubber samples were significantly affected by the content of CB, ZnO, and SA. The peak frequency decreased with the increase in CB content, however, the dielectric constant increased with an increase in CB content. The higher the ZnO content, the lower the peak frequency. In addition, the dielectric constant and loss factor increased with an increase in ZnO content. The higher the SA content, the greater the peak frequency. In addition, the dielectric constant and loss factor decreased with an increase in SA content. It is hoped that the experimental results obtained can provide guidance for the study of the dielectric properties, microwave absorption properties, and microwave heating characteristics of rubber polymers.

Tremendous efforts have been devoted to the design of solid Li+ electrolytes and the development of all-solid-state batteries. Compared with conventional Li-ion batteries, which use flammable liqui...

The circadian rhythm is a widespread physiological phenomenon present in almost all forms of life and is constituted by a system of interlocked transcriptional/translational feedback loops (TTFLs). External zeitgebers regulate biological rhythms through the direct or indirect regulation of circadian genes. Oxidative stress is involved in many diseases and injuries, such as ageing, diabetes, Alzheimer's disease, and cancer. Despite an increasing number of studies on circadian rhythm disorders caused by oxidative stress, little is known about the effects of oxidants on clock gene expression and the underlying mechanism. In this study, we found that the protein expression of circadian genes Clock, Bmal1, Per1/2, and Cry1/2 in NIH3T3 cells was upregulated by hydrogen peroxide (H2O2), an important mediator of oxidative stress. In addition, H2O2 modulated the circadian rhythm of Bmal1-luciferase via RORα, REV-ERBα (NR1D1), and REV-ERBβ (NR1D2). Further studies showed that H2O2 regulated biological rhythm by PRX2-STAT3-REV-ERBα/β pathway. These findings provide an accessory loop-related mechanism by which non-transcriptional oscillation interplays with TTFLs.

The lithium-manganese-rich layered oxide cathode (LMR-NMC), xLi2MnO3·(1 – x)LiMO2 (M = Co, Ni, and Mn), is on demand because of its high specific capacity of over 250 mA h g–1 between the voltage r...

Methanol synthesis via carbon dioxide (CO2) reduction is challenging and important because this technology can convert CO2 by solar- or wind-generated hydrogen into liquid fuel. The present work introduces the visible light as an external stimulus and for the first time demonstrates that methanol synthesis over Cu/ZnO catalysts can be effectively promoted by solar energy under atmospheric pressure. Experimental and theoretical studies document that hot electrons were photo-excited by localized surface plasmon resonance (LSPR) on Cu nanoparticles and such photo-excited hot electrons could transfer to ZnO through the metal-support interfaces. The hot electrons on Cu and ZnO synergistically facilitated the activation of reaction intermediates. Consequently, the activation energy was reduced by 40% and the methanol synthesis activity was promoted by 54%. This work provides a new strategy towards synthesis of liquid fuel via CO2 reduction under low pressure and sheds new light on the mechanism of photo-mediated catalysis.

The design of efficient and stable photocatalysts for robust CO2 reduction without sacrifice reagent or extra photosensitizer is still challenging. Herein, a single-atom catalyst of isolated single atom cobalt incorporated into Bi3O4Br atomic layers is successfully prepared. The cobalt single atoms in the Bi3O4Br favors the charge transition, carrier separation, CO2 adsorption and activation. It can lower the CO2 activation energy barrier through stabilizing the COOH* intermediates and tune the rate-limiting step from the formation of adsorbed intermediate COOH* to be CO* desorption. Taking advantage of cobalt single atoms and two-dimensional ultrathin Bi3O4Br atomic layers, the optimized catalyst can perform light-driven CO2 reduction with a selective CO formation rate of 107.1 µmol g−1 h−1, roughly 4 and 32 times higher than that of atomic layer Bi3O4Br and bulk Bi3O4Br, respectively.

Lithium metal is a promising anode for high-energy-density batteries owing to its large theoretical capacity and highly negative electrochemical potential. However, its commercial application is stalled by the undesired dendritic growth of lithium during cycling. Here we report a facile one-step electrodeposition process for low-cost, scalable fabrication of copper current collectors with 3-D architected porous structures composed of interconnected nanoparticles of Cu. Li anode deposited onto this porous current collector exhibits good cycling stability of > 340 h in symmetric cells without short-circuit. When tested in full cells with liquid or solid-state electrolyte, the Li anode hosted on the 3-D Cu current collector demonstrates excellent cycling performance with no dendrites formation. This process is extremely simple and scalable for mass production of dendrite-free and high capacity current collector for Li-batteries, which can be easily incorporated into the roll-to-roll manufacturing processes of battery industries.

While sodium-ion batteries (SIBs) hold great promise for large-scale electric energy storage and low speed electric vehicles, the poor capacity retention of the cathode is one of the bottlenecks in...

In this work, first principles calculations are performed to investigate the structural, electronic, and mechanical properties of the interface between β-SiC ceramics and Mn+1AlCn (M = Sc, Ti, V, Cr, Zr, Nb, Mo, Hf, Ta; n = 1,2) phases, with particular focus on Ti3AlC2 and Ti2AlC. The interface between the β-SiC(111) and Tin+1AlCn (0001) (n = 1,2) surfaces is most likely a stable interface because of the small misfit in lattice constants. Six different interface models between β-SiC(111) and Tin+1AlCn(0001) are examined. The optimized interfacial distances are determined using the universal binding energy relation method, and then each model is fully relaxed to calculate work of adhesion. By comparison, it is determined that the junctions connecting the C-terminated SiC(111) and Ti-terminated Tin+1AlCn(0001) surfaces are the most stable structures. Then the electronic structures for this interface model of Ti3AlC2/SiC are analyzed from the density of states, atomic charges, total electron densities and electron density difference. The elastic moduli are also computed in this study, and the data show that the mechanical properties for the composite Tin+1AlCn/SiC slab are between those of bulk Tin+1AlCn and β-SiC, with enhanced plasticity. Finally, the results for β-SiC/Tin+1AlCn are extended to study the interfacial stabilization of β-SiC ceramics and the wider class of Mn+1AlCn phase coatings (M = Sc, Ti, V, Cr, Zr, Nb, Mo, Hf, Ta; n = 1,2). It is found that SiC ceramics may be effectively joined by Mn+1AlCn with stable interfacial chemical bonding, which provides a theoretical basis for the effective junction in SiC composites.

The features of the electronic structure of semiconductor photocatalysts are fundamental to understanding the corresponding photocatalytic process. Besides the bandgap and edges, the behavior of photogenerated charge carriers and trap states can also greatly affect the photocatalytic process but it has been less considered during the material design. A previous study (G. Liu, J. Pan, L. Yin et al., Adv. Funct. Mater., 2012, 22, 3233-3238) showed that the interstitial boron on anatase {001} facets can change the photocatalytic preference from reductive H2 evolution to oxidative O2 evolution in the water splitting reaction, interpreted as the change in the band edges. In this work, we employed transient infrared absorption-excitation energy scanning spectroscopy and femtosecond time-resolved mid-infrared spectroscopy to investigate this phenomenon in view of the effect caused by the boron dopant on the photogenerated carrier kinetics and the energy level distribution of the trap states. We found that the surface boron doping eliminates significantly the trap states above the valence band, which improves its photocatalytic oxygen generation. On the other hand, surface boron doping also introduces a substantial amount of electron recombination centers (i.e., Bσ+ in the shell layer). Furthermore, surface boron doping also leads to an inefficient electron transfer from TiO2 to the co-catalyst Pt. Both of these effects give rise to its inferior photocatalytic capability in H2 evolution.

Honokiol is a pharmacologically active small molecule with multifunctional antitumor effects. Although plenty of literature is available on honokiol-triggered apoptosis and programmed necrosis, few studies have investigated the potential existence of death mode transition from apoptosis to programmed necrosis. In the current study, we demonstrated that the necrotic cell population (PI-positive) gradually increased and the early-stage apoptotic cell population (PI-negative and AV-positive) decreased in a dose- and time-dependent manner following honokiol treatment. Furthermore, we demonstrated that these PI-positive cells were under necrotic cell death, since no late-apoptosis characteristics including conspicuous chromatin condensation or DNA ladder patterns were detected. These results demonstrated that cells suffered death mode transition from early-stage apoptosis to programmed necrosis with the increase of honokiol dose or treatment time. The protein expression of RIP3 markedly increased in parallel with HNK-triggered death mode transition, while the expression of RIP1 decreased. Cyclophilin D expression increased during cell death mode transition, and inhibition of cyclophilin D by cyclosporin A clearly blocked HNK-triggered programmed necrosis. These data indicated that honokiol-induced programmed necrosis and death mode transition are potentially RIP3‑dependent, cyclophilin D-regulated. Further results showed that blocked cyclophilin D by cyclosporin A inhibited HNK-induced necrosis, but did not affect HNK-induced RIP3 overexpression. This indicated that cyclophilin D was a potential modulator at downstream of RIP3. In conclusion, honokiol triggers a potential RIP3-dependent cell death mode transition from early-stage apoptosis to programmed necrosis, which is highly regulated by cyclophilin D.

Objective: Severe acute pancreatitis (SAP) can lead to acute lung injury (ALI). This study investigated the therapeutic effect of emodin and its molecular mechanisms in a rat model of SAP-ALI.Methods: Forty male Sprague-Dawley rats were randomly divided into the groups: Control (CON), SAP (SAP), emodin (EMO), and C23 (C23). The latter three groups of rats were induced for SAP-ALI by retrograde injection of 5% sodium taurocholate into the biliary-pancreatic duct and were treated with vehicle, emodin or C23, respectively. One day post induction, their pancreatic and lung injury was assessed by histology and arterial blood gas analysis. In vitro, rat alveolar macrophages (NR8383 cells) were treated with recombinant rat CIRP in the presence or absence of TAK242 (a TLR4 inhibitor), C23 or emodin. The CIRP-mediated activation of the NLRP3/IL-1β/CXCL1 signaling in rat lungs and NR8383 cells was determined. Similarly, the role of IL-1β in the CIRP-induced CXCL1 expression was investigated.Results: Emodin treatment significantly reduced inflammation and tissue damages in the pancreatic and lung tissues in rats with SAP-ALI, accompanied by decreasing serum amylase, CIRP and IL-1β levels and improving lung function. Furthermore, emodin significantly mitigated the SAP-up-regulated CIRP expression in the pancreatic islets and lung tissues, and attenuated the SAP-activated NF-κB signaling, NLRP3 inflammasome formation and CXCL1 expression in lung resident macrophages as well as neutrophil infiltration in the lungs of rats. In addition, treatment with CIRP significantly activated the NF-κB signaling and NLRP3 inflammasome formation and induced IL-1β and CXCL1 expression and pyroptosis in NR8383 cells, which were abrogated by TAK242 and significantly mitigated by C23 or emodin. Moreover, CIRP only induced very lower levels of CXCL1 expression in IL-1β-silencing NR8383 cells and treatment with IL-1β induced CXCL1 expression in NR8383 cells in a dose and time-dependent manner.Conclusion: Emodin may inhibit the CIRP-activated NLRP3/IL-1β/CXCL1signaling to decrease neutrophil infiltration and ameliorate the SAP-ALI in rats.

Reprogramming glycolysis for directing glycolytic metabolites to a specific metabolic pathway is expected to be useful for increasing microbial production of certain metabolites, such as amino acids, lipids or considerable secondary metabolites. In this report, a strategy of increasing glycolysis by altering the metabolism of inositol pyrophosphates (IPs) for improving the production of S-adenosyl-l-methionine (SAM) for diverse pharmaceutical applications in yeast is presented. The genes associated with the metabolism of IPs, arg82, ipk1 and kcs1, were deleted, respectively, in the yeast strain Saccharomyces cerevisiae CGMCC 2842. It was observed that the deletions of kcs1 and arg82 increased SAM by 83.3 % and 31.8 %, respectively, compared to that of the control. In addition to the improved transcription levels of various glycolytic genes and activities of the relative enzymes, the levels of glycolytic intermediates and ATP were also enhanced. To further confirm the feasibility, the kcs1 was deleted in the high SAM-producing strain Ymls1ΔGAPmK which was deleted malate synthase gene mls1 and co-expressed the Acetyl-CoA synthase gene acs2 and the SAM synthase gene metK1 from Leishmania infantum, to obtain the recombinant strain Ymls1Δkcs1ΔGAPmK. The level of SAM in Ymls1Δkcs1ΔGAPmK reached 2.89 g L−1 in a 250-mL flask and 8.86 g L−1 in a 10-L fermentation tank, increasing 30.2 % and 46.2 %, respectively, compared to those levels in Ymls1ΔGAPmK. The strategy of increasing glycolysis by deletion of kcs1 and arg82 improved SAM production in yeast.

Mixing transition metal cations in nearly equiatomic proportions in layered oxide cathode materials is a new strategy for improving the performances of Na-ion batteries. The mixing of cations not only offers entropic stabilization of the crystal structure but also benefits the diffusion of Na ions with tuned diffusion activation energy barriers. In light of this strategy, a high-rate Na0.6(Ti0.2Mn0.2Co0.2Ni0.2Ru0.2)O2 cathode was designed, synthesized, and investigated, combining graph-based deep learning calculations and complementary experimental characterizations. This new cathode material delivers high discharge capacities of 164 mA g-1 at 0.1 C and 68 mAh g-1 at a very high rate of 86 C, demonstrating an outstanding high rate capability. Ex situ and operando synchrotron X-ray diffraction were used to reveal the detailed structural evolution of the cathode upon cycling. Using the climbing-image nudged elastic-band calculation and Ab initio molecular dynamics simulations, we show that the optimal transition metal composition enables a percolating network of low barrier pathways for fast, macroscopic Na diffusion, resulting in the observed high rate performance.

Ankylosis spondylitis (AS) is a disease mainly characterized by sacroiliac joint and spinal attachment point inflammation. Long non-coding RNA (lncRNA) plays a key role in the progression of many diseases. However, few studies have been conducted on the function of lncRNA maternally expressed gene 3 (MEG3) in AS. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure the relative levels of MEG3, microRNA let-7i, sclerostin (SOST), and inflammatory cytokines. Dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay and biotin-labeled RNA pull-down assay were used to confirm the interaction between MEG3 and let-7i or let-7i and SOST. In addition, western blot (WB) analysis was performed to detect the protein levels of osteogenesis markers and SOST. The expression levels of MEG3 and SOST were decreased and let-7i was increased in AS patients. MEG3 could interact with let-7i in AS fibroblasts, and let-7i overexpression reversed the suppressive effect of MEG3 upregulation on the inflammation and bone formation of AS. Additionally, let-7i could target SOST, and SOST silencing reversed the inhibitory effect of let-7i inhibitor or MEG3 overexpression on the inflammation and bone formation of AS. Furthermore, SOST expression was positively regulated by MEG3, while was negatively regulated by let-7i. Our results revealed that lncRNA MEG3 promoted SOST expression to restrain the progression of AS by sponging let-7i, which provided a treatment target for AS.

The outbreak of coronavirus disease 2019 (COVID-19) has spread across the world and was characterized as a pandemic. To protect medical laboratory personnel from infection, most laboratories inactivate the virus causing COVID-19, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in clinical samples before testing. However, the effect of inactivation on the detection results remains unknown. Here, we used a digital PCR assay to determine the absolute SARS-CoV-2 RNA copy number in 63 nasopharyngeal swab samples and assess the effect of inactivation methods on viral RNA copy number., The outbreak of coronavirus disease 2019 (COVID-19) has spread across the world and was characterized as a pandemic. To protect medical laboratory personnel from infection, most laboratories inactivate the virus causing COVID-19, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in clinical samples before testing. However, the effect of inactivation on the detection results remains unknown. Here, we used a digital PCR assay to determine the absolute SARS-CoV-2 RNA copy number in 63 nasopharyngeal swab samples and assess the effect of inactivation methods on viral RNA copy number. Viral inactivation was performed by three different methods: (i) incubation with the TRIzol LS reagent for 10 min at room temperature, (ii) heating in a water bath at 56°C for 30 min, and (iii) high-temperature treatment, including autoclaving at 121°C for 20 min, boiling at 100°C for 20 min, and heating at 80°C for 20 min. Compared to the amount of RNA in the original sample, TRIzol treatment destroyed 47.54% of the nucleocapsid protein (N) gene and 39.85% of open reading frame (ORF) 1ab. For samples treated at 56°C for 30 min, the copy number of the N gene and ORF 1ab was reduced by 48.55% and 56.40%, respectively. The viral RNA copy number dropped by 50 to 66% after heating at 80°C for 20 min. Nearly no viral RNA was detected after autoclaving at 121°C or boiling at 100°C for 20 min. These results indicate that inactivation reduced the quantity of detectable viral RNA and may cause false-negative results, especially in weakly positive cases. Thus, use of the TRIzol reagent rather than heat inactivation is recommended for sample inactivation, as the TRIzol reagent had the least effect on the RNA copy number among the tested methods.

Severe acute pancreatitis (SAP) activates the systemic inflammatory response and is potentially lethal. The aim of the present study was to determine the effects of emodin on acute lung injury (ALI) in rats with SAP and investigate the role of the Nod-like receptor protein 3 (NLRP3) inflammasome and its association with neutrophil recruitment. Sodium taurocholate (5.0%) was used to establish the SAP model. All animals were randomly assigned into four groups: Sham, SAP, emodin and dexamethasone (positive control drug) groups (n=10 mice per group). Histopathology observation of pancreatic and lung tissues was detected by hematoxylin and eosin staining. The levels of serum amylase, IL-1β and IL-18 were measured by ELISA. Single-cell suspensions were obtained from enzymatically digested lung tissues, followed by flow cytometric analysis for apoptosis. In addition, the expression levels of NLRP3 inflammasome-associated and apoptosis-associated proteins in lung tissues were measured by western blotting. Moreover, lymphocyte antigen 6 complex locus G6D+ (Ly6G+) cell recruitment was detected using immunohistochemical analysis. The results revealed that emodin markedly improved pancreatic histological injury and decreased the levels of serum amylase, IL-1β and IL-18. Pulmonary edema and apoptosis were significantly alleviated by emodin. Additionally, the protein expression levels of intercellular adhesion molecule 1, NLRP3, apoptosis-associated speck-like protein containing a CARD and cleaved caspase-1 were downregulated following emodin treatment. Moreover, emodin inhibited Ly6G+ cell recruitment in lung tissues. The present study demonstrated that emodin may offer protection against ALI induced by SAP via inhibiting and suppressing NLRP3 inflammasome-mediated neutrophil recruitment and may be a novel therapeutic strategy for the clinical treatment of ALI.

The development of novel antifungal agents with high efficacy, low drug tolerance and few side effects is urgent. MSI-1 (GIWKFLKKAKKFWK-NH2), a cationic antimicrobial peptide, may be an attractive antifungal agent because of its structural characteristics, perfect stability against pH and high-temperature/salt, low toxicity towards mammalian cells and low potential for emergence of drug tolerance. In this study, the antifungal activity of MSI-1 in vitro and in a murine model of cryptococcal meningoencephalitis was evaluated. Zeta potential assay, flow cytometry, fluorescence microscope, transmission electron microscopy and microscale thermophoresis were performed to clarify the mechanisms underlying MSI-1 against C. neoformans. The results showed that MSI-1 exerted effective anti-cryptococcal activity in vitro, with MICs of 8−16 μg/mL and MFCs of 8−32 μg/mL, and in a C neoformans-infected mouse model, with significantly improved animal survival, decreased production of pro-inflammatory cytokines and alleviated lung injury, because the potent and rapid fungicidal activity of MSI-1 could effectively eliminate fungal counts in mouse organs. We confirmed that the positively charged peptide bound to C. neoformans by electrostatic attraction after interacting with glucuronoxylomannan (the primary component of C. neoformans capsule). Subsequently, MSI-1 increased the membrane fluidity of fungal cells and the cell membrane permeability, causing destabilized membrane integrity and leading to the final death of fungi. Collectively, MSI-1 possessed potent anti-cryptococcal activity via its notable membrane disruption effect and may be a potential candidate for use in antifungal infection induced by C. neoformans, especially azole-resistant cryptococcus.

Physiological changes in humans are evident under environmental conditions similar to those on a Mars mission involving both a space factor (long-term isolation) and a time factor (the Mars solar day). However, very few studies have investigated the response of the liver to those conditions. Serum protein levels, bilirubin levels, aminotransferase activities, blood alkaline phosphatase, gamma-glutamyltransferase, lipid levels, and serum cytokines interleukin-6 and interferon-γ levels were analyzed 30 days before the mock mission; on days 2, 30, 60, 75, 90, 105, 120, 150, and 175 of the mission; and 30 days after the mission, in four subjects in 4-person 180-day Controlled Ecological Life Support System Experiment. Serum protein levels (total protein and globulin) decreased and bilirubin increased under the isolation environment from day 2 and exhibited chronic acclimatization from days 30 to 175. Effects of the Mars solar day were evident on day 75. Blood lipid levels were somewhat affected. No obvious peak in any enzyme level was detected during the mission. The change tendency of these results indicated that future studies should explore whether protein parameters especially globulin could serve as indicators of immunological function exposure to the stress of a Mars mission.

Acute lung injury (ALI) is the most common remote organ complication induced by severe acute pancreatitis (SAP). Almost 60-70% SAP-induced deaths are caused by ALI. Efficient clinical therapeutic strategy for SAP-induced ALI is still lacking. In this study, we demonstrate that Emodin (EMO) can significantly alleviate SAP-induced ALI. We investigate the therapeutic mechanisms of EMO by proteomic analysis, which indicates that EMO protects lung tissue against SAP-ALI by negative regulation of endopeptidase activity and inhibition of collagen-containing extracellular matrix degradation. Protein-protein interaction analysis showed Lamc2, Serpina1 and Serpinb1 play important roles in the above pathways. This study elucidates the possible mechanism and suggests the candidacy of EMO in the clinical treatment of SAP-ALI. SIGNIFICANCE: ALI is a major leading cause of death in SAP. DEX is the standard of care drug for treatment of SAP-ALI, but often associated with inevitable side effects. In the present study, EMO was demonstrated to greatly alleviate the lung injury induced by SAP. Through proteomic analysis, the recovered protein profiles in response to EMO treatment in SAP-ALI rat models was obtained, among which Lamc2, Serpina1 and Serpinb1 were discovered as crucial regulatory proteins in SAP-ALI disease. Our study provides the underlying mechanisms and novel targets of EMO protective effect against SAP-ALI.

The molecular structure of a catalytically active key intermediate is determined in solution by employing 2D IR spectroscopy measuring vibrational cross-angles. The formate intermediate (2) in the formic acid dehydrogenation reaction catalyzed by a phosphorus–nitrogen PN(3)P–Ru catalyst is elucidated. Our spectroscopic studies show that the complex features a formate ion directly attached to the Ru center as a ligand, and a proton added to the imine arm of the dearomatized PN(3)P* ligand. During the catalytic process, the imine arms are not only reversibly protonated and deprotonated, but also interacting with the protic substrate molecules, effectively serving as the local proton buffer to offer remarkable stability with a turnover number (TON) over one million.

The thylakoid membranes of plants play a critical role in electron transfer and energy fixation, and are highly dynamic. So far, studies on the thylakoid membranes have mainly focused on microalgae and higher plants, yet very little information is available on the macroalgal thylakoids. Here, we studied the structure and organization of the thylakoid membranes in Ulva prolifera, a representative species of the green macroalgae. We found that U. prolifera had few but long loosely stacked membranes which lack the conventional grana found in higher plants. However, the thylakoid membrane complexes demonstrate lateral heterogeneity. Moreover, we found a supercomplex composed of PSII, light-harvesting complex II (LHCII) and PSI from U. prolifera under salt stress. The supercomplex is approximately 720 kDa, and includes the two important photoprotection proteins, the PSII S subunit (PsbS) and the light-harvesting complex stress-related protein (LhcSR), as well as xanthophyll cycle pigments (violaxanthin, antheraxanthin and zeaxanthin). Time-resolved fluorescence analysis suggested that, in the supercomplex, excitation energy could efficiently be transferred from PSII to PSI, even when PSII was inhibited, a function which disappeared when the supercomplex was incubated in mild detergent. We suggest that the supercomplex might be an important mechanism to dissipate excess energy by PSI in green macroalgae under salt stress.

In this study, double-layer zinc oxide was synthesized on an aluminium substrate by combining a sol-gel and a hydrothermal method. The bottom layer was flower-like and the upper layer was rod-shaped. The aluminium sheet coated with zinc oxide was infiltrated into a lubricating oil for 2 h to obtain an aluminium-based double-layer ZnO super-slippery surface. Testing showed that the surface demonstrated a good anti-fouling effect. The coating was hydrophobic and oleophobic, and even fruit juice and jam slipped down the surface at a small tilt angle (

As-cast Al-6.0Mg-0.4Mn-0.1Cr-0.1Zr alloys containing different additions of Er were prepared. Then, the specimens were carried out homogenization heat treatment, hot rolling, cold rolling, and annealing. The effects of minor Er on the microstructure and properties of Al-6.0Mg-0.4Mn-0.1Cr-0.1Zr alloy were investigated. Results show that addition of Er can refine the microstructure and improve the mechanical properties of the alloys. As for the annealed alloys, the addition of 0.33%Er can increase the tensile strength by 29 MPa. Strength increment is mainly attributed to refinement and the precipitation of Al3Er and Al3(Er, Zr). Additionally, the minor Er can improve the corrosion resistance of the alloys, which can be attributed to the compact composite oxide film of Er-O and Al-O, purification, and modification.

Hot-carrier-induced molecular activation over photoexcited metal nanostructures is an important research field in solar-to-chemical energy conversion. Here, we report that visible light-illuminated TiO2-supported Rh nanoparticles could significantly enhance methane (CH4) activation in steam methane reforming at mild operating temperature (below 300 °C) with an ∼50% decrease in apparent activation energy compared to that of the pure thermal process. Femtosecond time-resolved infrared spectroscopic measurement and density functional theory calculations show an ultrafast separation of hot carriers at the Rh-TiO2 interface, resulting in the formation of an electron-deficient state of Rhδ+ at the surface for successive CH4 activation at low temperatures. Wavelength-dependent activities and kinetic isotope experiments validate that the photoexcited hot carriers in the Rh nanoparticles play a critical role in facilitating the rate-determining steps, i.e., the cleavage of the C–H bond in CH4. This study opens a p...

Toxic cyanobacteria (TCB) are well-known worldwide for their adverse impacts on humans. Species compositions and seasonal variations of TCB in reservoirs depend on interactions between physical and chemical factors. This study was conducted to evaluate the water quality in the Aha Reservoir, Southwest China, focusing on cyanobacteria and cyanotoxins. Water samples were collected weekly or biweekly from May to September of 2015 and used to delineate temporal variations in density and distribution of toxic cyanobacteria and cyanotoxins in the reservoir. Toxic cyanobacteria identified consisted of Aphanizomenon flos-aquae, Pseudanabaena limnetica, Cylindrospermopsis sp., and Microcystis sp., with Aphanizomenon flos-aquae and Pseudanabaena limnetica being the most common and significant toxic genera. The total biomass of cyanobacteria was 17.0 mg/L. Identification and quantification of microcystin variants were conducted by high performance liquid chromatography (HPLC) using a system equipped with a photodiode array detector. Microcystin levels were between 0-3.0 μg/L, MC-RR was around 0-3.0 μg/L and MC-LR was approximately 0-0.9 μg/L. Overall, the results of this study indicate that the investigated reservoirs should be monitored regularly to minimize potential health risks to the human population.

Aims Severe acute pancreatitis (SAP) is a serious disease associated with systematic inflammation and multiple organs dysfunction. Soluble ST2 (sST2), a member of the Toll interleukin (IL)-1 receptor (TIR) superfamily, has been demonstrated to exert immune-regulatory and anti-inflammatory properties in several inflammation-related diseases. In this study, we investigated whether transfer of sST2 gene by adenovirus vector could attenuate sodium taurocholate-induced SAP and associated cardiac injury. Main methods A rat model of SAP was induced by retrograde injection of 5% sodium taurocholate (1 ml/kg) into the biliopancreatic duct. Rats in the treatment groups were intravenously injected with adenovirus expressing sST2 (Ad-sST2, 1 × 109 particles/rat) or green fluorescent protein (Ad-GFP) via the tail vein 48 h before SAP induction. Histological changes in the pancreatic and heart tissues, and parameters for evaluating SAP and associated cardiac injury were determined at 24 h after SAP. Key findings Sodium taurocholate induced obvious pathological changes in pancreas and elevated serum levels of amylase and lipase. Furthermore, SAP animals exhibited significant cardiac impairment, evidenced by decreased cardiac function, increased myocardial apoptosis and cardiac-related enzymes including creatine kinase isoenzyme, lactate dehydrogenase, and Troponin T. Administration of Ad-sST2 markedly improved the structure of pancreas and heart tissues, and reversed the alterations in serum amylase, lipase and cardiac-related enzymes. In addition, Ad-sST2 treatment downregulated pro-inflammatory cytokines production, demonstrating the anti-inflammatory property of sST2. Significance Our results suggest that administration of Ad-sST2 significantly attenuated the severity of SAP and associated cardiac damage, and the cardioprotective effect is associated with its anti-inflammatory action.

Sodium-ion batteries (SIBs) are an emerging electrochemical energy storage technology that has high promise for electrical grid level energy storage. High capacity, long cycle life, and low cost cathode materials are very much desired for the development of high performance SIB systems. Sodium manganese oxides with different compositions and crystal structures have attracted much attention because of their high capacity and low cost. Here we report our investigations into a group of promising lithium doped sodium manganese oxide cathode materials with exceptionally high initial capacity of ∼223 mAh g−1 and excellent capacity retentions, attributed primarily to the absence of phase transformation in a wide potential range of electrochemical cycling, as confirmed by in-operando X-ray diffraction (XRD), Rietveld refinement, and high-resolution 7Li solid-state NMR characterizations. The systematic study of structural evolution and the correlation with the electrochemical behavior of the doped cathode materials provides new insights into rational design of high-performance intercalation compounds by tailoring the composition and the crystal structure evolution in electrochemical cycling.

This article investigates structures of ionic liquids., This article investigates structures of ionic liquids. Using a high-powered multiple-mode two dimensional infrared spectroscopic technique, we measure the anisotropy of interionic vibrational coupling in ionic liquids. Such anisotropy reports the relative orientation between cations and anions. Surprisingly, opposite to the well-propagated idea of ion pairing, a random orientation between the nearest non-spherically symmetric cation and anion is observed in ionic liquids. On the one hand, numerous previous experiments and theoretical calculations have shown that ionic liquids are highly ordered at the mesoscale, forming a bicontinuous nanostructure of ionic domains and hydrophobic domains. On the other hand, our results clearly prove that the ion ordering within the ionic domains is essentially random. Such an ordering at the larger scale (nanometers) and a lack of ordering at the smaller scale (sub-nanometer) is very rare for most liquids, or may even be unique to ionic liquids. Herein, we propose that ionic liquids may be regarded as 3D interconnecting nanocomposites of molten-salt-like domains and molecular-liquid-like domains. Such unique structuring could explain the fact that ionic liquids, like composite materials, often possess favorable properties of both “ionic” and “molecular” components.

All-solid-state batteries using lithium-conducting solid electrolytes (SEs) require not only favorable electrochemical properties but also optimal mechanical properties. SEs need to exhibit high enough stiffness to resist lithium dendrite growth while also being compliant and ductile enough to accommodate volumetric expansions of the electrodes. Thus, understanding the chemo-mechanical behavior of SE materials is essential for their effective development and deployment. In this work, the temperature-dependent deformation behavior of a range of inorganic sulfide (LSPS, LPSCl) and oxide (LAGP, LLZTO) SEs has been systematically investigated for the first time. Quasi-static, viscoelastic, and viscoplastic nanoindentation experimentation was conducted on these materials over a range of temperatures (from −40 to 300 °C). The elastic modulus and hardness properties of the sulfide vs. oxide material categories largely grouped together, with the cold pressed and subsequently sintered LLZTO oxide showing favorably low hardness and high tendency to creep. While all the oxide and sulfide materials exhibited minimal viscoelastic damping, consistent viscoplastic creep behavior was observed and quantitatively analyzed. The temperature dependence of the creep stress exponent was key for identifying the dominant creep mechanism in the material systems.

The ability to control and vary the atomic compositions of two-dimensional (2D) layered semiconductors is of considerable importance for tailoring their electronic and optoelectronic properties. The current methods to tailor chemical composition of 2D layered semiconductors is largely limited to vapor phase chemistry, and solution phase chemistry is insufficiently explored to date. Here, we report a general approach to prepare 2D layered transition metal dichalcogenides (TMDs) by ion exchange reactions in solution phase. By choosing four typical layered metal dichalcogenides including MoS2, MoSe2, WS2 and SnS2 as representative cases, the feasibility and versatility of both cation and anion exchange reactions in layered metal dichalcogenides are confirmed. Transient absorption results indicate that exciton lifetime of these samples as excitation energy is increased. The optoelectronic properties of these TMD nanosheets after the ion exchange exhibit potential for future devices. Our strategy can be employ...

Surface tensions for aqueous NaCl, NaBr, NaI, KCl, KBr, and KI solutions have been measured at different temperatures and different concentrations. The liquid densities and activity coefficients for electrolyte solutions are modeled accurately with the ion-based statistical associating fluid theory (SAFT2). Besides, a new surface tension prediction model on the basis of the Gibbs thermodynamic method, coupled with ion-based SAFT2 is established, which is applied to predict the surface tension of aqueous concentrated salt solutions at different concentrations and temperatures. In this model, we derived the relationship between the activity coefficient and surface tension, and the activity coefficient can be calculated by ion-based SAFT2. The model is found to give accurate prediction for the surface tension of aqueous concentrated electrolyte solutions at different concentrations and temperatures with the parameter obtained at one fixed temperature.