Improving NiFe Electrocatalysts through Fluorination-Driven Rearrangements for Neutral Water Electrolysis.

Neutral electrolysis to produce hydrogen is prime challenging owing to the sluggish kinetics of water dissociation for the electrochemical reduction of water to molecular hydrogen. An ion-enriched electrode/electrolyte interface for electrocatalytic reactions can efficiently obtain a stable electrolysis system. Herein, we found that interfacial accumulated fluoride ions and the anchored Pt single atoms/nanoparticles in catalysts can improve hydrogen evolution reaction (HER) activity of NiFe-based hydroxide catalysts, prolonging the operating stability at high current density in neutral conditions. NiFe hydroxide electrode obtains an outstanding performance of 1000 mA cm-2 at low overpotential of 218 mV with 1000 h operation at 100 mA cm-2. Electrochemical experiments and theoretical calculations have demonstrated that the interfacial fluoride contributes to promote the adsorption of Pt to proton for sustaining a large current density at low potential, while the Pt single atoms/nanoparticles provide H adsorption sites. The synergy effect of F and Pt species promotes the formation of Pt─H and F─H bonds, which accelerate the adsorption and dissociation process of H2O and promote the HER reaction with a long-term durability in neutral conditions.

Electrochemical Nitrate Reduction to Ammonia on AuCu Single-atom Alloy Aerogels under Wide Potential Window.

Electrocatalytic nitrate reduction to ammonia (NO3RR) is very attractive for nitrate removal and ammonia production in industrial processes. However, the nitrate reduction reaction is characterized by intense hydrogen competition at strong reduction potentials, which greatly limits the Faraday efficiency at strong reduction potentials. Herein, we reported an AuxCu single-atom alloy aerogels (AuxCu SAAs) with three-dimensional network structure with significant nitrate reduction performance of Faraday efficiency (FE) higher than 90% over a wide potential range (0 ~ -1 VRHE). The FE of the catalyst was close to 100% at a high reduction potential of -0.8 VRHE, accompanying with NH3 yield reaching 6.21 mmol h-1 cm-2. More importantly, the catalyst maintained a long-term operation over 400 h at 400 mA cm-2 for the NO3RR using a continuous flow system in a H-cell. Experimental and theoretical analysis demonstrate that the catalyst can lower the energy barrier for the hydrogenation reaction of *NO2, leading to a rapid consumption of the generated *H, facilitate the hydrogenation process of NO3RR, and inhibit the competitive HER at high overpotentials, which efficiently promotes the nitrate reduction reaction, especially in industrial applications.

Enhanced Charge-Carrier Dynamics and Efficient Photoelectrochemical Nitrate-to-Ammonia Conversion on Antimony Sulfide-Based Photocathodes.

The photoelectrochemical reduction of nitrate to ammonia (PEC NO3RR) has emerged as a promising pathway for facilitating the natural nitrogen cycle. The PEC NO3RR can lower the reduction potential needed for ammonia synthesis through photogenerated voltage, showcasing the significant potential for merging abundant solar energy with sustainable nitrogen fixation. However, it is influenced by the selective photocathodes with poor carrier kinetics, low catalytic selectivity, and ammonia yields. There are few reports on suitable photoelectrodes owning efficient charge transport on PEC NO3RR at low overpotentials. Herein, we rationally constructed the CuSn alloy co-catalysts on the antimony sulfides with a highly selective PEC ammonia and an ultra-low onset potential (0.62 VRHE). CuSn/TiO2/Sb2S3 photoelectrodes achieved an ammonia faradic efficiency of 97.82 % at a low applied potential of 0.4 VRHE, and an ammonia yield of 16.96 µmol h-1 cm-2 at 0 VRHE under one sun illumination. Dynamics experiments and theoretical calculations have demonstrated that CuSn/TiO2/Sb2S3 has an enhanced charge separation and transfer efficiency, facilitating photogenerated electrons to participate in PEC NO3RR quickly. Meanwhile, moderate NO2* adsorption on this photocathode optimizes the catalytic activity and increases the NH4 + yield. This work opens an avenue for designing sulfide-based photocathodes for the efficient route of solar-to-ammonia conversion.

Revisiting the Power Law Characteristics of the Plastic Shock Front under Shock Loading.

Under uniaxial shock compression, the steepness of the plastic shock front usually exhibits power law characteristics with the Hugoniot pressure, also known as the "Swegle-Grady law." In this Letter, we show that the Swegle-Grady law can be described better by a third power law rather than the classical fourth power law at the strain rate between 10^{5}-10^{7} s^{-1}. A simple dislocation-based continuum model is developed, which reproduced the third power law and revealed very good agreement with recent experiments of multiple types of metals quantitatively. New insights into this unusual macroscopic phenomenon are presented through quantifying the connection between the macroscopic mechanical response and the collective dynamics of dislocation assembles. It is found that the Swegle-Grady law results from the particular stress dependence of the plasticity behaviors, and that the difference between the third power scaling and the classical fourth power scaling results from different shock dissipative actions.

Controlled Defective Engineering on CuIr Catalyst Promotes Nitrate Selective Reduction to Ammonia.

Electrochemical nitrate reduction reaction (NO3-RR) is a promising low-carbon and environmentally friendly approach for the production of ammonia (NH3). Herein, we develop a high-temperature quenched copper (Cu) catalyst with the aim of inducing nonequilibrium phase transformation, revealing the multiple defects (distortion, dislocations, vacancies, etc.) presented in Cu, which lead to low overpotential for NO3-RR and high efficiency for NH3 production. Further loading a low content of iridium (Ir) species on the Cu surface improves the reactivity and ammonia selectivity. The resultant CuIr electrode exhibits a Faradaic efficiency of 93% and a record yield of 6.01 mmol h-1 cm-2 at -0.22 VRHE exceeding those of state-of-the-art NO3-RR catalysts. Detailed investigations have demonstrated that the synergistic effect between multiple defects and Ir decoration effectively regulate the d-band center of copper, change the adsorption state of the catalyst surface, and promote the adsorption and reduction of intermediates and reactants. The strong H* adsorption ability of the Ir element provides more active hydrogen for the generation of ammonia, promoting the reduction of nitrate to NH3.

Changes in the m6A RNA methylome accompany the promotion of soybean root growth by rhizobia under cadmium stress.

Cadmium (Cd) is the most widely distributed heavy metal pollutant in soil and has significant negative effects on crop yields and human health. Rhizobia can enhance soybean growth in the presence of heavy metals, and the legume-rhizobia symbiosis has been used to promote heavy-metal phytoremediation, but much remains to be learned about the molecular networks that underlie these effects. Here, we demonstrated that soybean root growth was strongly suppressed after seven days of Cd exposure but that the presence of rhizobia largely eliminated this effect, even prior to nodule development. Moreover, rhizobia did not appear to promote root growth by limiting plant Cd uptake: seedlings with and without rhizobia had similar root Cd concentrations. Previous studies have demonstrated a role for m6A RNA methylation in the response of rice and barley to Cd stress. We therefore performed transcriptome-wide m6A methylation profiling to investigate changes in the soybean RNA methylome in response to Cd with and without rhizobia. Here, we provide some of the first data on transcriptome-wide m6a RNA methylation patterns in soybean; m6A modifications were concentrated at the 3' UTR of transcripts and showed a positive relationship with transcript abundance. Transcriptome-wide m6A RNA methylation peaks increased in the presence of Cd, and the integration of m6A methylome and transcriptome results enabled us to identify 154 genes whose transcripts were both differentially methylated and differentially expressed in response to Cd stress. Annotation results suggested that these genes were associated with Ca2+ homeostasis, ROS pathways, polyamine metabolism, MAPK signaling, hormones, and biotic stress responses. There were 176 differentially methylated and expressed transcripts under Cd stress in the presence of rhizobia. In contrast to the Cd-only gene set, they were also enriched in genes related to auxin, jasmonic acid, and brassinosteroids, as well as abiotic stress tolerance. They contained fewer genes related to Ca2+ homeostasis and also included candidates with known functions in the legume-rhizobia symbiosis. These findings offer new insights into how rhizobia promote soybean root growth under Cd stress; they provide candidate genes for research on plant heavy metal responses and for the use of legumes in phytoremediation.

Nucleation and growth in shock-induced phase transitions and how they determine wave profile features.

Wave profile measurement and interpretation play a central role in shock physics research. We propose an approach to revealing the direct link between the wave profile and nucleation and growth process in shock-induced phase transition. Through phase field simulations, we show for the first time that it is possible to explain experimentally measured wave profiles directly from the viewpoint of nucleation and growth, and constrain from such profiles real nucleation and growth scenarios that are otherwise impossible to study.

[Determination of nicotine in wild edible fungi by QuEChERS-ultra performance liquid chromatography-triple quadrupole mass spectrometry].

Yunnan Province has many wild edible fungi resources, and of these, endogenous nicotine has received extensive attention in recent years. In this study, wild edible fungus was used as the research object, and the QuEChERS method was improved, including optimization of solvent extraction and purification conditions and optimization of the chromatographic behavior of nicotine under different mobile phase conditions for ultra performance liquid chromatography (UPLC). Combined with triple quadrupole mass spectrometry, a high-efficiency, rapid, and sensitive method for the determination of nicotine in wild edible fungi was established. The results showed that an ammonia:acetonitrile (6:94, v/v) mixed solution can completely extract nicotine from wild edible fungi, and the extraction solution was purified by graphitized carbon black (GCB) and N-propylethylenediamine (PSA) mixed filler. Then, a 0.1% (volume percentage) ammonia solution and acetonitrile were used as the mobile phases. The nicotine peak obtained in the positive ion multiple reaction monitoring (MRM) mode had a better peak shape and better response. The linear relationship of nicotine mass concentration with peak area in the range of 0.05-50.0 µg/L was good. The correlation coefficient (r2) was 0.9999. The limit of quantification was 0.2 µg/kg, and the limit of detection was 0.05 µg/kg. The average recovery rates at three spiked concentrations were in the range of 86.34%-96.4%, and the relative standard deviations varied from 4.44% to 6.3%. The sensitivity and recovery of this method are consistent with the rapid determination of nicotine in the edible fungus industry.

Expression of tubulin folding cofactor B in mouse hepatic ischemia-reperfusion injury.

The aim of the present study was to investigate the association between tubulin folding cofactor B (TBCB) expression and ischemia-reperfusion injury (IRI) in mice. A total of 48 C57BL/6 mice were randomly divided into a control group (Sham, n=6) and an ischemia-reperfusion group (n=42). The ischemia-reperfusion group was further divided into 6 subgroups as per different times after reperfusion (2, 4, 6, 8, 12 and 24 h), with 7 mice per subgroup. A hepatic IRI model was established in mice by clamping the hepatic hilum. Morphology, serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α), and the expression level of TBCB were detected. Compared with the control group, the livers from the ischemia-reperfusion group were significantly changed, particularly at 12 h following ischemia-reperfusion, with obvious hepatic cell degeneration and necrosis. The ALT, AST, IL-6 and TNF-α levels in the sera of the mice in the hepatic ischemia-reperfusion group were increased at all time points following ischemia-reperfusion, and were the highest at 12 h, demonstrating statistically significant differences when compared with the control group (P<0.05). Furthermore, the expression levels of TBCB, TNF-α and IL-6 were significantly increased at all time-points following ischemia-reperfusion, and were the most significant at 12 h. At 24 h following ischemia-reperfusion, the expression levels had decreased. The present study indicated that TBCB expression is associated with TNF-α and IL-6 expression levels in mice with hepatic ischemia-reperfusion, and may be key in the development of liver injury during ischemia-reperfusion in mice.

Heat shock factor 1 inhibits the mitochondrial apoptosis pathway by regulating second mitochondria-derived activator of caspase to promote pancreatic tumorigenesis.

BACKGROUND: As a relatively conservative transcriptional regulator in biological evolution, heat shock factor 1 (HSF1) is activated by, and regulates the expression of heat shock proteins (HSPs) in response to a variety of stress conditions. HSF1 also plays a key role in regulating the development of various tumors; however, its role in pancreatic cancer and the specific underlying mechanism are not clear. METHODS: We first examined HSF1 expression in pancreatic cancer tissues by immunohistochemistry, and then studied its clinical significance. We then constructed HSF1-siRNA to investigate the potential of HSF1 to regulate apoptosis, proliferation and the cell cycle of pancreatic cancer cells and the underlying mechanism both in vitro and in vivo. Protein chip analysis was used subsequently to explore the molecular regulation pathway. Finally, second mitochondria-derived activator of caspase (SMAC)-siRNA was used to validate the signaling pathway. RESULTS: HSF1 was highly expressed in pancreatic cancer tissues and the level of upregulation was found to be closely related to the degree of pancreatic cancer differentiation and poor prognosis. After HSF1-silencing, we found that pancreatic cancer cell proliferation decreased both in vitro and in vivo and the apoptotic cell ratio increased, while the mitochondrial membrane potential decreased, and the cells were arrested at the G0/G1 phase. In terms of the molecular mechanism, we confirmed that HSF1 regulated SMAC to inhibit mitochondrial apoptosis in pancreatic cancer cells, and to promote the occurrence of pancreatic tumors. SMAC silencing reversed the effects of HSF1 silencing. CONCLUSION: Our study provides evidence that HSF1 functions as a novel oncogene in pancreatic tumors and is implicated as a target for the diagnosis and treatment of pancreatic cancer.

DADLE improves hepatic ischemia/reperfusion injury in mice via activation of the Nrf2/HO­1 pathway.

Hepatic ischemia/reperfusion (I/R) injury is a common pathophysiological process that occurs following liver surgery, which is associated with oxidative stress, and can cause acute liver injury and lead to liver failure. Recently, the development of drugs for the prevention of hepatic I/R injury has garnered interest in the field of liver protection research. Previous studies have demonstrated that [D­Ala2, D­Leu5]­Enkephalin (DADLE) exerts protective effects against hepatic I/R injury. To further clarify the specific mechanism underlying the effects of DADLE on hepatic I/R injury, the present study aimed to observe the effects of various doses of DADLE on hepatic I/R injury in mice. The results indicated that DADLE, at a concentration of 5 mg/kg, significantly reduced the levels of alanine aminotransferase and aspartate aminotransferase in the serum, and the levels of malondialdehyde in the liver homogenate. Conversely, the levels of glutathione, catalase and superoxide dismutase in the liver homogenate were increased. In addition, DADLE was able to promote nuclear factor, erythroid 2 like 2 (Nrf2) nuclear translocation and upregulate the expression of heme oxygenase (HO)­1, which is a factor downstream of Nrf2, thus improving hepatic I/R injury in mice. In conclusion, the present study demonstrated that DADLE was able to significantly improve hepatic I/R injury in mice, and the specific mechanism may be associated with the Nrf2/HO­1 signaling pathway.

Collagen fiber angle in the submucosa of small intestine and its application in Gastroenterology.

AIM: To propose a simple and effective method suitable for analyzing the angle and distribution of 2-dimensional collagen fiber in larger sample of small intestine and to investigate the relationship between the angles of collagen fiber and the pressure it undergoes. METHODS: A kind of 2-dimensional visible quantitative analyzing technique was described. Digital image-processing method was utilized to determine the angle of collagen fiber in parenchyma according to the changes of area analyzed and further to investigate quantitatively the distribution of collagen fiber. A series of intestinal slice's images preprocessed by polarized light were obtained with electron microscope, and they were processed to unify each pixel. The approximate angles between collagen fibers were obtained via analyzing the images and their corresponding polarized light. The relationship between the angles of collagen fiber and the pressure it undergoes were statistically summarized. RESULTS: The angle of collagen fiber in intestinal tissue was obtained with the quantitative analyzing method of calculating the ratio of different pixels. For the same slice, with polarized light angle's variation, the corresponding ratio of different pixels was also changed; for slices under different pressures, the biggest ratio of collagen fiber area was changed either. CONCLUSION: This study suggests that the application of stress on the intestinal tissue will change the angle and content of collagen fiber. The method of calculating ratios of different pixel values to estimate collagen fiber angle was practical and reliable. The quantitative analysis used in the present study allows a larger area of soft tissue to be analyzed with relatively low cost and simple equipment.

Quantitative analysis of collagen fiber angle in the submucosa of small intestine.

It is of interest to know how distension changes the angle and content of collagen in the submucosa of small intestine. We describe the application of a two-dimensional quantitative analysis technology to determine the angles between collagen fibers in the submucosa using digital image processing. A polarization microscope was used to obtain a series of animal intestinal slice images. The images were studied by analyzing the relationship between the pixel values of each of the polarized angles to obtain the collagen fiber angle. The statistical distribution of the angle as function of the degree of distension can be analyzed.

Study of trilogy-imaging characteristics on TTM and its relationship with malignancies.

To study trilogy-imaging characteristics of thermal texture mapping (TTM) and its relationship with malignancies. TTM scanning was performed on 32 normal volunteers and 90 cancer patients who were included in this study. And the trilogy-imaging characteristics were observed. The percent of the characteristics of trilogy imaging on TTM is higher in cancer patients than normal control, P = 0.0000. In normal volunteers who have trilogy characteristics, the percent of the people with cancer family history was obviously higher than those without, P = 0.0003. Trilogy-imaging characteristics on TTM are correlated with the patients with malignancy or the normal people with cancer family history. Neuroendocrine-immunology thesis might be the underlying mechanism of that phenomenon.

Re-investigation of the mechanism of trilogy imaging characteristics on TTM in cancer patients.

According to neuro-endocrine-immune theory, we have done research and tried to find possible explanations of the relationship of trilogy imaging characteristics of thermal texture mapping (TTM) and patients with the malignancies, or the patients susceptible to malignancies. We performed another two experiments to study mechanism of trilogy imaging characteristics, however, the result was not as expected. We have to reconsider the relationship between 3 tumor platforms and hypothalamus-thyroid-pancreas. Is there any possible mechanism?.

A comparative study of thermal texture mapping in benign and malignant breast diseases.

The aim is to investigate differences of thermal texture mapping (TTM) between benign and malignant breast diseases. After receiving TTM, 100 patients were categorized into three groups in normal patient, benign change and malignant lesion. TTM demonstrated that the malignant lesion mostly appeared thermal features and deeper layer position with surrounding or penetrating vessels, and irregular thermal spread pattern with spinal margin in breast; there also appeared deeper layer abnormal thermal source in axilla and abnormal thermal pattern with circular, asteroid and agaric-like shape fixed near the left side of Angle of Louise of the sternum, which was irrelative to abnormal thermoradiation and lesion position in breast. Therefore, the difference of TTM appearance definitely exists between benign and malignant breast diseases.