Deep-learning enhanced high-quality imaging in metalens-integrated camera.

Because of their ultra-light, ultra-thin, and flexible design, metalenses exhibit significant potential in the development of highly integrated cameras. However, the performances of metalens-integrated camera are constrained by their fixed architectures. Here we proposed a high-quality imaging method based on deep learning to overcome this constraint. We employed a multi-scale convolutional neural network (MSCNN) to train an extensive pair of high-quality and low-quality images obtained from a convolutional imaging model. Through our method, the imaging resolution, contrast, and distortion have all been improved, resulting in a noticeable overall image quality with SSIM over 0.9 and an improvement in PSNR over 3 dB. Our approach enables cameras to combine the advantages of high integration with enhanced imaging performances, revealing tremendous potential for a future groundbreaking imaging technology.

High-Performance Macroporous Free-Standing Microbial Fuel Cell Anode Derived from Grape for Efficient Power Generation and Brewery Wastewater Treatment.

Microbial fuel cells (MFCs) have the potential to directly convert the chemical energy in organic matter into electrical energy, making them a promising technology for achieving sustainable energy production alongside wastewater treatment. However, the low extracellular electron transfer (EET) rates and limited bacteria loading capacity of MFCs anode materials present challenges in achieving high power output. In this study, three-dimensionally heteroatom-doped carbonized grape (CG) monoliths with a macroporous structure were successfully fabricated using a facile and low-cost route and employed as independent anodes in MFCs for treating brewery wastewater. The CG obtained at 900 °C (CG-900) exhibited excellent biocompatibility. When integrated into MFCs, these units initiated electricity generation a mere 1.8 days after inoculation and swiftly reached a peak output voltage of 658 mV, demonstrating an exceptional areal power density of 3.71 W m-2. The porous structure of the CG-900 anode facilitated efficient ion transport and microbial community succession, ensuring sustained operational excellence. Remarkably, even when nutrition was interrupted for 30 days, the voltage swiftly returned to its original level. Moreover, the CG-900 anode exhibited a superior capacity for accommodating electricigens, boasting a notably higher abundance of Geobacter spp. (87.1%) compared to carbon cloth (CC, 63.0%). Most notably, when treating brewery wastewater, the CG-900 anode achieved a maximum power density of 3.52 W m-2, accompanied by remarkable treatment efficiency, with a COD removal rate of 85.5%. This study provides a facile and low-cost synthesis technique for fabricating high-performance MFC anodes for use in microbial energy harvesting.

Identification of MET fusions in solid tumors: A multicenter, large scale study in China.

MET amplification and exon 14 skipping are well known as oncogenic drivers in multiple cancer types. However, MET fusions in most cancer types are poorly defined. To explore the profile and analyze the characteristics of MET fusions, a large-cohort study was conducted to screen MET fusions in clinical samples (n = 10 882) using DNA-based NGS. A total of 37 potentially functional MET fusions containing the intact tyrosine kinase domain (TKD) of MET were identified in 36 samples. Further, 15 novel MET fusions were identified in five cancer types, and the incidence of novel MET fusions accounted for 40.5% (15/37). Brain cancer had the highest incidence of MET fusion, with PTPRZ1-MET as the most common fusion (37.0%). All MET breakpoints in brain cancer (n = 27) were also located in intron 1, while those in lung cancer (n = 4) occurred in intron 1, intron 11, intron 14 and exon 14, respectively. The positive consistency of the common fusion group was 100% (11/11), while that of the rare fusion group was 53.8% (7/13). In conclusion, we provided a comprehensive genomic landscape of MET rearrangement and updated the MET fusions database for clinical test. In addition, we revealed that DNA-based NGS might serve as the clinical test for common MET fusions; however, rare MET fusions must be validated by both DNA-based NGS and RNA-based NGS. Prospective trials are necessary to confirm the treatment efficacy of MET inhibitors.

Facile Construction of Nanostructured Cermet Anodes with Strong Metal-Oxide Interaction for Efficient and Durable Solid Oxide Fuel Cells.

Nanostructured anodes generate massive reaction sites to oxidize fuels in solid oxide fuel cells (SOFCs); however, the nonexistence of a practically viable approach for the construction of nanostructures and the retention of these nanostructures under the harsh operating conditions of SOFCs poses a significant challenge. Herein, a simple procedure is reported for the construction of a nanostructured Ni-Gd-doped CeO2 anode based on the direct assembly of pre-formed nanocomposite powder with strong metal-oxide interaction. The directly assembled anode forms heterointerfaces with the electrolyte owing to the electrochemical polarization current and exhibits excellent structural robustness against thermal ripening. An electrolyte-supported cell with the directly assembled anode produces a peak power density of 0.73 W cm-2 at 800 °C, while maintaining stability for 100 h, which is in contrast to the drastic degradation of the cermet anode prepared using the conventional method. These findings provide clarity on the design and construction of durable nanostructured anodes and other electrodes for SOFCs.

Mechanistic insights into Fe3O4-modified biochar relieving inhibition from erythromycin on anaerobic digestion.

Anaerobic digestion (AD) of antibiotic manufacturing wastewater to degrade residual antibiotics and produce mixture of combustible gases has been investigated actively in the past decades. However, detrimental effect of residual antibiotic to microbial activities is commonly faced in AD process, leading to the reduction of treatment efficiency and energy recovery. Herein, the present study systematically evaluated the detoxification effect and mechanism of Fe3O4-modified biochar in AD of erythromycin manufacturing wastewater. Results showed that Fe3O4-modified biochar had stimulatory effect on AD at 0.5 g/L erythromycin existence. A maximum methane yield of 327.7 ± 8.0 mL/g COD was achieved at 3.0 g/L Fe3O4-modified biochar, leading to the increase of 55.7% compared to control group. Mechanistic investigation demonstrated that different levels of Fe3O4-modified biochar could improve methane yield via different metabolic pathways involved in specific bacteria and archaea. Low levels of Fe3O4-modified biochar (i.e., 0.5-1.0 g/L) led to the enrichment of Methanothermobacter sp., strengthening the hydrogenotrophic pathway. On the contrary, high levels of Fe3O4-modified biochar (2.0-3.0 g/L) favored the proliferation of acetogens (e.g., Lentimicrobium sp.) and methanogen (Methanosarcina sp.) and their syntrophic relations played vital role on the simulated AD performance at erythromycin stress. Additionally, the addition of Fe3O4-modified biochar significantly decreased the abundance of representative antibiotic resistant genes (ARGs), benefiting the reduction of environmental risk. The results of this study verified that the application of Fe3O4-modified biochar could be an efficient approach to detoxify erythromycin on AD system, which brings high impacts and positive implications for biological antibiotic wastewater treatment.

Removal Performance and Mechanism of Emerging Pollutant Chloroquine Phosphate from Water by Iron and Magnesium Co-Modified Rape Straw Biochar.

Chloroquine phosphate (CQP) is effective in treating coronavirus disease 2019 (COVID-19); thus, its usage is rapidly increasing, which may pose a potential hazard to the environment and living organisms. However, there are limited findings on the removal of CQP in water. Herein, iron and magnesium co-modified rape straw biochar (Fe/Mg-RSB) was prepared to remove CQP from the aqueous solution. The results showed that Fe and Mg co-modification enhanced the adsorption efficiency of rape straw biochar (RSB) for CQP with the maximum adsorption capacity of 42.93 mg/g (at 308 K), which was about two times higher than that of RSB. The adsorption kinetics and isotherms analysis, as well as the physicochemical characterization analysis, demonstrated that the adsorption of CQP onto Fe/Mg-RSB was caused by the synergistic effect of pore filling, π-π interaction, hydrogen bonding, surface complexation, and electrostatic interaction. In addition, although solution pH and ionic strength affected the adsorption performance of CQP, Fe/Mg-RSB still had a high adsorption capability for CQP. Column adsorption experiments revealed that the Yoon-Nelson model better described the dynamic adsorption behavior of Fe/Mg-RSB. Furthermore, Fe/Mg-RSB had the potential for repeated use. Therefore, Fe and Mg co-modified biochar could be used for the remediation of CQP from contaminated water.

A Stable Fe-Zn Modified Sludge-Derived Biochar for Diuron Removal: Kinetics, Isotherms, Mechanism, and Practical Research.

To remove typical herbicide diuron effectively, a novel sludge-derived modified biochar (SDMBC600) was prepared using sludge-derived biochar (SDBC600) as raw material and Fe-Zn as an activator and modifier in this study. The physico-chemical properties of SDMBC600 and the adsorption behavior of diuron on the SDMBC600 were studied systematically. The adsorption mechanisms as well as practical applications of SDMBC600 were also investigated and examined. The results showed that the SDMBC600 was chemically loaded with Fe-Zn and SDMBC600 had a larger specific surface area (204 m2/g) and pore volume (0.0985 cm3/g). The adsorption of diuron on SDMBC600 followed pseudo-second-order kinetics and the Langmuir isotherm model, with a maximum diuron adsorption capacity of 17.7 mg/g. The biochar could maintain a good adsorption performance (8.88-12.9 mg/g) under wide water quality conditions, in the pH of 2-10 and with the presence of humic acid and six typical metallic ions of 0-20 mg/L. The adsorption mechanisms of SDMBC600 for diuron were found to include surface complexation, π-π binding, hydrogen bonding, as well as pore filling. Additionally, the SDMBC600 was tested to be very stable with very low Fe and Zn leaching concentration ≤0.203 mg/L in the wide pH range. In addition, the SDMBC600 could maintain a high adsorption capacity (99.6%) after four times of regeneration and therefore, SDMBC600 could have a promising application for diuron removal in water treatment.

Effects of influent immigration and environmental factors on bacterial assembly of activated sludge microbial communities.

The functional mechanism of microbial assembly of activated sludge (AS) in urban wastewater treatment plants (UWTPs) remains unclear. A comprehensive quantitative evaluation of the contribution of influent immigration and environmental factors to AS community composition requires investigation. In this study, the microbial characteristics of six full-scale UWTPs with different influent compositions and environmental factors (altitude, temperature, dissolved oxygen (DO), pH, chemical oxygen demand (COD), total nitrogen (TN), ammonia nitrogen (NH4+-N), and total phosphorus (TP)) were analyzed to determine the main forces affecting the bacterial assembly of AS microbial communities. Abundant and core taxa were screened out based on the abundance and frequency of operational taxonomic units (OTUs) occurrence in all samples. Abundant OTUs (18.7% occurrence) accounted for 87.7% of the total 16S rRNA sequences, while rare OTUs (71.7% occurrence) accounted for only 7.8% of the total 16S rRNA sequences. A total of 135 OTUs were identified as core taxa, accounting for 14.6-26.2% of the total reads, of which 83 OTUs belonged to abundant taxa. The richness and uniformity of the influent community were significantly lower than those of the AS system. The community composition in influent varied from that in AS. Moreover, about 89.7% (86.5% of 16S rRNA sequences) OTUs in AS samples showed positive growth rates, indicating that immigration of influent communities had a limited effect on the microbial composition of AS. Redundancy analysis (RDA) combined with co-occurrence network showed that the bacterial assembly of microbial communities was significantly correlated with altitude, pH, and TN (P < 0.05), and these three parameters could explain 23.3%, 21.1%, and 17.7% of the bacterial assembly of AS microbial communities in UWTPs, respectively.

Acute toxic effects of diclofenac exposure on freshwater crayfish (Procambarus clarkii): Insights from hepatopancreatic pathology, molecular regulation and intestinal microbiota.

In this study, we exposed adult male crayfish (Procambarus clarkii) to different concentrations of diclofenac (DCF) for 96 h. In the meantime, we investigated the alternations of hepatopancreatic pathology, molecular regulation and intestinal microbiota of P. clarkii exposed to DCF. The results demonstrated DCF led to histological changes including epithelium vacuolization and tubule lumen dilatation in the hepatopancreas. Transcriptome sequencing analysis showed that 642 and 586 genes were differentially expressed in the hepatopancreas of P. clarkii exposed to 1 and 10 mg/L DCF, respectively. DCF could affect the functions of antioxidation, immunity and metabolism of hepatopancreas by inducing the abnormal expressions of immune- and redox-related genes. GO enrichment results demonstrated that 10 mg/L DCF exposure could modulate the processes of molting, amino sugar metabolism, protein hydrolysis and intracellular protein translocation of P. clarkii. Additionally, the abundances of bacterial families including Shewanellaceae, Bacteroidaceae, Vibrionaceae, Erysipelotrichaceae, Aeromonadaceae, Moraxellaceae, etc. in the intestine were significantly changed after DCF exposure, and the disruption of intestinal flora might further cause abnormal intestinal metabolism in P. clarkii. This study provides novel mechanistic insights into the toxic effects of anti-inflammatory drugs on aquatic crustaceans.

Titanium Vacancies in TiO2 Nanofibers Enable Highly Efficient Photodriven Seawater Splitting.

Photodriven seawater splitting is considered to be one of the most promising techniques for sustainable hydrogen production. However, the high salinity of seawater would deactivate catalysts and consume the photogenerated carriers. Metal vacancies in metal oxide semiconductors are critical to directed electron transfer and high salinity resistance; they are thus desirable but remain a challenge. We demonstrate a facile controllable calcination approach to synthesize TiO2 nanofibers with rich Ti vacancies with excellent photo/electro performances and long-time stability in photodriven seawater splitting, including photocatalysis and photo-electrocatalysis. Experimental measurements and theoretical calculations reveal the formation of titanium vacancies, as well as unidirectional electron trap and superior H+ adsorption ability for efficient charge transfer and resistance to corrosion by seawater. Therefore, atomic-/nanoscale characteristics and mechanism have been proposed to clarify the generation of titanium vacancies and the corresponding interfacial electron transfer.

Titanium Vacancies in TiO2 Nanofibers Enable Highly Efficient Photodriven Seawater Splitting.

Invited for the cover of this issue are Xiao-Yu Yang and co-workers at Wuhan University of Technology, Heinrich-Heine-Universität Düsseldorf, University of the Witwatersrand, and Ben-Gurion University of the Negev. The image depicts Ti vacancies in TiO2 as powerful drivers of photo- and photo-electrocatalytic seawater splitting for hydrogen production. Read the full text of the article at 10.1002/chem.202101817.

Sodium butyrate ameliorates Schistosoma japonicum-induced liver fibrosis by inhibiting HMGB1 expression.

Schistosomiasis is a prevalent zoonotic parasitic disease caused by schistosomes. Its main threat to human health is hepatic granuloma and fibrosis due to worm eggs. Praziquantel remains the first choice for the treatment of schistosomiasis but has limited benefit in treating liver fibrosis. Therefore, the need to develop effective drugs for treating schistosomiasis-induced hepatic fibrosis is urgent. High-mobility group box 1 protein (HMGB1) is a potential immune mediator that is highly associated with the development of some fibrotic diseases and may be involved in the liver pathology of schistosomiasis. We speculated that HMGB1 inhibitors could have an anti-fibrotic effect. Sodium butyrate (SB), a potent inhibitor of HMGB1, has shown anti-inflammatory activity in some animal disease models. In this study, we evaluated the effects of SB on a murine schistosomiasis model. Mice were percutaneously infected with 20 ± 2 cercariae of Schistosoma japonicum. SB (500 mg/kg/day) was administered every 3 days for the entire experiment period. The activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), liver histopathology, HMGB1 expression, and the levels of interferon gamma (IFN-γ), transforming growth factor-ß1 (TGF-ß1), and interleukin-6 (IL-6) in serum were analyzed. SB reduced hepatic granuloma and fibrosis of schistosomiasis, reflected by the decreased levels of ALT and AST in serum and the reduced expression of pro-inflammatory and fibrogenic cytokines (IFN-γ, TGF-ß1, and IL-6). The protective effect could be attributable to the inhibition of the expression of HMGB1 and release by SB.

Capsaicin alleviates acetaminophen-induced acute liver injury in mice.

Overdose of N-acetyl-para-aminophenol (APAP) can induce acute liver injury (ALI). We evaluated the potential protective effect of 8-methyl-N-geranyl-6-nonamide (capsaicin (CAP)) in APAP-induced ALI in mice. ALI was induced by APAP (150 mg/kg, i.p.) administration; CAP pretreatment (1 mg/kg) was undertaken before APAP injection for 3 consecutive days. We found that CAP pretreatment attenuated ALI significantly; improve the oxidative stress-associated indicators (hepatic expression of malondialdehyde (MDA) superoxide dismutase (SOD) and glutathione (GSH)); downregulate expression of proinflammatory cytokines (interleukin (IL)-6, IL-1ß, tumor necrosis factor-α) through the high-mobility group box 1/toll-like receptor-4/nuclear factor-kappa B (HMGB1/TLR4/NF-κB) signaling pathway; alleviate hepatocyte apoptosis by inhibiting expression of B-cell lymphoma-2-associated X, caspase-3 and cleaved caspase-3. CAP pretreatment reduced expression of B-cell lymphoma-2, which served as a hepatotoxic factor rather than an anti-apoptotic protein in our mouse model. We propose that CAP can alleviate APAP-induced ALI by inhibiting the inflammatory response, attenuating oxidative stress, and reducing hepatocyte apoptosis.

The renoprotective effect of curcumin against cisplatin-induced acute kidney injury in mice: involvement of miR-181a/PTEN axis.

Background: Nephrotoxicity, especially acute kidney injury (AKI), is the main dose-limiting toxicity of cisplatin. Although recent studies showed that curcumin prevented cisplatin-induced AKI effectively, further studies to understand the mechanism are required.Methods: We established an AKI mouse model. Male C57BL/6 mice were assigned to three groups: saline group (control), cisplatin group (CP), and curcumin + cisplatin group (CP + Cur). The CP group received a single intraperitoneal (i.p.) injection of cisplatin, while the control group received saline. The CP + Cur group received i.p. curcumin three days before cisplatin injection and curcumin administered for another three days until the day before euthanization. Renal injury was assessed by serological and histological analysis. Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) were used to detect the phosphatase and tensin homolog (PTEN), and microRNA (miR)-181a expression in the renal tissues. Bioinformatics prediction and western blotting methods validated the targets of miR-181a in vitro.Results: Curcumin treatment alleviated cisplatin-induced nephrotoxicity as validated by the blood urea nitrogen (BUN) values, and histological analysis of kidneys. At the molecular level, curcumin treatment decreased miR-181a expression level, which was induced by cisplatin and restored the in vivo expression of PTEN, which was suppressed by cisplatin. We verified the direct regulation of PTEN by miR-181a in cultured human embryonic kidney 293T cells.Conclusions: We showed the involvement of miR-181a/PTEN axis in the renoprotective effect of curcumin against cisplatin-induced AKI, and provide new evidence on the ability of curcumin to alleviate cisplatin-induced nephrotoxicity.

Microstructure evolution and kinetics of B-site nanoparticle exsolution from an A-site-deficient perovskite surface: a phase-field modeling and simulation study.

Segregation-exsolution of B-site catalytic dopants as nanoparticles from A-site-deficient perovskite (A1-xBO3-δ) surfaces has been actively used in recent years to promote the activity and durability of perovskite oxides towards efficient fuel oxidation and water splitting. The mechanistic understandings are currently gained from equilibrium thermodynamics, such as atomic scale density functional theory calculations, in terms of segregation energy, interaction energy and elastic energy. Herein, we have developed a micro-scale phase-field model framework that describes the kinetics and microstructure evolutions of the B-site segregation and nanoparticle exsolution from the A1-xBO3-δ surface. The model was derived in a thermodynamically consistent manner by employing a ternary regular-solution free-energy functional and Cahn-Hilliard kinetic equations. The key hypothesis is that the B-site nanoparticle is exsolved by a spinodal decomposition once the surface region of A1-xBO3-δ is driven to the spinodal region of the free-energy functional via B-site segregation to the surface and/or via expansion of the chemical spinodal region. The effects of oxygen partial pressure (or electric polarization), B-site supersaturation (or A-site deficiency), and segregation energy have been explicitly investigated, and the results obtained agree qualitatively with the experimental observations. The proposed model can serve as a multi-scale bridge that ties the atomic-scale understandings to the micro-scale observations and has the potential to be used for the design and optimization of nano-architectures of A1-xBO3-δ materials.

Small interfering LncRNA-TUG1 (siTUG1) decreases ketamine-induced neurotoxicity in rat hippocampal neurons.

Background: Ketamine (KET) is known to be used in pediatric anaesthetic, whereas many evidences revealed that KET generated neurotoxicity. In our study, we found KET decreased the level of LncRNA taurine-upregulated gene 1 (TUG1). Hence, the aim of our study is to investigate whether small interfering TUG1 (siTUG1) has effect on KET-induced rat hippocampal neurons. Material and methods: siTUG1 and KET alone or in combination was used to treat with neurons for 12 h. MTT assays was used to detect hippocampal neurons viability. Cell apoptosis and reactive oxygen species (ROS) level were analysed by flow cytometry assay. TUG1 level was determined via reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assay. The levels of Bax, Bcl-2, cleaved-caspase-3, p38 and p-p38 were measured by western blot (WB) assay. Results: Neurons treated by siTUG1 and KET had a higher optical density (OD) value, a lower apoptosis rate and lower ROS level. Neurons treated by the combination of siTUG1 and KET had lower levels of TUG1, cleaved-caspase-3 and p-p38 than those under KET treatment. Besides, siTUG1 + KET group (siTUG1 and KET treated neurons) had a higher Bcl-2 level than KET group. Conclusion: We found that siTUG1 decreased KET-induced hippocampal neurons apoptosis and ROS level, and increased hippocampal neurons viability. siTUG1 decreased neurons apoptosis via signaling pathways of Bax/Bcl-2 and Caspases, and increased neurons viability by signaling pathway of p38 MAPK. Our results indicate that KET-induced neurotoxicity might be reduced by inhibiting TUG1.

Growth and survival of Takifugu rubripes larvae cultured under different light conditions.

We assessed the effects of light intensity and spectrum on the growth and survival of Takifugu rubripes larvae from 30 to 69 days after hatching. Five lighting regimes were applied using 0.5, 1.5, and 3.0 W m-2 full spectrum white (W0.5, W1.5, W3.0), 0.5 W m-2 yellow (Y0.5), and 0.5 W m-2 blue light (B0.5). At the end of the experiment, body length, wet weight, and specific growth rate from day 0 to day 39 were significantly greater in larvae reared under W3.0 than under B0.5 (P Ë‚ 0.05). No significant differences were observed among W0.5, W1.5, and W3.0, or among W0.5, Y0.5, and B0.5 (P > 0.05). Survival rate was significantly higher in larvae reared under W1.5 than W0.5 (P Ë‚ 0.05), but no significant differences were observed among W0.5, Y0.5, and B0.5 (P > 0.05). Additionally, light conditioning did not affect the total thickness of the retina. Although the ratio of the thickness of the retinal pigment epithelium layer/total thickness (TT) was significantly higher in larvae exposed to W3.0 compared with those exposed to other light conditions, and the thickness of the outer nuclear layer/TT was significantly lower in larvae exposed to W3.0 compared with those exposed to W0.5 (P < 0.05), no relationship was confirmed between the structure of the retina and the growth performance of the T. rubripes larvae. Expression patterns of two stress-related and seven growth-related genes were also compared with the biometric parameters investigated in the experimental groups. No significant differences in the aanat1a, crh, ss1, igf1, or igf2 expression were observed among the five treatments. Pomc expression was significantly lower in larvae exposed to W1.5 than the larvae exposed to W0.5, and it was significantly lower in larvae exposed to Y0.5 than in larvae exposed to W0.5 or B0.5 (P < 0.05). Significant differences were also found in the expression of gh, with the highest levels being observed under W3.0, while the lowest levels were observed in B0.5 (P < 0.05). Ghrh expression was significantly higher in W3.0 (P < 0.05). These results should be considered when designing rearing protocols for fugu larvae in aquaculture systems.

Conserved and unique features of the homeologous maize Aux/IAA proteins ROOTLESS WITH UNDETECTABLE MERISTEM 1 and RUM1-like 1.

The maize (Zea mays L.) Aux/IAA protein RUM1 (ROOTLESS WITH UNDETECTABLE MERISTEM 1) is a key regulator of lateral and seminal root formation. An ancient maize genome duplication resulted in the emergence of its homeolog rum1-like1 (rul1), which displays 92% amino acid sequence identity with RUM1. Both, RUL1 and RUM1 exhibit the canonical four domain structure of Aux/IAA proteins. Moreover, both are localized to the nucleus, are instable and have similar short half-lives of ~23min. Moreover, RUL1 and RUM1 can be stabilized by specific mutations in the five amino acid degron sequence of domain II. In addition, proteins encoded by both genes interact in vivo with auxin response factors (ARFs) such as ZmARF25 and ZmARF34 in protoplasts. Although it was demonstrated that RUL1 and RUM1 can homo and heterodimerize in vivo, rul1 expression is independent of rum1. Moreover, on average rul1 expression is ~84-fold higher than rum1 in the 12 tested tissues and developmental stages, although the relative expression levels in different root tissues are very similar. While RUM1 and RUL1 display conserved biochemical properties, yeast-two-hybrid in combination with BiFC experiments identified a RUM1-associated protein 1 (RAP1) that specifically interacts with RUM1 but not with RUL1. This suggests that RUM1 and RUL1 are at least in part interwoven into different molecular networks.

Mechanism for the enhanced oxygen reduction reaction of La0.6Sr0.4Co0.2Fe0.8O3-δ by strontium carbonate.

Strontium doped lanthanum cobalt ferrite (LSCF) is a widely applied electrocatalyst for the oxygen reduction reaction (ORR) in solid-oxide fuel cells (SOFCs) operated at intermediate temperatures. Sr surface segregation in long-term operation has been reported to have contradicting effects that either degrade or improve the reaction. Thus, it is critical to understand the mechanism of surface Sr compounds on ORR kinetics. This work aims to verify the effect and propose the mechanism by decorating SrCO3 nanoparticles using the infiltration method. Electrochemical conductivity relaxation measurements show that SrCO3 particles improve the chemical oxygen surface exchange coefficient by up to a factor of 100. The electrochemical performance is significantly improved by the infiltration of SrCO3, which is comparable to those obtained by typical electrocatalysts including precious metals such as Pd and Rh. Distribution of relaxation time (DRT) analysis shows that the performance enhancement is strongly related to the improved kinetics of charge transfer and oxygen incorporation processes. Density functional theory calculations show that the surface SrCO3 reduces the O2 dissociation energy barrier from 1.01 eV to 0.33 eV, thus enhancing the ORR kinetics, possibly through changing the charge density distribution at the LSCF-SrCO3 interface.

LATERAL ROOT PRIMORDIA 1 of maize acts as a transcriptional activator in auxin signalling downstream of the Aux/IAA gene rootless with undetectable meristem 1.

Only little is known about target genes of auxin signalling downstream of the Aux/IAA-ARF module. In the present study, it has been demonstrated that maize lateral root primordia 1 (lrp1) encodes a transcriptional activator that is directly regulated by the Aux/IAA protein ROOTLESS WITH UNDETECTABLE MERISTEM 1 (RUM1). Expression of lrp1 is confined to early root primordia and meristems and is auxin-inducible. Based on its primary protein structure, LRP1 is predicted to be a transcription factor. This notion is supported by exclusive LRP1 localization in the nucleus and its ability to activate downstream gene activity. Based on the observation that lrp1 transcription is completely repressed in the semi-dominant gain of function mutant rum1, it was demonstrated that the lrp1 promoter is a direct target of RUM1 proteins. Subsequently, promoter activation assays indicated that RUM1 represses the expression of a GFP reporter fused to the native promoter of lrp1. Constitutive repression of lrp1 in rum1 mutants is a consequence of the stability of mutated rum1 proteins which cannot be degraded by the proteasome and thus constitutively bind to the lrp1 promoter and repress transcription. Taken together, the repression of the transcriptional activator lrp1 by direct binding of RUM1 to its promoter, together with specific expression of lrp1 in root meristems, suggests a function in maize root development via the RUM1-dependent auxin signalling pathway.