OsCBL5-CIPK1-PP23 module enhances rice grain size and weight through the gibberellin pathway.

Grain size is a key factor in determining rice (Oryza sativa) yield, and exploring new pathways to regulate grain size has immense potential to improve yield. In this study, we report that OsCBL5 encodes a calcineurin B subunit protein that significantly promotes grain size and weight. oscbl5 plants produced obviously smaller and lighter seeds. We further revealed that OsCBL5 promotes grain size by affecting cell expansion in the spikelet hull. Biochemical analyses demonstrated that CBL5 interacts with CIPK1 and PP23. Furthermore, double and triple mutations were induced using CRISPR/Cas9 (cr) to analyze the genetic relationship. It was found that the cr-cbl5/cipk1 phenotype was similar to that of cr-cipk1 and that the cr-cbl5/pp23, cr-cipk1/pp23, and cr-cbl5/cipk1/pp23 phenotype was similar to that of cr-pp23, indicating that OsCBL5, CIPK1, and PP23 act as a molecular module influencing seed size. In addition, the results show that both CBL5 and CIPK1 are involved in the gibberellic acid (GA) pathway and significantly affect the accumulation of endogenous active GA4 . PP23 participates in GA signal transduction. In brief, this study identified a new module that affects rice grain size, OsCBL5-CIPK1-PP23, which could potentially be targeted to improve rice yield.

Interfered chromosome pairing at high temperature promotes meiotic instability in autotetraploid Arabidopsis.

Changes in environmental temperature affect multiple meiotic processes in flowering plants. Polyploid plants derived from whole-genome duplication (WGD) have enhanced genetic plasticity and tolerance to environmental stress but face challenges in organizing and segregating doubled chromosome sets. In this study, we investigated the impact of increased environmental temperature on male meiosis in autotetraploid Arabidopsis (Arabidopsis thaliana). Under low to mildly increased temperatures (5°C-28°C), irregular chromosome segregation universally occurred in synthetic autotetraploid Columbia-0 (Col-0). Similar meiotic lesions occurred in autotetraploid rice (Oryza sativa L.) and allotetraploid canola (Brassica napus cv Westar), but not in evolutionarily derived hexaploid wheat (Triticum aestivum). At extremely high temperatures, chromosome separation and tetrad formation became severely disordered due to univalent formation caused by the suppression of crossing-over. We found a strong correlation between tetravalent formation and successful chromosome pairing, both of which were negatively correlated with temperature elevation, suggesting that increased temperature interferes with crossing-over predominantly by impacting homolog pairing. We also showed that loading irregularities of axis proteins ASY1 and ASY4 co-localize on the chromosomes of the syn1 mutant and the heat-stressed diploid and autotetraploid Col-0, revealing that heat stress affects the lateral region of synaptonemal complex (SC) by impacting the stability of the chromosome axis. Moreover, we showed that chromosome axis and SC in autotetraploid Col-0 are more sensitive to increased temperature than those in diploid Arabidopsis. Taken together, our data provide evidence suggesting that WGD negatively affects the stability and thermal tolerance of meiotic recombination in newly synthetic autotetraploid Arabidopsis.

Determination of free and total meropenem levels in human plasma and its application for the consistency evaluation of generic drugs.

RATIONALE: The consistency evaluation of generic drugs is important for the overall reformation of drug registration in China. In this study, we used meropenem as a model drug to explore the key techniques for clinical consistency evaluation by studying the plasma protein binding (PPB) ratio of different preparations. Because the free portion of drug is the effective part in vivo, it is essential to measure the free drug concentration in the circulatory system. Therefore, in this study, a fast and accurate high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method was developed to determine the total and free concentrations of meropenem in human plasma. METHODS: Simple protein precipitation procedures were used for the sample processing assay, and ultrafiltration was implemented for the separation of free drugs. Liquid chromatography separation was performed using a hydrophilic interaction liquid chromatography (HILIC) silica column (2.1 × 50 mm, 3 µm). The mobile phase and sample preparation procedures were optimized. Factors affecting the measurement of free drug concentration were also determined. Nonspecific binding of the ultrafiltration membrane was negligible because the recovery rate for post-ultrafiltration was greater than 96%. RESULTS: Under optimal conditions, the drug concentrations were linear from 0.5 to 50 µg/ml for both total and free drug concentrations. The PPB ratio was calculated based on the free and total drug concentrations. The PPB of meropenem varied from 1.4% to 24.2% in different subjects. The validated method was applied to evaluate PPB of four preparations, and the results varied from 6.57 ± 3.19% to 10.40 ± 8.31%. One-way analysis of variance (ANOVA) showed no significant differences between the four preparations. CONCLUSIONS: We established a rapid, robust, and reliable method for the determination of total and free meropenem concentrations using LC-MS/MS with ultrafiltration techniques. The method provided a new perspective for the clinical consistency evaluation of generic drugs.

Transformation mechanism of methylphosphonate to methane by Burkholderia sp: Insight from multi-labeled water isotope probing and transcriptomic.

Methylphosphonate (MPn), has been identified as a likely source of methane in aerobic ocean and may be responsible for the "ocean methane paradox", that is oversaturation of dissolved methane in oxic sea waters. However, the mechanism underlying the cleavage of C-P bonds during microbial degradation is not well understood. Using multi-labeled water isotope probing (MLWIP) and transcriptome analysis, we investigated the phosphate oxygen isotope systematics and mechanisms of microbial-mediated degradation of MPn in this study. In the aerobic culture containing MPn as the only phosphorus source, there was a significant release of inorganic phosphate (149.4 µmol/L) and free methane (268.3 mg/L). The oxygen isotopic composition of inorganic phosphorus (δ18OP) of accumulated released phosphate was 4.50‰, 23.96‰, and 40.88‰, respectively, in the corresponding 18O-labeled waters of -10.3‰, 9.9‰, and 30.6‰, and the slope obtained in plots of δ18OP versus the oxygen isotopic composition of water (δ18OW) was 0.89. Consequently, 89% of the oxygen atoms (Os) in phosphate (PO4) were exchanged with 18O-labeled waters in the medium, while the rest were exchanged with intracellular metabolic water. It has been confirmed that the C-P bond cleavage of MPn occurs in the cell with both ambient and metabolic water participation. Moreover, phn gene clusters play significant roles to cleave the C-P bond of MPn for Burkholderia sp. HQL1813, in which phnJ, phnM and phnI genes are significantly up-regulated during MPn decomposition to methane. In conclusion, the aerobic biotransformation of MPn to free methane by Burkholderia sp. HQL1813 has been elucidated, providing new insights into the mechanism that bio-cleaves C-P bonds to produce methane aerobically in aqueous environments for representative phosphonates.

Higher serum trimethylamine N-oxide (TMAO) levels are associated with increased visceral fat in hemodialysis patients.

BACKGROUND: Trimethylamine N-oxide (TMAO), a gut microbiota-derived metabolite, has emerged as a new potentially important cause of increased atherosclerosis and cardiovascular risk in chronic kidney disease (CKD) patients. However, the possible causes whereby TMAO potentiates atherosclerosis development remain poorly defined. The strong association between gut microbiota and obesity suggested that the TMAO pathway may be linked to the pathogenesis of obesity. MATERIALS AND METHODS: A total of 184 hemodialysis (HD) patients and 38 healthy controls were enrolled in the study from March 2019 to May 2019. We evaluated visceral fat area (VFA) by anthropometric measurement and measured serum TMAO concentrations using liquid chromatography/differential ion mobility spectrometry tandem mass spectrometry. We also examined the relationship between TMAO levels and visceral fat accumulation. RESULTS: TMAO level was markedly higher in HD patients than in control subjects (5.80 (3.96, 9.46) vs. 0.18 (0.11, 0.32) µg/mL, p < 0.01), and its level in diabetic HD patients was significantly higher than in nondiabetic patients (6.93 (4.67, 11.40) vs. 5.25 (3.78, 8.02) µg/mL, p < 0.01). A significant positive correlation was found between serum TMAO level and VFA in these patients (r = 0.282, p = 0.005). Multiple regression analysis showed that Ln(TMAO) was independently associated with Ln(VFA) in HD patients (p = 0.008). CONCLUSION: Our results showed that there was a significant positive correlation between serum TMAO levels and visceral fat in HD patients, which suggested that TMAO may predict cardiovascular risk through increased visceral fat.

CRISPR/Cas13d targeting GZMA in PARs pathway regulates the function of osteoclasts in chronic apical periodontitis.

Chronic apical periodontitis is a prevalent oral disease characterized by bone loss, and its underlying mechanisms remain unclear. This study aimed to investigate the role and mechanism of the serine protease GZMA in osteoclasts during chronic apical periodontitis. To address this, we employed crRNA/Cas13d to inhibit GZMA expression and examined its impact on osteoclast behavior. Our findings revealed that GZMA plays a significant role in promoting osteoclast cell proliferation while inhibiting cell apoptosis. Additionally, the inhibition of GZMA led to a notable increase in miR-25-3p expression, which, in turn, downregulated the expression of TGF-ß. Consequently, the reduction in TGF-ß expression led to a decrease in PAR1 expression within the PARs pathway. These results suggest that GZMA might serve as a promising therapeutic target for the treatment of chronic apical periodontitis. Furthermore, our study highlights the potential of targeting GZMA using crRNA/Cas13d as a valuable approach for future therapeutic interventions.

Full-length transcriptome reconstruction reveals genetic differences in hybrids of Oryza sativa and Oryza punctata with different ploidy and genome compositions.

BACKGROUND: Allopolyploid breeding is an efficient technique for improving the low seed setting rate of autotetraploids in plant breeding and one of the most promising breeding methods. However, there have been few comprehensive studies of the posttranscriptional mechanism in allopolyploids. RESULTS: By crossing cultivated rice (Oryza sativa, genome AA) with wild rice (Oryza punctata, genome BB), we created hybrid rice lines with different ploidy and genome compositions [diploid hybrid F01 (AB), allotetraploid hybrid F02 (AABB) and F03 (AAAB)]. The genetic differences of the hybrids and the mechanism of allopolyploid breeding dominance were revealed through morphological and cytological observations and single molecule real-time sequencing techniques. The tissues and organs of allotetraploid hybrid F02 exhibited "gigantism" and the highest levels of fertility. The numbers of non-redundant transcripts, gene loci and new isoforms in the polyploid rice lines were higher and the isoform lengths greater than those of the diploid line. Moreover, alternative splicing (AS) events occurred twice as often in the polyploid rice lines than the diploid line. During these events, intron retention dominated. Furthermore, a large number of new genes and isoforms specific to the lines of different ploidy were discovered. CONCLUSIONS: The results indicated that alternative polyadenylation (APA) and AS events contributed to the complexity and superiority of polyploids in the activity of translation regulators, nucleic acid binding transcription factor activities and the regulation of molecular function. Therefore, these APA and AS events in allopolyploid rice were found to play a role in regulation. Our study provides new germplasm for polyploid rice breeding and reveals complex regulatory mechanisms that may be related to heterosis and fertility.

Higher serum trimethylamine-N-oxide levels are associated with increased abdominal aortic calcification in hemodialysis patients.

INTRODUCTION: Vascular calcification (VC) is high prevalent and predicts cardiovascular mortality in dialysis patients. The mechanisms are not known clearly. Trimethylamine-N-oxide (TMAO), a gut-microbiota derivate metabolite, is also associated with cardiovascular outcomes in hemodialysis (HD) patients. This study aims to evaluate serum TMAO levels and establish their relation to VC in HD patients. METHODS: Serum TMAO concentrations were measured by high-performance liquid chromatography-mass spectrometry. Vascular calcification was evaluated by abdominal aortic calcification (AAC) scores. Taking the AAC score value 5.5 as the cutoff value, the participants were divided into the high AAC score group and the low AAC score group. RESULTS: A total of 184 HD patients and 39 healthy controls were enrolled in this cross-sectional study. Serum Ln(TMAO) (the natural logarithm of TMAO) concentrations were significantly higher in HD patients than that of control subjects (1.82 ± 0.62 vs. -1.60 ± 0.77, p < 0.001). Compared with the group with low AAC scores, the HD patients with high AAC scores showed significantly higher serum Ln(TMAO) levels (2.09 ± 0.55 vs. 1.67 ± 0.54, p < 0.001). In the multivariate regression analysis, serum Ln(TMAO), HD vintage, with diabetic mellitus, age and plasma intact parathyroid hormone (iPTH) were independent determinant factors for VC in HD patients. CONCLUSIONS: Higher serum TMAO levels, older age, longer HD vintage, higher plasma iPTH and with diabetes mellitus were independent risk factors for VC in HD patients. The underlying mechanism deserves further investigations and the finding hints at a new target for the treatment of VC.

Promotion properties of TLR7 in pediatric meningitis via the NF-κB pathway.

Meningitis outcome is associated with the severity of inflammation in the subarachnoid space and that the outcome can be improved through anti-inflammation. However, a comprehensive understanding of the molecular basis underlying inflammatory responses in meningitis remains enigmatic. In the current study, we sought to determine the molecular mechanism of TLR7/NF-κB on the development of meningitis in children. Cerebrospinal fluid of patients with meningitis and children with simple febrile convulsions was collected, and meningitis mouse model was induced. TLR7 expression was determined in the serum of meningitis model mice and the cerebrospinal fluid of patients using RT-qPCR and Western blot. Afterwards, loss- and gain- function assays were conducted to determine the functional role of TLR7 in meningitis mouse model. The level of procalcitonin (PCT) and the number of bacterial colonies in the serum were analyzed. ELISA was used to detect the expression of inflammatory factors. Upregulated level of TLR7 was observed in patients and mice with meningitis. Inhibiting the expression of TLR7 inhibited the development of meningitis. Overexpressing TLR7 can activate the NF-κB signaling pathway and promote mouse meningitis. NF-κB signaling pathway inhibitor reversed promotion of meningitis caused by TLR7 activation. Our study provides evidence that TLR7 elevation can activate the NF-κB signaling pathway and promote meningitis in mice.

A simple liquid chromatography/differential ion mobility spectrometry tandem mass spectrometry method for the determination of trimethylamine-N-oxide in human serum: An application in dialysis patients.

RATIONALE: Trimethylamine-N-oxide (TMAO) is a potential indicator of cardiovascular disease and chronic kidney disorders. It is important to monitor the TMAO level in plasma or serum of hemodialysis patients. A simple liquid chromatography/differential ion mobility spectrometry tandem mass spectrometry (HPLC/DMS-MS/MS) method was established and validated for the determination of TMAO in the serum of hemodialysis patients. METHODS: Chromatographic separation was performed on a Waters Atlantis HILIC silica column (2.1 × 50 mm, 3 µm). The gradient mobile phase consisted of 10 mM ammonium formate buffer and acetonitrile with 0.1% formic acid in both solvents. The serum sample was precipitated with acidic acetonitrile prior to HPLC/DMS-MS/MS analysis and TMAO-d9 was used as the internal standard. Data acquisition was performed in positive ion mode with a DMS system before the electrospray ionization source. The selected reaction monitoring transitions were m/z 76.0 → 58.0 and m/z 85.2 → 66.1 for TMAO and the internal standard, respectively. RESULTS: Excellent linearity was observed over the calibration range 0.05-20 µg/mL (r2 > 0.995). The method was validated for good specificity and sensitivity. The inter-run and intra-run precision and accuracy were less than 13.6% and 10.7%, respectively. CONCLUSIONS: We established a novel and robust HPLC/DMS-MS/MS method for the quantification of TMAO in human serum samples. The validated assay was simple, rapid, sensitive and reliable. The developed method could be applied to the assay of serum samples from patients with kidney disease who are undergoing hemodialysis.

FeO6 Octahedral Distortion Activates Lattice Oxygen in Perovskite Ferrite for Methane Partial Oxidation Coupled with CO2 Splitting.

Modulating lattice oxygen in metal oxides that conducts partial oxidation of methane in balancing C-H activation and syngas selectivity remains challenging. This paper describes the discovery of distorting FeO6 octahedra in La1-xCexFeO3 (x = 0, 0.25 0.5, 0.75, 1) orthorhombic perovskites for the promotion of lattice oxygen activation. By combined electrical conductivity relaxation measurements and density functional theory calculations studies, this paper describes the enhancement of FeO6 octahedral distortion in La1-xCexFeO3 promoting their bulk oxygen mobility and surface oxygen exchange capability. Consequently, La0.5Ce0.5FeO3 with the highest FeO6 distortion achieves exceptional syngas productivity of ∼3 and 8 times higher than LaFeO3 and CeFeO3, respectively, in CH4 partial oxidation step with simultaneous high CO2 conversion (92%) in the CO2-splitting step at 850 °C. The results exemplify the feasibility to tailor the active lattice oxygen of perovskite by modulating the distortion of BO6 in ABO3, which ultimately influences their reaction performance in chemical looping processes.

Rituximab treatment for lupus nephritis: A systematic review.

PURPOSE: We used the Cochrane systematic review to analyze the effectiveness and safety of rituximab for lupus nephritis. METHODS: Systematic search was performed among Cochrane clinical controlled trials database, MEDLINE, MEDLINE-IN-Process and Other Non-Indexed Citations, EMBASE, EBSCO CINAHL, CNKI, VIP and Wanfang database from the establishment of the database to February 2016. The effectiveness and safety were evaluated in terms of the complete remission rate, total remission rate, urinary protein, Systemic Lupus Erythematosus Disease Activity Index changes and adverse events rate. Data were analyzed by the Review Manager Software version 5.3. RESULTS: Five RCTs that met the inclusion criteria, including a total of 238 patients, were enrolled in our study. The results showed that the complete remission rate in rituximab group was a significantly higher than that of cyclophosphamide group. The difference between the two groups was statistically significant (OR=2.80, 95%CI(1.08,7.26), P=0.03). But there was no significant difference between the two groups in partial and total remission rate. The complete remission rate, partial remission rate and total remission rate in rituximab treatment group was similar compared with mycophenolate mofetil group and rituximab combined with cyclophosphamide group. The adverse reaction rate was also similar among the groups. CONCLUSION: The study systematically analyzed the effectiveness and safety of rituximab for lupus nephritis, which suggested that the complete remission rate of rituximab in the treatment of lupus nephritis was a significantly higher than that of cyclophosphamide group, while the effectiveness and safety was of no difference compared with cyclophosphamide and mycophenolate mofetil.

The decreased N6-methyladenine DNA modification in cancer cells.

N6-methyladenine (6 mA) is a recently characterized DNA modification in mammalian genomes, although its biological importance remains to be resolved. Using a highly sensitive HPLC/MS/MS approach, here we report regulation of 6 mA modification in mammalian cells. To these aspects, down-regulation of 6 mA modification was first characterized in human cancer cells and tissues, relative to their normal controls. In contrast to the relative stable 5 mC modification, a dramatic decrease of 6 mA modification was found, showing that 6 mA is the most regulated DNA modification in cancers. In addition to the regulation in cancer cells, a hundreds-fold increase of 6 mA modification was found for in vitro cultured human cells, relative to the in vivo cells. This up-regulation was also confirmed with in vitro cultured mouse cells. Taken together, our study revealed distinct 6 mA modification profiles in the cancer and cultured cells. Considering its distinct regulation from that of 5 mC, our study suggests that 6 mA DNA modification may play a crucial role in cell fate transition of mammalian cells.

tRNA modification profiles of the fast-proliferating cancer cells.

Despite the recent progress in RNA modification study, a comprehensive modification profile is still lacking for mammalian cells. Using a quantitative HPLC/MS/MS assay, we present here a study where RNA modifications are examined in term of the major RNA species. With paired slow- and fast-proliferating cell lines, distinct RNA modification profiles are first revealed for diverse RNA species. Compared to mRNAs, increased ribose and nucleobase modifications are shown for the highly-structured tRNAs and rRNAs, lending support to their contribution to the formation of high-order structures. This study also reveals a dynamic tRNA modification profile in the fast-proliferating cells. In addition to cultured cells, this unique tRNA profile has been further confirmed with endometrial cancers and their adjacent normal tissues. Taken together, the results indicate that tRNA is a actively regulated RNA species in the fast-proliferating cancer cells, and suggest that they may play a more active role in biological process than expected.

A validated HPLC-MS/MS method for the quantification of caderofloxacin in human plasma and its application to a clinical pharmacokinetic study.

A simple, selective and rapid HPLC-MS/MS method was developed and validated for the determination of caderofloxacin in human plasma. Sparfloxacin was used as the internal standard (IS). After precipitation with methanol and dilution with the mobile phase, the samples were injected into the HPLC-MS/MS system. The chromatographic separation was performed on a Zorbax XDB Eclipse C18 column (150 × 4.6 mm, 5 µm) with a mobile phase of ammonium acetate buffer (20 mm, pH 3.0)-methanol, 45:55 (v/v). The MS/MS analysis was done in positive mode. The multiple reaction monitoring transitions monitored were m/z 412.3 → 297.1 for caderofloxacin and m/z 393.2 → 292.2 for the IS. The calibration curve was linear over the range of 50.0-8000 ng/mL with an aliquot of 100 µL plasma. The precision of the assay was 2.0-9.4 and 6.6-11.5% for the intra- and inter-run variability, respectively. The intra- and inter-run accuracy (relative error) was 4.4-10.0 and -1.2-4.0%. The total run time was 3.5 min. The assay was fully validated in accordance with the US Food and Drug Administration guidance. It was successfully applied to a pharmacokinetic study of caderofloxacin in healthy Chinese volunteers.

A simple and sensitive LC-MS/MS method for the determination of sotalol in rat plasma.

A sensitive, rapid and robust HPLC method with tandem mass spectrometry (HPLC/MS/MS) detection has been developed and validated for the quantification of sotalol in rat plasma. Plasma samples were precipitated with acetonitrile before analysis. The chromatographic separation was performed on an Atlantis hydrophilic interaction liquid chromatography Silica column (50 × 2.1 mm, 3 µm) with a gradient mobile phase of 10 mm NH4 COOH (containing 0.2% of formic acid) as buffer A and acetonitrile as mobile phase B. Sotalol (m/z 273.2 → 255.1) and atenolol (the internal standard, IS, m/z 267.2 → 190.1) were monitored under positive ionization mode with 5500 QTRAP. Retention time of sotalol and the IS were 2.69 and 3.43 min, respectively. The linear range was 5-500 nm based on the analysis of 0.1 mL of plasma. The intrabatch precision ranged from 1.2 to 6.1%, and the inter-batch precision was from 3.3 to 6.5%. The coefficient of variation of IS-normalized matrix factor was 7.6%. Experiments for stability were performed and the analyte was sufficiently stable. A run time of 6 min for each injection made it possible to analyze a high throughput of plasma samples. The assay was successfully applied to the determination of sotalol in rat plasma after a micro-dose oral administration.

Mechanisms of TET protein-mediated DNA demethylation and its role in the regulation of mouse development.

TET (ten-eleven translocation) protein family includes three members TET1, TET2 and TET3, which belong to alpha-ketoglutaric acid ( α-KG )- and Fe(2+)-dependent dioxygenase superfamily, and have the capacity to convert 5-methylcytosine (5 mC) to 5-hydroxymethylcytosine (5 hmC), 5-formylcytosine (5 fC) and 5-carboxylcytosine (5 caC). At present, growing lines of evidence indicate that TET proteins are involved in the control of active or passive DNA demethylation via different mechanisms; moreover, their activities may be regulated by some cellular factors. TET proteins play vital roles in modulating mammal development, including primordial germ cell formation, embryonic development, stem cells pluripotency, nerve and brain development, etc. The identification of biological roles of TET proteins will open a new field in epigenetic research, and these studies on TET proteins are of great significance to life science research. Here, we review TET proteins from their structure, molecular mechanisms of DNA demethylation and function in the regulation of mouse development, which may provide the basis for understanding the functions of TET proteins.

Solution Blow Spinning Ultrafine Fiber Sponge-Loaded MOF-808 for Effective Adsorption and Degradation of Mustard Gas.

Functional materials that can quickly absorb and degrade mustard gas are essential for chemical warfare emergency response kits. In this study, a fiber membrane with excellent adsorption and catalytic degradation activity was developed by solution blow spinning polystyrene (PS)/polyurethane (PU) and hydrothermal in situ growth of a zirconium-based MOF (MOF-808). The mechanical properties of the PS/PU fibers were improved by adding a trimethylolpropane tris (2-methyl-1-aziridine propionate) (TTMA) cross-linking agent. Moreover, the C═O bonds in TTMA provided abundant growth sites for MOF-808 in the hydrothermal process, thereby greatly increasing the loading capacity. The fiber surface was completely covered with the MOF-808 particles within 24 h. The PS/PU/TTMA/MOF-808 fiber membrane was used for the catalytic degradation of 2-chloroethyl ethyl sulfide (CEES). The degradation efficiency reached 97.7% after 72 h, indicating its great application potential in emergency wiping cloths for mustard gas adsorption and degradation.

Atomically dispersed MoNi alloy catalyst for partial oxidation of methane.

The catalytic partial oxidation of methane (POM) presents a promising technology for synthesizing syngas. However, it faces severe over-oxidation over catalyst surface. Attempts to modify metal surfaces by incorporating a secondary metal towards C-H bond activation of CH4 with moderate O* adsorption have remained the subject of intense research yet challenging. Herein, we report that high catalytic performance for POM can be achieved by the regulation of O* occupation in the atomically dispersed (AD) MoNi alloy, with over 95% CH4 conversion and 97% syngas selectivity at 800 °C. The combination of ex-situ/in-situ characterizations, kinetic analysis and DFT (density functional theory) calculations reveal that Mo-Ni dual sites in AD MoNi alloy afford the declined O2 poisoning on Ni sites with rarely weaken CH4 activation for partial oxidation pathway following the combustion reforming reaction (CRR) mechanism. These results underscore the effectiveness of CH4 turnovers by the design of atomically dispersed alloys with tunable O* adsorption.

Endophytic bacteria for Cd remediation in rice: Unraveling the Cd tolerance mechanisms of Cupriavidus metallidurans CML2.

The utility of endophytic bacteria in Cadmium (Cd) remediation has gained significant attention due to their ability to alleviate metal-induced stress and enhance plant growth. Here, we investigate C. metallidurans CML2, an endophytic bacterial strain prevalent in rice, showing resilience against 2400 mg/L of Cd(II). We conducted an in-depth integrated morphological and transcriptomic analysis illustrating the multifarious mechanisms CML2 employs to combat Cd, including the formation of biofilm and CdO nanoparticles, upregulation of genes involved in periplasmic immobilization, and the utilization of RND efflux pumps to extract excess Cd ions. Beyond Cd, CML2 exhibited robust tolerance to an array of heavy metals, including Mn2+, Se4+, Ni2+, Cu2+, and Hg2+, demonstrating effective Cd(II) removal capacity. Furthermore, CML2 has exhibited plant growth-promoting properties through the production of indole-3-acetic acid (IAA) at 0.93 mg/L, soluble phosphorus compounds at 1.11 mg/L, and siderophores at 22.67%. Supportively, pot experiments indicated an increase in root lengths and a decrease in Cd bioaccumulation in rice seedlings inoculated with CML2, consequently reducing Cd translocation rates from 43% to 31%. These findings not only contribute to the understanding of Cd resistance mechanisms in C. metallidurans, but also underscore CML2's promising application in Cd remediation within rice farming ecosystems.