Generational Specific Recruitment of Arsenic- and Antimony-Reducing Microorganisms in Plant Root-Associated Niches for Adapting to Metalloid-Metal Pollution.

The recruitment of microorganisms by plants can enhance their adaptability to environmental stressors, but how root-associated niches recruit specific microorganisms for adapting to metalloid-metal contamination is not well-understood. This study investigated the generational recruitment of microorganisms in different root niches of Vetiveria zizanioides (V. zizanioides) under arsenic (As) and antimony (Sb) stress. The V. zizanioides was cultivated in As- and Sb-cocontaminated mine soils (MS) and artificial pollution soils (PS) over two generations in controlled conditions. The root-associated microbial communities were analyzed through 16S rRNA, arsC, and aioA gene amplicon and metagenomics sequencing. V. zizanioides accumulated higher As(III) and Sb(III) in its endosphere in MS in the second generation, while its physiological indices in MS were better than those observed in PS. SourceTracker analysis revealed that V. zizanioides in MS recruited As(V)- and Sb(V)-reducing microorganisms (e.g., Sphingomonales and Rhodospirillaceae) into the rhizoplane and endosphere. Metagenomics analysis further confirmed that these recruited microorganisms carrying genes encoding arsenate reductases with diverse carbohydrate degradation abilities were enriched in the rhizoplane and endosphere, suggesting their potential to reduce As(V) and Sb(V) and to decompose root exudates (e.g., xylan and starch). These findings reveal that V. zizanioides selectively recruits As- and Sb-reducing microorganisms to mitigate As-Sb cocontamination during the generational growth, providing insights into novel strategies for enhancing phytoremediation of metalloid-metal contaminants.

Phospholipid and glycerolipid metabolism as potential diagnostic biomarkers for acute pancreatitis.

BACKGROUND: Acute pancreatitis (AP) is characterized as a systemic inflammatory condition posing challenges in diagnosis and prognosis assessment. Lipid metabolism abnormalities, especially triacylglycerol (TAG) levels, have been reported, indicating their potential as biomarkers in acute pancreatitis. However, the performance of the TAG cycle, including phospholipid and glycerolipid metabolism, in AP patients has not yet been reported. METHODS: This study enrolled 91 patients with acute biliary pancreatitis (ABP), 27 with hyperlipidaemic acute pancreatitis (HLAP), and 58 healthy controls (HCs), and their plasma phospholipid and glycerolipid levels were analyzed through liquid chromatography‒mass spectrometry. The phospholipid and glycerolipid contents of plasma collected from AP patients on the first, third, and seventh days of hospitalization were also measured. An orthogonal partial least squares discriminant analysis model served to differentiate the ABP, HLAP and HC groups, and potentially diagnostic lipids were evaluated via receiver operating characteristic curves in both the test and validation sets. Correlations between clinical data and lipids were conducted using Spearman's method. Clustering via the 'mfuzz' R package and the Kruskal‒Wallis H test were conducted to monitor changes during hospitalization. RESULTS: Compared with those in HCs, the levels of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidic acid (PA) were lower in AP patients, whereas the levels of phosphatidylinositol (PI) and phosphatidylglycerol (PG) showed the opposite trend. Interestingly, TAG levels were positively correlated with white blood cell counts in ABP patients, and TAGs containing 44-55 carbon atoms were highly correlated with plasma TAG levels in HLAP patients. Phospholipid levels exhibited an inverse correlation with AP markers, in contrast to glycerolipids, which demonstrated a positive correlation with these markers. Additionally, PE (O-16:0/20:4) and PE (18:0/22:6) emerged as potential biomarkers because of their ability to distinguish ABP and HLAP patients from HCs, showing area under the curve (AUC) values of 0.932 and 0.962, respectively. PG (16:0/18:2), PG (16:0/20:4), PE (P-16:0/20:2), PE (P-18:2/18:2), PE (P-18:1/20:3), PE (P-18:1/20:4), PE (O-16:0/20:4), and TAG (56:6/FA18:0) were significantly changed in ABP patients who improved. For HLAP patients, PC (18:0/20:3), TAG (48:3/FA18:1), PE (P-18:0/16:0), and TAG (48:4/FA18:2) showed different trends in patients with improvement and deterioration, which might be used for prognosis. CONCLUSIONS: Phospholipids and glycerolipids were found to be potential biomarkers in acute pancreatitis, which offers new diagnostic and therapeutic insights into this disease.

Efficacy and safety of laparoscopic common bile duct exploration via choledochotomy with primary closure for the management of acute cholangitis caused by common bile duct stones.

BACKGROUND: T-tube drainage after laparoscopic common bile duct exploration (LCBDE) has been demonstrated to be safe and effective for patients with acute cholangitis caused by common bile duct stones (CBDSs). The outcomes after LCBDE with primary closure in patients with CBDS-related acute cholangitis are unknown. The present study aimed to evaluate the efficacy and safety of LCBDE with primary closure for the management of acute cholangitis caused by CBDSs. METHODS: Between June 2015 and June 2020, 368 consecutive patients with choledocholithiasis combined with cholecystolithiasis, who underwent laparoscopic cholecystectomy (LC) + LCBDE in our department, were retrospectively reviewed. A total of 193 patients with CBDS-related acute cholangitis underwent LC + LCBDE with primary closure of the CBD (PC group) and 62 patients underwent LC + LCBDE followed by T-tube placement (T-tube group). A total of 113 patients who did not have cholangitis were excluded. The clinical data were compared and analyzed. RESULTS: There was no mortality in either group. No significant differences were noted in morbidity, bile leakage rate, retained CBD stones, or readmission rate within 30 days between the two groups. Compared with the T-tube group, the PC group avoided T-tube-related complications and had a shorter operative time (121.12 min vs. 143.37 min) and length of postoperative hospital stay (6.59 days vs. 8.81 days). Moreover, the hospital expenses in the PC group were significantly lower than those in the T-tube group ($4844.47 vs. $5717.22). No biliary stricture occurred during a median follow-up of 18 months in any patient. No significant difference between the two groups was observed in the rate of stone recurrence. CONCLUSIONS: LCBDE with primary closure is a safe and effective treatment for cholangitis caused by CBDSs. LCBDE with primary closure is not inferior to T-tube drainage for the management of CBDS-related acute cholangitis in suitable patients.

iTRAQ-derived quantitative proteomics uncovers the neuroprotective property of bexarotene in a mice model of cerebral ischemia-reperfusion injury.

Bexarotene, a FDA-approved drug for cutaneous lymphoma, has been shown to exert brain protective effects. In previous study, we demonstrated that Bexarotene protects against cerebral ischemic stroke by suppressing the JNK/Caspase-3 signaling pathway. However, the molecular mechanisms by which Bexarotene-mediated neuroprotective are not fully understood. Based on the isobaric tags for relative and absolute quantification (iTRAQ)-derived proteomics and bioinformatics analysis, 4,454 differentially expressed proteins (DEPs) were identified in upstream of the JNK signaling pathway. Among them, 149 DEPs showed aberrant expression in the vehicle-versus Bexarotene-treated mice. DEPs were primarily enriched in the metabolism, calcium, and MAPK signaling pathways. The largest DEP increase was seen with heat shock protein HSP 70, whereas the largest DEP decrease was seen with JNK scaffold protein JIP3, both of which are involved in the MAPK network. Furthermore, we illustrated the Bexarotene obviously abolished oxygen and glucose deprivation/reperfusion (OGD/R)- induced LDH leakage, cells apoptosis, and the protein expression level of the JIP3,p-ASK1, p-JNK, and Cleaved Caspase3. Together, these results suggest a potential neuroprotective role of Bexarotene via inhibition of the JIP3/ASK1/JNK/Caspase 3 signaling pathway.

Synergetic Molecular Oxygen Activation and Catalytic Oxidation of Formaldehyde over Defective MIL-88B(Fe) Nanorods at Room Temperature.

Defective MIL-88B(Fe) nanorods are exploited as exemplary iron-bearing metal-organic framework (MOF) catalyst for molecular oxygen (O2) activation at ambient temperature, triggering effective catalytic oxidation of formaldehyde (HCHO), one of the major indoor air pollutants. Defective MIL-88B(Fe) nanorods, growing along the [001] direction, expose abundant coordinatively unsaturated Fe-sites (Fe-CUSs) along extended hexagonal channels with a diameter of ca. 5 Å, larger enough for the diffusion of O2 (3.46 Å) and HCHO (2.7 Å). The Lewis acid-base interaction between Fe-CUSs and accessible HCHO accelerates the FeIII/FeII cycle, catalyzing Fenton-like O2 activation to produce reactive oxidative species (ROSs), including superoxide radicals (•O2-), hydroxyl radicals (•OH), and singlet oxygen (1O2). Consequently, adsorbed HCHO can be oxidized into CO2 with a considerable mineralization efficiency (over 80%) and exceptional recyclability (4 runs, 48 h). Dioxymethylene (CH2OO), formate (HCOO-) species, and formyl radicals (•CHO) are recorded as the main reaction intermediates during HCHO oxidation. HCHO, H2O, and O2 are captured and activated by abundant FeIII/FeII-CUSs as acid/base and redox sites, triggering synergetic ROS generation and HCHO oxidation, involving cooperative acid-base and redox catalysis processes. This study will bring new insights into exploiting novel MOF catalysts for efficient O2 activation and reliable indoor air purification at ambient temperature.

Biodegradation of skatole by Burkholderia sp. IDO3 and its successful bioaugmentation in activated sludge systems.

Skatole is the key malodorous compound in livestock and poultry waste and wastewater with a low odor threshold. It not only causes serious nuisance to residents and workers, but also poses threat to the environment and human health due to its biotoxicity and recalcitrant nature. Biological treatment is an eco-friendly and cost-effective approach for skatole removal, while the bacterial resources are scarce. Herein, the Burkholderia strain was reported to efficiently degrade skatole for the first time. Results showed that strain IDO3 maintained high skatole-degrading performance under the conditions of pH 4.0-9.0, rotate speed 0-250 rpm, and temperature 30-35 °C. RNA-seq analysis indicated that skatole activated the oxidative phosphorylation and ATP production levels in strain IDO3. The oxidoreductase activity item which contained 373 differently expressed genes was significantly impacted by Gene Ontology analysis. Furthermore, the bioaugmentation experiment demonstrated that strain IDO3 could notably increase the removal of skatole in activated sludge systems. High-throughput 16S rRNA gene sequencing data indicated that the alpha-diversity and bacterial community tended to be stable in the bioaugmented group after 8 days operation. PICRUSt analysis indicated that xenobiotics biodegradation and metabolism, and membrane transport categories significantly increased, consistent with the improved skatole removal performance in the bioaugmented group. Burkholderia was survived and colonized to be the predominant population during the whole operation process (34.19-64.00%), confirming the feasibility of Burkholderia sp. IDO3 as the bioaugmentation agent in complex systems.

Bexarotene Attenuates Focal Cerebral Ischemia-Reperfusion Injury via the Suppression of JNK/Caspase-3 Signaling Pathway.

Apolipoprotein E (APOE) is implicated not only in chronic degenerative neurological diseases, such as Alzheimer's disease, but also in acute brain disorders, including traumatic brain injury. Bexarotene, a selective agonist of the retinoid X receptor, has been reported to enhance markedly the expression of APOE. Previous studies have indicated that bexarotene exerts neuroprotective effects in animal models of ischemic stroke by modulating the peripheral immune response and autophagy. However, the role of this drug in neuronal apoptosis and the potential mechanisms involved have yet to be elucidated. The present study employed transient middle cerebral artery occlusion (t-MCAO) as a model of acute cerebral ischemia/reperfusion injury. The experiments were performed in wild-type C57BL/6 mice and APOE gene knockout (APOE-KO) mice. After t-MCAO, mice received intraperitoneal injection of bexarotene (5 mg/kg) or an equal volume of the vehicle. The outcome measurements included neurological deficits, learning ability, spatial memory, infarct volume, histopathology, magnitude of apoptosis, and the level of expression of proteins of the JNK/caspase-3 signaling pathway. The obtained results demonstrated that bexarotene administration significantly improved neurological function, learning ability, and spatial memory in C57BL/6 mice, but not in APOE-KO mice. Infarct volume, tissue damage, neuronal apoptosis rate, and the expression of proteins involved in the JNK/caspase-3 signaling pathway were markedly increased after t-MCAO in both C57BL/6 and APOE-KO mice. Importantly, bexarotene treatment significantly ameliorated all these changes in C57BL/6, but not in APOE-KO mice. In conclusion, bexarotene markedly alleviates the neurological deficits, improves the histological outcome, and inhibits cell apoptosis in mice after t-MCAO. This effect is mediated, at least in part, by up-regulation of APOE. Thus, bexarotene may be a candidate drug for the treatment of cerebral ischemia patients.

Sustained production of H2O2 in alkaline water solution using borate and phosphate-modified Au/TiO2 photocatalysts.

UV irradiation of Au/TiO2 photocatalysts in the presence of borate and phosphate anions can produce H2O2 at a millimolar level in alkaline water solution. The positive effect of the anions is ascribed to the anion-mediated hole transfer from Au/TiO2 to an electron donor which thus accelerates the two-electron reduction of O2 to H2O2.

Performance and Mechanism of Piezo-Catalytic Degradation of 4-Chlorophenol: Finding of Effective Piezo-Dechlorination.

Piezo-catalysis was first used to degrade a nondye pollutant, 4-chlorophenol (4-CP). In this process, hydrothermally synthesized tetragonal BaTiO3 nano/micrometer-sized particles were used as the piezo-catalyst, and the ultrasonic irradiation with low frequency was selected as the vibration energy to cause the deformation of tetragonal BaTiO3. It was found that the piezoelectric potential from the deformation could not only successfully degrade 4-chlorophenol but also effectively dechlorinate it at the same time, and five kinds of dechlorinated intermediates, hydroquinone, benzoquinone, phenol, cyclohexanone, and cyclohexanol, were determined. This is the first sample of piezo-dechlorination. Although various active species, including h+, e-, •H, •OH, •O2-, 1O2, and H2O2, were generated in the piezoelectric process, it was confirmed by ESR, scavenger studies, and LC-MS that the degradation and dechlorination were mainly attributed to •OH radicals. These •OH radicals were chiefly derived from the electron reduction of O2, partly from the hole oxidation of H2O. These results indicated that the piezo-catalysis was an emerging and effective advanced oxidation technology for degradation and dechlorination of organic pollutants.

Efficient removal of gaseous formaldehyde in air using hierarchical titanate nanospheres with in situ amine functionalization.

Removing formaldehyde (HCHO) in air by efficient and recyclable adsorbents is crucial for improving indoor air quality. Nanosized adsorbents with a higher surface area and abundant functional groups are highly desirable. In this report, hierarchical titanate nanospheres (HTS) were prepared as effective adsorbents by the diethylenetriamine (DETA) mediated one-pot solvothermal process. Typically, the HTS adsorbents were assembled by titanate nanosheets with abundant in situ grafted amine groups. Impressively, because of their hierarchical assembled structure, considerable specific surface area and pore volume, and abundant surface amine groups, the optimized HTS adsorbents exhibited excellent HCHO adsorption properties, with nearly 100% removal efficiency for HCHO in air at room temperature. Moreover, the recyclability of optimized HTS adsorbents is considerable, with only a very slight decrease in removal efficiency after 6 cycles. The DETA introduced into the synthesis system is crucial for both chemical and textural modifications of HTS adsorbents. Specifically, the DETA mediator not only affects significantly the phase, morphology, and textural properties of the obtained titanate products, but also induces in situ grafted surface amine groups. As a consequence, the adsorption capacity and recyclability of HTS adsorbents can be largely modified by adding different amounts of DETA to the synthesis system.

Aggregation morphologies of a series of heterogemini surfactants with a hydroxyl head group in aqueous solution.

The aggregation behaviors of a series of heterogemini surfactants N,N-dimethyl-N-[3-(alkyloxy)-2-hydroxypropyl]-alkylammonium bromide, abbreviated as CmOhpNCn (m, n = 10, 8; 10, 14; 12, 8; 12, 10; 12, 12; 12, 14; 14, 8 and 14, 10), have been investigated in aqueous solution. Electric conductivity, steady-state and frequency sweep rheological measurements were adopted to study the micellar morphology affected by molecular structure, concentration and temperature, and a close relationship among them was established. Electric conductivity measurement results indicated that Krafft temperatures were mainly related to the total number of carbon atoms, while the CMC values were affected by the combined factors of alkyl chain length, degree of dissymmetry and hydroxyl head group. And some unusual values may come from the poor water solubility induced by the relatively long alkyl chain n. Dynamic rheological results and cryo-TEM images revealed various micellar behaviors of CmOhpNC8 affected by different combined factors. When m value was increased, the formation of quite long rodlike or wormlike micelles derived from the enhanced hydrophobility and hydrogen bonding. And the effect of concentration on aggregation behavior was similar to that of m value except for formation of micellar joints. With temperature increase, the decreased viscosity of C14OhpNC8 was due to formation of micellar joints and weakening of hydrogen bonding, which could be confirmed by dynamic light scattering (DLS). Furthermore, the C14OhpNC8 aggregates formed below the Krafft temperature were more likely to be affected by temperature at high concentrations.

Efficacy and safety of ultrasound-guided thermal ablation of graves' disease: a retrospective cohort study.

BACKGROUND: Ultrasound-guided thermal ablation (TA) has emerged as a robust therapeutic approach for treating solid tumors in multiple organs, including the thyroid. Yet, its efficacy and safety profile in the management of Graves' Disease (GD) remains to be definitively established. METHODS: A retrospective study was conducted on 50 GD patients treated with TA between October 2017 and December 2021. Key metrics like thyroid volume, volume reduction rate (VRR), thyroid hormones, and basal metabolic rate (BMR) were evaluated using paired Wilcoxon tests. RESULTS: The intervention of ultrasound-guided TA yielded a statistically significant diminution in total thyroid volume across all postoperative follow-up intervals-1, 3, 6, and 12 months-relative to pre-intervention baselines (p < 0.001). The median VRR observed at these time points were 17.5%, 26.5%, 34.4%, and 39.8%, respectively. Euthyroid status was corroborated in 96% of patients at the one-year follow-up milestone. Transient tachycardia and dysphonia were observed in three patients, while a solitary case of skin numbness was noted. Crucially, no instances of enduring injury to the recurrent laryngeal nerve (RLN) were documented. CONCLUSIONS: Our investigation substantiates ultrasound-guided TA as a pragmatic, well-tolerated, and safe therapeutic modality for GD. It effectively improves symptoms of hyperthyroidism, engenders a substantial reduction in thyroid volume, and restores thyroid hormone and BMR to physiological levels. Given its favorable safety profile, enhanced cosmetic outcomes, and minimally invasive nature, ultrasound-guided TA is a compelling alternative to thyroidectomy for GD patients.

SHMT2 Mediates Small-Molecule-Induced Alleviation of Alzheimer Pathology Via the 5'UTR-dependent ADAM10 Translation Initiation.

It is long been suggested that one-carbon metabolism (OCM) is associated with Alzheimer's disease (AD), whereas the potential mechanisms remain poorly understood. Taking advantage of chemical biology, that mitochondrial serine hydroxymethyltransferase (SHMT2) directly regulated the translation of ADAM metallopeptidase domain 10 (ADAM10), a therapeutic target for AD is reported. That the small-molecule kenpaullone (KEN) promoted ADAM10 translation via the 5' untranslated region (5'UTR) and improved cognitive functions in APP/PS1 mice is found. SHMT2, which is identified as a target gene of KEN and the 5'UTR-interacting RNA binding protein (RBP), mediated KEN-induced ADAM10 translation in vitro and in vivo. SHMT2 controls AD signaling pathways through binding to a large number of RNAs and enhances the 5'UTR activity of ADAM10 by direct interaction with GAGGG motif, whereas this motif affected ribosomal scanning of eukaryotic initiation factor 2 (eIF2) in the 5'UTR. Together, KEN exhibits therapeutic potential for AD by linking OCM with RNA processing, in which the metabolic enzyme SHMT2 "moonlighted" as RBP by binding to GAGGG motif and promoting the 5'UTR-dependent ADAM10 translation initiation.

Ionic-liquid-assisted synthesis of uniform fluorinated B/C-codoped TiO2 nanocrystals and their enhanced visible-light photocatalytic activity.

Exploiting advanced photocatalysts under visible light is of primary significance for the development of environmentally relevant photocatalytic decontamination processes. In this study, the ionic liquid (IL), 1-butyl-3-methylimidazolium tetrafluoroborate, was employed for the first time as both a structure-directing agent and a dopant for the synthesis of novel fluorinated B/C-codoped anatase TiO(2) nanocrystals (T(IL)) through hydrothermal hydrolysis of tetrabutyl titanate. These T(IL) nanocrystals feature uniform crystallite and pore sizes and are stable with respect to phase transitions, crystal ripening, and pore collapse upon calcination treatment. More significantly, these nanocrystals possess abundant localized states and strong visible-light absorption in a wide range of wavelengths. Because of synergic interactions between titania and codopants, the calcined T(IL) samples exhibited high visible-light photocatalytic activity in the presence of oxidizing Rhodamine B (RhB). In particular, 300 °C-calcined T(IL) was most photocatalytically active; its activity was much higher than that of TiO(1.98)N(0.02) and reference samples (T(W)) obtained under identical conditions in the absence of ionic liquid. Furthermore, the possible photocatalytic oxidation mechanism and the active species involved in the RhB degradation photocatalyzed by the T(IL) samples were primarily investigated experimentally by using different scavengers. It was found that both holes and electrons, as well as their derived active species, such as (·)OH, contributed to the RhB degradation occurring on the fluorinated B/C-codoped TiO(2) photocatalyst, in terms of both the photocatalytic reaction dynamics and the reaction pathway. The synthesis of the aforementioned novel photocatalyst and the identification of specific active species involved in the photodegradation of dyes could shed new light on the design and synthesis of semiconductor materials with enhanced photocatalytic activity towards organic pollutants.

Enhanced photocatalytic H2-production activity of TiO2 using Ni(NO3)2 as an additive.

Herein, we for the first time report the production of H2 using Degussa P25 TiO2 powder (P25) from a mixed aqueous solution of methanol and Ni(NO3)2. The effect of the amount of Ni(NO3)2 on the photocatalytic H2-production activity of TiO2 was investigated and discussed. The results indicate that the photocatalytic H2-production activity of TiO2 is significantly enhanced in the presence of Ni(NO3)2. The optimal Ni(NO3)2 amount (the molar ratio of Ni(NO3)2 to TiO2 and Ni(NO3)2) was found to be 0.32 mol%, giving a H2-production rate of 2547 µmol h(-1) g(-1) with a quantum efficiency (QE) of 8.1% at 365 nm, exceeding that of pure TiO2 by 135 times. This high photocatalytic H2-production activity is due to the adsorption of Ni(2+) on the surface of TiO2. The potential of Ni(2+)/Ni (Ni(2+) + 2e(-) = Ni, E(o) = -0.23 V) is slightly lower than the conduction band (CB) of anatase TiO2 (-0.26 V), but higher than the reduction potential of H(+)/H2 (2H(+) + 2e(-) = H2, E(o) = -0.00 V), which favors electron transfer from TiO2 to Ni(2+) and reduction of Ni(2+) to Ni(0). The role of metallic Ni is to help charge separation and to act as a co-catalyst for H2 production, thus enhancing the photocatalytic H2-production activity of TiO2.

Experimental investigation of seismic response of precast concrete panels with castellated keys support pillar connections under in-plane cyclic loading.

The reliable joint connection between precast members is vital to resisting earthquake loads in precast concrete structures. To further improve the convenience of precast construction, this paper presents a new horizontal joint of precast concrete panels with castellated keys supports pillar connections based on the stable mechanical properties of the wet concrete joint. To examine the seismic response of this connection type, a series of in-plane cyclic loading tests were carried out using six full-size precast specimens and one cast-in-place specimen for comparison. The influences of axial compression ratio, joint width, and joint concrete strength on the seismic indicators of the precast concrete panel were considered in the design of specimens. The test results showed all specimens had the same damage process, and the ultimate failure modes combined compression and bending. The precast specimens exhibited similar seismic performance to the cast-in-place specimen, especially whose joint concrete strength is higher than the precast concrete panel. Based on the load-displacement test curve, a hysteretic curve model that included both the envelope curve and the stiffness degradation law was proposed. The predictions from the model showed good compatibility with the experimental results, and the model can be used as a reference for analyzing the elastic-plastic response of the precast concrete panels with castellated keys supporting pillar connections.

Antimony efflux underpins phosphorus cycling and resistance of phosphate-solubilizing bacteria in mining soils.

Microorganisms play crucial roles in phosphorus (P) turnover and P bioavailability increases in heavy metal-contaminated soils. However, microbially driven P-cycling processes and mechanisms of their resistance to heavy metal contaminants remain poorly understood. Here, we examined the possible survival strategies of P-cycling microorganisms in horizontal and vertical soil samples from the world's largest antimony (Sb) mining site, which is located in Xikuangshan, China. We found that total soil Sb and pH were the primary factors affecting bacterial community diversity, structure and P-cycling traits. Bacteria with the gcd gene, encoding an enzyme responsible for gluconic acid production, largely correlated with inorganic phosphate (Pi) solubilization and significantly enhanced soil P bioavailability. Among the 106 nearly complete bacterial metagenome-assembled genomes (MAGs) recovered, 60.4% carried the gcd gene. Pi transportation systems encoded by pit or pstSCAB were widely present in gcd-harboring bacteria, and 43.8% of the gcd-harboring bacteria also carried the acr3 gene encoding an Sb efflux pump. Phylogenetic and potential horizontal gene transfer (HGT) analyses of acr3 indicated that Sb efflux could be a dominant resistance mechanism, and two gcd-harboring MAGs appeared to acquire acr3 through HGT. The results indicated that Sb efflux could enhance P cycling and heavy metal resistance in Pi-solubilizing bacteria in mining soils. This study provides novel strategies for managing and remediating heavy metal-contaminated ecosystems.

Catalytic ozonation mechanism over M1-N3C1 active sites.

The structure-activity relationship in catalytic ozonation remains unclear, hindering the understanding of activity origins. Here, we report activity trends in catalytic ozonation using a series of single-atom catalysts with well-defined M1-N3C1 (M: manganese, ferrum, cobalt, and nickel) active sites. The M1-N3C1 units induce locally polarized M - C bonds to capture ozone molecules onto M atoms and serve as electron shuttles for catalytic ozonation, exhibiting excellent catalytic activities (at least 527 times higher than commercial manganese dioxide). The combined in situ characterization and theoretical calculations reveal single metal atom-dependent catalytic activity, with surface atomic oxygen reactivity identified as a descriptor for the structure-activity relationship in catalytic ozonation. Additionally, the dissociation barrier of surface peroxide species is proposed as a descriptor for the structure-activity relationship in ozone decomposition. These findings provide guidelines for designing high-performance catalytic ozonation catalysts and enhance the atomic-level mechanistic understanding of the integral control of ozone and methyl mercaptan.

Accurate estimation of fractional vegetation cover for winter wheat by integrated unmanned aerial systems and satellite images.

Accurate estimation of fractional vegetation cover (FVC) is essential for crop growth monitoring. Currently, satellite remote sensing monitoring remains one of the most effective methods for the estimation of crop FVC. However, due to the significant difference in scale between the coarse resolution of satellite images and the scale of measurable data on the ground, there are significant uncertainties and errors in estimating crop FVC. Here, we adopt a Strategy of Upscaling-Downscaling operations for unmanned aerial systems (UAS) and satellite data collected during 2 growing seasons of winter wheat, respectively, using backpropagation neural networks (BPNN) as support to fully bridge this scale gap using highly accurate the UAS-derived FVC (FVCUAS) to obtain wheat accurate FVC. Through validation with an independent dataset, the BPNN model predicted FVC with an RMSE of 0.059, which is 11.9% to 25.3% lower than commonly used Long Short-Term Memory (LSTM), Random Forest Regression (RFR), and traditional Normalized Difference Vegetation Index-based method (NDVI-based) models. Moreover, all those models achieved improved estimation accuracy with the Strategy of Upscaling-Downscaling, as compared to only upscaling UAS data. Our results demonstrate that: (1) establishing a nonlinear relationship between FVCUAS and satellite data enables accurate estimation of FVC over larger regions, with the strong support of machine learning capabilities. (2) Employing the Strategy of Upscaling-Downscaling is an effective strategy that can improve the accuracy of FVC estimation, in the collaborative use of UAS and satellite data, especially in the boundary area of the wheat field. This has significant implications for accurate FVC estimation for winter wheat, providing a reference for the estimation of other surface parameters and the collaborative application of multisource data.

The vertically-stratified resistomes in mangrove sediments was driven by the bacterial diversity.

Early evidence has elucidated that the spread of antibiotic (ARGs) and metal resistance genes (MRGs) are mainly attributed to the selection pressure in human-influenced environments. However, whether and how biotic and abiotic factors mediate the distribution of ARGs and MRGs in mangrove sediments under natural sedimentation is largely unclear. Here, we profiled the abundance and diversity of ARGs and MRGs and their relationships with sedimental microbiomes in 0-100 cm mangrove sediments. Our results identified multidrug-resistance and multimetal-resistance as the most abundant ARG and MRG classes, and their abundances generally decreased with the sediment depth. Instead of abiotic factors such as nutrients and antibiotics, the bacterial diversity was significantly negatively correlated with the abundance and diversity of resistomes. Also, the majority of resistance classes (e.g., multidrug and arsenic) were carried by more diverse bacterial hosts in deep layers with low abundances of resistance genes. Together, our results indicated that bacterial diversity was the most important biotic factor driving the vertical profile of ARGs and MRGs in the mangrove sediment. Given that there is a foreseeable increasing human impact on natural environments, this study emphasizes the important role of biodiversity in driving the abundance and diversity of ARGs and MRGs.