Cancer cells exhibit slightly elevated levels of reactive oxygen species (ROS) compared with normal cells, and approximately 90% of intracellular ROS is produced in mitochondria. In situ ...mitochondrial ROS amplification is a promising strategy to enhance cancer therapy. Here we report cancer cell and mitochondria dual-targeting polyprodrug nanoreactors (DT-PNs) covalently tethered with a high content of repeating camptothecin (CPT) units, which release initial free CPT in the presence of endogenous mitochondrial ROS (mtROS). The in situ released CPT acts as a cellular respiration inhibitor, inducing mtROS upregulation, thus achieving subsequent self-circulation of CPT release and mtROS burst. This mtROS amplification endows long-term high oxidative stress to induce cancer cell apoptosis. This current strategy of endogenously activated mtROS amplification for enhanced chemodynamic therapy overcomes the short lifespan and action range of ROS, avoids the penetration limitation of exogenous light in photodynamic therapy, and is promising for theranostics.
Trichoderma harzianum strain SQR-T037 is a biocontrol agent that has been shown to enhance the uptake of nutrients (macro- and microelements) by plants in fields. The objective of this study was to ...investigate the contribution of SQR-T037 to P and microelement (Fe, Mn, Cu and Zn) nutrition in tomato plants grown in soil and in hydroponic conditions. Inoculation with SQR-T037 significantly improved the biomass and nutrient uptake of tomato seedlings grown in a nutrient-limiting soil. So we investigated the capability of SQR-T037 to solubilise sparingly soluble minerals in vitro via four known mechanisms: acidification by organic acids, chelation by siderophores, redox by ferric reductase and hydrolysis by phytase. SQR-T037 was able to solubilise phytate, Fe2O3, CuO, and metallic Zn but not Ca3(PO4)2 or MnO2. Organic acids, including lactic acid, citric acid, tartaric acid and succinic acid, were detected by HPLC and LC/MS in two Trichoderma cultures. Additionally, we inoculated tomato seedlings with SQR-T037 using a hydroponic system with specific nutrient deficiencies (i.e., nutrient solutions deficient in P, Fe, Cu or Zn and supplemented with their corresponding solid minerals) to better study the effects of Trichoderma inoculation on plant growth and nutrition. Inoculated seedlings grown in Cu-deficient hydroponic conditions exhibited increases in dry plant biomass (92%) and Cu uptake (42%) relative to control plants. However, we did not observe a significant effect on seedling biomass in plants grown in the Fe- and Zn-deficient hydroponic conditions; by contrast, the biomass decreased by 82% in the P-deficient hydroponic condition. Thus, we demonstrated that Trichoderma SQR-T037 competed for P (phytate) and Zn with tomato seedlings by suppressing root development, releasing phytase and/or chelating minerals. The results of this study suggest that the induction of increased or suppressed plant growth occurs through the direct effect of T. harzianum on root development, in combination with indirect mechanisms, such as mineral solubilisation (including solubilisation via acidification, redox, chelation and hydrolysis).
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Coastal saline soil is an important reserve land resource that has high potential for agricultural utilization. The present study adopted a high-throughput absolute quantification 16S rRNA sequencing ...method to investigate the effect of four different fertilization regimes (namely 100% of bio-organic fertilizer, 70% of bio-organic fertilizer +30% of chemical fertilizer, 30% of bio-organic fertilizer +70% of chemical fertilizer, and 100% of chemical fertilizer) on bacterial community assembly in a tomato cultivated saline soil. The results from the field experiment showed that a combination of 70% bio-organic fertilizer plus 30% of chemical fertilizer was the optimal dose to develop tomato cultivation (for improving yield and fruit quality) in this coastal tidal zone. The pot experiment gave the similar results on tomato growth and indicated the application of 70% bio-organic fertilizer plus 30% of chemical fertilizer as the best treatment to active the soil microbiome. The input of nutrients by fertilizers increased the total abundance of bacteria (to >3 fold compared to the initial soil) and simultaneously led to a significant loss of bacterial diversity in soil. The predominant phyla including Proteobacteria, Bacteroidetes and Firmicutes were the main contributors in the microbiome shift especially shown by their remarkable enrichment in the soil that treated by 70% of bio-organic fertilizer and those by the 100% chemical fertilizer. The RDA and Pearson correlation analyses indicated that the soil nutrient availability, especially available P and K, and soil salinity were the key environmental factors that shaped the bacterial community in this ecosystem, though the organic matter content and soil pH also played important roles in microbiome assembly.
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•Bacterial absolute abundance in saline soil increases >3 folds in all four fertilization regimes.•Bacterial diversity in saline soil decreases significantly in all fertilizer-applied samples.•Soil salinity and nutrient availability (P and K) play key roles in shaping bacterial community.•70% bio-organic fertilizer plus 30% of chemical fertilizer is the optimal dose for tomato growth.•Absolute 16S-seq allows more precise investigation on microbial dynamics across multi samples.
The detection of obstructive sleep apnea (OSA) based on single-lead electrocardiogram (ECG) is better suited to the noninvasive needs and hardware conditions of wearable mobile devices. From previous ...ECG-based OSA detection methods, we can find that deep learning methods have shown great potential and advantages. However, due to the nonstationarity of sympathetic nerve signals and the complex characteristics of heart rate variability (HRV), the neural network under a single scale cannot effectively capture the features of HRV. In this study, an OSA detection method based on a multiscale dilation attention 1-D convolutional neural network (MSDA-1DCNN) and a weighted-loss time-dependent (WLTD) classification model were proposed. The introduction of dilated convolution effectively balanced the relationship between model parameters and performance. Attention mechanism technology modified the multiscale features after fusion and improved the weight of features under important channels. In the final classification part of the network, the combination of weighted cross-entropy loss function and hidden Markov model effectively alleviated the problem of data imbalance and improved the classification accuracy of the classifier. In segment identification, the accuracy, sensitivity, and specificity of the proposed method are 89.4%, 89.8%, and 89.1%, respectively; as for individual identification, the accuracy of that achieved 100%. The results demonstrated that the method proposed in this study can identify sleep apnea accurately.
Catalytic asymmetric Tsuji-Trost benzylation is a promising strategy for the preparation of chiral benzylic compounds. However, only a few such transformations with both good yields and ...enantioselectivities have been achieved since this reaction was first reported in 1992, and its use in current organic synthesis is restricted. In this work, we use N-unprotected amino acid esters as nucleophiles in reactions with benzyl alcohol derivatives. A ternary catalyst comprising a chiral aldehyde, a palladium species, and a Lewis acid is used to promote the reaction. Both mono- and polycyclic benzyl alcohols are excellent benzylation reagents. Various unnatural optically active α-benzyl amino acids are produced in good-to-excellent yields and with good-to-excellent enantioselectivities. This catalytic asymmetric method is used for the formal synthesis of two somatostatin mimetics and the proposed structure of natural product hypoestestatin 1. A mechanism that plausibly explains the stereoselective control is proposed.
• Plant roots exhibit diverse root functional traits to enable soil phosphorus (P) acquisition, including changes in root morphology, root exudation and mycorrhizal symbioses. Yet, whether these ...traits are differently coordinated among crop species to enhance P acquisition is unclear.
• Here, eight root functional traits for P acquisition were characterized in 16 major herbaceous crop species grown in a glasshouse under limiting and adequate soil P availability.
• We found substantial interspecific variation in root functional traits among species. Those with thinner roots showed more root branching and less first-order root length, and had consistently lower colonization by arbuscular mycorrhizal fungi (AMF), fewer rhizosheath carboxylates and reduced acid phosphatase activity. In response to limiting soil P, species with thinner roots showed a stronger response in root branching, first-order root length and specific root length of the whole root system, Conversely, species with thicker roots exhibited higher colonization by AMF and/or more P-mobilizing exudates in the rhizosheath.
• We conclude that, at the species level, tradeoffs occur among the three groups of root functional traits we examined. Root diameter is a good predictor of the relative expression of these traits and how they change when P is limiting.
This brief proposes an independent component analysis-principal component analysis (ICA-PCA) integrating with relevance vector machine (RVM) for multivariate process monitoring. Given the fact that ...the distribution of industrial process variables is mostly non-Gaussian and PCA cannot well deal with the non-Gaussian part. A hybrid ICA-PCA method is proposed to simultaneously extract the non-Gaussian and Gaussian information of multivariate processes. ICA is first used to monitor the non-Gaussian part of the process and then the Gaussian part of the residual process can be extracted using PCA. After feature extraction, a Bayesian-based classifier named RVM is established to make fault detection for the sake of both preventing the chosen of threshold as in traditional method and compensating for the single statistic. The performance of the proposed approach is validated using the Tennessee Eastman process. Simulation results verified the effectiveness of the proposed method.
In photoelectrochemical CO2 conversion, the concentration of fixed CO2 on the photocathode surface is of primary concern. Herein, a CO2 adsorption-enhanced semiconductor/metal-complex hybrid ...photoelectrocatalytic interface was established by utilizing a carbon aerogel as the CO2 fixation substrate. In CO2 reduction photoelectrocatalysis, Co3O4 was employed as the light harvester, and Ru(bpy)2dppz was utilized as the electron transfer mediator and CO2 activator. The CO2 surface concentration exhibited a 380-fold increase on this hybrid interface than that on Co3O4/FTO. The CO2 conversion to formate occurred at an onset potential of -0.45 V (vs. normal hydrogen electrode, NHE) under photoelectrochemical conditions, 160 mV more positive than its thermodynamic redox potential. At an applied potential of -0.60 V (vs. NHE), the selectivity of the formate yield reached 99.95%, with a production rate of approximately 110 mu mol cm-2 h-1 and a Faradaic efficiency of 86%. Such a conversion has an electron transfer rate of 2.94 10-3 cm s-1. The CO2 conversion to formate was confirmed to be an instantaneous proton-coupled electron transfer process, originating from the rapid photoelectrochemical activation of bpy and dppz in Ru(bpy)2dppz as well as the synergic effect of the promoted CO2 adsorption and the applied molecular catalysis.
Carbon dioxide (CO2) reduction to useful chemicals is of great significance to global climate and energy supply. In this study, CO2 has been photoelectrocatalytically reduced to formate at metallic ...Cu nanoparticles (Cu NPs) decorated Co3O4 nanotube arrays (NTs) with high yield and high selectivity of nearly 100%. Noticeably, up to 6.75 mmol·L–1·cm–2 of formate was produced in an 8 h photoelectrochemical process, representing one of the highest yields among those in the literature. The results of scanning electron microscopy, transmission electron microscopy and photoelectrochemical characterization demonstrated that the enhanced production of formate was attributable to the self-supported Co3O4 NTs/Co structure and the interface band structure of Co3O4 NTs and metallic Cu NPs. Furthermore, a possible two-electron reduction mechanism on the selective PEC CO2 reduction to formate at the Cu–Co3O4 NTs was explored. The first electron reduction intermediate, CO2 ads •–, was adsorbed on Cu in the form of Cu–O. With the carbon atom suspended in solution, CO2 ads •– is readily protonated to form the HCOO– radical. And HCOO– as a product rapidly desorbs from the copper surface with a second electron transfer to the adsorbed species.
Nowadays, the state‐of‐the‐art electrocatalysts for hydrogen evolution reaction (HER) are platinum group metals. Nonetheless, Pt‐based catalysts show decreased HER activity in alkaline media compared ...with that in acidic media due to the sluggish dissociation process of H2O on the surface of Pt. With a cost 1/25 that of Pt, Ru demonstrates a favorable dissociation kinetics of absorbed H2O. Herein, crystalline Ru0.33Se nanoparticles are decorated onto TiO2 nanotube arrays (TNAs) to fabricate Ru0.33Se @ TNA hybrid for HER. Owing to the large‐specific surface area, Ru0.33Se nanoparticles are freely distributed and the particle aggregation is eliminated, providing more active sites. The contracted electron transport pathway rendered by TiO2 nanotubes and the synergistic effect at the interface significantly improve the charge transfer efficiency in the hybrid catalyst. Compared with Ru0.33Se nanoparticles deposited directly on the Ti foil (Ru0.33Se/Ti) or carbon cloth (Ru0.33Se/CC), Ru0.33Se @ TNA shows an enhanced catalytic activity with an overpotential of 57 mV to afford a current density of 10 mA cm−2, a Tafel slope of 50.0 mV dec−1. Furthermore, the hybrid catalyst also exhibits an outstanding catalytic stability. The strategy here opens up a new synthetic avenue to the design of highly efficient hybrid electrocatalysts for hydrogen production.
A hybrid hydrogen evolution reaction catalyst is fabricated by decorating TiO2 nanotube arrays with crystalline Ru0.33Se nanoparticles. Owing to the merits of the two components and the synergistic effect at the interface, the hybrid catalyst demonstrates an outstanding performance with a small overpotential of 57 mV to acquire a current density of 10 mA cm−2.
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