Quantitative identification of the saline soil salinity content is a necessary precondition for the reasonable improvement and utilization of saline land, the article aimed at comparing the different quantitative analysis methods and achieving fast estimation of the saline soil salt content in the Yellow River Delta based on the visible-near infrared spectroscopy. Kenli County in Shandong Province was selected as the experimental area, firstly, the representative soil samples were selected, hyperspectral reflectance of the soil samples were measured in situ and transformed to the first deviation. Secondly the correlate spectra, the characteristic spectra and indices were firstly filtered using correlation analysis. Finally, the estimation models of soil salinity content were built using the multiple linear regression (MLR), back propagation neural network (BPNN) and support vector machine (SVM) respectively. The results indicated that the characteristic wave bands of soil salinity were 684 nm and 2058 nm. On the condition of the same input variables, the prediction precision of the SVM models was the highest, followed by the BPNN, the MLR was the lowest. The SVM model based on the first deviation of the reflectance at 684 and 2058nm had the highest precision, with the calibration R 2 of 0.91 and RMSE as 0.11%, the validation R 2 of 0.93, RMSE as 0.26% and RPD as 2.61, which had very good prediction accuracy of soil salt content, and was very stable and reliable. Different input variables had a great impact on the model accuracy, among of the MLR models, only the precision of the model based on characteristic spectral indices was slightly higher and could be used to estimate salt content, among of the BPNN and SVM models, the precision of the models based on characteristic spectra and indices was more high and stable significantly than the models on the correlate spectra. Therefore, for the three modeling methods of multiple linear regression, back propagation neural network and support vector machine, building the estimation model of saline soil salinity content based on characteristic spectra indices was effective.
Radiotherapy (RT) is a primary clinical approach for cancer treatment, but its efficacy is often hindered by various challenges, especially radiation resistance, which greatly compromises the therapeutic effectiveness of RT. Mitochondria, central to cellular energy metabolism and regulation of cell death, play a critical role in mechanisms of radioresistance. In this context, cuproptosis, a novel copper-induced mitochondria-respiratory-dependent cell death pathway, offers a promising avenue for radiosensitization. In this study, an innovative theranostic nanoplatform was designed to induce cuproptosis in synergy with low-dose radiation therapy (LDRT, i.e., 0.5–2 Gy) for the treatment of in situ hepatocellular carcinoma (HCC). This approach aims to reverse the hypoxic tumor microenvironment, promoting a shift in cellular metabolism from glycolysis to oxidative phosphorylation (OXPHOS), thereby enhancing sensitivity to cuproptosis. Concurrently, the Fenton-like reaction ensures a sustained supply of copper and depletion of glutathione (GSH), inducing cuproptosis, disrupting mitochondrial function, and interrupting the energy supply. This strategy effectively overcomes radioresistance and enhances the therapeutic efficacy against tumors. In conclusion, this study elucidates the intricate interactions among tumor hypoxia reversal, cuproptosis, metabolic reprogramming, and radiosensitization, particularly in the context of treating in situ hepatocellular carcinoma, thereby providing a novel paradigm for radiotherapy.
In this study, a targeted analytical method was developed for measuring multiple mono/di-chloropropanols containing 3-chloro-1,2-propanediol(3-MCPD), 2-chloro-1,3-propanediol(2-MCPD), 1,3-dichloro-2-propanol(1,3-DCP), and 2,3-dichloro-1-propanol(2,3-DCP) in food contact papers. This method was demonstrated as an accurate and sensitive technique for detecting multiple chlopropanols with satisfactory recoveries (95.4%-109%), and the limits of detection (LOD) and quantification (LOQ) were achieved at 2 μg kg -1 , and 6 μg kg -1 , respectively. A total of 126 food contact papers collected in China were investigated for their occurrence and potential health risk. The results indicated chloropropanols were widely detected in water extract of food contact papers, while 50.0% samples were non-compliant with the regulatory limits. Both highest detection frequency and concentration of chloropropanols were observed in kitchen papers where mean concentration of 3-MCPD and 1,3-DCP in water extract was 201.9 μg L -1 , and 12.5 μg L -1 , respectively. 3-MPCD and 1,3-MPCD were found to be the predominant chloropropanols with mean concentration of 49.2 μg L -1 and 6.1 μg L -1 in water extract, respectively, while the concentration of 2-MCPD and 2,3-DCP were relatively low. 3-MPCD was significantly responsible for high concentration of chloropropanols at level above 40 μg kg -1 . The estimated daily intake for typical exposure consumer (Mean) and high-exposure consumer (P75, P95) to 3-MCPD are greater than 10% of tolerable daily intake(TDI) establlised by European Food Safety Authority (EFSA), suggesting the release of 3-MCPD from food contact papers pose a potential health risk to certain groups of consumers.
Abstract We report an organocatalyst that combines a triazolium N-heterocyclic carbene (NHC) with a squaramide as a hydrogen-bonding donor (HBD), which can effectively catalyze the atroposelective ring-opening of biaryl lactams via a unique amide C–N bond cleavage mode. The free carbene species attacks the amide carbonyl, forming an axially chiral acyl-azolium intermediate. Various axially chiral biaryl amines can be accessed by this methodology with up to 99% ee and 99% yield. By using mercaptan as a catalyst turnover agent, the resulting thioester synthon can be transformed into several interesting atropisomers. Both control experiments and theoretical calculations reveal the crucial role of the hybrid NHC-HBD skeleton, which activates the amide via H-bonding and brings it spatially close to the carbene centre. This discovery illustrates the potential of the NHC-HBD chimera and demonstrates a complementary strategy for amide bond activation and manipulation.
Inspired by the effective interfacial interactions between natural creatures (e.g., cockleburs and viruses) and their bio-hosts, we developed a novel gold-manganese oxide nanoparticle (Au-MnOx) nanoenzyme with a spiky surface for NIR-II light-induced synergistic antibacterial therapy. Au-MnOx with favorable photothermal performance and peroxidase-like activity could achieve combined photothermal therapy (PTT)/chemodynamic therapy (CDT) under NIR-II irradiation with a low concentration. Of special note, the spiky surface endows Au-MnOx robust bacterial adhesion, in turn favoring the following synergistic PTT/CDT through effective interaction between Au-MnOx and bacteria. In vitro results display that our combined antibacterial nanoplatforms possess the broad-spectrum antibacterial ability against both Escherichia coli (E. coli, Gram-negative) and Staphylococcus aureus (S. aureus, Gram-positive). Moreover, satisfactory in vivo bactericidal efficacy and good cytocompatibility could be obtained in the rat wound model with the mixed bacterial infections. This study puts forward a facile one-pot method to establish the well-designed Au-MnOx nanozymes with a spiky surface for NIR-II light-enhanced bacterial elimination. The meteor hammer-like Au-MnOx holds great potential in construction of a novel antibacterial treatment system to settle the overuse of antibiotics.
Quaternary triphenylphosphonium compounds (TPP+) have been widely recognized as an important antimicrobial because of their fast antimicrobial speed and broad antimicrobial spectrum. However, small-molecule TPP+ compounds have the defects of toxicity, which is the key factor that limits their practical applications. Here, two mono- and one bis-quaternary phosphonium tosylate compounds with different lengths of oligo(ethylene glycol) (OEG) chains and TPP+ as the active moiety were synthesized. Bis-TPP+ have a short OEG chain coupling two TPP+ at both ends, while mono-TPP+ attaches the OEG chain at one end in one molecule. In vitro antibacterial activities were evaluated against both Gram-positive as well as Gram-negative bacteria in terms of the inhibition zone (ZOI) and minimum inhibitory concentration (MIC). To investigate the antibacterial mechanism, β-galactosidase activity was monitored for measuring the degree of membrane permeability correlated to the abilities to disrupt the membranes of bacteria. Moreover, their structure-antibacterial activity and structure-cytotoxicity relationships were further analyzed. The results indicated that bis-TPP+ synthesized can reach the sterilization rate 90% or more against Escherichia coli and Staphylococcus aureus at MICs of 3.1 and 1.5 mg/mL, respectively, and meanwhile, the cell proliferation can reach more than 80%. This paper represents an excellent approach for development of bis-TPP+ bactericidal molecules that would achieve an optimal balance between antimicrobial activity and cytotoxicity.
Following brain trauma, secondary injury from molecular and cellular changes causes progressive cerebral tissue damage. Acute/chronic neuroinflammation following traumatic brain injury (TBI) is a key player in the development of secondary injury. Rapidly elevated cell-free DNAs (cfDNAs) due to cell death could lead to production of inflammatory cytokines that aggravate TBI. Herein, we designed poly(amino acid)-based cationic nanoparticles (cNPs) and applied them intravenously in a TBI mice model with the purpose of scavenging cfDNA in the brain and suppressing the acute inflammation. In turn, these cNPs could effectively eliminate endogenous cfDNA, inhibit excessive activation of inflammation, and promote neural functional recovery.
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