Influence of Galvanic Interaction between the Iron Grinding Medium and Chalcopyrite on Collectorless Flotation Behavior of Chalcopyrite: Experimental and Density Functional Theory Study.

The eco-friendly flotation process for chalcopyrite is economically significant and promotes sustainable development in mining. Collectorless flotation is a green and clean method for chalcopyrite utilization, but galvanic interactions during the grinding process can affect the surface structure, chemical composition, and electrochemical properties, impacting collectorless flotation recovery. This article uses a self-made device and flotation experiments to study galvanic interactions and their effects on surface oxidation and collectorless flotation behavior under different grinding conditions (including mineral particle size, slurry water content, pressure, and galvanic interaction time). The impact of galvanic interaction on the surface chemical composition and electrochemical properties of chalcopyrite is studied using high-performance liquid chromatography (HPLC), X-ray photoelectron spectroscopy (XPS), and electrochemical tests. Additionally, the effect of the galvanic interaction on the surface structure is analyzed with density functional theory. XPS and HPLC results show that iron grinding media contact with chalcopyrite, reducing elemental sulfur content of the chalcopyrite surface, improving hydrophilicity, and decreasing chalcopyrite collectorless flotation recovery. Grinding conditions, such as mineral particle size, slurry water content, and galvanic interaction time, significantly impact collectorless flotation and can be regulated to optimize results.

Selenomethionine preconditioned mesenchymal stem cells derived extracellular vesicles exert enhanced therapeutic efficacy in intervertebral disc degeneration.

Extracellular vesicles (EVs) derived from Mesenchymal Stromal Cells (MSCs) have shown promising therapeutic potential for multiple diseases, including intervertebral disc degeneration (IDD). Nevertheless, the limited production and unstable quality of EVs hindered the clinical application of EVs in IDD. Selenomethionine (Se-Met), the major form of organic selenium present in the cereal diet, showed various beneficial effects, including antioxidant, immunomodulatory and anti-apoptotic effects. In the current study, Se-Met was employed to treat MSCs to investigate whether Se-Met can facilitate the secretion of EVs by MSCs and optimize their therapeutic effects on IDD. On the one hand, Se-Met promoted the production of EVs by enhancing the autophagy activity of MSCs. On the other hand, Se-Met pretreated MSC-derived EVs (Se-EVs) exhibited an enhanced protective effects on alleviating nucleus pulposus cells (NPCs) senescence and attenuating IDD compared with EVs isolated from control MSCs (C-EVs) in vitro and in vivo. Moreover, we performed a miRNA microarray sequencing analysis on EVs to explore the potential mechanism of the protective effects of EVs. The result indicated that miR-125a-5p is markedly enriched in Se-EVs compared to C-EVs. Further in vitro and in vivo experiments revealed that knockdown of miR-125a-5p in Se-EVs (miRKD-Se-EVs) impeded the protective effects of Se-EVs, while overexpression of miR-125a-5p (miROE-Se-EVs) boosted the protective effects. In conclusion, Se-Met facilitated the MSC-derived EVs production and increased miR-125a-5p delivery in Se-EVs, thereby improving the protective effects of MSC-derived EVs on alleviating NPCs senescence and attenuating IDD.

Correction: Steam turbine power prediction based on encode-decoder framework guided by the condenser vacuum degree.

[This corrects the article DOI: 10.1371/journal.pone.0275998.].

Characterization of Cu-SSZ-13 NH3 SCR catalysts: an in situ FTIR study.

The adsorption of CO and NO over Cu-SSZ-13 zeolite catalysts, highly active in the selective catalytic reduction of NO(x) with NH(3), was investigated by FTIR spectroscopy, and the results obtained were compared to those collected from other Cu-ion exchanged zeolites (Y,FAU and ZSM-5). Under low CO pressures and at room temperature (295 K), CO forms monocarbonyls exclusively on the Cu(+) ions, while in the presence of gas phase CO dicarbonyls on Cu(+) and adsorbed CO on Cu(2+) centers form, as well. At low (cryogenic) sample temperatures, tricarbonyl formation on Cu(+) sites was also observed. The adsorption of NO produces IR bands that can be assigned to nitrosyls bound to both Cu(+) and Cu(2+) centers, and NO(+) species located in charge compensating cationic positions of the chabasite framework. On the reduced Cu-SSZ-13 samples the formation of N(2)O was also detected. The assignment of the adsorbed NO(x) species was aided by adsorption experiments with isotopically labeled (15)NO. The movement of Cu ions from the sterically hindered six member ring position to the more accessible cavity positions as a result of their interaction with adsorbates (NO and H(2)O) was clearly evidenced. Comparisons of the spectroscopy data obtained in the static transmission IR system to those collected in the flow-through diffuse reflectance cell points out that care must be taken when general conclusions are drawn about the adsorptive and reactive properties of metal cation centers based on a set of data collected under well defined, specific experimental conditions.

Preparation and Desalination of Semi-Aromatic Polyamide Reverse Osmosis Membranes (ROMs).

Reverse osmosis membrane (ROM) technology has a series of advantages, such as a simple process, no secondary pollution, high efficiency, energy saving, environmental protection, and good separation and purification effects. High-performance semi-aromatic polyamide reverse osmosis membranes (ROMs) were prepared by interfacial polymerization (IP) of novel cyclopentanecarbonyl chloride (CPTC) and m-phenylenediamine (MPD) monomers. The surface morphology, hydrophilicity and charge of the ROMs were characterized by field-emission scanning electron microscopy (SEM), a contact angle tester and a solid-surface zeta potential analyzer. The effects of CPTC concentration, MPD concentration, oil-phase solvent type, IP reaction time and additive concentration on the performance of semi-aromatic polyamide ROMs were studied. SEM morphology characterization showed that the surface of the prepared polyamide ROMs presented a multinodal structure. The performance test showed that when the concentration of MPD in the aqueous phase was 2.5 wt.%, the concentration of sodium dodecylbenzene sulfonate (SDBS) was 0.2%, the residence time in the aqueous phase was 2 min, the concentration of CPTC/cyclohexane in the oil phase was 0.13 wt.%, the IP reaction was 20 s, the NaCl rejection rate of the semi-aromatic polyamide ROM was 98.28% and the flux was 65.38 L/m2·h, showing good desalination performance. Compared with an NF 90 commercial membrane, it has a good anti-BSA pollution ability.

New technology for preparing energetic materials by nanofiltration membrane (NF): rapid and efficient preparation of high-purity ammonium dinitramide (ADN).

The development of environment-friendly and non-toxic green energetic materials and their safe, environmentally friendly, and economical production is very important to the national economy and national security. As an innovative, efficient, and environmentally friendly energetic material, the preferred preparation method of ammonium dinitramide (ADN) is the nitro-sulfur mixed acid method, which has the advantages of high yield, simple method, and easy access to raw materials. However, the large number of inorganic salt ions introduced by this method limits the large-scale production of ADN. Nanofiltration (NF) has been widely used in various industrial processes as a separation method with high separation efficiency and simple operation. In this study, NF was used for the desalination and purification of ADN synthesized by the mixed acid method. The effects of NF types, operation process (pressure, temperature, and feed solution concentration) on desalination efficiency, and membrane flux during purification were examined. The results showed that 600D NF could achieve the efficient desalination and purification of ADN. It was verified that the highest desalination and purification efficiency was achieved at 2 MPa pressure, 25 °C, and 1 time dilution of the feed solution, and the membrane flux of the desalination and purification process was stable. Under the optimized process conditions, the removal rate of inorganic salts and other impurities reached 99% (which can be recycled), the purity of ADN reached 99.8%, and the recovery rate reached 99%. This process has the potential for the large-scale production of ADN and provides a new process for the safe, efficient, and cheap preparation of energetic materials.

Metabolome combined with transcriptome profiling reveals the dynamic changes in flavonoids in red and green leaves of Populus × euramericana 'Zhonghuahongye'.

Flavonoids are secondary metabolites that have economic value and are essential for health. Poplar is a model perennial woody tree that is often used to study the regulatory mechanisms of flavonoid synthesis. We used a poplar bud mutant, the red leaf poplar variety 2025 (Populus × euramericana 'Zhonghuahongye'), and green leaves as study materials and selected three stages of leaf color changes for evaluation. Phenotypic and biochemical analyses showed that the total flavonoid, polyphenol, and anthocyanin contents of red leaves were higher than those of green leaves in the first stage, and the young and tender leaves of the red leaf variety had higher antioxidant activity. The analyses of widely targeted metabolites identified a total of 273 flavonoid metabolites (114 flavones, 41 flavonols, 34 flavonoids, 25 flavanones, 21 anthocyanins, 18 polyphenols, 15 isoflavones, and 5 proanthocyanidins). The greatest difference among the metabolites was found in the first stage. Most flavonoids accumulated in red leaves, and eight anthocyanin compounds contributed to red leaf coloration. A comprehensive metabolomic analysis based on RNA-seq showed that most genes in the flavonoid and anthocyanin biosynthetic pathways were differentially expressed in the two types of leaves. The flavonoid synthesis genes CHS (chalcone synthase gene), FLS (flavonol synthase gene), ANS (anthocyanidin synthase gene), and proanthocyanidin synthesis gene LAR (leucoanthocyanidin reductase gene) might play key roles in the differences in flavonoid metabolism. A correlation analysis of core metabolites and genes revealed several candidate regulators of flavonoid and anthocyanin biosynthesis, including five MYB (MYB domain), three bHLH (basic helix-loop-helix), and HY5 (elongated hypocotyl 5) transcription factors. This study provides a reference for the identification and utilization of flavonoid bioactive components in red-leaf poplar and improves the understanding of the differences in metabolism and gene expression between red and green leaves at different developmental stages.

Synthesis and biological evaluation of cyanoguanidine derivatives of loratadine.

Cyanoguanidine derivatives of loratadine (3a-i) were synthesized and screened for antitumor and anti-inflammatory activity. The most promising compound 3c (R=n-C(8)H(17)) possessed at least twofold higher in vitro cytotoxicity than 5-fluorouracil against mammary (MCF-7 and MDA-MB 231) as well as colon (HT-29) carcinoma cells. The mode of action, however, is so far unclear. The participation of the COX-1/2 enzymes on the cytotoxicity, however, is very unlikely. Nevertheless all compounds showed stronger in vivo anti-inflammatory activity than ibuprofen in the xylene-induced ear swelling assay in mice.

Synthesis and in vitro antitumor activity of novel scopoletin derivatives.

Twenty scopoletin derivatives were developed by a systematic combinatorial chemical approach and their chemical structures were confirmed by MS, IR, (1)H NMR spectra and elemental analysis. Primary screening against mammary (MCF-7 and MDA-MB 231) and colon (HT-29) carcinoma cells indicated that five compounds (8d, 8g, 8j, 11b and 11g) displayed high antitumor potencies with IC(50) values below 20 µM whereas scopoletin showed IC(50) values above 100 µM. Moreover, the most promising compound 11g was more active than 5-fluorouracil. These results clearly indicated that the modification of the scopoletin structure could greatly increase its antitumor activity in vitro.

Design and synthesis of thiourea derivatives containing a benzo[5,6]cyclohepta[1,2-b]pyridine moiety as potential antitumor and anti-inflammatory agents.

Thiourea derivatives (6a-e) were developed and screened for antitumor and anti-inflammatory activity. Most of the compounds exhibited growth inhibitory effects comparable to 5-fluorouracil in vitro against mammary (MCF-7 and MDA-MB 231) as well as colon (HT-29) carcinoma cells. They also showed stronger anti-inflammatory activity than ibuprofen in vivo in the xylene-induced ear swelling assay in mice.

Investigation of Biaxial Properties of CFRP with the Novel-Designed Cruciform Specimens.

The biaxial loading properties of carbon-fiber-reinforced polymer (CFRP) are critical for evaluating the performance of composite structures under the complex stress state. There are currently no standardized specimens for the CFRP biaxial experiments. This work developed a new design criterion for the cruciform specimen coupled with the Hashin criterion. The finite element analysis was conducted to investigate the effect of geometric parameters on the stress distribution in the test area. The embedded continuous laying method (ECLM) was proposed to achieve the thinning of the center of the test region without introducing defects. The manufacturing quality of the cruciform specimens was verified by the ultrasonic C-scanning test. The biaxial test platform consisting of the biaxial loading system, digital image correlation (DIC) system, strain electrical measurement system, and acoustic emission detection system was constructed. The biaxial tensile tests under different biaxial loading ratios were conducted. The results showed that the biaxial failure efficiently occurred in the test area of the cruciform specimens designed and manufactured in this paper. The failure modes and morphology were characterized using macro/microscopic experimental techniques. The biaxial failure envelope was obtained. The results can be used to guide the design of composite structures under biaxial stress.

Steam turbine power prediction based on encode-decoder framework guided by the condenser vacuum degree.

The steam turbine is one of the major pieces of equipment in thermal power plants. It is crucial to predict its output accurately. However, because of its complex coupling relationships with other equipment, it is still a challenging task. Previous methods mainly focus on the operation of the steam turbine individually while ignoring the coupling relationship with the condenser, which we believe is crucial for the prediction. Therefore, in this paper, to explore the coupling relationship between steam turbine and condenser, we propose a novel approach for steam turbine power prediction based on the encode-decoder framework guided by the condenser vacuum degree (CVD-EDF). In specific, the historical information within condenser operation conditions data is encoded using a long-short term memory network. Moreover, a connection module consisting of an attention mechanism and a convolutional neural network is incorporated to capture the local and global information in the encoder. The steam turbine power is predicted based on all the information. In this way, the coupling relationship between the condenser and the steam turbine is fully explored. Abundant experiments are conducted on real data from the power plant. The experimental results show that our proposed CVD-EDF achieves great improvements over several competitive methods. our method improves by 32.2% and 37.0% in terms of RMSE and MAE by comparing the LSTM at one-minute intervals.

[Reactive oxygen species and mitochondrial membrane potential changes in leukemia cells during 6-gingerol induced apoptosis].

OBJECTIVE: To observe the effects of 6-gingerol on reactive oxygen species (ROS) and mitochondrial membrane potential(deltapsim) of chronic myeloid leukemia K562 cells and human acute T lymphoblastic leukemia MOLT4 cells, to investigate the role of mitochondrial pathway in the signal transduction of leukemia cell. METHODS: With different concentrations of 6-gingerol treatment, using 2,7-dichloro fluoresceinciactate (DCFH-DA) as ROS probe, rhodamine-123 as deltapsim probe, the levels of ROS and deltapsim of K562 cells and MOLT4 cells were tested by flow cytomentry. RESULTS: After treated with 6-gingerol, the ROS levels of K562 cells were significantly higher than control group (P < 0.01), while the deltapsim were significantly lower than control group (P < 0.01), and the ROS levels of MOLT4 cells were significantly higher than control group (P < 0.05). CONCLUSIONS: 6-gingerol can significantly increase ROS levels of K562 cells and MOLT4 cells, decrease deltapsim of K562 cells,induce apoptosis of leukemia cells by mitochondrial pathway.

Anti-inflammatory and anti-gouty-arthritic effect of free Ginsenoside Rb1 and nano Ginsenoside Rb1 against MSU induced gouty arthritis in experimental animals.

Ginsenoside Rb1 (GsRb1) is the best constituent of ginseng and although it shows clinical efficacy as an antineoplastic, antioxidative and antirheumatic agent, its oral bioavailability is poor due to its limited solubility. In this study, the solubility of GsRb1 was improved by encapsulating it in polymeric nanocapsules (encapsulation efficiency: 99.79%), therefore, improving the oral bioavailability. The encapsulation resulted in stable, homogenous and well-dispersed nano-GsRb1, whose mean particle size and zeta potential were 183.9 nm and +36.9 mV, respectively. A significant improvement was observed in the in vitro release profile of nano-GsRb1 as compared to its free form. Our study also indicated a significant repression of the degradation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα), the nuclear factor kappa B (NF-κB) signaling pathway, NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome activation, and the mitochondrial damage, thereby, reducing inflammation and gouty arthritis induced by monosodium urate (MSU), when compared to free GsRb1, strongly suggesting that polymeric nano-particles can be a novel approach for delivering the GsRb1 into the inflamed joints for a better treatment effectiveness.

Overexpression of LMP-1 Decreases Apoptosis in Human Nucleus Pulposus Cells via Suppressing the NF-κB Signaling Pathway.

Intervertebral disc degeneration (IDD) is a prevalent disease characterized by low back pain. Increasing extracellular matrix (ECM) synthesis and decreasing nucleus pulposus cell (NPC) apoptosis are promising strategies to recover degenerated NP. LIM mineralization protein- (LMP-) 1 has anti-inflammatory potential and is a promising gene target for the treatment of NP degeneration. In this study, we measured the expression of LMP-1 in the NP of patients. Then, we constructed LMP-1-overexpressing NPCs using lentiviral vectors and investigated the effects of LMP-1 on cell proliferation, apoptosis, and ECM synthesis in NPCs. The results showed that LMP-1 was highly expressed in the NP of patients. LMP-1 overexpression significantly increased proliferation and decreased apoptosis in NPCs. The expression of collagen II and sulfated glycosaminoglycan (sGAG) in NPCs was also upregulated after LMP-1 was overexpressed. Moreover, we demonstrated that LMP-1 decreased apoptosis of NPCs by inhibiting NF-κB signaling activation. These findings suggest that LMP-1 plays an essential role in mediating apoptosis in NPCs by regulating NF-κB signaling and can be used as a gene target for the treatment of IDD.

Photo and Reduction Dual-Responsive Hydrogel for Regulating Cell Adhesion and Cell Sheet Harvest.

Regulating cell-surface interactions plays a key role for biomaterials and their applications in cell-based therapies. In this paper, we demonstrated a dual-responsive hydrogel platform to achieve phototriggered protein immobilization and reduction-induced protein release. By o-nitrobenzyl photochemistry, including sequential aldehyde generation upon light irradiation and imine ligation with amine compounds, adhesive proteins can be effectively immobilized on the hydrogel with spatial and quantitative control, thus mediating cell adhesion in designed areas. By reduction chemistry of the disulfide bond, the patterned proteins can be released from the hydrogel, thus detaching cells in a noninvasive manner. Finally, the dynamic adsorption-dissociation of proteins enables the hydrogel to be tactfully used for cell sheet harvesting in an enzyme-free mode with light-defined shapes. This work not only provides an efficient strategy for recovery of cells and cell sheets but also provides insights into cell-material interactions mediated by proteins.

MuscNet, a Weighted Voting Model of Multi-Source Connectivity Networks to Predict Mild Cognitive Impairment Using Resting-State Functional MRI.

The neurological disorder mild cognitive impairment (MCI) demonstrates minor impacts on the patient's daily activities and may be ignored as the status of normal aging. But some of the MCI patients may further develop into severe statuses like Alzheimer's disease (AD). The brain functional connectivity network (BFCN) was usually constructed from the resting-state functional magnetic resonance imaging (rs-fMRI) data. This technology has been widely used to detect the neurodegenerative dementia and to reveal the intrinsic mechanism of neural activities. The BFCN edge was usually determined by the pairwise correlation between the brain regions. This study proposed a weighted voting model of multi-source connectivity networks (MuscNet) by integrating multiple BFCNs of different correlation coefficients. Our model was further improved by removing redundant features. The experimental data demonstrated that different BFCNs contributed complementary information to each other and MuscNet outperformed the existing models on detecting MCI patients. The previous study suggested the existence of multiple solutions with similarly good performance for a machine learning problem. The proposed model MuscNet utilized a weighted voting strategy to slightly outperform the existing studies, suggesting an effective way to fuse multiple base models. The reason may need further theoretical investigations about why different base models contribute to each other for the MCI prediction.

A highly ordered self-assembly three-grade porous helical silica tube.

A novel three-grade porous helical silica tube is prepared through an ingenious multi-soft-template pathway. This study reveals that three-(or multi-)grade self-assembly porous structure can be realized by using the synergistic effect of soft-templates. Our finding can offer an opportunity for nanofabrication including rational molecular design, spatial control on a nanoscale, and hierarchical assembly of complex architectures of porous materials.

Influence of magnesia modification on the properties of copper oxide supported on gamma-alumina.

XRD, BET, TPR, UV-vis DRS and in situ FT-IR were employed to investigate the dispersion, reduction and CO(2)-adsorption behaviors of copper oxide supported on magnesia modified gamma-Al(2)O(3) (Mg-Al) samples. The results indicate that magnesia could be highly dispersed on the surface of gamma-Al(2)O(3) to form a monolayer and the dispersion capacity is about 1.55 mmol/(100 m(2)gamma-Al(2)O(3)). For copper oxide supported on Mg-Al samples, both the dispersion capacity and the reduction temperature of surface CuO decrease with the MgO loading. CO(2)-adsorption IR results show that the surface strong basic amount for the catalysts increases with the dispersed MgO loading. In addition, the activity of CO oxidation suggests that the main active species in this system should be small CuO cluster and the existence of dispersed MgO enhances the activity of CO oxidation. The catalysts might be applied in pollution control devices for vehicle exhaust, CO gas sensors, catalytic combustion and gas purification of CO(2) lasers. All the results have been discussed by the consideration of the variation of gamma-Al(2)O(3) surface structure before and after magnesia modification.

The mechanism of selective catalytic reduction of NOx on Cu-SSZ-13 - a computational study.

The copper-exchanged aluminosilicate zeolite SSZ-13 is a leading catalyst for the selective catalytic reduction of NO. Density functional theory calculations are used to construct a complete catalytic cycle of this process paying special attention to the coordination geometries and redox states of copper. N2 can be produced in the reduction half-cycle via a nitrosamine intermediate generated from the reaction of the additive reductant NH3 with a NO+ intermediate stabilized by the zeolite lattice. The decomposition of this nitrosamine species can be assisted by incipient Brønsted acid sites generated during catalysis. Our calculations also suggest that the reoxidation of Cu(i) to Cu(ii) requires the addition of both NO and O2. The production of a second equivalent of N2 during the oxidation half-cycle proceeds through a peroxynitrite intermediate to form a Cu-nitrite intermediate, which may react with an acid, either HNO2 or NH4+ to close the catalytic cycle. Models of copper neutralized by an external hydroxide ligand are also examined. These calculations form a key basis for understanding the mechanism of NO reduction in Cu-SSZ-13 in order to develop strategies for rationally optimizing the performance in future experiments.