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The selective separation of MoS42- and WO42- using quaternary ammonium salt through solvent extraction or ion exchange methods has been well-established in the metallurgical industry. However, the conventional electrostatic adsorption theory falls short in explaining the separation mechanism. Through first-principles density functional theory (DFT) calculations and newly self-developed deep potential molecular dynamics (DPMD) simulation method, our work first reveals that the disparity in hydration structures of MoS42- and WO42- plays a crucial role in their selective separation. It is proposed that MoS42- and WO42- anions undergo hydration to form [MoS4(H2O)n]2- and [WO4(H2O)n]2-, respectively, facilitated by hydrogen bond (H-bond) interactions. Emphasis is placed on the discrepancy between MoS42- and WO42- in hydration structures by the hydration energy, Hirshfeld charge, evaluation of weak interactions, hydration radius, hydration coordination number, and H-bonds distribution. MoS42- presents a larger first hydration radius and a lower first hydration coordination number due to weaker interactions with H2O, while WO42- is subjected to enhanced hydration shielding, resulting in MoS42- anions being more susceptible to be selectively separated by a quaternary ammonium salt. This insight paves the way for the selective separation of MoS42- and WO42-, further bridging the gap between theory and industry applications.
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Nonfunctioning pituitary adenoma (NFPA) is one of the major subtypes of pituitary adenomas (PA) and its primary treatment is surgical resection. However, normal surgery fails to remove lesions completely and there remains in lack of frontline treatment, so the development of new drugs for NFPA is no doubt urgent. Oridonin (ORI) has been reported to have antitumor effects on a variety of tumors, but whether it could exhibit the same effect on NFPA requires to be further investigated. The effects of ORI on pituitary-derived folliculostellate cell line (PDFS) cell viability, colony formation, proliferation ability, migration, and invasion were examined by Cell Counting Kit-8, colony formation assay, 5Ethynyl2'deoxyuridine proliferation assay, wound-healing assay, and Transwell assay. The differentially expressed genes in the control and ORI-treated groups were screened by transcriptome sequencing analysis and analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment. Cell cycle analysis was performed to detect changes in cell cycle. Annexin V-fluorescein isothiocyanate/propidium iodide staining was performed to detect apoptosis in ORI-treated cells. Western blot assay was performed to detect Bax, Bcl-2, and cleaved Caspase-3 protein expression. ORI inhibited PDFS cell viability and significantly suppressed cell proliferation, migration, and invasion. GO and KEGG results showed that ORI was associated with signaling pathways such as cell cycle and apoptosis in PDFS cells. In addition, ORI blocked cells in G2/M phase and induced apoptosis in PDFS cells. ORI can trigger cell cycle disruption and apoptosis collaboratively in PDFS cells, making it a promising and effective agent for NFPA therapy.
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Apoptose , Proliferação de Células , Diterpenos do Tipo Caurano , Neoplasias Hipofisárias , Diterpenos do Tipo Caurano/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias Hipofisárias/tratamento farmacológico , Neoplasias Hipofisárias/patologia , Proliferação de Células/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Adenoma/tratamento farmacológico , Adenoma/patologiaRESUMO
BACKGROUND: Capsular contracture is one of the most severe complications following breast augmentation surgery. It has been reported that botulinum toxin Type A (BTX-A) can inhibit capsular contracture, but the exact mechanisms remain unclear. Therefore, this study aims to explore the potential mechanisms behind BTX-A's inhibition of capsular contracture by observing its effects on the biological behavior of fibroblasts and its impact on the TGF-ß/Smad signaling pathway. METHODS: In vitro experiments involved culturing fibroblasts on PDMS surfaces, subsequently treating them with various concentrations of BTX-A. Fibroblast proliferation activity was assessed using the CCK-8 assay, while the migration and cytoskeletal morphology of the fibroblasts were meticulously examined. ELISA was utilized to quantify the expression of fibrosis-related cytokines. Gene and protein expressions related to the TGF-ß/Smad pathway were analyzed through real-time PCR and Western blotting techniques. RESULTS: BTX-A moderately enhanced the early proliferation and migration of fibroblasts on the surface of PDMS silicone sheets and reduced the synthesis of collagen types I and III. Furthermore, under the influence of BTX-A, the expression of TGF-ßR2 and α-SMA in the TGF-ß/Smad pathway was significantly inhibited. CONCLUSIONS: This study demonstrates that BTX-A can inhibit fibroblast differentiation by downregulating the expression of TGF-ßR2, thereby suppressing the TGF-ß/Smad pathway. This suggests a possible mechanism through which BTX-A mitigates capsular contracture. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
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The current paradigm considers the control of the MOF/polymer interface mostly for achieving a good compatibility between the two components to ensure the fabrication of continuous mixed-matrix metal-organic framework (MMMOF) membranes. Here, we unravel that the interfacial pore shape nanostructure plays a key role for an optimum molecular transport. The prototypical ultrasmall pore AlFFIVE-1-Ni MOF was assembled with the polymer PIM-1 to design a composite with gradually expanding pore from the MOF entrance to the MOF/polymer interfacial region. Concentration gradient-driven molecular dynamics simulations demonstrated that this pore nanostructuring enables an optimum guided path for the gas molecules at the MOF/polymer interface that decisively leads to an acceleration of the molecular transport all along the MMMOF membrane. This numerical prediction resulted in the successful fabrication of a [001]-oriented nanosheets AlFFIVE-1-Ni/PIM-1 MMMOF membrane exhibiting an excellent CO2 permeability, better than many MMMs, and ideally associated with a sufficiently high CO2/CH4 selectivity that makes this membrane very promising for natural gas/biogas purification.
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Photodynamic therapy has been regarded as a noninvasive treatment for cancer with spatiotemporal control over drug activation. Bis-terpyridyl Ru(II) complexes exhibit a promising achiral structure but suffer from low photoreactivity due to deviation from the ideal octahedral geometry. Herein, we introduce the donor-acceptor-donor motif to construct a dinuclear bis-terpyridyl Ru(II) complex (Ru2). Ru2 exhibits superior light absorption properties compared with mononuclear complex Ru1. Importantly, upon 595 nm light excitation, Ru2 shows promising synergetic type I/II photosensitization and photocatalytic activity, while Ru1 is inactive. Anticancer mechanistic studies reflect that Ru2 induces intracellular redox imbalance and affects the biosynthetic and metabolic processes, leading to cell apoptosis. Overall, this work provides a simple strategy to rouse the PDT efficiency of bis-terpyridyl Ru(II) complexes.
Assuntos
Antineoplásicos , Complexos de Coordenação , Fotoquimioterapia , Fármacos Fotossensibilizantes , Rutênio , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Rutênio/química , Rutênio/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/síntese química , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/síntese química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Piridinas/farmacologia , Piridinas/química , Piridinas/síntese química , Ensaios de Seleção de Medicamentos Antitumorais , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
Metal-organic frameworks (MOFs) incorporating open metal sites (OMS) have been identified as promising sorbents for many societally relevant-adsorption applications including CO2 capture, natural gas purification and H2 storage. This has been ascribed to strong specific interactions between OMS and the guest molecules that enable the MOF to achieve an effective capture even under low gas pressure conditions. In particular, the presence of OMS in MOFs was demonstrated to substantially boost the H2 binding energy for achieving high adsorbed hydrogen densities and large usable hydrogen capacities. So far, there is a critical bottleneck to computationally attain a full understanding of the thermodynamics and dynamics of H2 in this sub-class of MOFs since the generic classical force fields (FFs) are known to fail to accurately describe the interactions between OMS and any guest molecules, in particular H2. This clearly hampers the computational-assisted identification of MOFs containing OMS for a target adsorption-related application since the standard high-throughput screening approach based on these generic FFs is not applicable. Therefore, there is a need to derive novel FFs to achieve accurate and effective evaluation of MOFs for H2 adsorption. On this path, as a proof-of-concept, the soc-MOF-1d containing OMS, previously envisaged as a potential platform for H2 adsorption, was selected as a benchmark material and a machine learning potential (MLP) was derived for the Al-soc-MOF-1d from a dataset initially generated by ab initio molecular dynamics (AIMD) simulations. This MLP was further implemented in MD simulations to explore the H2 binding modes as well as the temperature dependence distribution of H2 in the MOF pores from 10 K to 80 K. MLP-Grand Canonical Monte Carlo (GCMC) simulations were then performed to predict the H2 sorption isotherm of Al-soc-MOF-1d at 77 K that was further confirmed using sorption data we collected on this sample. As a further step, MLP-based molecular dynamics (MD) simulations were conducted to anticipate the kinetics of H2 in this MOF. This work delivers the first MLP able to describe accurately the interactions between the challenging H2 guest molecule and MOFs containing OMS. This innovative strategy applied to one of the most complex molecules owing to its highly polarizable nature, paves the way towards a more systematic accurate and efficient in silico assessment of MOFs containing OMS for H2 adsorption and beyond to the low-pressure capture of diverse molecules.
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Zeolite-catalyzed dimethyl ether (DME) carbonylation provides a novel route to producing methyl acetate (MeOAc). Mordenite (MOR) has drawn significant interest because of its remarkable MeOAc selectivity in DME carbonylation, albeit with limited catalytic stability. Herein, novel MOR-based DME carbonylation catalysts, distinguished by long-term stability and high activity were successfully developed, based on an H2-promoted benign coke strategy. Both the H2 cofeeds and the presence of metal species with hydrogenation capability are demonstrated to be crucial for the regulation of coke depositions. The coke deposits can potentially cover the acid sites in the 12-MR main channels, thereby mitigating the occurrence of undesirable methanol-to-hydrocarbon side reactions. Meanwhile, the elimination of ultralarge coke species under the assistance of H2 and Cu species could ensure smooth mass transfer within the catalyst, contributing to its remarkable catalytic performance. The most highlighted DME carbonylation performance was achieved on coke-mediated CuZn-HMOR with a high MeOAc yield of 0.4-0.5 g·gcat-1·h-1 for over 520 h (over 50× enhancement versus HMOR), exhibiting promising industrial application potential. The current strategy is expected to inspire further research into zeolite-catalyzed reactions, which could be potentially improved by the presence of benign coke.
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CALF-20 was recently identified as a benchmark sorbent for CO2 capture at the industrial scale, however comprehensive atomistic insight into its mechanical/thermal properties under working conditions is still lacking. In this study, we developed a general-purpose machine-learned potential (MLP) for the CALF-20 MOF framework that predicts the thermodynamic and mechanical properties of the structure at finite temperatures within first-principles accuracy. Interestingly, CALF-20 was demonstrated to exhibit both negative area compression and negative thermal expansion. Most strikingly, upon application of the tensile strain along the [001] direction, CALF-20 was shown to display a distinct two-step elastic deformation behaviour, unlike typical MOFs that undergo plastic deformation after elasticity. Furthermore, this MOF was shown to exhibit a fracture strain of up to 27% along the [001] direction at room temperature comparable to that of MOF glasses. These abnormal thermal and mechanical properties make CALF-20 as attractive material for flexible and stretchable electronics and sensors.
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Mythimna separata (Lepidoptera: Noctuidae) is an omnivorous pest that poses a great threat to food security. Insect antimicrobial peptides (AMPs) are small peptides that are important effector molecules of innate immunity. Here, we investigated the role of the AMP cecropin B in the growth, development, and immunity of M. separata. The gene encoding M. separata cecropin B (MscecropinB) was cloned. The expression of MscecropinB was determined in different developmental stages and tissues of M. separata. It was highest in the prepupal stage, followed by the pupal stage. Among larval stages, the highest expression was observed in the fourth instar. Tissue expression analysis of fourth instar larvae showed that MscecropinB was highly expressed in the fat body and haemolymph. An increase in population density led to upregulation of MscecropinB expression. MscecropinB expression was also upregulated by the infection of third and fourth instar M. separata with Beauveria bassiana or Bacillus thuringiensis (Bt). RNA interference (RNAi) targeting MscecropinB inhibited the emergence rate and fecundity of M. separata, and resulted in an increased sensitivity to B. bassiana and Bt. The mortality of M. separata larvae was significantly higher in pathogen plus RNAi-treated M. separata than in controls treated with pathogens only. Our findings indicate that MscecropinB functions in the eclosion and fecundity of M. separata and plays an important role in resistance to infection by B. bassiana and Bt.
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Proteínas de Insetos , Larva , Mariposas , Animais , Mariposas/imunologia , Mariposas/genética , Mariposas/microbiologia , Mariposas/crescimento & desenvolvimento , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Larva/crescimento & desenvolvimento , Larva/microbiologia , Bacillus thuringiensis , Beauveria/fisiologia , Peptídeos Antimicrobianos/genética , Pupa/crescimento & desenvolvimento , Interferência de RNARESUMO
A rapid and eco-friendly route has been developed for the synthesis of SAPO-34 with short crystallization time (1-3 h), low silica content (as low as 6.2 wt%) and excellent methanol-to-olefin (MTO) catalytic performance by utilization of a recycled mother liquid at elevated crystallization temperature.
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The separation of high-value-added chemicals from organic solvents is important for many industries. Membrane-based nanofiltration offers a more energy-efficient separation than the conventional thermal processes. Conceivably, mixed-matrix membranes (MMMs), encompassing metal-organic frameworks (MOFs) as fillers, are poised to promote selective separation via molecular sieving, synergistically combining polymers flexibility and fine-tuned porosity of MOFs. Nevertheless, conventional direct mixing of MOFs with polymer solutions results in underutilization of the MOF fillers owing to their uniform cross-sectional distribution. Therefore, in this work, a multizoning technique is proposed to produce MMMs with an asymmetric-filler density, in which the MOF fillers are distributed only on the surface of the membrane, and a seamless interface at the nanoscale. The design strategy demonstrates five times higher MOF surface coverage, which results in a solvent permeance five times higher than that of conventional MMMs while maintaining high selectivity. Practically, MOFs are paired with polymers of similar chemical nature to enhance their adhesion without the need for surface modification. The approach offers permanently accessible MOF porosity, which translates to effective molecular sieving, as exemplified by the polybenzimidazole and Zr-BI-fcu-MOF system. The findings pave the way for the development of composite materials with a seamless interface.
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Trehalose is an important carbohydrate substance in insect hemolymph. Chitin is the main component of cuticle and peritrophic matrix in insects. Trehalase (Tre) catalyzes the decomposition of trehalose. Few studies of trehalase in lepidopteran insects have been conducted. Here, the functions of soluble Tre (Tre1) and membrane-bound Tre (Tre2) in the growth and development of Mythimna separata were investigated. We cloned and identified Tre1 and Tre2 cDNA sequences in M. separata. Analysis expression revealed that MsTre1 and MsTre2 were highly expressed in midgut and integument, respectively. The expression of MsTre1 and MsTre2 was highest in the pupal stage. We used RNA interference (RNAi) to inhibit Tre expression in M. separata larvae. Injection of dsMsTre1 or dsMsTre2 resulted in abnormal phenotypes and impeded normal molting. Silencing of MsTre1 and MsTre2 resulted in significant changes in the expression of genes in the trehalose and chitin metabolism pathways, significantly increased the trehalose and glycogen content, and significantly decreased MsTre1 and MsTre2 activity, the glucose content, and the chitin content in midgut and integument. Silencing of MsTre1 slowed larval molting, and the new cuticle was significantly thinner. These results indicate that RNAi of Tre may be useful for control strategies against M. separata.
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Cytochrome P450 (CYP) is a group of important detoxification enzymes found in insects related to their resistance to insecticides. To elucidate the CYP6 family genes of P450, which are potentially related to imidacloprid resistance in Aphis glycines, the CYP6 cDNA sequences of A. glycines were studied. The transcriptome of A. glycines was constructed, and the CYP6 cDNA sequences of A. glycines were screened. Their relative expression levels in response to imidacloprid induction were examined through qRT-PCR, and the CYP6s with higher expression levels were used to study the detoxification of imidacloprid through RNA interference and a bioassay. Twelve CYP6s were obtained from the A. glycines transcriptome. These samples were named by the International P450 Nomenclature Committee and registered in GenBank. After 3, 6, 12, 24 and 48 h of induction with LC50 concentrations of imidacloprid, the relative expression levels of these CYP6s increased; the expression level of CYP6CY7 experienced the highest increase, being more than 3-fold higher than that of those of the non-imidacloprid-induced CYP6s. After RNA interference for CYP6CY7, the relative expression level of CYP6CY7 significantly decreased after 3, 6 and 12 h, while the corresponding P450 enzyme activity decreased after 12 and 24 h. The mortality of A. glycines due to imidacloprid treatment increased by 14.71% at 24 h. CYP6CY7 might detoxify imidacloprid in A. glycines. This study provides a theoretical basis for the further study of the mechanism of action of CYP6s and potential new methods for improving insecticidal efficacy.
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The autonomic nervous system plays a crucial role in regulating bone metabolism, with sympathetic activation stimulating bone resorption and inhibiting bone formation. We found that fractures lead to increased sympathetic tone, enhanced osteoclast resorption, decreased osteoblast formation, and thus hastened systemic bone loss in ovariectomized (OVX) mice. However, the combined administration of parathyroid hormone (PTH) and the ß-receptor blocker propranolol dramatically promoted systemic bone formation and osteoporotic fracture healing in OVX mice. The effect of this treatment is superior to that of treatment with PTH or propranolol alone. In vitro, the sympathetic neurotransmitter norepinephrine (NE) suppressed PTH-induced osteoblast differentiation and mineralization, which was rescued by propranolol. Moreover, NE decreased the PTH-induced expression of Runx2 but enhanced the expression of Rankl and the effect of PTH-stimulated osteoblasts on osteoclastic differentiation, whereas these effects were reversed by propranolol. Furthermore, PTH increased the expression of the circadian clock gene Bmal1, which was inhibited by NE-ßAR signaling. Bmal1 knockdown blocked the rescue effect of propranolol on the NE-induced decrease in PTH-stimulated osteoblast differentiation. Taken together, these results suggest that propranolol enhances the anabolic effect of PTH in preventing systemic bone loss following osteoporotic fracture by blocking the negative effects of sympathetic signaling on PTH anabolism.
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Anabolizantes , Reabsorção Óssea , Fraturas por Osteoporose , Camundongos , Animais , Hormônio Paratireóideo/farmacologia , Anabolizantes/farmacologia , Fraturas por Osteoporose/tratamento farmacológico , Propranolol/farmacologia , Fatores de Transcrição ARNTL , Reabsorção Óssea/tratamento farmacológico , Antagonistas Adrenérgicos beta/farmacologiaRESUMO
BACKGROUND: Ferroptosis, a unique type of cell death triggered by iron-dependent lipid peroxidation, plays a critical role in the pathogenesis of Alzheimer's disease (AD), a debilitating condition marked by memory loss and cognitive impairment due to the accumulation of beta-amyloid (Aß) and hyperphosphorylated Tau protein. Increasing evidence suggests that inhibitors of ferroptosis could be groundbreaking in the treatment of AD. METHOD: In this study, we established in vitro ferroptosis using erastin-, RSL-3-, hemin-, and iFSP1-induced PC-12 cells. Using MTT along with Hoechst/PI staining, we assessed cell viability and death. To determine various aspects of ferroptosis, we employed fluorescence probes, including DCFDA, JC-1, C11 BODIPY, Mito-Tracker, and PGSK, to measure ROS production, mitochondrial membrane potential, lipid peroxidation, mitochondrial morphology, and intracellular iron levels. Additionally, Western blotting, biolayer interferometry technology, and shRNA were utilized to investigate the underlying molecular mechanisms. Furthermore, p-CAX APP Swe/Ind- and pRK5-EGFP-Tau P301L overexpressing PC-12 cells, along with Caenorhabditis elegans (C. elegans) strains CL4176, CL2331, and BR5270, were employed to examine ferroptosis in AD models. RESULTS: Here, we conducted a screening of our natural medicine libraries and identified the ethanol extract of Penthorum chinense Pursh (PEE), particularly its ethyl acetate fraction (PEF), displayed inhibitory effects on ferroptosis in cells. Specifically, PEF inhibited the generation of ROS, lipid peroxidation, and intracellular iron levels. Furthermore, PEF demonstrated protective effects against H2O2-induced cell death, ROS production, and mitochondrial damage. Mechanistic investigations unveiled PEF's modulation of intracellular iron accumulation, GPX4 expression and activity, and FSP1 expression. In p-CAX APP Swe/Ind and pRK5-EGFP-Tau P301L overexpressing PC-12 cells, PEF significantly reduced cell death, as well as ROS and lipid peroxidase production. Moreover, PEF ameliorated paralysis and slowing rate in Aß and Tau transgenic C. elegans models, while inhibiting ferroptosis, as evidenced by decreased DHE intensity, lipid peroxidation levels, iron accumulation, and expression of SOD-3 and gst-4. CONCLUSION: Our findings highlight the suppressive effects of PEF on ferroptosis in AD cellular and C. elegans models. This study helps us better understand how ferroptosis affects AD and emphasizes the potential of PCP as a candidate for AD intervention.
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Doença de Alzheimer , Ferroptose , Animais , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Caenorhabditis elegans , Espécies Reativas de Oxigênio/metabolismo , Peróxido de Hidrogênio/farmacologia , Ferro/metabolismoRESUMO
Herein, a robust microporous aluminum tetracarboxylate framework, MIL-120(Al)-AP, (MIL, AP: Institute Lavoisier and Ambient Pressure synthesis, respectively) is reported, which exhibits high CO2 uptake (1.9 mmol g-1 at 0.1 bar, 298 K). In situ Synchrotron X-ray diffraction measurements together with Monte Carlo simulations reveal that this structure offers a favorable CO2 capture configuration with the pores being decorated with a high density of µ2-OH groups and accessible aromatic rings. Meanwhile, based on calculations and experimental evidence, moderate host-guest interactions Qst (CO2) value of MIL-120(Al)-AP (-40 kJ mol-1) is deduced, suggesting a relatively low energy penalty for full regeneration. Moreover, an environmentally friendly ambient pressure green route, relying on inexpensive raw materials, is developed to prepare MIL-120(Al)-AP at the kilogram scale with a high yield while the Metal- Organic Framework (MOF) is further shaped with inorganic binders as millimeter-sized mechanically stable beads. First evidences of its efficient CO2/N2 separation ability are validated by breakthrough experiments while operando IR experiments indicate a kinetically favorable CO2 adsorption over water. Finally, a techno-economic analysis gives an estimated production cost of ≈ 13 $ kg-1, significantly lower than for other benchmark MOFs. These advancements make MIL-120(Al)-AP an excellent candidate as an adsorbent for industrial-scale CO2 capture processes.
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Atomic doping in catalysts is an effective strategy for adjusting their catalytic activity, which has recently been applied to promote sulfur reduction reactions (SRRs) on the cathode of lithium-sulfur (Li-S) batteries. Herein, the electrocatalytic SRR mechanism of eight metal atom (Ca, Ti, V, Cr, Mn, Fe, Co or Ni) doped Chevrel phase Mo6Se8 were investigated using density functional theory (DFT) calculations. The results reveal that the interaction between polysulfides and the catalyst mainly originates from the coupling of dz2 and dxz orbitals of doped metals and the 3p orbitals of S. The Ti-doped Mo6Se8 system significantly reduces the overpotential of the SRR to only 0.21 V. After analyzing SRR processes over doped and undoped Mo6Se8, no scalar relationship was found between the adsorption energies (Ead) of various polysulfides. Instead, a linear relationship is established between 4Ead-Li2S* - Ead-Li2S4* and overpotential. Finally, a linear relationship between overpotential and descriptors was established based on a machine learning (ML) method, which can accurately predict the overpotential of the SRR over the Mo6Se8 catalyst. This work provides new theoretical insights into the SRR mechanism over metal-selenides and the rational design of a catalyst for Li-S batteries.
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Marine sponges are well known as prolific producers of structurally diverse molecules with valuable pharmacological potential. As part of our ongoing program to discover bioactive compounds from marine sponges collected from the Xisha Islands in the South China Sea, a chemical study on the specimens of Hippospongia lachne was conducted. As a result, eight undescribed compounds, including four zwitterionic alkylpyridinium salts, hippospondines A-D (1-4), and four 3-alkylpyridine alkaloids, hippospondines E (5), F (6), and (±)-hippospondine G (7), were isolated from the marine sponge H. lachne, together with one known 3-alkylpyridine alkaloid (8). The undescribed structures were elucidated by HRESIMS, NMR, DP4+ and CP3 probability analysis, and the Snatzke's method. Hippospondines A-D (1-4) represent the rare example of inner salt type alkylpyridinium alkaloid with a farnesyl moiety. Compounds 1-3 and 8 were subjected to cytotoxic and lymphocyte proliferation assays. Compound 3 exhibited a weak promotion effect on the ConA-induced T lymphocyte proliferation.