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Converting into high-value-added products represents the most optimal approach to CO2 utilization. The substitution of CO with CO2 as a potential critical material for formamide production is widely regarded as an ideal pathway and has garnered significant attention. However, high temperatures and pressures remain essential for the reaction, exerting a substantial influence on the utilization process. Herein, N-formylmorpholine was creatively synthesized by integrating the capture and solar-driven utilization of CO2 with morpholine. Notably, a remarkable N-formylmorpholine yield of 11433.3 µmol·h-1·g-1 was obtained, surpassing pure MoO3 by an astounding factor of 89.1 with a N-formylmorpholine yield of 63.8 µmol in 6 h, which is an astonishing increase of 57.5 times compared to MoO3. Both experimental results and density functional theory calculations suggest that the inclusion of Fe can effectively reduce the formation energy barrier while facilitating the desorption process of N-formylmorpholine, thereby optimizing the overall performance.
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Atomically dispersed Fe was designed on TiO2 and explored as a Janus electrocatalyst for both nitrogen oxidation reaction (NOR) and nitrogen reduction reaction (NRR) in a two-electrode system. Pulsed electrochemical catalysis (PE) was firstly involved to inhibit the competitive hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Excitingly, an unanticipated yield of 7055.81â µmol h-1 g-1 cat. and 12 868.33â µmol h-1 g-1 cat. were obtained for NOR and NRR at 3.5â V, respectively, 44.94 times and 7.8 times increase in FE than the conventional constant voltage electrocatalytic method. Experiments and density functional theory (DFT) calculations revealed that the single-atom Fe could stabilize the oxygen vacancy, lower the energy barrier for the vital rupture of N≡N, and result in enhanced N2 fixation performance. More importantly, PE could effectively enhance the N2 supply by reducing competitive O2 and H2 agglomeration, inhibit the electrocatalytic by-product formation for longstanding *OOH and *H intermediates, and promote the non-electrocatalytic process of N2 activation.
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Traditionally, the enhancement of nucleation rates in the presence of heterogeneous surfaces in crystallisation processes has been attributed to the modification of the interfacial energy of the system according to the classical nucleation theory. However, recent developments have shown that heterogeneous surfaces instead alter the pre-exponential factor of nucleation. In this work, the nucleation kinetics of glycine and diglycine in aqueous solutions have been explored in the presence and absence of a heterogeneous surface. Results from induction time experiments show that the presence of a heterogeneous surface increases the pre-exponential factor by 2-fold or more for both glycine and diglycine, while the interfacial energy remains unchanged for both species. This study suggests that the heterogeneous surface enhances the nucleation rate via hydrogen bond formation with both glycine and diglycine. This is verified by hydrogen bond propensity calculations, molecular functionality analysis, and calculation of the time taken for a solute molecule to attach to the growing nucleus, which is an order of magnitude shorter than the estimated lifetime of the hydrogen bond. The effect of the heterosurface is of greater magnitude for diglycine than for glycine, which may be due to the heightened molecular complementarity between the hydrogen bond donor and acceptor sites on diglycine and the heterosurface.
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Glicina , Glicilglicina , Cristalização , Cinética , SoluçõesRESUMO
The aggregation of crystals is a common phenomenon during the crystallization process. However, the formation mechanism of the aggregates remains elusive. In this work, we combine experiments with molecular simulations to investigate the attachment behavior of an organic compound photoinitiator bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (XBPO) in different solvents. The simulation results were highly in line with the experimental results. The results indicate that the aggregation behavior occurs on the high-energy surface (1 0 0) and the attachment angle is 0° during the solvothermal process. Meanwhile, solvents play the critical role in the formation of aggregated particles. It was found that the solvents with high Kamlet-Taft dipolarity/polarizability can promote the aggregation behavior of photoinitiator XBPO crystals. Furthermore, a solvent-mediated growth mechanism assisted by "oriented attachment"-like and Ostwald ripening mechanisms was proposed to elucidate the growth and aggregation of particles. We anticipate that this study will provide a comprehensive understanding of the attachment behavior and be helpful to control the aggregation of crystals.
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To explore the effect of chain length and conformation on the nucleation of peptides, the primary nucleation induction time of glycine homopeptides in pure water at different supersaturation levels under various temperatures has been determined. Nucleation data suggest that longer chains will prolong the induction time, especially for chains longer than three, where nucleation will occur over several days. In contrast, the nucleation rate increased with an increase in the supersaturation for all homopeptides. Induction time and nucleation difficulty increase at lower temperatures. However, for triglycine, the dihydrate form was produced with an unfolded peptide conformation (pPII) at low temperature. The interfacial energy and activation Gibbs energy of this dihydrate form are both lower than those at high temperature, while the induction time is longer, indicating the classical nucleation theory is not suitable to explain the nucleation phenomenon of triglycine dihydrate. Moreover, gelation and liquid-liquid separation of longer chain glycine homopeptides were observed, which was normally classified to nonclassical nucleation theory. This work provides insight into how the nucleation process evolves with increasing chain length and variable conformation, thereby offering a fundamental understanding of the critical peptide chain length for the classical nucleation theory and complex nucleation process for peptides.
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Biomaterials integrated with both topological cues and biological modifications are urgently needed in regenerative medicine. Here, aligned nanofibrous scaffolds decorated with nanoscale SiO2 protrusions and galectin-1 coating are reported. Prospects in neurite outgrowth and neural stem cell migration are discussed for suitable use in neural tissue engineering.
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Nanofibras , Células-Tronco Neurais , Alicerces Teciduais , Galectina 1 , Dióxido de Silício , Engenharia Tecidual , Crescimento NeuronalRESUMO
This study is aimed at investigating the effect and mechanism of long noncoding RNA (lncRNA) KCNQ1OT1 on pituitary adenoma (PA). The KCNQ1OT1 expression in invasive and noninvasive PA tissues was detected by real-time fluorescence quantitative polymerase chain reaction (qPCR). The effects of KCNQ1OT1 on the proliferation of PA cells, namely, GH3 and HP75, were detected by CCK-8 experiment. The Transwell assay detected the effect of KCNQ1OT1 on the invasion of GH3 and HP75 cells. The effect of KCNQ1OT1 on the clonal formation ability was detected by clonal formation experiment. The double luciferase reporter assay and the miRNA pull down assay verified the binding of KCNQ1OT1 to miR-140-5p. Meanwhile, the regulatory effect of miR-140-5p on RAB11A was verified. qPCR results showed that KCNQ1OT1 was significantly increased in invasive PA compared with noninvasive PA tissues. Knockdown KCNQ1OT1 inhibited PA cell stemness, angiogenesis, and EMT. In addition, knockdown KCNQ1OT1 inhibited the proliferation, invasion, and clonal formation of PA. miR-140-5p is the target gene of KCNQ1OT1. miR-140-5p targets RAB11A directly. RAB11A can mediate the biological effects of KCNQ1OT1. Meanwhile, lncRNA KCNQ1OT1 can promote the EMT and cellular stemness of PA. Its mechanism of action is realized by inhibiting miR-140-5p. This result can provide a molecular basis for the further study of PA.
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Electrochemical N2 oxidation reaction (NOR), using water and N2 in the atmosphere, represents a sustainable approach for nitric production to replace the conventional industrial synthesis with high energy consumption and greenhouse gas emission. Meanwhile, owing to chemical inertness of N2 and sluggish kinetics for 10-electron transfer, emerging electrocatalysts remain largely underexplored. Herein, Ru-nanoclusters-coupled Mn3 O4 catalysts decorated with atomically dispersed Ru atoms (Ru-Mn3 O4 ) are designed and explored as an advanced electrocatalyst for ambient N2 oxidation, with an excellent Faraday efficiency (28.87%) and a remarkable NO3 - yield (35.34 µg h-1 mg-1 cat. ), respectively. Experiments and density functional theory calculations reveal that the outstanding activity is ascribed to the coexistence of Ru clusters and single-atom Ru. The synergistic effect between the Ru clusters and Mn3 O4 can effectively activate the chemically inert N2 , lowering the kinetic barrier for the vital breakage of N≡N. The intensive *OH supply and enhanced conductivity are used to regulate the catalytic kinetics for optimized performance. This work provides brand-new ideas for the rational design of electrocatalysts in complicated electrocatalytic reactions with multiple dynamics-different steps.
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Oral squamous cell carcinoma represents 90% of all oral cancers. Recurrence prevention remains an important prognostic factor in patients with oral squamous cell carcinoma, and the recovery of the oral epithelium post-surgery is still a challenge. Thus, there is an urgent need to develop a smart carrier material to realize the spatiotemporally controlled release of anticancer drugs, instead of multiple oral administrations, for recurrence prevention and promoting the reconstruction of injured epithelial tissues. Here, we developed a multi-layered nanofiber patch capable of the photothermal-triggered release of low-molecular-weight fucoidan (LMWF) from the sandwiched layer, together with electrospun fibers as the backing and top layers. The sandwiched layer was made of phase-change materials loaded with indocyanine green, a photosensitive dye, for the localized release of LMWF in response to near-infrared irradiation. We showed that the on-demand release of LMWF was able to kill oral cancer cells effectively. Furthermore, adding acellular dermal matrix to the top nanofiber layer improved the proliferation of human oral keratinocytes, while the hydrophobic back layer served as a barrier to prevent loss of the drug. Taken together, this study provides a feasible and smart material system for killing oral squamous cancer cells together with the recovery of oral epithelium.
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To investigate the effect of long noncoding RNA ST8SIA6-AS1 on the epithelial-to-mesenchymal transition (EMT) and angiogenesis of pituitary adenoma and its possible mechanism. The expression levels of ST8SIA6-AS1 and HOXA9 in noninvasive pituitary adenoma and invasive pituitary adenoma were detected using qRT-PCR. sh-ST8SIA6-AS1 transfection silenced the expression of ST8SIA6-AS1 in GH3 and GTI-1 cells. The effects of ST8SIA6-AS1 on the proliferation, invasion, angiogenesis, and EMT of GH3 and GTI-1 pituitary adenoma cells were detected. The migration ability of cells was detected through scratch assay. Dual luciferase analysis verified the targeting relationship between ST8SIA6-AS1 and miR-5195-3p. ST8SIA6-AS1 and HOXA9 were highly expressed in invasive pituitary adenoma. In pituitary adenomas, miR-5195-3p directly targeted HOXA9. miR-5195-3p is the target gene of ST8SIA6-AS1. ST8SIA6-AS1 knockdown inhibited the proliferation, invasion, angiogenesis, and EMT of pituitary adenoma. HOXA9 expression mediates the biological effect of ST8SIA6-AS1. ST8SIA6-AS1 targets miR-5195-3p to regulate the expression of HOXA9 and promote the EMT of pituitary adenomas.
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Polyproline II (pPII) is a left-handed 31-helix conformation, which has been observed to be the most abundant secondary structure in unfolded peptides and proteins compared to α-helix and ß-sheet. Although pPII has been reported as the most stable conformation for several unfolded short chain peptides in aqueous solution, it is rarely observed in their solid state. Here, we show for the first time a glycine homopeptide (gly-gly-gly) adopting the pPII conformation in its crystalline dihydrate structure. The single crystal X-ray structure with molecular dynamic simulation suggests that a network of water and the charged carboxylate group is critical in stabilizing the pPII conformation in solid state, offering an insight into the structures of unfolded regions of proteins and the role of water in peptide crystallization.
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Oligopeptídeos/química , Peptídeos/química , Água/química , Cristalização , Conformação MolecularRESUMO
The structuring of component particles in binary compositions affects the solid-solid interfacial properties. This work reports the effect of interparticle interactions in binary powder compositions of D-Mannitol and glass beads through the heterogeneity data obtained from Finite Dilution Inverse Gas Chromatography (FD-IGC). Three different scenarios viz. structured, random and segregated systems of the binary powder composition were considered for the analysis in the IGC column. Binary mixtures with large size disparity between the components produced structured mixtures exhibiting a guest-host type of interactions and energetic homogeneity irrespective of the energetics of the finer component. Random and segregated systems revealed a heterogeneous trend in the data indicating preferential probing of the active sites of the composition, particularly at the lower probe coverages. The results demonstrate that in the multicomponent binary systems the surface energetics is influenced by the solid-solid interfaces and structuring of the component particles within the mix i.e., the surface energy analysis could reveal a mixing behavior in powders. Furthermore, an adsorption energy distribution model based on Boltzmann statistics and simulation fitting approach was employed to deconvolute the distribution of the changing energy landscape of the binary mixtures.
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Química Farmacêutica/métodos , Manitol/síntese química , Manitol/metabolismo , Tamanho da Partícula , Excipientes/síntese química , Excipientes/metabolismo , Pós , Propriedades de Superfície , Difração de Raios X/métodosRESUMO
OBJECTIVE: To investigate the feasibility and efficacy of combination of imiquimod and 5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) for the treatment of genital Bowenoid papulosis (BP). MATERIALS AND METHODS: A total of 27 BP patients were randomized into two groups. Fifteen (12 male and 3 female, age 22-56 years old) were treated with topical application of 5% imiquimod cream (three times a week) and ALA-PDT (100J/cm(2) at 100mW/cm(2), once a week) for 1-4 times. For comparison, other 12 (6 male and 6 female, age 29-58 years old) were treated with CO2 laser vaporization as a control. Patients were followed up for 3-12 months. Biopsies were taken from BP lesions prior to treatment and tested for HPV-16 and HPV-18 DNA. RESULTS: In combined therapy group, 60% (9/15) patients showed complete remission and only one recurred (11.1%) during follow up. Local side effects included mild erythema, edema, erosion and burning and/or stinging sensation. No systemic side effect was found. In CO2 laser vaporization group, 83.3% (10/12) patients showed complete remission. However, recurrence occurred in six patients (60.0%). Local side effects included mild to moderate edema, erosion, ulceration, delayed healing, prolonged pain and scarring. The difference of recurrence rate between two groups was statistically significant (P<0.05). CONCLUSION: Topical application of imiquimod cream and ALA-PDT is safe, effective and associated with low recurrence and less side effect.
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Abnormal visual experience can affect the brain structure and function. Visual functional performances of high myopia (HM) individuals were observed to be abnormal in contrast to emmetropics, even with a corrected visual acuity. Attention deficits and brain morphological changes have been revealed in the HM, but it is unknown whether there are functional connectivity (FC) alterations. The current study combined the resting-state functional connectivity density (FCD) mapping and seed-based correlation analysis to investigate FC alterations in the brain of HM. In our results, the HM exhibited decreased short- and long-range FCD in the posterior cingulate cortex/precuneus and decreased long-range FCD in the inferior temporal gyrus, supramarginal gyrus and rostrolateral prefrontal cortex. Specially, long-range FCD in the rostrolateral prefrontal cortex showed a significant positive correlation with the uncorrected visual acuity in the HM. Moreover, the HM showed significantly decreased FC not only between the supramarginal gyrus and rostrolateral prefrontal cortex, but also between networks they belong to, the ventral attention and frontoparietal control networks. These results provide evidence for the FC changes in the HM and may help to understand the attention deficits in myopes.
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Encéfalo/fisiopatologia , Miopia/fisiopatologia , Adulto , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/fisiopatologia , Adulto JovemRESUMO
The present work reports the green synthesis of gold nanoparticles (AuNPs) by water extract of Eucommia ulmoides (E. ulmoides) bark. The effects of various parameters such as the concentration of reactants, pH of the reaction mixture, temperature and the time of incubation were explored to the controlled formation of gold nanoparticles. The characterization through high resolution-transmission electron microscopic (HRTEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) infer that the as-synthesized AuNPs were spherical in shape with a face cubic crystal (FCC) structure. The results from zeta potential and dynamic light scattering (DLS) suggest the good stability and narrow size distribution of the AuNPs. This method for synthesis of AuNPs is simple, economic, nontoxic and efficient. The as-synthesized AuNPs show excellent catalytic activity for the catalytic reducing decoloration of model compounds of azo-dye: reactive yellow 179 and Congo red.
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Eucommiaceae/química , Ouro/química , Nanopartículas Metálicas/química , Extratos Vegetais/química , Química Verde , Nanopartículas Metálicas/ultraestrutura , Água/químicaRESUMO
Amblyopia is a neurological disorder of vision that follows abnormal binocular interaction or visual deprivation during early life. Previous studies have reported multiple functional or structural cortical alterations. Although white matter was also studied, it still cannot be clarified clearly which fasciculus was affected by amblyopia. In the present study, tract-based spatial statistics analysis was applied to diffusion tensor imaging (DTI) to investigate potential diffusion changes of neural tracts in anisometropic amblyopia. Fractional anisotropy (FA) value was calculated and compared between 20 amblyopic children and 18 healthy age-matched controls. In contrast to the controls, significant decreases in FA values were found in right optic radiation (OR), left inferior longitudinal fasciculus/inferior fronto-occipital fasciculus (ILF/IFO) and right superior longitudinal fasciculus (SLF) in the amblyopia. Furthermore, FA values of these identified tracts showed positive correlation with visual acuity. It can be inferred that abnormal visual input not only hinders OR from well developed, but also impairs fasciculi associated with dorsal and ventral visual pathways, which may be responsible for the amblyopic deficiency in object discrimination and stereopsis. Increased FA was detected in right posterior part of corpus callosum (CC) with a medium effect size, which may be due to compensation effect. DTI with subsequent measurement of FA is a useful tool for investigating neuronal tract involvement in amblyopia.
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Ambliopia/patologia , Substância Branca/patologia , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , Interpretação Estatística de Dados , Imagem de Tensor de Difusão , Feminino , Humanos , Masculino , Fibras Nervosas/patologia , Acuidade Visual , Substância Branca/fisiopatologiaRESUMO
In this paper the response characteristic of the nerve fiber to the modulation magnetic field induction is studied by using the method of numeric simulation. It is found that the nerve fiber is sensitive to the low frequency modulated signal but not to the high frequency carrier wave. A simulative EEG signal generator is developed according to the change of EEG rhythm during the sleep. The simulative EEG square wave is modulated by high-frequency magnetic impulse. The modulation magnetic field is coupled into the rabbit's brain to study the influence of magnetic stimulation on the discharge of 5-hydroxytryptamine (5-HT) nerve cell. The experiment results demonstrate that discharge frequency of median raphe nuclei related to sleep changes significantly and the discharge becomes slow, which shows that magnetic stimulation can inhibit electrical activity of 5-HT nerve cell and provide a new way to improve insomnia.
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Eletroencefalografia , Núcleos da Rafe/fisiologia , Serotonina/metabolismo , Sono/fisiologia , Animais , Encéfalo/metabolismo , Encéfalo/fisiologia , Simulação por Computador , Campos Eletromagnéticos , Eletrofisiologia , Humanos , Neurônios/fisiologia , Coelhos , Núcleos da Rafe/metabolismo , Distúrbios do Início e da Manutenção do Sono/metabolismo , Distúrbios do Início e da Manutenção do Sono/fisiopatologiaRESUMO
Amblyopia is a developmental disorder resulting from anomalous binocular visual input in early life. Task-based neuroimaging studies have widely investigated cortical functional impairments in amblyopia, but changes in spontaneous neuronal functional activities in amblyopia remain largely unknown. In the present study, functional connectivity density (FCD) mapping, an ultrafast data-driven method based on fMRI, was applied for the first time to investigate changes in cortical functional connectivities in amblyopia during the resting-state. We quantified and compared both short- and long-range FCD in both the brains of children with anisometropic amblyopia (AAC) and normal sighted children (NSC). In contrast to the NSC, the AAC showed significantly decreased short-range FCD in the inferior temporal/fusiform gyri, parieto-occipital and rostrolateral prefrontal cortices, as well as decreased long-range FCD in the premotor cortex, dorsal inferior parietal lobule, frontal-insular and dorsal prefrontal cortices. Furthermore, most regions with reduced long-range FCD in the AAC showed decreased functional connectivity with occipital and posterior parietal cortices in the AAC. The results suggest that chronically poor visual input in amblyopia not only impairs the brain's short-range functional connections in visual pathways and in the frontal cortex, which is important for cognitive control, but also affects long-range functional connections among the visual areas, posterior parietal and frontal cortices that subserve visuomotor and visual-guided actions, visuospatial attention modulation and the integration of salient information. This study provides evidence for abnormal spontaneous brain activities in amblyopia.
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Ambliopia/fisiopatologia , Encéfalo/fisiopatologia , Adolescente , Mapeamento Encefálico , Criança , Pré-Escolar , Feminino , Humanos , Imageamento por Ressonância Magnética , MasculinoRESUMO
AIMS: To investigate the potential morphological alterations of grey and white matter in monocular amblyopic children using voxel-based morphometry (VBM) and diffusion tensor imaging (DTI). METHODS: A total of 20 monocular amblyopic children and 20 age-matched controls were recruited. Whole-brain MRI scans were performed after a series of ophthalmologic exams. The imaging data were processed and two-sample t-tests were employed to identify group differences in grey matter volume (GMV), white matter volume (WMV) and fractional anisotropy (FA). RESULTS: After image screening, there were 12 amblyopic participants and 15 normal controls qualified for the VBM analyses. For DTI analysis, 14 amblyopes and 14 controls were included. Compared to the normal controls, reduced GMVs were observed in the left inferior occipital gyrus, the bilateral parahippocampal gyrus and the left supramarginal/postcentral gyrus in the monocular amblyopic group, with the lingual gyrus presenting augmented GMV. Meanwhile, WMVs reduced in the left calcarine, the bilateral inferior frontal and the right precuneus areas, and growth in the WMVs was seen in the right cuneus, right middle occipital and left orbital frontal areas. Diminished FA values in optic radiation and increased FA in the left middle occipital area and right precuneus were detected in amblyopic patients. CONCLUSIONS: In monocular amblyopia, cortices related to spatial vision underwent volume loss, which provided neuroanatomical evidence of stereoscopic defects. Additionally, white matter development was also hindered due to visual defects in amblyopes. Growth in the GMVs, WMVs and FA in the occipital lobe and precuneus may reflect a compensation effect by the unaffected eye in monocular amblyopia.