RESUMO
Znln2S4 has great prospects for photocatalytic water splitting to hydrogen by visible light. Herein, a novel Znln2S4-In-MOF (ZnInMS4) photocatalyst is elaborately synthesized by in situ method with In-MOF as the template and In3+ as the source. ZnInMS4 overcomes the fast interface charge recombination and a sluggish charge lifetime via the formed heterojunctions. Photoelectrochemical measurements reveal that the charge-transfer kinetics is enhanced since In-MOF is introduced to act as a reliable charge-transport channel. ZnInMS4 exhibits outstanding cocatalyst-free H2 evolution rate of 70 µmol h-1 under irradiation (λ > 420 nm), which is 3.2-fold higher than that of Znln2S4. In addition, the ZnInMS4 photocatalyst shows good stability in the 16 h continuous reaction. This work illustrates the feasibility of the MOF precursor instead of inorganic salts to directly synthesize photocatalysts with high performance.
RESUMO
Catalysis is the most efficient and economical method for treating volatile organic pollutants (VOCs). Among the many materials that are used in engineering, platinized carbon nitride (Pt/g-C3N4) is an efficient and multifunctional catalyst which has strong light absorption and mass transfer capabilities, which enable it to be used in photocatalysis, thermal catalysis and photothermal synergistic catalysis for the degradation of benzene. In this work, Pt/g-C3N4 was prepared by four precursors for the photothermal synergistic catalytic degradation of benzene, which show different activities, and many tests were carried out to explore the possible reasons for the discrepancy. Among them, the Pt/g-C3N4 prepared from dicyanamide showed the highest activity and could convert benzene (300 ppm, 20 mL·min-1) completely at 162 °C under solar light and 173 °C under visible light. The reaction temperature was reduced by nearly half compared to the traditional thermal catalytic degradation of benzene at about 300 °C.
Assuntos
Benzeno , Metais , Luz , CatáliseRESUMO
In recent studies, phase junctions constructed as photocatalysts have been found to possess great prospects for organic degradation with visible light. In this study, we designed an elaborate rhombohedral corundum/cubic In2O3 phase junction (named MIO) combined with polymeric carbon nitride (PCN) via an in situ calcination method. The performance of the MIO/PCN composites was measured by photodegradation of Rhodamine B under LED light (λ = 420 nm) irradiation. The excellent performance of MIO/PCN could be attributed to the intimate interface contact between MIO and PCN, which provides a reliable charge transmission channel, thereby improving the separation efficiency of charge carriers. Photocatalytic degradation experiments with different quenchers were also executed. The results suggest that the superoxide anion radicals (O2-) and hydroxyl radicals (·OH) played the main roles in the reaction, as opposed to the other scavengers. Moreover, the stability of the MIO/PCN composites was particularly good in the four cycling photocatalytic reactions. This work illustrates that MOF-modified materials have great potential for solving environmental pollution without creating secondary pollution.
Assuntos
Poluentes Ambientais , Catálise , Fotólise , PolímerosRESUMO
Yi Guan Jian (YGJ), one of the most commonly used traditional Chinese medicines, has been reported to possess significant antifatigue effects. However, the mechanisms underlying its antifatigue effects remain largely unresolved. In this study, a metabonomics approach, involving gas chromatography coupled to mass spectrometry and a multivariate statistical technique, was developed to estimate the extent to which YGJ alleviated the exhausting swimming-induced fatigue of mice. High-dose treatment with YGJ significantly extended the swimming time of fatigued mice. Significant alterations of metabolites involving amino acids, organic acids and carbohydrates were observed in the serum of fatigued mice, which were reversed by YGJ treatment while biochemical indexes returned to normal. These metabolic changes suggest that the antifatigue effect of YGJ is associated with the impairement of amino acid, organic acids and carbohydrates. It also appears that YGJ can induce significant metabolic alterations independent of the exhausting swimming-induced metabolic changes. The significantly altered metabolites induced by YGJ intervention include l-2-amino-acetoacetate, taurine, fumaric acid, malic acid, oxoadipic acid and l-aspartate, all of which are associated with antifatigue properties. This suggests that YGJ exerts chemopreventive effects via antifatigue mechanisms.
Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Fadiga/metabolismo , Cromatografia Gasosa-Espectrometria de Massas/métodos , Metaboloma/efeitos dos fármacos , Metabolômica/métodos , Aminoácidos/sangue , Animais , Carboidratos/sangue , Ácidos Carboxílicos/sangue , Medicamentos de Ervas Chinesas/administração & dosagem , Teste de Esforço/efeitos dos fármacos , Masculino , Medicina Tradicional Chinesa , Camundongos , Análise de Componente PrincipalRESUMO
Stent implantation has been a promising therapy for congenital heart disease (CHD) due to better efficacy. Compared to permanent metal stents, bioresorbable polymer stents have shown a great advantage in accommodating the vascular growth of pediatric patients, but the application is still limited due to inferior radial strength. Here, bioresorbable poly(p-dioxanone) (PPDO) sliding-lock stents for CHD treatment were fabricated by fused deposition modeling (FDM). The effects of FDM processing parameters, including nozzle temperature, bed temperature, layer thickness, and printing speed, on the mechanical properties of PPDO parts were investigated to optimize the processing condition to enhance the radial strength of stents. Finite element analysis (FEA) was also used to evaluate the mechanical properties of stents. PPDO sliding-lock stents fabricated under optimized FDM parameters showed radial strength of 3.315 ± 0.590 N/mm, superior to benchmark commercial metal stents. Radial strength curve and compression behavior of PPDO sliding-lock stents were investigated. Results of FEA exhibited that strut width, shape of the mesh cell and surface coverage ratio had an impact on the compression force of PPDO sliding-lock stents. PPDO sliding-lock stents fabricated with optimized FDM parameters show favorable mechanical performance and meet the requirement of CHD treatment.
Assuntos
Implantes Absorvíveis , Cardiopatias Congênitas , Humanos , Criança , Stents , Fenômenos Mecânicos , PressãoRESUMO
Polymeric carbon nitride (PCN) with vacancies usually exhibits distinguished mass transfer efficiency, outstanding carrier kinetics and excellent photoactivity. Previous studies have revealed the effect of edge vacancies in heptazine units of PCN; however, the roles of central nitrogen vacancies are scarcely investigated. Herein, central nitrogen vacancies polymeric carbon nitride (PCN-NVC) is rationally prepared for photocatalytic H2O2 production with a rate of 25.1 umol/h (λ > 420 nm), which is 3.5 times than that of pristine PCN. Photoelectronic measurements reveal that the central nitrogen vacancies optimize the kinetic process of electron-hole pairs. Density functional theory (DFT) calculations disclose that PCN-NVC displays lower O2 adsorption energy, thereby accelerating the OOH* formation and decreasing the H2O2 generation energy barrier. This work not only provides a strategy for constructing central nitrogen vacancies polymeric carbon nitrogen, but also affords a deep understanding of its roles in photocatalytic H2O2 production.
RESUMO
Photocatalytic water splitting is one of the promising approaches to solving environmental problems and energy crises. However, the sluggish 4e- transfer kinetics in water oxidation half-reaction restricts the 2e- reduction efficiency in photocatalytic water splitting. Herein, cobalt vanadate-decorated polymeric carbon nitride (named CoVO/PCN) was constructed to mediate the carrier kinetic process in a photocatalytic water oxidation reaction (WOR). The photocatalysts were well-characterized by various physicochemical techniques such as XRD, FT-IR, TEM, and XPS. Under UV and visible light irradiation, the O2 evolution rate of optimized 3 wt% CoVO/PCN reached 467 and 200 µmol h-1 g-1, which were about 6.5 and 5.9 times higher than that of PCN, respectively. Electrochemical tests and PL results reveal that the recombination of photogenerated carriers on PCN is effectively suppressed and the kinetics of WOR is significantly enhanced after CoVO introduction. This work highlights key features of the tuning carrier kinetics of PCN using charge-conducting materials, which should be the basis for the further development of photocatalytic O2 reactions.
RESUMO
Structure-guided isolation of a CH2Cl2-soluble fraction of the heartwood of Catalpa bungei "Jinsi" provided two new naphthoquinones, 9-hydroxy-4-oxo-α-lapachone (1) and 6-hydroxy-4-oxo-α-lapachone (2), together with three undescribed ones (3-5) and six known ones (6-11). The structures were elucidated on the basis of spectroscopic methods including electronic circular dichroism calculation. The antiproliferative effects of these isolates were evaluated in human breast adenocarcinoma cells MCF7. (4R)-4,9-dihydroxy-α-lapachone (5) and (4S)-4,9-dihydroxy-α-lapachone (6) exhibited the significant activities with IC50 values of 2.19 and 2.41 µM, respectively. The structure-activity relationship of 1-11 in the antiproliferative assay was then discussed. The most potent 5 and 6 were found to induce cell arrest in G1 phage through DNA damage. The findings provided some valuable insights for the discovery and structural modification of α-lapachone as antiproliferative lead compounds against human breast adenocarcinoma cells.
Assuntos
Adenocarcinoma , Bignoniaceae , Naftoquinonas , Bignoniaceae/química , Dano ao DNA , Humanos , Estrutura Molecular , Naftoquinonas/química , Naftoquinonas/farmacologiaRESUMO
The characterization of geometrically necessary dislocation (GND) is central to understanding the plastic deformation in materials. Currently, fast and accurate determination of GND density via Electron Backscatter Diffraction (EBSD) remains a challenge. Here, a multi-modal deep learning approach is proposed to predict GND density in terms of electron backscatter patterns (EBSPs) and dislocation configurations. The proposed multi-modal architecture consists of two separated convolutional neural network (CNN) processing streams. One CNN stream aims at extracting pattern shifts from EBSPs, and the other CNN stream focuses on learning suitable representations of dislocation configurations. We also introduce a specific data augmentation strategy termed neighboring pairs generating strategy for the GND prediction task. Taking the GND density from dictionary indexing-based analysis as the target property, high accuracy is achieved on several aluminum samples. Also, our networks are robust to various forms of noise, and the prediction speed is as fast as modern EBSD scanning rates, enabling real-time GND density analysis possible.
RESUMO
OBJECTIVE: To compare the analgesic effect of Jin Ling Zi Powder (JLZ) and its two single herbs. METHODS: The hot plate method was used to induce pain. Totally 36 mice were randomly divided into 6 groups by a complete random design, including control, model, aspirin (ASP, 0.14 g/kg body weight), JLZ (14 g/kg body weight), Corydalis yanhusuo (YHS, 14 g/kg body weight), and Toosendan Fructus (TF, 14 g/kg body weight) groups, 6 mice in each group. The mice in the control and model groups were given the same volume of saline, daily for 2 consecutive weeks. At 30, 60, 90, and 120 min after the last administration, the pain threshold of mice in each group was measured, and the improvement rate of pain threshold was calculated. Serum endogenous metabolites were analyzed by gas chromatography-mass spectrometry (GC-MS). RESULTS: There was no statistical difference in pain threshold among groups before administration (P>0.05). After 2 weeks of administration, compared with the model group, the pain threshold in JLZ, YHS, TF and ASP groups were increased to varying degrees (P<0.05). JLZ had the best analgesic effect and was superior to YHS and TF groups. A total of 14 potential biomarkers were screened in serum data analysis and potential biomarkers levels were all reversed to different degrees after the treatment with JLZ and its single herbs. These potential biomarkers were mainly related to glyoxylate and dicarboxylate metabolism, glycine, serine and threonine metabolism, valine, leucine and isoleucine biosynthesis, aminoacyl-tRNA biosynthesis and inositol phosphate metabolism. CONCLUSIONS: The analgesic mechanism of JLZ and YHS was mainly due to the combination of glycine and its receptor, producing post-synaptic potential, reducing the excitability of neurons, and weakening the afferent effect of painful information.
Assuntos
Medicamentos de Ervas Chinesas , Isoleucina , Animais , Camundongos , Analgésicos/farmacologia , Analgésicos/uso terapêutico , Aspirina/farmacologia , Biomarcadores , Peso Corporal , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico , Glicina , Glioxilatos , Fosfatos de Inositol , Leucina , Metabolômica/métodos , Pós , RNA de Transferência , Serina , Treonina , ValinaRESUMO
BACKGROUND: : Coronavirus disease 2019 (COVID-19) is an emerging and rapidly evolving disease, with no recommended effective anti-coronavirus treatments. Traditional Chinese Medicine (TCM) has been widely used to treat COVID-19 in China, and the most used one is Lianhuaqingwen (LH). This study aimed to assess the efficacy and safety of LH combined with usual treatment vs usual treatment alone in treating mild or moderate COVID-19 by a meta-analysis of randomized controlled trials (RCTs). METHODS AND ANALYSIS: : We systematically searched the Medline (OVID), Embase, the Cochrane Library, and 4 Chinese databases from inception to July 2020 to include the RCTs that evaluated the efficacy and safety of LH in combination with usual treatment vs usual treatment for mild or moderate COVID-19. A meta-analysis was performed to calculate the risk ratio (RR) and 95% confidence interval (CI) for binary outcomes and mean difference (MD) for continuous outcomes. RESULTS: : A total of 5 RCTs with 824 individuals with mild or moderate COVID 19 were included. Compared with the usual treatment alone, LH in combination with usual treatment significantly improved the overall clinical efficacy (RRâ=â2.39, 95% CI 1.61-3.55), increased the rate of recovery of chest computed tomographic manifestations (RRâ=â1.80, 95% CI 1.08-3.01), reduced the rate of conversion to severe cases (RRâ=â0.47, 95% CI 0.29-0.74), shorten the duration of fever (MDâ=â-1.00, 95% CI -1.17 to -0.84). Moreover, LH in combination with usual treatment did not increase the occurrence of the adverse event compared to usual treatment alone. CONCLUSION: : Our meta-analysis of RCTs indicated that LH in combination with usual treatment may improve the clinical efficacy in patients with mild or moderate COVID-19 without increasing adverse events. However, given the limitations and poor quality of included trials in this study, further large-sample RCTs or high-quality real-world studies are needed to confirm our conclusions.
Assuntos
Antivirais/administração & dosagem , COVID-19/terapia , Medicamentos de Ervas Chinesas/administração & dosagem , Oxigênio/administração & dosagem , Antivirais/efeitos adversos , COVID-19/diagnóstico , COVID-19/virologia , China , Terapia Combinada/efeitos adversos , Terapia Combinada/métodos , Medicamentos de Ervas Chinesas/efeitos adversos , Humanos , Pulmão/diagnóstico por imagem , Apoio Nutricional , Oxigênio/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , SARS-CoV-2/isolamento & purificação , Índice de Gravidade de Doença , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
Yi Guanjian (YGJ), one of the Chinese herbal medicines most commonly used in western countries, reported to possess significant anti-inflammatary effects that inhibit the process of inflammation. However, the mechanisms underlying its anti-inflammation effects remain largely unresolved. This study was aimed to investigate the anti-inflammatory activity of YGJ and to explore its potential anti-inflammatory mechanisms by serum metabonomics approach. An xylene-induced mouse right-ear-edema model was used as an inflammatory response in vivo model. Ear edema, prostaglandin E2 (PGE2) and Tumor-Necrosis-Factor-alpha (TNF-α) were detected. Then, serum metabolic profiling was analyzed and pathway analysis performed on the biomarkers reversed after YGJ administration and further integration of metabolic networks. The results showed that YGJ alleviated ear edema and decreased serum PGE2 and TNF-α levels. Fourteen biomarkers were screened, and the levels were all reversed to different degrees after YGJ administration. These biomarkers were mainly related to linoleic acid metabolism, taurine and hypotaurine metabolism, glyoxylate and dicarboxylate metabolism, glycine, serine and threonine metabolism and citrate cycle (TCA cycle). In metabolic networks, glycine and pyruvate were node molecules. This indicated that YGJ could significantly inhibit inflammatory response triggered by acute local stimulation and exerted anti-inflammatory activity mainly by regulating node molecules.