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61.
Fe(Ш)-doped graphitic carbon nitride (Fe(Ш)-CN) photocatalysts with various Fe(Ш) ions content were prepared via ultrasonic method. Detailed physical characterization indicated that Fe(Ш) ions had been successfully doped into the frame of g-C3N4. The photocatalytic activities were investigated, and methyl orange (MO) and tetracycline hydrochloride (TC) were used as the targeted pollutants. The as-prepared Fe(Ш)-CN materials exhibited higher photocatalytic activities than those of the pure g-C3N4. Specifically, the degradation rate of 2Fe(Ш)-CN under visible light was 2.06 times higher for MO and 2.65 times higher for TC than that of g-C3N4. The increased photocatalytic activities of Fe(Ш)-CN were mainly attributed to the enhanced light absorption ability and the rapid separation of photogenerated carriers. Moreover, the importance of active species during the reaction process was also explored, and the results indicated that •O2 is the main active species.  相似文献   
62.
This research aims to develop new high-energy dense ordinary- and nano-energetic composites based on hydrazine 3-nitro-1,2,4-triazol-5-one (HNTO) and nitrated cellulose and nanostructured nitrocellulose (NC and NMCC). The elaborated energetic formulations (HNTO/NC and HNTO/NMCC) were fully characterized in terms of their chemical compatibility, morphology, thermal stability, and energetic performance. The experimental findings implied that the designed HNTO/NC and HNTO/NMCC formulations have good compatibilities with attractive characteristics such as density greater than 1.780 g/cm3 and impact sensitivity around 6 J. Furthermore, theoretical performance calculations (EXPLO5 V6.04) displayed that the optimal composition of the as-prepared energetic composites yielded excellent specific impulses and detonation velocities, which increased from 205.7 s and 7908 m/s for HNTO/NC to 209.6 s and 8064 m/s for HNTO/NMCC. Moreover, deep insight on the multi-step kinetic behaviors of the as-prepared formulations was provided based on the measured DSC data combined with isoconversional kinetic methods. It is revealed that both energetic composites undergo three consecutive exothermic events with satisfactory activation energies in the range of 139–166 kJ/mol for HNTO/NC and 119–134 kJ/mol for HNTO/NMCC. Overall, this research displayed that the new developed nanoenergetic composite based on nitrated cellulose nanostructure could serve as a promising candidate for practical applications in solid rocket propellants and composite explosives.  相似文献   
63.
Molybdenum cofactor (Moco) deficiency (MoCD) is characterized by neonatal-onset myoclonic epileptic encephalopathy and dystonia with cerebral MRI changes similar to hypoxic–ischemic lesions. The molecular cause of the disease is the loss of sulfite oxidase (SOX) activity, one of four Moco-dependent enzymes in men. Accumulating toxic sulfite causes a secondary increase of metabolites such as S-sulfocysteine and thiosulfate as well as a decrease in cysteine and its oxidized form, cystine. Moco is synthesized by a three-step biosynthetic pathway that involves the gene products of MOCS1, MOCS2, MOCS3, and GPHN. Depending on which synthetic step is impaired, MoCD is classified as type A, B, or C. This distinction is relevant for patient management because the metabolic block in MoCD type A can be circumvented by administering cyclic pyranopterin monophosphate (cPMP). Substitution therapy with cPMP is highly effective in reducing sulfite toxicity and restoring biochemical homeostasis, while the clinical outcome critically depends on the degree of brain injury prior to the start of treatment. In the absence of a specific treatment for MoCD type B/C and SOX deficiency, we summarize recent progress in our understanding of the underlying metabolic changes in cysteine homeostasis and propose novel therapeutic interventions to circumvent those pathological changes.  相似文献   
64.
A different type of MnO2-induced oxidative cyclization of dihydrotriazines has been developed. These dihydrotriazines are considered as a “formal” Schiff’s base. This method provided easy access to naphthofuro-fused triazine via the C-C/C-O oxidative coupling reaction. The reaction sequence comprised the nucleophilic addition of 2-naphthol or phenol to 1,2,4-triazine, followed by oxidative cyclization. The scope and limitations of this novel coupling reaction have been investigated. Further application of the synthesized compound has been demonstrated by synthesizing carbazole-substituted benzofuro-fused triazines. The scalability of the reaction was demonstrated at a 40 mmol load. The mechanistic study strongly suggests that this reaction proceeds through the formation of an O-coordinated manganese complex.  相似文献   
65.
Metastasis is an important cause of cancer-related death. Previous studies in our laboratory found that pregnane alkaloids from Pachysandra terminalis had antimetastatic activity against breast cancer cells. In the current study, we demonstrated that treatment with one of the alkaloid derivatives, (Z)-3β-ethylamino-pregn-17(20)-en (1), led to the downregulation of the HIF-1α/VEGF/VEGFR2 pathway, suppressed the phosphorylation of downstream molecules Akt, mTOR, FAK, and inhibited breast cancer metastasis and angiogenesis both in vitro and in vivo. Furthermore, the antimetastasis and antiangiogenesis effects of 1 treatment (40 mg/kg) were more effective than that of Sorafenib (50 mg/kg). Surface plasmon resonance (SPR) analysis was performed and the result suggested that HSP90α was a direct target of 1. Taken together, our results suggested that compound 1 might represent a candidate antitumor agent for metastatic breast cancer.  相似文献   
66.
To reveal the nature of CO2 reduction to formate with high efficiency by in situ hydrogen produced from hydrothermal reactions with iron, DFT calculations were used. A reaction pathway was proposed in which the formate was produced through the key intermediate species, namely iron hydride, produced in situ in the process of hydrogen gas production. In the in situ hydrogenation of CO2, the charge of H in the iron hydride was −0.135, and the Fe–H bond distance was approximately 1.537 Å. A C-H bond was formed as a transition state during the attack of Hδ− on Cδ+. Finally, a HCOO species was formed. The distance of the C-H bond was 1.107 Å. The calculated free energy barrier was 16.43 kcal/mol. This study may provide new insight into CO2 reduction to formate in hydrothermal reactions with metal.  相似文献   
67.
68.
A robust metal- and solvent-free cascade radical-induced C-N cleavage/intramolecular 6-endo-dig annulation/hydrocarbonylation for the synthesis of the valuable 2-aryl-4H-chromen-4-ones is described. This practical synthesis strategy utilizes propargylamines and air as the oxygen source and green carbonylation reagent, in which propargylamines are activated by the inexpensive and available dimethyl 2,2′-azobis(2-methylpropionate) (AIBME) and (PhSe)2 as the radical initiators. This simple and green protocol features wide substrate adaptability, good functional group tolerance, and amenability to scaling up and derivatizations.  相似文献   
69.
70.
The liver is a crucial organ among body organs due to its wide functions, in particular, detoxification and metabolism. Exposure to detrimental chemicals or viral infections may provoke liver dysfunction and ultimately induce liver tissue damage. Finding natural substances for liver disease treatment to overcome the conventional treatments’ side effects has attracted the attention of researchers worldwide. Our current work was conducted to investigate the hepato-therapeutic activities of essential oil (EO) isolated from Tagetes patula flowers. EO was extracted using the hydro-distillation (HD) technique and its chemical composition was identified by GC/MS. Then, the hepatic treatment potential of extracted EO was evaluated in vivo against CCL4 in rats. HD of T. patula flowers yielded highly chemical constituents of EO along with significant antioxidant potential. A coherent molecular network was fashioned via the Global Natural Products Social Molecular Networking (GNPS) to visualize the essential components and revealed that the sesquiterpene (E)-β-caryophyllene was the most predominant volatile constituent which accounted for 24.1%. The treatment of CCL4 led to significant induced oxidative stress markers malonaldehyde, total protein, and non-protein sulfhydryl, as well as elevated serum aminotransferase, gamma-glutamyl transferase, alkaline phosphatase, and bilirubin. In addition, it disrupted the level of lipid profile. The post-treatment using T. patula EO succeeded in relieving all toxic effects of CCl4 and recuperating the histopathological signs induced by CCL4. Silymarin was used as a standard hepatoprotective agent. The obtained results demonstrated that the extracted EO exerted high protective activities against the toxicity of CCL4. Moreover, the T. patula flowers EO can be used as a natural remedy to relieve many contemporary liver diseases related to oxidative stress.  相似文献   
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