RESUMEN
Selective activation of C-H bonds in light alkanes under mild conditions is challenging but holds the promise of efficient upgrading of abundant hydrocarbons. In this work, we report the conversion of propane to propylene with â¼95% selectivity on Cu(I)-ZSM-5 with O2 at room temperature and pressure. The intraporous Cu(I) species was oxidized to Cu(II) during the reaction but could be regenerated with H2 at 220 °C. Diffuse reflectance ultraviolet spectroscopy indicated the presence of both Cu+-O2 and Cu2(µ-O2)2+ species in the zeolite pores during the reaction, and electron paramagnetic resonance results showed that propane activation occurred via a radical-mediated pathway distinct from that with H2O2 as the oxidant. Correlation between spectroscopic and reactivity results on Cu(I)-ZSM-5 with different Cu loadings suggests that the isolated intraporous Cu(I) species is the main active species in propane activation.
RESUMEN
Precise regulation of the active site structure is an important means to enhance the activity and selectivity of catalysts in CO2 electroreduction. Here, we creatively introduce anionic groups, which can not only stabilize metal sites with strong coordination ability but also have rich interactions with protons at active sites to modify the electronic structure and proton transfer process of catalysts. This strategy helps to convert CO2 into fuel chemicals at low overpotentials. As a typical example, a composite catalyst, CuO/Cu-NSO4/CN, with highly dispersed Cu(II)-SO4 sites has been reported, in which CO2 electroreduction to formate occurs at a low overpotential with a high Faradaic efficiency (-0.5â V vs. RHE, FEformate=87.4 %). Pure HCOOH is produced with an energy conversion efficiency of 44.3 % at a cell voltage of 2.8â V. Theoretical modeling demonstrates that sulfate promotes CO2 transformation into a carboxyl intermediate followed by HCOOH generation, whose mechanism is significantly different from that of the traditional process via a formate intermediate for HCOOH production.
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BACKGROUND: Heat shock protein family A member 9 (HSPA9) prevents unfolded and dysfunctional protein accumulation, with genetic variants known to be pathogenic. Here, we determined the genetic cause of Even-Plus syndrome (OMIM: 616854) in a Chinese family. METHODS: We collected samples from two affected and two normal individuals. Whole-exome sequencing was performed to identify their genetic profiles. Potential variants were validated using Sanger sequencing. Assisted reproduction with mutation-free embryos successfully blocked the transmission of mutations. RESULTS: We identified novel inherited pathogenic complex heterozygous variations in the HSPA9 gene in the two affected fetuses. Three-dimensional spatial simulation of the HSPA9 protein after prediction of the mutated RNA splicing pattern abolished part of the substrate-binding domain of the protein. According to ACMG guidelines, c. 1822-1G>A and c. 1411-3T>G were classified as pathogenic and likely pathogenic, respectively. Mutation-free embryos were selected for transplantation and reconfirmed to possess no mutations. A healthy daughter was successfully born into the family. CONCLUSIONS: This study is the first to report complex heterozygous variations in the HSPA9 gene that influence alternative splicing in early pregnancy. Our findings expand on the mutational spectrum leading to Even-Plus syndrome and provide a basis for genetic counseling and future embryonic studies.
Asunto(s)
Diagnóstico Preimplantación , Embarazo , Femenino , Humanos , Linaje , Mutación , Heterocigoto , Empalme del ARN , Proteínas HSP70 de Choque Térmico/genética , Proteínas Mitocondriales/genéticaRESUMEN
Using 70 U/ml or 35 U/ml as CA125 routine abnormal threshold may result in omissions in the relapse detection of Ovarian cancer (OvCa). This study aimed to clarify the association between a biochemical relapse (only the elevation of CA125) and an image-identified relapse to predict the relapsed lesions better. 162 patients who achieved complete clinical response were enrolled from women diagnosed with stage I-IV serous ovarian, tubal, and peritoneal cancers from January 2013 to June 2019 at our center. The CA125 level of 2 × nadir was defined as the indicator of image-identified relapse (P < 0.001). Compared to CA125 level exceeding 35 U/ml, the 2 × nadir of CA125 improve the sensitivity of image-identified relapse (84.9% vs 67.4%, P < 0.001); the 2 × nadir value can act as an earlier warning relapse signal with a longer median time to image-identified relapse (2.7 vs. 0 months, P < 0.001). Of the relapsed population, there was no difference of CA125 changing trend between the neoadjuvant chemotherapy (NACT) and primary debulking surgery (PDS) group after initial treatment. Compared with 35 U/ml, CA125 reaching 2 × nadir during the follow-up process might be a more sensitive and early relapse signal in patients with serous OvCa. This criterion may help guide patients to be recommended for imaging examination to detect potential relapse in time.