Search

Background Postpartum depression (PPD) is one of the most common health problems among postpartum women worldwide, and it is also the most disabling disorder in reproductive period of women, which has a negative impact on the physical and mental health of mothers, infants and their families. Objective To analyze the causes of PPD, validate or revise the previous theoretical hypothesis "self-interpersonal model of PPD from the perspective of role transition", and provide intervention targets for the construction of effective prevention programs. Methods Using the explanatory case study method, based on the previous theoretical hypothesis, 15 women who experienced PPD symptoms and underwent routine postpartum checkups in the postpartum rehabilitation clinic of Obstetrics and Gynaecology Hospital of Fudan University from November 2022 to January 2023 were selected as the cases using the theoretical sampling method and following the "replication logic", who were interviewed by face-to-face, semi-structured in-depth personal interviews. Max QDA 2022 qualitative data analysis software was used to summarize the textual information, analytical method of constructive interpretation was used to analyze the results of each case in comparison to the previous theoretical hypotheses. Results The causes of maternal PPD symptoms in this study did not go beyond the self and interpersonal aspects of the previous theoretical hypotheses and could be further summarized as four types of stressors, including "cannot take care of oneself" "cannot take care of the baby" "cannot manage the relationship with spouse" "cannot manage relationships with significant others". Conclusion The previous theoretical hypothesis of the "self-interpersonal model of PPD from the perspective of role transition" has been validated and concretized, in view of this, the four types of stressors can be used as targets for the development of PPD prevention programs to prevent PPD in the future.

Catalytic conversion of CO2 to CO via the reverse water gas shift (RWGS) reaction has been identified as a promising approach for CO2 utilization and mitigation of CO2 emissions. Bare Pt shows low activity for the RWGS reaction due to its low oxophilicity, with few research works having concentrated on the inverse metal oxide/Pt catalyst for the RWGS reaction. In this work, MnOx was deposited on the Pt surface over a SiO2 support to prepare the MnOx/Pt inverse catalyst via a co-impregnation method. Addition of 0.5 wt% Mn to 1 wt% Pt/SiO2 improved the intrinsic reaction rate and turnover frequency at 400 °C by two and twelve times, respectively. Characterizations indicate that MnOx partially encapsulates the surface of the Pt particles and the coverage increases with increasing Mn content, which resembles the concept of strong metal–support interaction (SMSI). Although the surface accessible Pt sites are reduced, new MnOx/Pt interfacial perimeter sites are created, which provide both hydrogenation and C-O activation functionalities synergistically due to the close proximity between Pt and MnOx at the interface, and therefore improve the activity. Moreover, the stability is also significantly improved due to the coverage of Pt by MnOx. This work demonstrates a simple method to tune the oxide/metal interfacial sites of inverse Pt-based catalyst for the RWGS reaction. [ABSTRACT FROM AUTHOR]

Water is typically treated as an implicit solvent in modeling electrochemical reactions in an aqueous environment. Such treatment may not be adequate, as a series of concerted or sequential proton-electron transfer steps that explicitly involve water molecules are likely to play important roles in a reaction, such as the electrochemical hydrogenation of CO2. Herein, we use the electrochemical hydrogenation of CO2 on the Sn(112) surface as a model, and employ the density functional theory (DFT) method to examine the effect of up to 12 explicit water molecules on the stability of the hydrogenation intermediates. Our results show that six water molecules are needed to account for the local interaction between an intermediate and the water solvent. Furthermore, the hydrogen bonding interaction between the explicit water molecules and intermediates causes a significant stabilization to the O-containing intermediates, such as the HCOO* and CHO* + OH* species. The inclusion of explicit water molecules also altered the prediction of the potential-limiting step from the formation of H* atoms without the explicit water molecules to the formation of H2COO* in the presence of water molecules and increased selectivity towards methane. This work provides useful insights into the electrocatalytic hydrogenation of CO2, emphasizing the importance of including explicit water molecules to account for the hydrogen bonding interaction between solvent water molecules and the reaction intermediates. [ABSTRACT FROM AUTHOR]

A series of rutile TiO2-supported Ni catalysts with varying Ni sizes were prepared and reduced at 650 °C to explore the effect of Ni size on the strong metal–support interactions (SMSI) and its consequences on the hydrodeoxygenation (HDO) of m-cresol at 350 °C and atmospheric pressure. When the Ni size increases from 4 to 29.1 nm, the SMSI becomes stronger, e.g., the thickness of the TiOx overlayer and the coverage extent of TiOx on the Ni particle surface increase. Direct deoxygenation to toluene is the dominant pathway on Ni/TiO2 catalysts with varying Ni loadings, with almost no CH4 being formed. These results indicate that the TiOx overlayer significantly alters the property of Ni. That is, the C-C hydrogenolysis activity on bare Ni is completely inhibited due to SMSI, while the deoxygenation activity is improved at the Ni-TiOx interfacial perimeter sites. Meanwhile, the turnover frequency of HDO on small Ni particles of 4 nm is > 2 times higher than that on large Ni particles of 29.1 nm, indicating that the small Ni particle with moderate SMSI appears to be optimal for the direct deoxygenation of m-cresol to toluene. The results suggest HDO activity may be enhanced by tuning the metal particle size and SMSI degree. [ABSTRACT FROM AUTHOR]