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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.

The direct conversion of methane to methanol has attracted increasing interest due to abundant and low-cost natural gas resources. Herein, by anchoring Cr-oxo/-oxyhydroxides on UiO-66 metal–organic frameworks, we demonstrate that reactive anionic oxyl radicals can be formed by controlling the coordination environment based on the results of density functional theory calculations. The anionic oxyl radicals produced at the completely oxidized CrVI site acted as the active species for facile methane activation. The thermodynamically stable CrVI-oxo/-oxyhydroxides with the anionic oxyl radicals catalyze the activation of the methane C–H bond through a homolytic mechanism. An analysis of the results showed that the catalytic performance of the active oxyl species correlates with the reaction energy of methane activation and H adsorption energies. Following methanol formation, N2O can regenerate the active sites on the most stable CrVI oxyhydroxides, i.e., the Cr(O)4Hf species. The present study demonstrated that the anionic oxyl radicals formed on the anchored CrVI oxyhydroxides by tuning the coordination environment enabled facile methane activation and facilitated methanol production. [ABSTRACT FROM AUTHOR]

Heteroatom (such as Ti, Sn, Zr, and Hf) zeolites that contain Lewis acid site (LAS) centers with tetrahedral coordination confined in micropores with various topologies are able to catalyze reactions distinct from those catalyzed by Brønsted acid sites (BASs). In particular, these LAS centers are able to coordinate with two oxygen atoms of one or two oxygenated molecules on a single LAS simultaneously, which are suitable for the conversion of biomass-derived oxygenates via unique reaction pathways, and have been widely explored in the conversion of biomass-derived oxygenates to value-added products. In this review, methods of conventional hydrothermal synthesis, improved direct synthesis (such as interzeolite transformation and dry gel conversion) and post-synthesis (such as solid-state ion change, structural reconstruction and grafting) are compared. Next, approaches for the qualification and quantification of the location (framework or extra-framework), fine structure (closed or open), and acidity of heteroatom centers are summarized. Thereafter, we present the applications of Lewis acid zeolites in the conversion of platform oxygenates of hexoses, furan derivatives and acid derivatives via reactions of isomerization, Meerwein–Ponndorf–Verley reduction, oxidation, and ketonization. Notably, the integration of multiple steps into a one-pot cascade reaction for the conversion of oxygenates (for example, glucose to 5-hydroxymethylfurfural and furfural to γ-valerolactone) mediated by the synergy of LASs and BASs or metal sites is also discussed. Finally, the opportunities and challenges in the low-cost synthesis and large-scale application of Lewis acid zeolites for the green and sustainable synthesis of chemicals are proposed. [ABSTRACT FROM AUTHOR]

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]

Understanding structural transformation and phase transition accompanying reactions in a solid as a catalyst or oxygen carrier is important to the design and optimization of many catalytic or chemical looping reaction processes. Herein, we combined density functional theory calculation with the stochastic surface walking global optimization approach to track the structural transformation accompanying the reduction of CuO upon releasing oxygen. We then used machine learning (ML) methods to correlate the structural properties of CuOx with varying x. By decomposing a reduction step into oxygen detachment and structural reconstruction, we identified two types of pathways: (1) uniform reduction with minimal structural changes; (2) segregated reduction with significant reconstruction. The results of ML analysis showed that the most important feature is the radial distribution functions of Cu–O at a percentage of oxygen vacancy [C(OV)] < 50% and Cu–Cu at C(OV) > 50% for CuOx formation. These features reflect the underlying physicochemical origin, i.e., Cu–O breaking and Cu–Cu formation in the respective stage of reduction. Phase diagram analysis indicates that CuO will be reduced to Cu2O under a typical oxygen uncoupling condition. This work demonstrates the complexity of solid structural transformation and the potential of ML methods in studying solid state materials involved in many chemical processes. [ABSTRACT FROM AUTHOR]

Catalytic direct deoxygenation (DDO) of phenolic compounds to aromatics is an appealing approach for utilization of biomass‐lignin with minimal amount of H2 consumption. Metal/reducible metal oxide catalysts provide two functionalities, i. e., C−H bond formation (hydrogenation) and C−O bond breakage (deoxygenation), required for this reaction that takes place at the interfacial perimeter sites. Strong metal‐support interactions (SMSI) can profoundly alter the density and property of such sites. This short review summarized recent advances in tuning SMSI for enhancing DDO of phenolics. The approaches of varying reduction temperature, modulation of crystal facets and crystal phases of metal oxide, and reduction of mixed metal oxide were discussed for the origin for formation of SMSI, the degree of SMSI, and its consequence on the DDO performance. The analysis revealed that intermediate degree of SMSI with maximal density of metal/oxide interfacial perimeter site enhances DDO while minimizing unfavorable side reactions. This short review highlights the concept of tuning the interfacial perimeter sites via SMSI for reactions which require multiple functionalities and take place at the metal/oxide interface. [ABSTRACT FROM AUTHOR]