Prenatal Silicon Dioxide Nanoparticles Exposure Reduces Female Offspring Fertility Without Affecting Males.

Silicon dioxide nanoparticles (SiO NPs) are widely utilized in biomedicine due to their controllable size and biocompatibility. While previous studies have demonstrated that prenatal exposure to SiO NPs can traverse the placental barrier and induce neurotoxicity in offspring. However, their reproductive toxicity remains unclear.

Assessment and analysis of the balance between economic development and ecological environment protection and its implementation strategy derived from spatial planning-Take three heterogeneous and representative provinces in China as an example.

Balancing ecological environment protection (EEP) and economic development (ED) (balance for short) is a difficult problem that must be solved in the development of modern society, particularly important for realizing UN Sustainable Development Goals. How to assess the regional balance situation and reveal the spatial and temporal heterogeneous characteristics of the balance (especially for the vast China) and its influencing factors are the primary scientific problems and realistic needs. Taking Zhejiang, Hunan and Gansu Provinces in the eastern, central and western region of China as a regional representative, an index system characterizing EEP and ED were established, which were processed by extreme difference method and entropy weight method.

Electrophilic Selenium Catalysis with Electrophilic N-F Reagents as the Oxidants.

A suitable oxidative system is crucial to electrophilic selenium catalysis (ESC). This short review offers the overview of recent development in ESC with electrophilic N-F reagents as the oxidants. Several highly selective transformations of alkenes such as allylic or vinylic imidation, pyridination, -dichlorination, oxidative cyclization and asymmetric cyclization have been described.

Organoselenium-Catalyzed Regioselective C-H Pyridination of 1,3-Dienes and Alkenes.

An efficient approach for organoselenium-catalyzed regioselective C-H pyridination of 1,3-dienes to form pyridinium salts has been developed. This method was also successfully applied to direct C-H pyridination of alkenes. Fluoropyridinium reagents, or initially loaded pyridine derivatives, acted as pyridine sources in the pyridination reactions.

Organoselenium-Catalyzed Synthesis of Oxygen- and Nitrogen-Containing Heterocycles.

A new and efficient approach for the synthesis of oxygen and nitrogen heterocycles by organoselenium catalysis has been developed. The exo-cyclization proceeded smoothly under mild conditions with good functional group tolerance and excellent regioselectivity. Mechanistic studies revealed that 1-fluoropyridinium triflate is key for oxidative cyclization.