Objective: To investigate the effects of estrogen deficiency on depression-like behavior and mitochondrial function in hippocampus，and to study the underlying mechanisms． Methods: The female adult C57BL /6 mice were randomly assigned to Sham group，Ovx group and Ovx + E2 group．On the 7th day after operation，Ovx + E2 group was subcutaneously injected with 17 β-estradiol ( E2 ) for 4 weeks．Then another 48 female adult C57BL /6 mice were randomly divided into Sham group，Sham + MnTBAP group，Ovx group and Ovx + MnTBAP group．After operation for one week，MnTBAP was injected into the hippocampus of mice in Sham + MnTBAP group and Ovx + MnTBAP group．The depression-like behaviors of the mice were monitored by sucrose preference test and forced swimming test．Then the mice were decapitated，and the hippocampus samples were collected．Mitochondria of hippocampus were isolated using mitochondria fractionation kit．The concentrations of adenosine triphosphate (ATP) ， reactive oxygen species ( ROS) and mitochondrial membrane potential were determined，respectively. Results: Compared with Sham mice，Ovx showed a decrease in the percentage of sucrose consumption，an increase in immobility time and the alterations of hippocampal mitochondrial function，which were reversed by estrogen treatment. Intrahippocampal injection of MnTBAP significantly increased the percentage of sucrose consumption and decreased immobility time in Ovx mice． Conclusion Hippocampal mitochondrial dysfunction contributes to estrogen deficiency-induced depression-like behaviors.

Abstract Pancreatic cancer is a highly malignant gastrointestinal cancer with a poor prognosis, and early diagnosis remains challenging. The use of reliable biomarkers can significantly enhance the early evaluation and management of this disease. Circulating tumor cells(CTCs) are released into the bloodstream and can be obtained easily through minimally invasive liquid-based biopsy, making them promising candidates for early tumor diagnosis, prognosis assessment, and monitoring therapeutic responses. This paper reviews the advancements in CTCs detection technology and their clinical applications in pancreatic cancer over the past decade, both domestically and internationally, which offer a new perspective on the early diagnosis and prognosis of pancreatic cancer.