Mechanisms of well iron clogging in groundwater heat pump systems: Insights from video imaging, hydrogeochemical analysis, and geochemical modeling.

Groundwater heat pump (GWHP) systems are increasingly popular as low-carbon and environmentally friendly technologies, but well clogging induced by iron remains a significant issue. This study investigated the clogging characteristics and biogeochemistry of three typical wells (pumping, injection, and observation wells) in an operating GWHP system using video imaging, sampling, and analysis of hydrogeochemical and microbial data. The results revealed that iron-induced well clogging is a complex process involving physical, chemical, and microbial factors. Pumping wells experience clogging due to water mixing with varying redox conditions, resulting in hematite-based iron oxide deposits. Injection wells exhibit higher clogging severity, with transformed oxidation and accumulation of reduced iron minerals at the solid-liquid interface, resulting in darker colored clogs with magnetite. Clogging in both extraction and injection wells is closely related to iron-rich aquifer sections, where severe clogging occurs. Shallow clogging due to iron oxide is limited and attributed to the oxidation of zero-valent iron in well casing material. Iron-oxidizing bacteria and iron-reducing bacteria were detected in the consolidated deposits of clogged wells, indicating their involvement in the clogging formation process. Moreover, a strong correlation was observed between the presence of nitrate-reducing bacteria in the water phase and the severity of clogging, suggesting a possible link between iron oxidation and nitrate reduction in the system. Geochemical modeling results further supported the observed clogging severity in GWHP systems and confirmed varying clogging mechanisms in different wells and depths. These findings contribute to the understanding of clogging in GWHP operations, aiding in robust water utilization and energy-saving efforts, and supporting global carbon reduction initiatives.

The causal effects of genetically determined immune cells on gynecologic malignancies: a Mendelian randomization study.

Background: Evidence from observational studies suggested a connection between immune cells and gynecologic malignancies. To investigate potential causative associations between immunophenotype traits and gynecologic malignancies, we used a two-sample Mendelian randomization analysis. Methods: The genetic instrumental variables of 731 immunophenotypes of peripheral blood were obtained by the GWAS database; the GWAS data of common gynecologic cancers were obtained from FinnGen study. The main statistic method was the inverse-variance weighted method. We also used the weighted mode, weighted median, and MR Egger for evaluations. The MR Steiger directionality test was further used to ascertain the reverse causal relationship between immune cells and gynecologic cancers. Results: We identified 50 highly probable immunophenotypes and 65 possible ones associated with gynecologic malignancies. The majority of the B cell panel was protective factors in cervical cancer. However, there was a correlation found in the B cells panel with a probable factor associated with an elevated risk of endometrial cancer. Immunophenotypes in the monocyte panel were linked to a lower probability of ovarian cancer and vulvar cancer. All of the gynecologic cancers in our study had no statistically significant impact on immune cells, according to reverse MR analysis. Conclusion: Our study firstly emphasized the genetically predicted causality between immune cells and gynecologic malignancies. This knowledge will be critical to formulating the measures to prevent malignancies in female at risk in future clinical practice.

Metformin and survival of women with breast cancer: A meta-analysis of randomized controlled trials.

WHAT IS KNOWN AND OBJECTIVE: Metformin has been suggested to confer anticancer efficacy. However, it remains uncertain whether additional use of metformin could improve survival of women with breast cancer. We performed a meta-analysis of randomized controlled trials (RCTs) to evaluate the influence of metformin on survival outcome in women with breast cancer. METHODS: Relevant RCTs were obtained by search of PubMed, Embase and Cochrane's Library databases from inception to 15 May 2021. A random-effects model incorporating the potential publication bias was used to pool the results. RESULTS AND DISCUSSION: Five phase II RCTs including 396 non-diabetic women with breast cancer were included in the meta-analysis. Pooled results showed that additional use of metformin was not associated with improved progression-free survival (PFS, hazard ratio [HR]: 1.00, 95% confidence interval [CI]: 0.70 to 1.43, p = 0.98; I2  = 32%) or overall survival (OS, HR: 1.00, 95% CI: 0.71 to 1.39, p = 0.98; I2  = 0%). Sensitivity analysis by excluding one study at a time showed consistent results (HR for PFS: 0.91 to 1.14, p all >0.05; HR for OS: 0.88 to 1.21, P all >0.05). WHAT IS NEW AND CONCLUSION: Current evidence from phase II clinical trials does not support that additional use of metformin could improve the survival outcome in women with breast cancer.