Gut microbiota-astrocyte axis: new insights into age-related cognitive decline

With the rapidly aging human population,age-related cognitive decline and dementia are becoming increasingly prevalent worldwide.Aging is considered the main risk factor for cognitive decline and acts through alterations in the composition of the gut microbiota,microbial metabolites,and the functions of astrocytes.The microbiota–gut–brain axis has been the focus of multiple studies and is closely associated with cognitive function.This article provides a comprehensive review of the specific changes that occur in the composition of the gut microbiota and microbial metabolites in older individuals and discusses how the aging of astrocytes and reactive astrocytosis are closely related to age-related cognitive decline and neurodegenerative diseases.This article also summarizes the gut microbiota components that affect astrocyte function,mainly through the vagus nerve,immune responses,circadian rhythms,and microbial metabolites.Finally,this article summarizes the mechanism by which the gut microbiota–astrocyte axis plays a role in Alzheimer’s and Parkinson’s diseases.Our findings have revealed the critical role of the microbiota–astrocyte axis in age-related cognitive decline,aiding in a deeper understanding of potential gut microbiome-based adjuvant therapy strategies for this condition.

TLR2 was overexpressed independent of IL-6 in patients with valvular atrial fibrillation

Toll-like receptor 2 （TLR2） has recently been shown to be up-regulated in patients with non-valvular atrial fi-brillation （AF）. The present study was aimed to determine whether the pathogenesis and development of AF is associated with the up-regulation of TLR2. Clinical data and right atrial appendage （RAA） specimens were col-lected from 20 patients with persisten AF （PeAF）, 15 patients with paroxysmal AF （PaAF） and 13 patients with no history of AF undergoing valvular replacement. The results showed that gene expression and protein content of TLR2 were increased in both the AF subgroups, compared with the sinus rhythm （SR） group. Between the two AF subgroups, PaAF had a higher TLR2 level than PeAF. However, no difference in interluekin （IL）-6 content was found among the three groups, and no correlation was found between TLR2 and IL-6 in PeAF patients （r = 0.090, P = 0.706）, PaAF patients （r = 0.408, P = 0.131） and AF patients （r = -0.301, P = 0.079）. Immunohistochemical analysis revealed that TLR2 was distributed in RAAs of AF patients and confirmed the immunoblotting results. In conclusion, we demonstrated that TLR2 was elevated in AF （especially PaAF） patients with valvular heart disease, further implicating inflammation involved in the pathogenesis and development of AF.

Familial cardiac myxoma with multifocal recurrences:a case report and review of the literature

We report a case of myxoma with multiple recurrences in both the atrium and ventricle in a 26-year-old woman five years after the surgical removal of left atrial myxoma, Her 52-year-old mother had a similar medical history. To our knowledge, this was the first familial case who suffered multifocal cardiac myxoma recurrences without any sign of the myxoma complex. Based on our understanding of the mechanism of recurrence, the approaches to prevent the recurrence, and markers to predict recurrence, we propose that multifocal recurrences, as reported herein, may result from a combination of familial predisposition and multifocal onset. The hi-atrial surgical approach and transesophageal echocardiography are preferred for patients with recurrent cardiac myxomas, especially for those with multiple recurrences and familial myxoma. Immunological and genetic screenings may help to identify family members at risk for developing this disease.

Quasi <i>In-Situ</i>Study on Microstructure Evolution of Al 2014 Alloy during Thermal Deformation and Following Solution Treatment

Microstructure evolution of 2014 aluminum alloy was studied by hot compression deformation at 410?C to 470?C and strain rates of 0.07 s?1 to 0.53 s?1, to provide manufacturing references for aluminum plate. The deformation temperature and especially strain rate ranges were chosen very close to the actual processing condition. The results show that the stress-strain curves display a stable flow at the given deformation conditions, corresponding a dominant microstructure evolution behavior of dynamic recovery (DRV) and few dynamic recrystallization (DRX). After solution treated at 502?C for 3 hours, quasi in-situ observation shows that static recrystallization (SRX) develop typical fine grains with several microns at grain boundaries, while static recovery (SRV) dominants the microstructure evolution during the soaking time, leading to a similar microstructure to that of the as-deformed. The average low angle grain boundaries (LAGBs) and high angle grain boundaries (HAGBs) display weak differences between as-deformed and solution treated specimens, which reveals a good thermal stability of microstructure for 2014 alloy. However, the deformation at the lower temperature has an obvious trend to induce SRX during solution soaking.

Predicting geogenic groundwater fluoride contamination throughout China

Endemic fluorosis exists in almost all provinces of China.The long-term ingestion of groundwater containing high concentrations of fluoride is one of the main causes of fluoro-sis.We used artificial neural network to model the relationship between groundwater fluo-ride concentrations from throughout China and environmental variables such as climatic,geological.and soil parameters as proxy predictors.The results show that the accuracy and area under the receiver operating characteristic curve of the model in the test dataset are 80.5%and 0.86%,respectively,and climatic variables are the most effective predictors.Based on the artificial neural network model,a nationwide prediction risk map of fluoride concen-trations exceeding 1.5 mg/L with a 0.5×0.5 arc minutes resolution was generated.The high risk areas are mainly located in western provinces of Xinjiang,Tibet,Qinghai,and Sichuan,and the northern provinces of Inner Mongolia,Hebei and Shandong.The total number of people estimated to be potentially at risk of fluorosis due to the use of untreated high flu-oride groundwater as drinking water is about 89 million,or 6%of the population.The high fluoride groundwater risk map helps the authorities to prioritize areas requiring mitigation measures and thus facilitates the implementation of water improvement and defluorida-tion projects.