Excessive amounts of fluoride in drinking groundwater are harmful to human health, but the mechanisms responsible for fluoride enrichment in groundwater are not fully understood. Samples from two ...neighboring areas with endemic fluorosis were collected to test the hypothesis that there are distinctly different mechanisms responsible for the enrichment of fluoride in these groundwater. Hydrochemistry, stable isotopes and geochemical simulation were conducted together to investigate the fluoride spatial distribution and the diversity of responsible mechanisms. Our results showed that the spatial distributions of fluoride are different: I) high F in fresh shallow groundwater (SGQJ) and II) medium F in fresh to brackish deep groundwater (DGQJ) in the Qiji area; and III) medium F in brackish shallow groundwater (SGYH) and IV) low F in fresh deep groundwater (DGYH) in the Yanhu area. We also found that the fluoride concentration in groundwater is primarily controlled by the dissolution equilibrium of fluorite, as suggested by the correlation between F and Ca. However, there are other significant mechanisms: 1) for SGQJ, fluoride-bearing minerals (such as fluorite) dissolution, along with moderate evaporation, cation exchange and the more alkaline conditions are the driving factors; 2) for SGYH, the contributing factors are strong evaporation, the salt effect, dissolution of evaporites, gypsum and dolomite, bicarbonate-fluoride competition and anthropogenic activity; 3) for DGQJ, cation exchange, alkaline conditions and competitive adsorption are major factors; and 4) dolomite dissolution promotes the F increase in DGYH. Our findings suggest that the hydrogeochemical conditions play key roles in the enrichment of fluoride and that caution should be taken in the future when evaluating fluoride occurrence in groundwater, even in nearby areas.
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•Groundwater samples were from two neighboring typical fluorosis areas.•Significant difference of occurrences patterns of fluoride exist in aquifers in the two neighboring sties.•Mechanisms diversity in controlling fluoride concentration were interpreted.•Cautions should be taken when evaluating fluoride occurrence in groundwater, even in neighboring sites.
Significant differences in the spatial distributions of fluoride exist in the shallow and deep aquifers in two neighboring sites, and diverse mechanisms are responsible.
Tumor cells reside in a highly complex and heterogeneous tumor microenvironment (TME), which is composed of a myriad of genetically stable non-cancer cells, including fibroblasts, immune cells, ...endothelial cells, and epithelial cells, and a tumor-specific extracellular matrix (ECM). Cancer-associated fibroblasts (CAFs), as an abundant and active stromal cell population in the TME, function as the signaling center and remodeling machine to aid the creation of a desmoplastic tumor niche. Although there is no denial that the TME and CAFs may have anti-tumor effects as well, a great deal of findings reported in recent years have convincingly revealed the tumor-promoting effects of CAFs and CAF-derived ECM proteins, enzymes, chemical factors and other downstream effectors. While there is growing enthusiasm for the development of CAF-targeting therapies, a better understanding of the complexities of CAF-ECM and CAF-cancer cell interactions is necessary before novel therapeutic strategies targeting the malignant tumor "soil" can be successfully implemented in the clinic.
This paper provides a promising strategy for the high yield production of FAL from the CTH of FF with UiO-66.
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•97 % of FAL yield was obtained from the CTH of FF on UiO-66 in the IPA ...system.•Lewis-acid and structural properties of MOFs are essential to the high yield of FAL.•UiO-66 shows good recyclability and easy regeneration for producing FAL from FF.•UiO-66 has a universal activity in the CTH of different aldehydes to alcohols in IPA.•This CTH system open a promising route for yielding FAL from FF in large-scale.
In this paper, the as-prepared metal-organic frameworks material UiO-66 and other Zr-MOFs were directly used as catalytic transfer hydrogenation (CTH) catalysts to catalyze furfural (FF) to furfuryl alcohol (FAL) with 2-propanol (IPA) acted as both solvent and hydrogen donor. The results showed that the as-prepared UiO-66 had satisfactory catalytic activity and selectivity in yielding FAL (97 %) from the CTH of FF at 140 °C within 5 h. Moreover, the as-prepared UiO-66 exhibited relatively stable catalytic activity over five cycles and easy regeneration. Interestingly, UiO-66 was also applicable for the CTH of the other aldehydes such as 5-hydroxymethyfurfural, 5-methylfurfural, 4-methoxybenzaldehyde, and n-hexanal to the corresponding alcohols, affording high product yields up to 98 %. This work provides a green, simple and sustainable process for the catalytic production of FAL from biomass-based furfural, which has certain significance for the sustainable utilization of biomass.
The development of blood-based biomarkers of Alzheimer’s disease (AD) pathology as tools for screening the general population, and as the first step in a multistep process to determine which ...non-demented individuals are at greatest risk of developing AD dementia, is essential. Proteins that are reflective of AD pathology, such as amyloid beta 42 (Aβ
42
), tau proteins total tau (T-tau) and phosphorylated tau (P-tau), and neurofilament light chain (NfL), are detectable in the blood. However, a major challenge in measuring these blood-based proteins is that their concentrations are much lower in plasma or serum than in the cerebrospinal fluid. Single molecule array (SiMoA) is an ultrasensitive technology that can detect proteins in blood at sub-femtomolar concentrations (i.e., 10
−16
M). In this review, we focus on the utility of SiMoA assays for the measurement of plasma or serum Aβ
42
, P-tau, T-tau, and NfL levels and discuss future directions.
Head and neck squamous cell carcinomas (HNSCCs) are often aggressive, making advanced disease very difficult to treat using contemporary modalities, such as surgery, radiation therapy, and ...chemotherapy. However, targeted therapy, e.g., cetuximab, an epidermal growth factor receptor inhibitor, has demonstrated survival benefit in HNSCC patients with locoregional failure or distant metastasis. Molecular imaging aims at various biomarkers used in targeted therapy, and nuclear medicine-based molecular imaging is a real-time and non-invasive modality with the potential to identify tumor in an earlier and more treatable stage, before anatomic-based imaging reveals diseases. The objective of this comprehensive review is to summarize recent advances in nuclear medicine-based molecular imaging for HNSCC focusing on several commonly radiolabeled biomarkers. The preclinical and clinical applications of these candidate imaging strategies are divided into three categories: those targeting tumor cells, tumor microenvironment, and tumor angiogenesis. This review endeavors to expand the knowledge of molecular biology of HNSCC and help realizing diagnostic potential of molecular imaging in clinical nuclear medicine.
Students' math motivation can predict engagement, achievement, and career interest in science, technology, engineering, and mathematics (STEM). However, it is not well understood how personality ...traits and math anxiety may be linked to different types or qualities of math motivation, particularly during high-stress times such as the COVID-19 pandemic. In this study, we examined how fearful or avoidant temperaments contribute to math anxiety and math motivations for college students during the COVID-19 pandemic. Ninety-six undergraduate students from a large public university were assessed on temperamental fear, math anxiety, and math motivation in an online math course. Results showed that higher levels of temperamental fear are directly linked to higher levels of math anxiety. In addition, temperamental fear is indirectly linked to higher levels of autonomous motivation (i.e., intrinsic motivation and identified regulation) and lower levels of controlled motivation (i.e., external regulation) through math anxiety. Results have implications for helping students at high risk for both high math anxiety and for low motivation to engage in math learning.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
, one species of
spp., has the greatest impact on human health and is the main cause of bacterial sexually transmitted diseases and preventable blindness among all
spp. species. The obligate ...intracellular parasitism and unique biphasic developmental cycle of
are the main barriers for the development of tools of genetic manipulation. The past decade has witnessed significant gains in genetic manipulation of
, including chemical mutagenesis, group II intron-based targeted gene knockout, fluorescence-reported allelic exchange mutagenesis (FRAEM), CRISPR interference (CRISPRi) and the recently developed transposon mutagenesis. In this review, we discuss the current status of genetic manipulations of
and highlights new challenges in the nascent field of
genetics.
The role of cellular senescence in age-related diseases has been fully recognized. In various age-related-chronic lung diseases, the function of alveolar epithelial cells (AECs) is impaired and ...alveolar regeneration disorders, especially in bronchopulmonary dysplasia，pulmonary fibrosis (PF), chronic obstructive pulmonary disease (COPD), cancer, etc. Except for age-related-chronic lung diseases, an increasing number of studies are exploring the role of cellular senescence in developmental chronic lung diseases, which typically originate in childhood and even in the neonatal period. This review provides an overview of cellular senescence and lung diseases from newborns to the elderly, attempting to draw attention to the relationship between cellular senescence and developmental lung diseases.
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•Cellular senescence occurs from embryonic development to tissue aging.•Senescent cells exhibit four interdependent hallmarks: permanent cell cycle arrest, macromolecular damage, SASP, and deregulated metabolism.•The senescence of type II cells in the lung is a prophase of most pathologies.•Senolytics and Senomorphics are currently important applications in senescence-associated lung diseases.
Doxorubicin (DOX) is a popular and potent anticancer drug, but its cardiotoxicity limits its clinical application. Shikonin has a wide range of biological functions, including antioxidant and ...anti-inflammatory effects. The aim of this study was to investigate the effects of shikonin on DOX-induced cardiac injury and to identify the underlying mechanisms. Mice receiving shikonin showed reduced cardiac injury response and enhanced cardiac function after DOX administration. Shikonin significantly attenuated DOX-induced oxidative damage, inflammation accumulation and cardiomyocyte apoptosis. Shikonin protects against DOX-induced cardiac injury by inhibiting Mammalian sterile 20-like kinase 1 (Mst1) and oxidative stress and activating the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. In conclusion, shikonin alleviates DOX-induced cardiotoxicity by inhibiting Mst1 and activating Nrf2. Shikonin may be used to treat DOX-induced cardiac injury.
Amino acid metabolism has been implicated in tumorigenesis and tumor progression. Alterations in intracellular and extracellular metabolites associated with metabolic reprogramming in cancer have ...profound effects on gene expression, cell differentiation, and tumor immune microenvironment. However, the prognostic significance of amino acid metabolism in head and neck cancer remains to be further investigated. In this study, we identified 98 differentially expressed genes related to amino acid metabolism in head and neck cancer in The Cancer Genome Atlas. Using batch univariate Cox regression and Lasso regression, we extracted nine amino acid metabolism-related genes. Based on that, we developed the amino acid metabolism index. The prognostic value of this index was validated in two Gene Expression Omnibus cohorts. The results show that this model can help predict tumor recurrence and prognosis. The infiltration of immune cells in the tumor microenvironment was analyzed, and it was discovered that the high index is associated with an immunosuppressive microenvironment. In addition, this study demonstrated the impact of the amino acid metabolism index on clinical indicators, survival of patients with head and neck cancer, and the prediction of treatment response to immune checkpoint inhibitors. We conducted several cell experiments and demonstrated that epigenetic drugs could affect the index and enhance tumor immunity. In conclusion, our study demonstrates that the index not only has important prognostic value in head and neck cancer patients but also facilitates patient stratification for immunotherapy.
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