Black shale deposition and early diagenetic dolomite cementation during Oceanic Anoxic Event 1: The mid-Cretaceous Maracaibo Platform, northwestern South America

Thin laterally continuous organic-rich dolomitic marlstones were deposited in the extended Late Aptian - Early Albian epicontinental sea of northwestern South America. These intervals are the proximal equivalents of thick hemipelagic black shale-ammonitic floatstone couplets, deposited in the distally stepped, differentially subsiding part of the Maracaibo Platform. The marlstones reflect the dynamic conditions resulting from orbital forcing mechanisms and can be genetically related to (1) minor sea-level changes, (2) proximal turnovers in marine productivity, and (3) sudden climate shifts affecting mid-Cretaceous shoaling upward, shallow marine, carbonate cyclicity. Therefore, the marlstones may well be linked to the multiple environmental perturbations collectively referred to as Oceanic Anoxic Event 1. The interstitial euhedral dolomite has a medium crystallinity, and exhibits unusual textural relations with framboidal pyrite and gypsum. The authigenic mineral assemblage also includes quartz, Ca-F apatite, and barite, which together with the chemical signals of dolomite, point to an unsteady climate regime. Bulk-rock biomarker parameters, rare earth element geochemistry, and iron speciation data point to widespread photic zone anoxia and transient shallow marine euxinia by the time of deposition, with climatic instability driving the delivery of oxidized detritus from the hinterlands. These conditions led to a schizohaline redox stratified environment favorable to dolomite precipitation. In such a depositional setting, the bio-utilization of Fe, Mn, and sulfur for organic matter respiration sustained elevated pore-water alkalinity and pH, and allowed for the pre-compactional growth of interstitial dolomite

Erythrocyte aldose reductase activity and sorbitol levels in diabetic retinopathy

PurposeActivation of polyol pathway due to increased aldose reductase (ALR2) activity has been implicated in the development of diabetic complications including diabetic retinopathy (DR), a leading cause of blindness. However, the relationship between hyperglycemia-induced activation of polyol pathway in retina and DR is still uncertain. We investigated the relationship between ALR2 levels and human DR by measuring ALR2 activity and its product, sorbitol, in erythrocytes.MethodsWe enrolled 362 type 2 diabetic subjects (T2D) with and without DR and 66 normal subjects in this clinical case-control study. Clinical evaluation of DR in T2D patients was done by fundus examination. ALR2 activity and sorbitol levels along with glucose and glycosylated hemoglobin (HbA1C) levels in erythrocytes were determined.ResultsT2D patients with DR showed significantly higher specific activity of ALR2 as compared to T2D patients without DR. Elevated levels of sorbitol in T2D patients with DR, as compared to T2D patients without DR, corroborated the increased ALR2 activity in erythrocytes of DR patients. However, the increased ALR2 activity was not significantly associated with diabetes duration, age, and HbA1C in both the DR group and total T2D subjects.ConclusionsLevels of ALR2 activity as well as sorbitol in erythrocytes may have value as a quantitative trait to be included among other markers to establish a risk profile for development of DR

Inhibition of aldose reductase by dietary antioxidant curcumin: Mechanism of inhibition, specificity and significance

AbstractAccumulation of intracellular sorbitol due to increased aldose reductase (ALR2) activity has been implicated in the development of various secondary complications of diabetes. In this study we show that curcumin inhibits ALR2 with an IC50 of 10μM in a non-competitive manner, but is a poor inhibitor of closely-related members of the aldo-keto reductase superfamily, particularly aldehyde reductase. Results from molecular docking studies are consistent with the pattern of inhibition of ALR2 by curcumin and its specificity. Moreover, curcumin is able to suppress sorbitol accumulation in human erythrocytes under high glucose conditions, demonstrating an in vivo potential of curcumin to prevent sorbitol accumulation. These results suggest that curcumin holds promise as an agent to prevent or treat diabetic complications

Analysis of the diagnostic and economic impact of the combined artificial intelligence algorithm for analysis of 10 pathological findings on chest computed tomography

BACKGROUND: Artificial intelligence technology can help solve the significant problem of missed findings in radiology studies. An important issue is assessing the economic benefits of implementing artificial intelligence. AIM: To evaluate the frequency of missed pathologies detection and the economic potential of artificial intelligence technology for chest computed tomography compared and validated by experienced radiologists. MATERIALS AND METHODS: This was an observational, single-center retrospective study. The study included chest computed tomography without IV contrast from June 1 to July 31, 2022, in Clinical Hospital in Yauza, Moscow. The computed tomography was processed using a complex artificial intelligence algorithm for 10 pathologies: pulmonary infiltrates, typical for viral pneumonia (COVID-19 in pandemic conditions); lung nodules; pleural effusion; pulmonary emphysema; thoracic aortic dilatation; pulmonary trunk dilatation; coronary artery calcification; adrenal hyperplasia; and osteoporosis (vertebral body height and density changes). Two experts analyzed computed tomography and compared results with artificial intelligence. Further routing was determined according to clinical guidelines for all findings initially detected and missed by radiologists. The hospital price list determined the potential revenue loss for each patient. RESULTS: From the final 160 computed tomographies, the artificial intelligence identified 90 studies (56%) with pathologies, of which 81 (51%) were missing at least one pathology in the report. The second-stage lost potential revenue for all pathologies from 81 patients was RUB 2,847,760 ($37,251 or CNY 256,218). Lost potential revenue only for those pathologies missed by radiologists but detected by artificial intelligence was RUB 2,065,360 ($27,017 or CNY 185,824). CONCLUSION: Using artificial intelligence as an assistant to the radiologist for chest computed tomography can dramatically minimize the number of missed abnormalities. Compared with the normal model without artificial intelligence, using artificial intelligence can provide 3.6 times more benefits. Using advanced artificial intelligence for chest computed tomography can save money

Conserved genes underlie phenotypic plasticity in an incipiently social bee

Despite a strong history of theoretical work on the mechanisms of social evolution, relatively little is known of the molecular genetic changes that accompany transitions from solitary to eusocial forms. Here we provide the first genome of an incipiently social bee that shows both solitary and social colony organization in sympatry, the Australian carpenter bee Ceratina australensis. Through comparative analysis, we provide support for the role of conserved genes and cis-regulation of gene expression in the phenotypic plasticity observed in nest-sharing, a rudimentary form of sociality. Additionally, we find that these conserved genes are associated with caste differences in advanced eusocial species, suggesting these types of mechanisms could pave the molecular pathway from solitary to eusocial living. Genes associated with social nesting in this species show signatures of being deeply conserved, in contrast to previous studies in other bees showing novel and faster-evolving genes are associated with derived sociality. Our data provide support for the idea that the earliest social transitions are driven by changes in gene regulation of deeply conserved genes