The Uptake of Ethinyl-Estradiol and Cortisol From Water by Mussels (Mytilus spp.)

Previous toxicokinetic studies have shown that mussels (Mytilus spp.) can readily absorb the three main mammalian sex steroids, estradiol (E2), testosterone (T) and progesterone (P) from water. They also have a strong ability to store E2 and the 5α-reduced metabolites of T and P in the form of fatty acid esters. These esters were shown to have half-lives that were measured in weeks (i.e. they were not subject to fast depuration). The present study looked at the toxicokinetic profile of two other common steroids that are found in water, the potent synthetic oestrogen, (ethinyl-estradiol) (EE2; one of the two components of ‘the pill’), and cortisol, a natural stress steroid in vertebrates. In the first three hours of uptake, tritiated EE2 was found to be taken up at a similar rate to tritiated E2. However, the levels in the water plateaued sooner than E2. The ability of the animals to both esterify and sulphate EE2 was found to be much lower than E2, but nevertheless did still take place. After 24 h of exposure, the majority of radiolabelled EE2 in the animals was present in the form of free steroid, contrary to E2, which was esterified. This metabolism was reflected in a much lower half-life (of only 15 h for EE2 in the mussels as opposed to 8 days for E2 and >10 days for T and P). Intriguingly, hardly any cortisol (in fact none at all in one of the experiments) was absorbed by the mussels. The implications of this finding in both toxicokinetic profiling and evolutionary significance (why cortisol might have evolved as a stress steroid in bony fishes) are discussed.

Study on the Rock Fracture during Fluid Injection Using a Coupled Flow-Stress-Damage (FSD) Model: Insight into the Stress Shadow Effect

In order to investigate the influence of pore pressure on hydraulic fracturing behavior in the local and whole model, the coupled flow-stress-damage (FSD) analysis system RFPA-Flow was used to study the influence of rock heterogeneity, natural stress ratio, double-hole spacing, and water pressure gradient on the stress shadow effect. The numerical results show that the tensile crack induced by pore water pressure is significantly affected by the pore water pressure and water pressure gradient. The larger the pore pressure gradient is, the more asymmetrical the crack development pattern and the smaller the instability pressure of the model. In addition, the shape of hydraulic fracture becomes much more irregular with the increase in rock heterogeneity. The number and shape of tip microcracks under the influence of local water pressure are closely related to the homogeneity of rock. Moreover, when the natural stress difference is large, the hydraulic fracture propagates parallel to the maximum principal stress; when the stress field is close and the spacing between two holes is less than 5 times the diameter, the propagation direction of hydraulic fractures between holes is perpendicular to the maximum principal stress. It is found that no hydraulic fractures occur between the two holes when the distance between holes is greater than 5 times the diameter.

Analysis of Heart Diseases in Pregnancy

Introduction: Cardiac diseases complicate 1% of all pregnancies. It is one of the 3 major indirect causes of maternal mortality in India. Methodology: This qualitative study was conducted at Saveetha medical college and hospital. Out of 1320 women who delivered between June 2020 to June 2021, 15 women had heart disease and they were included in the study. All the 15 women were asymptomatic. Results: A total of 15 pregnant women were included in the study. There were no twin pregnancies. In total, 2 women presented with congenital heart disease and 13 women with acquired heart disease. Out of the 15 women, 4 delivered vaginally and the remaining 11 had undergone LSCS. Discussion: During pregnancy, major changes occur in the cardiovascular system to meet the increasing metabolic needs of the mother and fetus. If these changes are not met with, it can lead to maternal and fetal morbidity. Failure to make normal adjustments can worsen an existing heart condition or early manifestations of a previously unknown condition, and therefore pregnancy is a natural stress test. The changes that occur during pregnancy and the physiology of pregnancy itself will enhance some pathological processes of the heart. Understanding these changes is important, and adjustments may vary from person to person. Conclusion: A developing cardiovascular disorder should be detected as early as possible and also it should be a priority in pregnancy monitoring, and if a disorder is identified, the cardiologist team should be involved immediately. Many groups dedicated to managing heart problems during pregnancy, is recommended as it leads to better clinical outcomes.

ESTIMATED ANALYSIS OF THE NATURAL STRESS FIELDS COMPLEXITY IN EASTERN SAYAN GOLD-ORE VEIN DEPOSITS

The article presents the main results of studies of initial stresses of three gold vein de-posits located in the Eastern Sayan Mountains: Zun-Kholbinsky, Barun-Kholbinsky, Konevin-sky, in the depth range of 120…940 m. Insitu measurements by the slot unloading method and reverse calculation of primary stresses on the basis of 49 rock pressure cases were made. Key geomechanical factors were determined, and average statistical parameters of natural stresses depending on the combination of these factors were estimated.

Numerical simulation of stress distribution

The Rogun hydropower plant is being constructed in Tajikistan, in the valley of the Vakhsh River. The construction site is located in a narrow gorge separating the Vakhsh and Surkh-Ku ridges. Most of the hydroelectric complex structures are located within a single tectonic block, which is bounded by two faults - Ionakhsh and Gulizindan, which are proximal to the Vakhsh regional fault. The study of stress distribution around the diversion tunnel was carried out by numerical simulation, which aimed to identify the stress distribution in the strongly dislocated heterogeneous rock massif before and after the tunnel creation. The underground cavity of the tunnel is a significant factor influencing the natural stress field of the rock massif. An area with critical values of the strength coefficient in the working roof, caused by the presence of a weak layer of Lower Cretaceous siltstones, is revealed in the tunnel location. The size of this area reaches two tunnel diameters. The change of stresses and their concentration around the underground working can cause deformations in the roof (collapse or rock bumps).