Experimental and Numerical Thickness Analysis of TRIP Steel under Various Degrees of Deformation in Bulge Test

To design a reliable forming process it is necessary to determine the mechanical and formability properties of the processed material, which are used as input parameters for forming simulations. High-strength steel is irreplaceable as a material for producing the deformation zones of current automobiles. This type of steel can be processed by conventional or unconventional forming methods. In the sheet forming process, the material is usually under uniaxial and biaxial stress. The bulge test is utilized for determination of biaxial stress–strain curves, which are often used as input material data for forming simulations. In this work, numerical simulations of bulge tests using TRIP RAK 40/70 steel were performed to study the impact of yield criteria and hardening laws on the accuracy of thickness prediction of the deformed steel sheet. Additionally, the impact of different solvers and integration schemes on the thickness prediction was tested. Furthermore, the impact of various degrees of deformation (various dome heights) on thickness prediction accuracy was evaluated. Numerical results showed a good correlation with experimental data. When the Hill90 yield criterion was used, the software with implicit solver was more accurate in predicting thickness compared to software with explicit integration scheme, in most cases. In addition, the thickness prediction of parts with lower deformation was more accurate compared to parts with greater deformation (higher dome height).     

Beta Blocker Therapy After Acute Myocardial Infarction in Patients with Heart Failure and Systolic Dysfunction

The benefit of beta blockade has been well established in acute myocardial infarction for several decades, and its benefit in chronic heart failure has been proven since the early 1990's. Several large retrospective analyses suggested the benefit of beta blockers in post-MI systolic dysfunction. Only recently has the benefit of beta blockers been proven in addition to ACE inhibitors, antiplatelet agents, and reperfusion therapy. In the year 2000, CAPRICORN became the first randomized trial to directly address beta blockade in patients with post-infarction systolic dysfunction. The trial showed a 23% reduction in all-cause mortality with carvedilol, in patients already receiving ACE inhibitors, antiplatelet agents, and reperfusion therapy. This is a review of the literature on the administration of beta blockade in patients after acute myocardial infarction with left ventricular systolic dysfunction, as well as a comment on other current treatment modalities for this subset of patients.     

Distinguishing Incubation and Acute Disease Stages of Mild-to-Moderate COVID-19

While numerous studies have already compared the immune responses against SARS-CoV-2 in severely and mild-to-moderately ill COVID-19 patients, longitudinal trajectories are still scarce. We therefore set out to analyze serial blood samples from mild-to-moderately ill patients in order to define the immune landscapes for differently progressed disease stages. Twenty-two COVID-19 patients were subjected to consecutive venipuncture within seven days after diagnosis or admittance to hospital. Flow cytometry was performed to analyze peripheral blood immune cell compositions and their activation as were plasma levels of cytokines and SARS-CoV-2 specific immunoglobulins. Healthy donors served as controls. Integrating the kinetics of plasmablasts and SARS-CoV-2 specific antibodies allowed for the definition of three disease stages of early COVID-19. The incubation phase was characterized by a sharp increase in pro-inflammatory monocytes and terminally differentiated cytotoxic T cells. The latter correlated significantly with elevated concentrations of IP-10. Early acute infection featured a peak in PD-1⁺ cytotoxic T cells, plasmablasts and increasing titers of virus specific antibodies. During late acute infection, immature neutrophils were enriched, whereas all other parameters returned to baseline. Our findings will help to define landmarks that are indispensable for the refinement of new anti-viral and anti-inflammatory therapeutics, and may also inform clinicians to optimize treatment and prevent fatal outcomes.     

Bacterial invasion of vascular cell types: vascular infectology and atherogenesis

To portray the chronic inflammation in atherosclerosis, leukocytic cell types involved in the immune response to invading pathogens are often the focus. However, atherogenesis is a complex pathological deterioration of the arterial walls, where vascular cell types are participants with regards to deterioration and disease. Since other recent reviews have detailed the role of both the innate and adaptive immune response in atherosclerosis, herein we will summarize the latest developments regarding the association of bacteria with vascular cell types: infections as a risk factor for atherosclerosis; bacterial invasion of vascular cell types; the atherogenic sequelae of bacterial presence such as endothelial activation and blood clotting; and the identification of the species that are able to colonize this niche. The evidence of a polybacterial infectious component of the atheromatous lesions opens the doors for exploration of the new field of vascular infectology and for the study of atherosclerosis microbiome.     

Physician visits by rheumatoid arthritis patients: A prospective analysis

Obejective. To examine prospectively, using the behavioral model of health service utilization, patient-initiated physician visits, physician-requested visits, and visits for disease flares by 270 patients with rheumatoid arthritis (RA). Methods. Four waves of telephone interviews were conducted over 2 years. Hierarchical regression analyses were used to assess the relative contributions to variance explained by blocks of variables indicating need for care and predisposing and enabling factors. Results. Predisposing and enabling factors accounted for 50–67% of the explained variance in the 3 types of visits, while need accounted only for 33–50%. Conclusions. Studies seeking to identify factors other than need for care that facilitate or inhibit physician visits among RA patients are essential to analyzing the costs of care.     

Temporary loss of perivascular aquaporin-4 in neocortex after transient middle cerebral artery occlusion in mice

The aquaporin-4 (AQP4) pool in the perivascular astrocyte membranes has been shown to be critically involved in the formation and dissolution of brain edema. Cerebral edema is a major cause of morbidity and mortality in stroke. It is therefore essential to know whether the perivascular pool of AQP4 is up- or down-regulated after an ischemic insult, because such changes would determine the time course of edema formation. Here we demonstrate by quantitative immunogold cytochemistry that the ischemic striatum and neocortex show distinct patterns of AQP4 expression in the reperfusion phase after 90 min of middle cerebral artery occlusion. The striatal core displays a loss of perivascular AQP4 at 24 hr of reperfusion with no sign of subsequent recovery. The most affected part of the cortex also exhibits loss of perivascular AQP4. This loss is of magnitude similar to that of the striatal core, but it shows a partial recovery toward 72 hr of reperfusion. By freeze fracture we show that the loss of perivascular AQP4 is associated with the disappearance of the square lattices of particles that normally are distinct features of the perivascular astrocyte membrane. The cortical border zone differs from the central part of the ischemic lesion by showing no loss of perivascular AQP4 at 24 hr of reperfusion but rather a slight increase. These data indicate that the size of the AQP4 pool that controls the exchange of fluid between brain and blood during edema formation and dissolution is subject to large and region-specific changes in the reperfusion phase.     

THE OCCURRENCE OF ANTIGOITROUS SUBSTANCES IN PLANTS

The development of simple goiter in rabbits, which results when they are fed on a diet consisting chiefly of cabbage (or other Brassica) can be prevented by the feeding of certain fresh plants. Lawn grass, fresh alfalfa, skunk cabbage and steamed cabbage press juice have been found effective. Washing Brassicae with water improves their goiter-producing action, probably by the removal of goiter-preventing substances. The antigoitrous effect of plant juices was found to vary with the amount of reducing substance other than glutathione present. Skunk cabbage press juice, obtained from growing plants during the spring months, contained a large amount of iodine-absorbing material, and was very effective in involuting hyperplastic glands while juice obtained from mature plants in July when the iodine-absorbing material had nearly all disappeared, was quite ineffective. Certain extracts from cabbage administered parenterally, containing the reducing material, also had a marked involuting action on the thyroid. These extracts were practically iodine-free. The substance or substances believed to be responsible are easily soluble in water, ethyl alcohol, aqueous ethyl alcohol and are precipitable by lead acetate at a pH of 0.68–0.70. They are partially destroyed by exposure to air and by steam at 100°. Hexuronic acid isolated by Szent-Györgyi from cabbage, orange juice and suprarenal glands could be the antigoitrous agent. It cannot be glutathione.     

Ueber Fremdkörpertuberculose und Fremd-körperriesenzellen

Ohne ZusammenfassungHierzu Taf. VII–VIII.