Formation Mechanism of Iron-Rich Olivine: Experimental Constrains into Early Fluid-Assisted Hydration and Dehydration Processes on Asteroids

Iron-rich olivine is one of the major minerals in the matrices of unequilibrated ordinary (UOCs) and carbonaceous (CV, CK, CO) chondrites whose petrologic type is >3.1. There has been an extensive discussion in the literature as to the formation mechanism of these olivines; however, their origin is poorly understood. The formation of ferroan olivine during hydrothermal alteration has been demonstrated to be thermodynamically viable. The stability of ferroan olivine is highly dependent on several variables, including temperature, water/ rock (W/R) ratio, pressure, oxygen fugacity, and bulk rock composition. So far, hydrothermal alteration experiments have not been successful at forming FeO-rich olivines with the compositions and textures observed in the matrices of chondrites. Therefore, understanding the formation conditions of FeO-rich olivines remains a key problem to explain the effects of hydrothermal alteration on chondrite matrices

Laboratory findings in COVID-19 - alterations of hematological, immunological, biochemical, hormonal and other lab panels: a narrative review

Up to the present date, according to the official reports of the World Health Organization (WHO), 205,338,159 patients have been confirmed with the coronavirus disease (COVID-19) and 4,333,094 have died as a consequence of this infectious disorder. The majority of COVID-19 patients will develop hematological, biochemical, immunological, hormonal and other complex alterations of their laboratory data which may be diagnosed using different biomarkers. In this paper, we review the alterations of the hematology, immunology, biochemistry, hormonal and other laboratory panels discovered in the subjects diagnosed with SARS-CoV-2 infection, based on the available data in the literature

Extracellular Vesicles as Intercellular Communication Vehicles in Regenerative Medicine

Extracellular vesicles (EVs) represent cell-specific carriers of bioactive cargos that can be of importance in either physiological or pathological processes. Frequently, EVs are seen as intercellular communication vehicles, but it has become more and more evident that their usefulness can vary from circulating biomarkers for an early disease diagnosis to future therapeutic carriers for slowing down the evolution of different afflictions and their ability to restore damaged tissue/organs. Here, we summarize the latest progress of EVs classification, biogenesis, and characteristics. We also briefly discuss their therapeutic potential, with emphasis on their potential application in regenerative medicine

Influx of nitrogen-rich material from the outer Solar System indicated by iron nitride in Ryugu samples

Large amounts of nitrogen compounds, such as ammonium salts, may be stored in icy bodies and comets, but the transport of these nitrogen-bearing solids into the near-Earth region is not well understood. Here, we report the discovery of iron nitride on magnetite grains from the surface of the near-Earth C-type carbonaceous asteroid Ryugu, suggesting inorganic nitrogen fixation. Micrometeoroid impacts and solar wind irradiation may have caused the selective loss of volatile species from major iron-bearing minerals to form the metallic iron. Iron nitride is a product of nitridation of the iron metal by impacts of micrometeoroids that have higher nitrogen contents than the CI chondrites. The impactors are probably primitive materials with origins in the nitrogen-rich reservoirs in the outer Solar System. Our observation implies that the amount of nitrogen available for planetary formation and prebiotic reactions in the inner Solar System is greater than previously recognized

A dehydrated space-weathered skin cloaking the hydrated interior of Ryugu

Without a protective atmosphere, space-exposed surfaces of airless Solar System bodies gradually experience an alteration in composition, structure and optical properties through a collective process called space weathering. The return of samples from near-Earth asteroid (162173) Ryugu by Hayabusa2 provides the first opportunity for laboratory study of space-weathering signatures on the most abundant type of inner solar system body: a C-type asteroid, composed of materials largely unchanged since the formation of the Solar System. Weathered Ryugu grains show areas of surface amorphization and partial melting of phyllosilicates, in which reduction from Fe3+ to Fe2+ and dehydration developed. Space weathering probably contributed to dehydration by dehydroxylation of Ryugu surface phyllosilicates that had already lost interlayer water molecules and to weakening of the 2.7 µm hydroxyl (–OH) band in reflectance spectra. For C-type asteroids in general, this indicates that a weak 2.7 µm band can signify space-weathering-induced surface dehydration, rather than bulk volatile loss

The Involvement of Oxidative Stress in Psoriasis: A Systematic Review

Psoriasis is a chronic, immune-mediated inflammatory dermatosis characterized by the appearance of erythematous plaques, covered by white scales, occasionally pruritogenic, and distributed mainly on the extensor areas. Oxidative stress is defined as an imbalance or a transient or chronic increase in the levels of free oxygen/nitrogen radicals, either as a result of the exaggerated elevation in their production or the decrease in their ability to be eliminated by antioxidant systems. Although the pathogenesis of psoriasis remains far from elucidated, there are studies that delineate an involvement of oxidative stress in this skin disorder. Thus, a systematic search was computed in PubMed/Medline, Web of Science and SCOPUS and, in total, 1293 potentially eligible articles exploring this research question were detected. Following the removal of duplicates and the exclusion of irrelevant manuscripts based on the screening of their titles and abstracts (n = 995), 298 original articles were selected for full-text review. Finally, after we applied the exclusion and inclusion criteria, 79 original articles were included in this systematic review. Overall, the data analyzed in this systematic review point out that oxidative stress markers are elevated in psoriasis and share an association with the duration and severity of the disease. The concentrations of these biomarkers are impacted on by anti-psoriasis therapy. In addition, the crosstalk between psoriasis and oxidative stress is influenced by several polymorphisms that arise in genes encoding markers or enzymes related to the redox balance. Although the involvement of oxidative stress in psoriasis remains undisputable, future research is needed to explore the utility of assessing circulating serum, plasma, urinary and/or skin biomarkers of oxidative stress and of studying polymorphisms in genes regulating the redox balance, as well as how can these findings be translated into the management of psoriasis, as well in understanding its pathogenesis and evolution

Polypharmacy in Type 2 Diabetes Mellitus: Insights from an Internal Medicine Department

Background and Objectives: Polypharmacy heavily impacts the quality of life of patients worldwide. It is a necessary evil in many disorders, and especially in type 2 diabetes mellitus, as patients require treatment both for this condition and its related or unrelated comorbidities. Thus, we aimed to evaluate the use of polypharmacy in type 2 diabetes mellitus vs. non-diabetes patients. Materials and Methods: A cross-sectional retrospective observational study was conducted. We collected the medical records of patients hospitalized in the Internal Medicine Clinic of the Clinical Emergency Hospital of Bucharest, Romania, for a period of two months (01/01/2018–28/02/2018). Patients diagnosed with type 2 diabetes mellitus were included in the study group, whereas patients who were not diabetic were used as controls. Results: The study group consisted of 63 patients with type 2 diabetes mellitus (mean age 69.19 ± 9.67 years, range 46–89 years; 52.38% males). The control group included 63 non-diabetes patients (mean age 67.05 ± 14.40 years, range 42–93 years, 39.68% males). Diabetic patients had more comorbidities (10.35 ± 3.09 vs. 7.48 ± 3.59, p = 0.0001) and received more drugs (7.81 ± 2.23 vs. 5.33 ± 2.63, p = 0.0001) vs. non-diabetic counterparts. The mean number of drug-drug and food-drug interactions was higher in type 2 diabetes mellitus patients vs. controls: 8.86 ± 5.76 vs. 4.98 ± 5.04, p = 0.0003 (minor: 1.22 ± 1.42 vs. 1.27 ± 1.89; moderate: 7.08 ± 4.08 vs. 3.54 ± 3.77; major: 0.56 ± 0.74 vs. 0.37 ± 0.77) and 2.63 ± 1.08 vs. 2.19 ± 1.42 (p = 0.0457), respectively. Conclusions: Polypharmacy should be an area of serious concern also in type 2 diabetes mellitus, especially in the elderly. In our study, type 2 diabetes mellitus patients received more drugs than their non-diabetes counterparts and were exposed to more drug-drug and food-drug interactions

Vulvar and Vaginal Melanomas—The Darker Shades of Gynecological Cancers

Melanomas of the skin are poorly circumscribed lesions, very frequently asymptomatic but unfortunately with a continuous growing incidence. In this landscape, one can distinguish melanomas originating in the mucous membranes and located in areas not exposed to the sun, namely the vulvo-vaginal melanomas. By contrast with cutaneous melanomas, the incidence of these types of melanomas is constant, being diagnosed in females in their late sixties. While hairy skin and glabrous skin melanomas of the vulva account for 5% of all cancers located in the vulva, melanomas of the vagina and urethra are particularly rare conditions. The location in areas less accessible to periodic inspection determines their diagnosis in advanced stages, often metastatic. Moreover, despite the large number of drugs newly approved in recent decades for the treatment of cutaneous melanoma, especially in the category of biological drugs, the mortality of vulvo-vaginal melanomas has remained almost constant. This, together with the absence of specific treatment guidelines due to the lack of a sufficient number of cases to conduct randomized clinical trials, makes melanomas with this localization a discouraging diagnosis, associated with a very poor prognosis. Our aim is therefore to draw attention to this oftentimes overlooked entity in order to encourage the community to employ various strategies meant to increase research in this area. By highlighting the main risk factors of vulvar and vaginal melanomas, as well as the clinical manifestations and molecular changes underlying these neoplasms, ideally novel therapeutic schemes will, in time, be brought into effect

Bulk Oxygen Isotopic Composition of Antarctic Micrometeorites: Effect of Atmospheric Entry

International audienceThe bulk O isotopic compositions of Antarctic micrometeorites are broadly compatible with that of carbonaceous chondrites, but systematic heavy O isotopic enrichments due to atmospheric entry were observed in partially melted particles

Dolomites in hydrated fine-grained Antarctic micrometeorites: Effective tools for analyzing secondary processes

International audienceWe report detailed transmission electron microscope (TEM) observations of carbonates from one hydrated fine-grained Antarctic micrometeorite (H-FgMM). These carbonates show the occurrence of complex chemical variations and microstructures that provide important evidence regarding the formation and evolution of rarely analyzed H-FgMMs. The chemical variations were identified at both micrometer and nanometer scales, indicating that these carbonates formed under localized fluid conditions that suggest a variable chemical microenvironment. Individual carbonates grew from isolated reservoirs of fluid. Moreover, these carbonates contain manganese amounts almost twice as high as those measured in CM chondrites but similar to those identified in CI chondrites. Their particular compositions indicate reducing and progressively evolving conditions in the fluid from which these carbonates precipitated, probably due to water consumption during phyllosilicates formation. In addition to the compositional variability, microstructural features are pervasive in these carbonates, similar to those described in heavily shocked meteorites indicating that these carbonates were probably modified during shock processes after their formation. Since carbonates are highly susceptible to shock metamorphism, we suggest that it is essential to investigate their structure in detail before interpreting the isotopic measurements related to the time of their formation. Additionally, associated with carbonates, ubiquitous phosphates were identified in the micrometeorite analyzed. Future studies of these mineral associations will provide us further insight into the formation and evolution of asteroids, especially since they were both identified in the surface materials of Ryugu and Bennu