Dopant Concentration Induced Optical Changes in Ca, Eu-α-Sialon

The phosphor powders of Ca(m/2)–xEuxSi12–(m+n)Alm+nOnN16–n (m = 1.6, n = 0.8, x in the range of 0–0.08) were synthesized by means of a solid state reaction in flowing nitrogen in a carbon resistant furnace and the influence of Eu concentration on the crystal structure and photoluminescent properties was thoroughly studied. The optical properties of selected α-sialon:Eu2+ samples at temperatures in the range of 10 to 500 K and pressures up to 240 kbar are presented. The crystal lattice parameters were affected by doping with europium and some increase of the unit cell volume was observed up to 6 mol % of Eu. The higher concentration of europium led to subtle changes in the overall structure of the produced sialon phosphors. It was shown that the chemical composition of Ca, Eu-α-sialon phosphor was slightly different from the designed one and the phosphor powders were contaminated by AlN. The phosphor particle surface showed significant europium and oxygen enrichment with Eu3+ but below the thin surface layer Eu2+ was dominant and higher nitrogen content was observed. After examination of absorption, excitation, and emission spectra it was found that the emission peak position shifted toward longer wavelengths with rising Eu2+ concentration from 565 nm (0.1 mol % Eu2+) to 585 nm (10 mol % Eu2+). The quantum yield of the phosphors reached the maximum at a rather low concentration of 4 mol % of Eu. Excitation spectra depend on the monitored wavelength which is typical for multisite Eu2+. The existence of many Eu2+ sites in the sample was supported by the dependence of the decay time on the monitored wavelength

Feto-maternal haemorrhage assessment in a woman with a large population of red blood cells containing fetal haemoglobin

Background: FMH quantification is necessary to calculate an individual dose of prophylactic anti-RhD immunoglobulin and to diagnose fetal anaemia causes. We encountered a healthy woman with a numerous RBCs containing fetal haemoglobin (HbF). Aims: To investigate the cause of this sign and the correct evaluation of fetal RBCs in maternal circulation. Materials and Methods: Patient’s samples and artificial mixtures were tested by microscopic Kleihaur-Betke (KB) and flow cytometric (FC) tests with anti-HbF + anti-CA (carbonic anhydrase), and with anti-D. The patient’s blood count with reticulocyte parameters, and concentration of bilirubin, haptoglobin, iron, transferrin, ferritin, hepcidin, sTR, HbF, HbA2 were measured. Genes coding the β- and γ-globin were sequenced. Results: It was impossible to distinguish the population of fetal and maternal HbF positive cells using KBT and FC with anti-HbF. Application of anti-CA and anti-D allowed to separate them. Maternal blood haematological and biochemical parameters were normal but HbF was 3.3% of total Hb concentration (norma

Novel concept in the mechanism of injury and protection of gastric mucosa : role of renina-angiotensin system and active metabolites of angiotensin

The term cytoprotection pioneered by Robert and colleagues has been introduced to describe the remarkable ability of endogenous and exogenous prostaglandins (PGs) to prevent acute gastric hemorrhagic lesions induced by noxious stimuli such as ethanol, bile acids, hiperosmolar solutions and nonsteroidal anti-inflammatory agents such as aspirin. Since that time many factors were implicated to possess gastroprotective properties such as growth factors including epidermal growth factor (EGF) and transforming factor alpha (TGFα), vasodilatory mediators such as nitric oxide (NO) and calcitonin gene related peptide (CGRP) as well as appetite gut hormones including gastrin and cholecystokinin (CCK), leptin and recently ghrelin. This protective action of gut peptides has been attributed to the release of PG but question remains whether another peptide angiotensin, the classic component of the systemic and local renin-angiotensin system (RAS) could be involved in the mechanism of gastric integrity and gastroprotection. After renin stimulation, the circulating angiotensin I is converted to angiotensin II (ANG II) by the activity of the Angiotensin Converting Enzyme (ACE). The ANG II acting via its binding to two major receptor subtypes the ANG type 1 (AT1) and type 2 (AT2) has been shown be activated during stress and to contribute to the pathogenesis of cold stress- and ischemia-reperfusion-induced gastric lesions. All bioactive angiotensin peptides can be generated not only in systemic circulation, but also locally in several tissues and organs. Recently the new functional components of RAS, such as Ang-(1-7), Ang IV, Ang-(1-12) and novel pathways ACE2 have been described suggesting the gastroprotective role for the novel ANG II metabolite, Ang-(1-7). The fact that Ang-(1-7) is produced in excessive amounts in the gastric mucosa of rodents and that pretreatment by Ang-(1-7) exhibits a potent gastroprotective activity against the gastric lesions induced by cold-restraint stress suggests that this and possibly other vasoactive metabolites of ANG II pathway could be involved in the mechanism of gastric integrity and gastroprotection. This review summarizes the novel gastroprotective factors and mechanisms associated with metabolic fate of systemic and local RAS activation with major focus to recent advancement in the angiotensin pathways in the gut integrity

The impact of COVID-19 pandemic on reproductive intentions among the Polish population

Objectives: The study was conducted in order to determine the impact of the COVID-19 pandemic on the fertility intentions among the Polish population. Material and methods: A cross-sectional, questionnaire-based online study was carried out among Polish adults in order to determine the impact of the COVID-19 pandemic on the reproductive plans of the Polish society. A total of 984 participants correctly completed the survey. Results: The pandemic has affected the reproductive intentions of 22% (n = 216) of the respondents, most of them want to have a child later than they previously planned (74.1%). The relationship between the change in reproductive intentions and the concerns about the pandemic was found. Most of those who changed their plans were afraid that the access to prenatal care and delivery services could be limited (86.6%) or were afraid about giving birth at the hospital (81%). More than half (51.9%) of those who changed reproductive plans were afraid of losing their income and 40.3% had already experienced a decrease in their income. The change in partner’s emotional relationships was also observed. More than half of respondents (56.7%) admitted that during the pandemic they had developed a deeper emotional relationship with their partners or felt more emotionally supported (56.6%). Most participants responded that the frequency of their sexual intercourses was not affected (66.7%) and that they had not experienced limited access to contraceptives (95.1%) during the pandemic. Conclusions: The COVID-19 pandemic has affected Polish people’s reproductive intentions. Concerns related to healthcare access and the economic difficulties have the most significant impact