No massive black holes in the Milky Way halo.

The gravitational wave detectors have shown a population of massive black holes that do not resemble those observed in the Milky Way and whose origin is debated. According to a possible explanation, these black holes may have formed from density fluctuations in the early Universe (primordial black holes), and they should comprise several to 100% of dark matter to explain the observed black hole merger rates. If these black holes existed in the Milky Way dark matter halo, they would cause long-timescale gravitational microlensing events lasting years.

[The exposure routes of micro- and nanoplastics and their potential toxic effects on human health].

This article discusses the classification of micro- and nanoplastics (MNP), the routes of their exposure and the effects of MNP on the reproductive, respiratory, digestive and immune systems based on in vitro and in vivo studies, as well as available epidemiological data. The MNP can enter our body through inhalation, food or skin. The presence of microplastics (MP) in tap, bottled and deep sea water, as well as in sea salt, fruit and vegetables has been demonstrated.

The effects of co-exposure to methyl paraben and dibutyl phthalate on cell line derived from human skin.

Data on the cumulative effects of chemical substances are necessary for the proper risk assessment, but their availability is still insufficient. The aim of the study was to evaluate the cytotoxic effect of methyl paraben (MePB) and dibutyl phthalate (DBP) on the cells of the skin line (A431) and to compare the cytotoxic effects of the tested substances after single application to A431 cells with the effects of an equimolar/equitoxic (1:1) binary mixture of these compounds as well as their mixtures in ratio 1:3: and 3:1. On the basis of the obtained results, it was found that there were interactions between the tested compounds in terms of cytotoxic effect on A431, assessed on the basis of metabolic activity of cells (MTT test) and integrity of their cell membranes (NRU test).

[The transposition of directive 2019/1831/EU of October 24, 2019 establishing a fifth list of indicative occupational exposure limit values into national law].

The issue of the regulations amending the Regulation of the Minister of Family, Labour and Social Policy on the maximum admissible concentrations and intensities of agents harmful to health in the working environment resulted from the requirement to implement into national law the provisions of Commission Directive (EU) 2019/1831 of 24 October 2019 establishing a fifth list of indicative occupational exposure limit values pursuant to Council Directive 98/24/EC, and amending Commission Directive 2000/39/EC, the provisions of which Member States had to introduce by 20 May August 2021. The Regulation takes into account 3 motions submitted by the Interdepartmental Commission for Maximum Admissible Concentrations and Intensities for Agents Harmful to Health in the Working Environment to the minister of labour in the years 2017-2020. The Commission was appointed by the Regulation of the Prime Minister of December 15, 2008 (Journal of Laws of 2015, item 1772, with amendments), and its tasks include submitting to the minister of labour motions on the value of the maximum admissible concentrations and intensities for agents harmful to health in the working environment.

A three-dimensional map of the Milky Way using classical Cepheid variable stars.

The Milky Way is a barred spiral galaxy, with physical properties inferred from various tracers informed by the extrapolation of structures seen in other galaxies. However, the distances of these tracers are measured indirectly and are model-dependent. We constructed a map of the Milky Way in three dimensions, based on the positions and distances of thousands of classical Cepheid variable stars.

[Priority: safe working conditions].

The drawing up of a new regulation of the Minister of Family, Labour and Social Policy regarding the maximum admissible concentrations and intensities of agents harmful to health in the working environment resulted from the obligatory implementation into national law the provisions of Commission Directive (EU) 2017/164 of 31 January 2017 establishing a fourth list of indicative occupational exposure limit values pursuant to Council Directive 98/24/EC, and amending Commission Directives 91/322/EEC, 2000/39/EC and 2009/161/EU, the provisions of which Member States had to introduce by 21 August 2018, and partly Directive 2017/2398/EU of the European Parliament and of the Council of 12 December 2017 amending Directive 2004/37/EC on the protection of workers from the risks related to exposure to carcinogens or mutagens at work. The Regulation takes into account 13 applications submitted in the years 2014-2017 by the Interdepartmental Commission for Maximum Admissible Concentrations and Intensities for Agents Harmful to Health in the Working Environment to the minister competent for labour issues. The Commission was appointed by way of the regulation of the Prime Minister of 15 December 2008 (Journal of Laws 2015, item 1772, as amended), and its tasks include submitting to the minister competent for labour issues applications regarding the value of the maximum admissible concentrations and intensities for agents harmful to health in the working environment.

No large population of unbound or wide-orbit Jupiter-mass planets.

Planet formation theories predict that some planets may be ejected from their parent systems as result of dynamical interactions and other processes. Unbound planets can also be formed through gravitational collapse, in a way similar to that in which stars form. A handful of free-floating planetary-mass objects have been discovered by infrared surveys of young stellar clusters and star-forming regions as well as wide-field surveys, but these studies are incomplete for objects below five Jupiter masses.

The awakening of a classical nova from hibernation.

Cataclysmic variable stars-novae, dwarf novae, and nova-likes-are close binary systems consisting of a white dwarf star (the primary) that is accreting matter from a low-mass companion star (the secondary). From time to time such systems undergo large-amplitude brightenings. The most spectacular eruptions, with a ten-thousandfold increase in brightness, occur in classical novae and are caused by a thermonuclear runaway on the surface of the white dwarf.

The frequency of snowline-region planets from four-years of OGLE-MOA-Wise second-generation microlensing.

We present a statistical analysis of the first four seasons from a "second-generation" microlensing survey for extrasolar planets, consisting of near-continuous time coverage of 8 deg of the Galactic bulge by the OGLE, MOA, and Wise microlensing surveys. During this period, 224 microlensing events were observed by all three groups. Over 12% of the events showed a deviation from single-lens microlensing, and for ~1/3 of those the anomaly is likely caused by a planetary companion.

Extremely metal-poor stars from the cosmic dawn in the bulge of the Milky Way.

The first stars are predicted to have formed within 200 million years after the Big Bang, initiating the cosmic dawn. A true first star has not yet been discovered, although stars with tiny amounts of elements heavier than helium ('metals') have been found in the outer regions ('halo') of the Milky Way. The first stars and their immediate successors should, however, preferentially be found today in the central regions ('bulges') of galaxies, because they formed in the largest over-densities that grew gravitationally with time.

[Occupational exposure to chromium(VI) compounds].

This article discusses the effect of chromium(VI) (Cr(VI)) on human health under conditions of acute and chronic exposure in the workplace. Chromium(VI) compounds as carcinogens and/or mutagens pose a direct danger to people exposed to them. If carcinogens cannot be eliminated from the work and living environments, their exposure should be reduced to a minimum.

Rules and recent trends for setting health-based occupational exposure limits for chemicals.

The working environment is the special case of the non-natural environment created by man in which the increased production activity brings about the concentration of stimulators particularly aggressive to the human organism, such as chemical hazards, noise, vibration, extreme temperatures, and finally, intensified psychological and emotional stress. Depending on the nature and intensity, working environment factors have been classified into dangerous, harmful and annoying. The workers are more and more frequently exposed to dangerous chemicals in the working environment.

Exoplanet detection. A terrestrial planet in a ~1-AU orbit around one member of a ~15-AU binary.

Using gravitational microlensing, we detected a cold terrestrial planet orbiting one member of a binary star system. The planet has low mass (twice Earth's) and lies projected at ~0.8 astronomical units (AU) from its host star, about the distance between Earth and the Sun.

[Principles of establishing occupational exposure limits for carcinogens in Poland and in other EU countries].

The principles of determining exposure limits for carcinogens adopted in Poland, the European Union and in other selected countries of the EC are discussed in this article. Carcinogens and/or mutagens pose a direct health risk to people exposed to them. If carcinogens cannot be eliminated from the work and living environments, their exposure should be kept at the lowest possible level.

[Reporting on data from cardiopulmonary resuscitation].

Background: In-hospital cardiac arrest is still associated with a high mortality rate, due to late recognition of life-threatening processes such as progressive hypotension, or cerebral ischemia.The aim of the study was to analyse some selected parameters influencing early results of in-hospital cardiopulmonary resuscitation.

Methods: We analysed cardiopulmonary resuscitation reports, prepared following in-hospital cardiac arrests, according to the Utstein templates.

On the effectiveness of ion range determination from in-beam PET data.

At present, in-beam positron emission tomography (PET) is the only method for in vivo and in situ range verification in ion therapy. At the GSI Helmholtzzentrum für Schwerionenforschung GmbH (GSI) Darmstadt, Germany, a unique in-beam PET installation has been operated from 1997 until the shut down of the carbon ion therapy facility in 2008. Therapeutic irradiation by means of (12)C ion beams of more than 400 patients have been monitored.

Antecedent interventions in the management of maladaptive behaviours in a child with brain injury.

Typically behaviour management plans attempt to change behaviour by manipulating the environmental consequences of selected behaviour. However, identifying the antecedent events that precede behaviour has also been demonstrated to be an important component of effective behaviour change programmes. The present case presentation attempts to demonstrate how antecedent procedures could be used to effectively manage behaviour problems in individuals with brain injury.

Cytotoxicity of resorcinol under short- and long-term exposure in vitro.

Cytotoxicity of resorcinol to 3T3 fibroblast in short- (3 hrs) and long-term (72 hrs or 6 weeks) exposure was investigated. The effects of resorcinol on cell viability (neutral red uptake, NRU assay), mitochondrial function (MTT assay) and total cell protein (Kenacid Blue assay) were estimated. As a model for long-term exposure an INTEGRA CL 6-WELL bioreactor was used.

Germ cells with nuclear DNA fragmentation related to apoptotic cells in rat testis in experimental hyperprolactinemia induced by metoclopramide.

The cells with nuclear DNA fragmentation related to apoptosis were detected by TUNEL technique in the seminiferous epithelium of control rats and of rats with experimental hyperprolactinemia induced by metoclopramide. The percentage of convoluted tubules with apoptotic cells and the number of apoptotic cells (predominantly spermatogonia and spermatocytes) was increased in the experimental group. The results indicated stage-specific germ cell apoptosis.

The cytotoxicity of some organic solvents on isolated hepatocytes in monolayer culture.

The cytotoxic effects of volatile and water-insoluble organic solvents (ethylbenzene, tetrachloroethylene, n-hexane) were tested on isolated hepatocytes in monolayer culture by using the 3-(4,5 dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) reduction assay. All of the tested compounds inhibited metabolic activity of hepatocytes and this effect depended on the concentration of solvents in the incubatory medium. The presence of fetal calf serum in the medium did not change the cytotoxicity of xenobiotics.

[The effect of iron on peritoneal macrophage activity and sperm phagocytosis in rats].

Excessive activation of macrophages is considered to be the etiological factor of marital infertility. Peritoneal macrophages participate in the phagocytosis of menstrual detritus and sperm in the peritoneal cavity. Iron ingested by peritoneal macrophages could be responsible for their increased spermiophagy.

Interactions of some organic solvents: hydrocarbons and chloroalkene.

Metabolic and toxicodynamic interactions of some organic solvents in rats repeatedly treated with medium dose levels were examined. It was shown that both n-hexane and ethylbenzene significantly inhibited tetrachloroethylene metabolism during a 2-week period. n-Hexane and tetrachloroethylene enhanced metabolism of ethylbenzene whereas ethylbenzene suppressed n-hexane metabolism only at the end of the experiment.

Polish system of assessing occupational risk posed by chemical compounds.

According to the Polish Labour Code &elpar;Ustawa, 1974) employers are legally obligated to provide workers with information about occupational health and safety risks. Maximum allowable concentrations (MAC) and the results of determining chemical compounds in workplace air are used for assessing occupational exposure and risk. A computer-assisted system STER, developed in the Central Institute for Labour Protection, helps to register and document occupational risk assessment and all actions resulting from those assessments.

Classification of the Substances on the Basis of the Acute-Toxic-Class Method (ATC).

The acute-toxic-class method (ATC) is an alternative to the classical LD&inf50; test. Four substances were tested with an ATC testing procedure. The results were compared with LD&inf50; data obtained from the literature.