Level and relationship of elements in scalp hair of males : effect of air pollution and smoking habits

Concentrations of Cd, Cr, Cu, Mn, Mo, Ni, Pb, Se, Tl and Zn were analyzed by ICP-MS in the scalp hair of male subjects from an urban area, three different quarters of Krakow, Poland, and from a rural area as control, which were assumed to differ in ambient pollution by metals. A questionnaire on personal data, nutritional habits, socioeconomic, occupation and health status was completed by the subjects. Significant differences (p < 0.05) were found in the levels of Cd, Cu, Mn and Ni between the locations. Using statistical methods of principal components analysis, the relationships were found between metals in the scalp hair as follows: Mn-Ni, Cr-Tl and Cd-Pb. Two separated clusters of smokers were revealed in the principal components, space suggesting other factors like environmental contamination could confound the values of parameters and relationships between them

Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal

Measuring system for in vivo multichannel neural signals recording

W pracy opisano system przeznaczony do rejestracji sygnałów neuronowych mózgu zwierzęcia znajdującego się pod narkozą. System pozwala na jednoczesny pomiar sygnałów z 64 kanałów za pośrednictwem ostrzowej matrycy elektrod. Składa się on z dedykowanego układu scalonego do wzmacniania i filtracji sygnałów, układów zasilających oraz układu kontrolnego. Do akwizycji danych wykorzystywany jest komputer typu PXI (ang. Peripheral Component Interconnect eXtensions for Instrumentation). Wstępne testy przeprowadzone przy pomocy sygnałów imitujących potencjały czynnościowe podanych za pośrednictwem elektrod i płynu fizjologicznego potwierdzają poprawne działanie systemu.This paper describes a system for recording neural signals from the brain of the animal under anesthesia. The system allows for simultaneous measurement of signals from 64 points by means of penetrating microelectrode matrix. It consists of dedicate integrated circuit for signal amplification and filtering, power supply module and control module. Dedicated data acquisition is peiformed using PXI (Peripheral Component Interconnect eXtensions for Instrumentation) computer and a custom application. Preliminary tests conducted with action potentials simulating signals provided through the electrodes and saline show that the system operates properly

Single-Bond Force Measured by Means of Scanning Force MicroscopyD

The aim of this investigation was to determine the adhesion force as a function of calcium dichloride concentration in water. The studies were performed with two surfaces carrying opposite charge in water solution: mica - as a negatively charged surface and glass covered with poly-L-lysine - as a positively charged surface, the latter due to the presence of amino groups. The surfaces were immersed in a CaCl$\text{}_{2}$ solution in the range of concentration varied from 0 to 100 mM. The scanning force microscopy was applied to determine the adhesion force by measurements of the pull-off force. Additionally, the values of the single bond force were estimated basing on the Poisson distribution of the number of binding sites

A system for in vitro multichannel recording of field and action potentials using planar array of microelectrodes

Jednoczesna wielopunktowa rejestracja potencjałów czynnościowych i polowych jest kluczem do zrozumienia mechanizmów działania mózgu [1]. Postęp w technologiach mikroobróbki oraz produkcji układów scalonych o dużym stopniu integracji pozwoliły na budowę systemów umożliwiających rejestrację aktywności mózgu z kilkuset punktów. W pracy zaprezentowano system pomiarowy do rejestracji in vitro sygnałów neuronowych przy pomocy płaskiej matrycy elektrod ostrzowych o rozmiarze 16 na 16 elektrod.Simultaneous multi-point recording of activity of living neural networks is the key to understanding the mechanisms of the brain operation [1]. Advances in micromachining technology and production of integrated circuits with a high degree of integration made it possible to build systems capable of recording brain activity of electrode arrays containing up to several hundred points [2]. Neural signal recording methods can be divided into in vivo and in vitro. In vivo method consists in introducing the electrode into the brain through a hole in the skull The animal under anesthesia may be mounted in the holder (acute neural recording) or canmove freely (chronic neural recording). In the in vitro method previously extracted piece of brain tissue is arranged on a matrix of electrodes (Fig. 2) placed in a container of liquid with a suitable composition and temperature. The in vitro method allows direct injection of chemicals and is more accurate than the method for in vivo determination of the signal origin. The paper presents a system for in vitro recording of neural signals by using a planar array of 256 electrodes (16x16). The system consists of a life-support system (temperature, nutrient fluid) (Fig. 3) and a recording system. The recording system is based on a specially designed integrated circuit fabricated in CMOS 0.18 žm technology [4]. Initial tests confirmed that the system is capable of recording both field and action potentials

Study of Adhesion Interaction Using Atomic Force Microscopy

An atomic force microscope is a useful tool to study the interaction forces at molecular level. In particular the atomic force microscope can measure an unbinding force needed to separate the two single molecule complexes. Recent studies have shown that such unbinding force depends linearly on the logarithm of the applied loading rate, defined as a product of scanning velocity and the spring constant characterizing the investigated system (cantilever vs. surface). This dependence can be used to study the energy landscape shape of a molecular complex by the estimation of energy barrier locations and the related dissociation rates. In the present work the complex consisting of ethylene(di)aminetetraacetic acid and the bovine serum albumin was measured. The dependence between the unbinding force and the logarithm of the loading rate was linear. Using the Bell model describing the dissociation of the above molecules caused by the action of the external bond breaking force, two parameters were estimated: the dissociation rate and the position of the energy barrier needed to overcome during a transition from a bound to unbound state. The obtained results are similar to those obtained for a typical ligand-receptor interaction

Study of Adhesion Interaction Using Atomic Force Microscopy

An atomic force microscope is a useful tool to study the interaction forces at molecular level. In particular the atomic force microscope can measure an unbinding force needed to separate the two single molecule complexes. Recent studies have shown that such unbinding force depends linearly on the logarithm of the applied loading rate, defined as a product of scanning velocity and the spring constant characterizing the investigated system (cantilever vs. surface). This dependence can be used to study the energy landscape shape of a molecular complex by the estimation of energy barrier locations and the related dissociation rates. In the present work the complex consisting of ethylene(di)aminetetraacetic acid and the bovine serum albumin was measured. The dependence between the unbinding force and the logarithm of the loading rate was linear. Using the Bell model describing the dissociation of the above molecules caused by the action of the external bond breaking force, two parameters were estimated: the dissociation rate and the position of the energy barrier needed to overcome during a transition from a bound to unbound state. The obtained results are similar to those obtained for a typical ligand-receptor interaction

Testing the efficiency of the Si3N4 membranes for charged particles registration

Testing Si3N4 membrane windows is a preliminary research for the single-ion-single-cell irradiating programme prepared at the Cracow nuclear microprobe facility. The present investigation is concerned with finding a method to register every single particle of the microprobe beam when passing through a membrane to the atmosphere. The 200 nm thick membranes covered with different layers were investigated. The alpha particles, after passing the membrane window, were registered by a particle detector. Secondary electrons ejected from the membrane by alpha particles were registered by a channeltron. The channeltron signals were collected in coincidence with the silicon detector signals. The detection efficiency is the ratio of the fast coincident channeltron signal number to the total number of the silicon detector signals. The results of investigation of the membranes with different coverages are reported in the present work