A simple experimental checking of Heisenberg's uncertainty relations

We show that the quantum mechanical interpretation of the diffraction of light on a slit, when a wave function is assigned to a photon, can be used for a direct experimental study of Heisenberg's position-momentum and equivalent position-wave vector uncertainty relation for the photon. Results of an experimental test of the position-wave vector uncertainty relation, where the wavelength is used as the input parameter, are given and they very well confirm our approach. The same experimental results can also be used for a test of the position-momentum uncertainty relation when the momentum p_0 of a photon is known as the input parameter. We show that a measurement of p_0, independent of the knowledge of the value of the Planck's constant, is possible. Using that value of p_0, a test of the position-momentum uncertainty relation could be regarded as a method for a direct measurement of the Planck's constant. This is discussed, since the diffraction pattern is also well described by classical electrodynamics in the considered experimental conditions. This approach for testing the Heisenberg's uncertainty relations is very simple and consequently suitable as a quantitative exercise in undergraduate experimental courses, as well as a visual and attractive demonstration of the Heisenberg's uncertainty principle in courses of quantum mechanics

Jednostavna eksperimentalna provjera heisenbergovih relacija neodređenosti

We show that the quantum mechanical interpretation of the diffraction of light on a slit, when a wave function is assigned to a photon, can be used for a direct experimental study of Heisenberg\u27s position-momentum and equivalent position-wave vector uncertainty relation for the photon. Results of an experimental test of the position-wave vector uncertainty relation, where the wavelength is used as the input parameter, are given and they very well confirm our approach. The same experimental results can also be used for a test of the position-momentum uncertainty relation when the momentum p0 of a photon is known as the input parameter. We show that a measurement of p0, independent of the knowledge of the value of the Planck\u27s constant, is possible. Using that value of p0, a test of the position-momentum uncertainty relation could be regarded as a method for a direct measurement of the Planck\u27s constant. This is discussed, since the diffraction pattern is also well described by classical electrodynamics in the considered experimental conditions. This approach for testing the Heisenberg\u27s uncertainty relations is very simple and consequently suitable as a quantitative exercise in undergraduate experimental courses, as well as a visual and attractive demonstration of the Heisenberg\u27s uncertainty principle in courses of quantum mechanics.Pokazujemo da se kvantno-mehaničko tumačenje ogiba svjetlosti na pukotini, u kojem smo fotonu pridijelili uobičajenu valnu funkciju, može upotrijebiti za izravnu eksperimentalnu provjeru Heisenbergovih relacija neodređenosti položaj–impuls i ekvivalentnih položaj–valni vektor. Rezultati testiranja relacije neodređenosti položaj–valni vektor, u kojem smo uzeli valnu duljinu lasera kao ulazni parametar, dobro potvrđuju na pristup. Na istovjetan način se može napraviti provjera relacija neodređenosti položaj–impuls ako je impuls p0 laserskih fotona poznat kao ulazni parametar. Dokazujemo da je moguće mjeriti p0 neovisno o poznavanju vrijednosti Plankove konstante. S tako dobivenom vrijednošću p0 opisani eksperiment se može promatrati i kao način mjerenja Plankove konstante. To smo detaljnije pojasnili s obzirom da ogibnu sliku u danim eksperimentalnim uvjetima možemo također odlično opisati i klasičnom elektrodinamikom. Opisani eksperimentalni pristup za provjeru Heisenbergovih relacija neodređenosti je vrlo jednostavan, te je stoga pogodan kao vježba u studentskim praktikumima ali i kao vizualno atraktivna demonstracija na predavanjima iz kvantno-mehaničkih kolegija

Structure of the small ribosomal subunit from T. Thermophilus

Die kleine ribosomale Untereinheit vollzieht die Dekodierung der genetischen Information in der Protein-Biosynthese. Die Struktur dieser Untereinheit von Thermus thermophilus zeigt, daß das Dekodierungszentrum, in dem die mRNA und die drei tRNA-Moleküle positioniert werden, ausschließlich aus RNA aufgebaut ist. Der Eingang zum mRNA-Kanal wird durch eine flexible, molekulare Klammer, die wesentlich an dem präzisen Transport der mRNA durch das Ribosom beteiligt ist, umschlossen. RNA-Helizes, die die ribosomale Untereinheit in ihrer ganzen Länge durchziehen, können periphere strukturelle Änderungen innheralb des Moleküls weiterleiten, und so mit dem Zyklus der mRNA-Translokation synchronisieren. 96% der Nukleotide und die Faltung aller Proteine konnten modelliert werden. Die ribosomalen Proteine sind zum Teil an der Peripherie des Moleküls und tragen als Linker zur Organisation der RNA bei. In gewissen Maße können manche der Proteine zur Translokation beitragen

Jednostavna eksperimentalna provjera heisenbergovih relacija neodređenosti

We show that the quantum mechanical interpretation of the diffraction of light on a slit, when a wave function is assigned to a photon, can be used for a direct experimental study of Heisenberg\u27s position-momentum and equivalent position-wave vector uncertainty relation for the photon. Results of an experimental test of the position-wave vector uncertainty relation, where the wavelength is used as the input parameter, are given and they very well confirm our approach. The same experimental results can also be used for a test of the position-momentum uncertainty relation when the momentum p0 of a photon is known as the input parameter. We show that a measurement of p0, independent of the knowledge of the value of the Planck\u27s constant, is possible. Using that value of p0, a test of the position-momentum uncertainty relation could be regarded as a method for a direct measurement of the Planck\u27s constant. This is discussed, since the diffraction pattern is also well described by classical electrodynamics in the considered experimental conditions. This approach for testing the Heisenberg\u27s uncertainty relations is very simple and consequently suitable as a quantitative exercise in undergraduate experimental courses, as well as a visual and attractive demonstration of the Heisenberg\u27s uncertainty principle in courses of quantum mechanics.Pokazujemo da se kvantno-mehaničko tumačenje ogiba svjetlosti na pukotini, u kojem smo fotonu pridijelili uobičajenu valnu funkciju, može upotrijebiti za izravnu eksperimentalnu provjeru Heisenbergovih relacija neodređenosti položaj–impuls i ekvivalentnih položaj–valni vektor. Rezultati testiranja relacije neodređenosti položaj–valni vektor, u kojem smo uzeli valnu duljinu lasera kao ulazni parametar, dobro potvrđuju na pristup. Na istovjetan način se može napraviti provjera relacija neodređenosti položaj–impuls ako je impuls p0 laserskih fotona poznat kao ulazni parametar. Dokazujemo da je moguće mjeriti p0 neovisno o poznavanju vrijednosti Plankove konstante. S tako dobivenom vrijednošću p0 opisani eksperiment se može promatrati i kao način mjerenja Plankove konstante. To smo detaljnije pojasnili s obzirom da ogibnu sliku u danim eksperimentalnim uvjetima možemo također odlično opisati i klasičnom elektrodinamikom. Opisani eksperimentalni pristup za provjeru Heisenbergovih relacija neodređenosti je vrlo jednostavan, te je stoga pogodan kao vježba u studentskim praktikumima ali i kao vizualno atraktivna demonstracija na predavanjima iz kvantno-mehaničkih kolegija

Shunt in the Diagnosis of Initial Lung Lesion in Smokers

Cigarette smoking is an important risk factor for all respiratory tract diseases. Unfortunately, the symptoms develop slowly, thus patients feel the consequences of the slowly developing inflammation too late. The inflammation first develops in the area of respiratory bronchioles. In this stage, the disease is asymptomatic. The study included a sample of 31 smokers, mean age 36.38 years, with normal spirometry indices, acid-base status and arterial blood gases. The mean smoking index was 11.28 smoking/years. All subjects were healthy, without any subjective health problems or disease indicators. The aim was to define dead lung area (V/Q) as an early indicator of changes in smokers. Study results demonstrated the mean shunt value in smokers of 8.25%, which showed positive correlation with smoking. The shunt size yielded negative correlation with the forced expiratory volume in one second and midexpiratory flow in smokers. In conclusion, determination of lung shunt is a simple method that is sensitive enough in the diagnosis of initial lung lesion due to cigarette smoking

Influence of Passive Smoking on Basic Anthropometric Characteristics and Respiratory Function in Young Athletes

The primary objective of this study is to investigate the maintenance difference in basic anthropometric characteristics and to outline the dynamics of respiratory function change in youngsters athletes exposed to passive smoking (PS) and athletes not exposed to passive smoking in their families (NPS). High and weight were determined as basis anthropometric characteristics. Measured parameters for respiratory function were vital capacity (VC), forced expiratory volume in the first second (FEV1), maximum expiratory flow (PEF), forced expiratory flow at 50% forced vital capacity (MEF 50) and forced expiratory flow at 25% forced vital capacity (MEF 25). Significant statistical differences in separate spirometric variable were found in three variables (FEV1, MEF50, and MEF25) for group older youngsters. Analysis of variance showed statistical differences between athletes unexposed to passive smoking (NPS) and athletes exposed to passive smoking (PS) in even four spirometric variables (VC, FEV1, MEF50 and MEF25)

A simple experimental checking of Heisenberg's uncertainty relations

We show that the quantum mechanical interpretation of the diffraction of light on a slit, when a wave function is assigned to a photon, can be used for a direct experimental study of Heisenberg's position-momentum and equivalent position-wave vector uncertainty relation for the photon. Results of an experimental test of the position-wave vector uncertainty relation, where the wavelength is used as the input parameter, are given and they very well confirm our approach. The same experimental results can also be used for a test of the position-momentum uncertainty relation when the momentum p_0 of a photon is known as the input parameter. We show that a measurement of p_0, independent of the knowledge of the value of the Planck's constant, is possible. Using that value of p_0, a test of the position-momentum uncertainty relation could be regarded as a method for a direct measurement of the Planck's constant. This is discussed, since the diffraction pattern is also well described by classical electrodynamics in the considered experimental conditions. This approach for testing the Heisenberg's uncertainty relations is very simple and consequently suitable as a quantitative exercise in undergraduate experimental courses, as well as a visual and attractive demonstration of the Heisenberg's uncertainty principle in courses of quantum mechanics

The Effect of Analgesics and Physical Therapy on Respiratory Function after Open and Laparoscopic Cholecystectomy

In this study we present prospective clinical trial included 100 patients. One half of the patients underwent open cholecystectomy, whereas laparoscopic cholecystectomy was performed in the other half. Spirometric parameters, arterial blood gases, acid-base balance, were determined preoperatively, and then at 6 h, 24 h, 72 h and 144 h postoperatively. The impact of physical therapy on the respiratory parameter patterns, VAS-pain score and use of tramadol were studied after cholecystectomy. Significantly lower VAS-pain score and less tramadol use, higher values and faster recovery of ventilation parameters and PaO2 were recorded after laparoscopic cholecystectomy than after open cholecystectomy (p=0.001 for both). Physical therapy resulted in a significant improvement in the values of respiratory parameters in the open cholecystectomy group within a short time (30 min) after therapy was performed. Physical therapy failed to produce any improvement of respiratory parameters in laparoscopic cholecystectomy, whereas in open cholecystectomy group who had a favorable although transient effect, strictly limited to the short time from its application. (p=0.005). The patients operated on by open cholecystectomy had statistically significantly more pronounced disturbances including hypoxia, hypocapnia and hyperventilation when compared to the group submitted to laparoscopic cholecystectomy. It is recommended that physical therapy be more frequently performed during the postoperative period in patients submitted to open cholecystectom

Shunt in the Diagnosis of Initial Lung Lesion in Smokers

Cigarette smoking is an important risk factor for all respiratory tract diseases. Unfortunately, the symptoms develop slowly, thus patients feel the consequences of the slowly developing inflammation too late. The inflammation first develops in the area of respiratory bronchioles. In this stage, the disease is asymptomatic. The study included a sample of 31 smokers, mean age 36.38 years, with normal spirometry indices, acid-base status and arterial blood gases. The mean smoking index was 11.28 smoking/years. All subjects were healthy, without any subjective health problems or disease indicators. The aim was to define dead lung area (V/Q) as an early indicator of changes in smokers. Study results demonstrated the mean shunt value in smokers of 8.25%, which showed positive correlation with smoking. The shunt size yielded negative correlation with the forced expiratory volume in one second and midexpiratory flow in smokers. In conclusion, determination of lung shunt is a simple method that is sensitive enough in the diagnosis of initial lung lesion due to cigarette smoking