Coherence loss and revivals in atomic interferometry: A quantum-recoil analysis

The coherence effects induced by external photons coupled to matter waves inside a Mach-Zehnder three-grating interferometer are analyzed. Alternatively to atom-photon entanglement scenarios, the model considered here only relies on the atomic wave function and the momentum shift induced in it by the photon scattering events. A functional dependence is thus found between the observables, namely the fringe visibility and the phase shift, and the transversal momentum transfer distribution. A good quantitative agreement is found when comparing the results obtained from our model with the experimental data.Comment: 18 pages, 4 figure

Hemijske modifikacije β-laktoglobulina hinonima

The avarone/avarol quinone/hydroquinone couple. as well as their derivatives show considerable antitumor activity. In this work, covalent modifications of beta-lactogglobulin. isolated from cow milk by avarone, its model compound 2-tert-butyl-1,4-benzoquinone. and several of their alkylthio derivatives were studied. The techniques applied for as-saying the modifications were: UV/VIS spectrophotometry, SDS PAGE and isoelectrofocusing. The results of the SDS PAGE suggest that polymerisation of the protein occurs. The shift of the pI of the protein upon modification toward lower values indicates that lysine amino groups are the principal site of die reaction of beta-lactoglobulin with the quinones.Hinonsko/hidrohinonski par avaron/avarol i njihovi derivati pokazuju značajnu antitumorsku aktivnost. U ovom radu proučavane su kovalentne modifikacije β-laktoglobulina, izolovanog iz kravljeg mleka, avaronom, njegovim model-jedinjenjem 2-tert-butil-1,4-benzohinonom i njihovim alkiltio-derivatima. Za ispitivanje modifikacija korišćene su UV/VIS spektrofotometrija, SDS PAGE i izoelektrofokusiranje. Rezultat SDS PAGE ukazuje da se protein polimerizuje. Pomeranje pI vrednosti proteina nakon modifikacije ka nižim vrednostima pokazuje da su amino grupe lizina glavna mesta reakcije β-laktoglobulina sa hinonima

Characterization of trypsin-like enzymes from the midgut of Morimus funereus (Coleoptera: Cerambycidae) larvae

The pH along the midgut of M. funereus larvae had different values, being acidic in the anterior section and basic in the middle and posterior sections. Elastase- and chymotrypsin-like activities were highest in the middle, low in the anterior, and negligible in the posterior section of the midgut. Trypsin-like activities were detected along the whole midgut, with more than 90% of activity in the anterior section. The level of elastase- and chymotrypsin-like activity was very low compared to trypsin-like activity. In the anterior section of the midgut, two isoforms of trypsin-like enzymes were found, both being basic and almost completely inhibited by benzamidine

Association and. Precipitation of Alkaline Earth Dodecyl Sulphate in Aqueous Media

The equilibrium in aqueous alkaline earth dodecyl sulphate solutions were examined by determining solubilities at different ratios of precipitation component amounts. The interpretation of the results indicates the formation of simple associates such as Me(C12H25S04)2. The !=!quilibrium constants of their formation were also determined

Comparison of α-amylase isoforms from the midgut of Cerambyx cerdo L. (Coleoptera: Cerambycidae) larvae developed in the wild and on an artificial diet

α-Amylase isoforms of Cerambyx cerdo larvae from the wild (ML and SL) and reared in the laboratory (ADL) were compared. Three amylase isoforms were presented in the SL and ML extracts while two isoforms were presented in the ADL according to zymogram after isoelectric focusing (IEF). All C. cerdo amylase isoforms were acidic proteins (pI < 3.5). Seven amylase isoforms (ACC 1-7) from the midgut of C. cerdo larvae were found in the ML midgut extract, six in the SL extract, and four in the ADL extract according to native PAGE zymogram. The ADL amylase had the highest activity. All crude midgut extracts of C. cerdo larvae were fractionated on a Superose 12 HR column. The molecular mass of the ACC was estimated to be 34 kDa.Upoređene su izoforme α-amilaze larvi Cerambyx cerdo sakupljenih iz prirode (ML i SL) i gajenih na veštačkoj podlozi u laboratoriji (ADL). Zimogramskom detekcijom posle IEF-a po tri izoforme su detektovane u ML i SL ekstraktima, a u ADL dve izoforme. Sve amilazne izoforme iz C. cerdo su bile kisele (pI < 3.5). Zimogramskom detekcijom posle nativne elektroforeze sedam izoformi je detektovano u ML ekstraktu, šest u SL ekstraktu i četiri u ADL ekstraktu. Najveća amilazna aktivnost je detektovana u ADL ekstraktu. Svi ekstrakti srednjih creva larvi C. cerdo su frakcionisani na koloni Superose 12 HR. Molekulska masa ACC-a je bila 34 kDa.Projekat ministarstva br. 142026

The influence of boron addition on properties of copper-zirconium alloys

Copper-zirconium alloys with high conductivity were produced using powder metallurgy. Two-steps manufacturing process, containing mechanical alloying followed by hot pressing, was applied in achieving improved mechanical and physical properties of Cu-Zr alloy. In this paper, the influence of boron on Cu-Zr alloys properties was studied on Cu-1Zr (wt.%) and Cu-1.1Zr-0.3B (wt.%) systems. Scanning electron microscopy, laser nanoparticle sizer, computed tomography and X-ray diffraction were employed for observation of changes in the microstructure during production steps. More specifically – variations in size of the Cu particles, powder mixtures’ structural parameters, and development of CuZr phase in binary alloy, CuZr phase and ZrB2 particles in ternary alloy were observed. It was shown that presence of boron increases dislocation density in ternary alloy over the mechanical alloying time compared to binary alloy. The results presented in this study show higher hardening effect in Cu-Zr-B alloy compared to Cu-Zr alloy, resulting in stable hardness values during thermomechanical treatment. Further, it can be seen that finely dispersed reinforcing ZrB2 particles in copper matrix does not have significant influence on its conductivity. Moreover, both systems Cu-Zr and Cu-Zr-B exhibit better electrical conductivity after thermomechanical treatment as a result of zirconium reduction in solid solution due to its precipitation.Високо проводне легуре бакра са додатком цирконијума произведене су металургијом праха. У постизању побољшаних механичких и физичких својстава CuZr легуре примењен је двостепени процес производње, који садржи механичко легирање праћено топлим пресовањем. У овом раду проучаван је утицај бора на својства Cu-Zr легура поређењем система Cu-1Zr (теж.%) и Cu-1.1Zr-0.3В (теж.%). Промене у микроструктури током производних корака праћене су помоћу метода: скенирајућа електронска микроскопија, ласерско одређивање величина микро- и наночестица, компјутерска томографија и рендгенска дифракција. Посебно су посматране варијације у величини честица бакра, структурних параметара мешавине праха и развој CuZr фазе у бинарној легури, као и CuZr фазе и ZrВ2 честица у терцијарној легури. Показало се да присуство бора повећава густину дислокација у терцијарној легури током механичког легирања у поређењу са бинарном легуром. Резултати приказани у овој студији показују већи ефекат ојачавања у легури Cu-Zr-B у поређењу са легуром Cu-Zr, што резултира стабилним вредностима тврдоће током термичке обраде. Даље, може се видети да фино дисперговане честице ZrB2 у матрици бакра показују незнатан утицај на њену проводљивост. Такође, оба система Cu-Zr и Cu-Zr-B показују бољу електричну проводљивост након термичке обраде као резултат редукције цирконијума у чврстом раствору услед његовог таложења

On the influence of resonance photon scattering on atom interference

Here, the influence of resonance photon-atom scattering on the atom interference pattern at the exit of a three-grating Mach-Zehnder interferometer is studied. It is assumed that the scattering process does not destroy the atomic wave function describing the state of the atom before the scattering process takes place, but only induces a certain shift and change of its phase. We find that the visibility of the interference strongly depends on the statistical distribution of transferred momenta to the atom during the photon-atom scattering event. This also explains the experimentally observed (Chapman et al 1995 Phys. Rev. Lett. 75 2783) dependence of the visibility on the ratio d_p/\lambda_i = y'_{12} (2\pi/kd\lambda_i), where y'_{12} is distance between the place where the scattering event occurs and the first grating, k is the wave number of the atomic center-of-mass motion, $d$ is the grating constant and \lambda_i is the photon wavelength. Furthermore, it is remarkable that photon-atom scattering events happen experimentally within the Fresnel region, i.e. the near field region, associated with the first grating, which should be taken into account when drawing conclusions about the relevance of "which-way" information for the interference visibility.Comment: 9 pages, 1 figur

Design and In Vitro Biological Evaluation of a Novel Organotin(IV) Complex with 1-(4-Carboxyphenyl)-3-ethyl-3-methylpyrrolidine-2,5-dione

A novel triphenyltin(IV) compound with 1-(4-carboxyphenyl)-3-ethyl-3-methylpyrrolidine-2,5-dione was synthesized and characterized by IR, NMR spectroscopy, mass spectrometry, and elemental analysis. In vitro anticancer activity of ligand precursor and synthesized organotin(IV) compound was determined against tumor cell lines: human adenocarcinoma (HeLa), human myelogenous leukemia (K562), and human breast cancer (MDA-MB-453), using microculture tetrazolium test (MTT) assay. The results indicate that complex exhibited very high antiproliferative activity against all tested cell lines with IC50 values in the range of 0.22 to 0.53 mu M. The highest activity organotin(IV) compound expressed against the HeLa cells (IC50=0.22 +/- 0.04 mu M). The ligand precursor did not show anticancer activity (IC50>200 mu M). Furthermore, fluorescence microscopy analysis of HeLa cells reveal that organotin(IV) complex induced apoptosis as a mode of cell death, which is consistent with the increase of cells in the sub-G1 phase