Local probe of single phonon dynamics in warm ion crystals.

The detailed characterization of non-trivial coherence properties of composite quantum systems of increasing size is an indispensable prerequisite for scalable quantum computation, as well as for understanding non-equilibrium many-body physics. Here, we show how autocorrelation functions in an interacting system of phonons as well as the quantum discord between distinct degrees of freedoms can be extracted from a small controllable part of the system. As a benchmark, we show this in chains of up to 42 trapped ions, by tracing a single phonon excitation through interferometric measurements of only a single ion in the chain. We observe the spreading and partial refocusing of the excitation in the chain, even on a background of thermal excitations. We further show how this local observable reflects the dynamical evolution of quantum discord between the electronic state and the vibrational degrees of freedom of the probe ion.

Michelson-Morley analogue for electrons using trapped ions to test Lorentz symmetry.

All evidence so far suggests that the absolute spatial orientation of an experiment never affects its outcome. This is reflected in the standard model of particle physics by requiring all particles and fields to be invariant under Lorentz transformations. The best-known tests of this important cornerstone of physics are Michelson-Morley-type experiments verifying the isotropy of the speed of light. For matter, Hughes-Drever-type experiments test whether the kinetic energy of particles is independent of the direction of their velocity, that is, whether their dispersion relations are isotropic. To provide more guidance for physics beyond the standard model, refined experimental verifications of Lorentz symmetry are desirable. Here we search for violation of Lorentz symmetry for electrons by performing an electronic analogue of a Michelson-Morley experiment. We split an electron wave packet bound inside a calcium ion into two parts with different orientations and recombine them after a time evolution of 95 milliseconds. As the Earth rotates, the absolute spatial orientation of the two parts of the wave packet changes, and anisotropies in the electron dispersion will modify the phase of the interference signal. To remove noise, we prepare a pair of calcium ions in a superposition of two decoherence-free states, thereby rejecting magnetic field fluctuations common to both ions. After a 23-hour measurement, we find a limit of h × 11 millihertz (h is Planck's constant) on the energy variations, verifying the isotropy of the electron's dispersion relation at the level of one part in 10(18), a 100-fold improvement on previous work. Alternatively, we can interpret our result as testing the rotational invariance of the Coulomb potential. Assuming that Lorentz symmetry holds for electrons and that the photon dispersion relation governs the Coulomb force, we obtain a fivefold-improved limit on anisotropies in the speed of light. Our result probes Lorentz symmetry violation at levels comparable to the ratio between the electroweak and Planck energy scales. Our experiment demonstrates the potential of quantum information techniques in the search for physics beyond the standard model.

Potential Use of Transferred Lymph Nodes as Metastasis Detectors after Tumor Excision

Due to the fact that it reliably results in positive outcomes, lymph node flap transfer is becoming an increasingly popular surgical procedure for the prevention and treatment of lymphedema. This technique has been shown to stimulate lymphoangiogenesis and restore lymphatic function, as well as decreasing infection rates, minimizing pain, and preventing the recurrence of lymphedema. In this article, we investigate possible additional benefits of lymph node flap transfer, primarily the possibility that sentinel lymph nodes may be used to detect micro-metastasis or in-transit metastasis and may function as an additional lymphatic station after the excision of advanced skin cancer.

Lymphedema Fat Graft: An Ideal Filler for Facial Rejuvenation

Lymphedema is a chronic disorder characterized by lymph stasis in the subcutaneous tissue. Lymphatic fluid contains several components including hyaluronic acid and has many important properties. Over the past few years, significant research has been performed to identify an ideal tissue to implant as a filler. Because of its unique composition, fat harvested from the lymphedema tissue is an interesting topic for investigation and has significant potential for application as a filler, particularly in facial rejuvenation. Over a 36-month period, we treated and assessed 8 patients with lymphedematous limbs who concurrently underwent facial rejuvenation with lymphedema fat (LF). We conducted a pre- and post-operative satisfaction questionnaire survey and a histological assessment of the harvested LF fat. The overall mean general appearance score at an average of 6 months after the procedure was 7.2+/-0.5, demonstrating great improvement. Patients reported significant improvement in their skin texture with a reading of 8.5+/-0.7 and an improvement in their self-esteem. This study demonstrates that LF as an ideal autologous injectable filler is clinically applicable and easily available in patients with lymphedema. We recommend the further study and clinical use of this tissue as it exhibits important properties and qualities for future applications and research.

Superantigen Staphylococcal enterotoxin B induces release of IL-1beta in human epidermis.

Lesional skin in patients with inflammatory skin diseases is often colonized with Staphylococcus aureus, which is capable of releasing superantigens. We therefore studied whether application of superantigen on the skin led to release of cytokines, especially IL-1beta. Suction blisters were raised on vehicle- and superantigen-treated skin and IL-1beta protein levels measured in suction blister fluid and supernatant from blister roofs. In all volunteers studied, application of the superantigen Staphylococcal enterotoxin B led to increased release of IL-1beta protein from suction blister roofs (n=7). In contrast, we did not detect any difference in IL-1beta in the blister fluid (n=5). IL-1beta is known as a mediator of inflammation, and the increase in IL-1beta may be involved in the aggravation of inflammatory skin diseases seen following Staphylococcus aureus colonization.

Efficient method for preparation of highly purified lipopolysaccharides by hydrophobic interaction chromatography.

A method for the efficient preparation of highly purified lipopolysaccharides (LPSs) by hydrophobic interaction chromatography (HIC) has been developed. The procedure can be used for the purification of cell wall bound LPSs after hot phenol-water extraction and for the isolation of extracellular LPSs from the supernatant, respectively. The method described has been tested with artificial mixtures containing LPSs, polysaccharide, protein and RNA and subsequently employed for the preparative purification of two LPSs of different origin, namely the extracellular LPS secreted by Escherichia coli E49 into the culture medium, and the cell wall bound LPS from Pseudomonas aeruginosa VA11465/1. Compared to currently used methods for LPS purification such as enzymatic digestion and ultracentrifugation, the chromatographic separation reported here combines superior purity with minimal loss of LPS, high reproducibility and simple handling. The removal of contaminants such as protein, RNA and polysaccharides and the recovery of LPSs were monitored by appropriate assays.

Studies of the biosynthesis of tentoxin by Alternaria alternata.

Biosynthesis of the phytotoxin, tentoxin, its regulation and the enzymic synthesis steps were studied in vivo and in vitro. The physiology of biosynthesis of tentoxin in vivo was investigated by using sections of mycelial mats incubated in buffer. Differentiated mycelia could be studied under defined conditions. The de novo synthesis of tentoxin was measured by incorporation of [U-14C]leucine into tentoxin. The investigation system was stable for 10 h. Biosynthesis and the growth of biomass started before day 5 of culture, with the maximum between days 9 and 12. After this, biosynthesis quickly declined. pH values about 7 were optimal, and pH values above and below this led to an increased release of tentoxin stored in the cells. The formation of tentoxin by older mycelia was not regulated by acetate, phosphate or glucose, which was not utilized. Precursor amino acids, applied at the start of the culture, slightly activated the synthesis of tentoxin. Older mycelia were inhibited. Substances from the host plant (Brassica chinensis) reduced the de novo synthesis of tentoxin. Enzyme separation studies suggested that biosynthesis of tentoxin involves a multienzyme (> or = 400 kDa), which is a polyfunctional protein without subunits. Experiments suggested that the synthetase contains active SH-groups and an integrated activity of methyltransferase. The precursor amino acids are activated by ATP and bound at the enzyme. N-Methylation occurs with the enzyme-bound amino acids or during the elongation of the growing peptide chain. Methionine is the primary donor of the methyl groups, but the immediate methylation reaction needs 5-adenosyl methionine (SAM). The methylation is essential for the continuation of biosynthesis. The elongation proceeds either stepwise from glycine by binding alanine/methylalanine, phenylalanine/methylphenylalanine and leucine or by formation and linkage of two dipeptides glycine-alanine/methylalanine and phenylalanine/methylphenylalanine-leucine. At the end of this process dihydrotentoxin, the direct precursor of tentoxin, is released from the synthetase probably by cyclization. Independent of this first enzyme, dihydrotentoxin is transformed into tentoxin. This last reaction step is reversible. The rate of transformation of dihydrotentoxin to tentoxin is higher, but in this direction the native turnover is relatively low.(ABSTRACT TRUNCATED AT 400 WORDS)

Structural studies of the side chain of outer membrane lipopolysaccharide from Pseudomonas syringae pv. coriandricola W-43.

The lipopolysaccharide (LPS) was isolated from Pseudomonas syringae pv. coriandricola W-43 by hot phenol-water extraction. Rhamnose and 3-N-acetyl-3-deoxyfucose were found to be the major sugar constituents of the LPS together with N-acetylglucosamine, N-acetylgalactosamine, heptose, and 3-deoxy-D-manno-octulosonic acid (Kdo). The main fatty acids of lipid A of the LPS were 3-OH-C:10, C12:0, 2-OH-C12:0, and 3-OH-C12:0. The O-specific polysaccharide liberated from the LPS by mild-acid hydrolysis was purified by gel permeation chromatography. The compositional analysis of the O-specific polysaccharide revealed the presence of L-rhamnose and 3-N-acetyl-3-deoxy-D-fucose in a molar ratio of 4:1. The primary structure of the O-specific polysaccharide was established by methylation analysis together with 1H and 13C nuclear magnetic resonance spectroscopy, including two-dimensional shift-correlated and one-dimensional nuclear Overhauser effect spectroscopy. The polysaccharide moiety was found to consist of a tetrasaccharide rhamnan backbone, and 3-N-acetyl-3-deoxy-D-fucose constitutes the side chain of the branched pentasaccharide repeating unit of the polysaccharide.

[Modeling of unstable heat-mass air exchange in the lungs]. / Modelirovanie nestatsionarnogo teplomassoobmena vozdukha v legkikh.

A mathematical model of the unsteady-state heat and mass exchange of expired air in the bronchial tree is suggested. The model includes heat and mass exchange between air and bronchial walls, and heat exchange between blood circulation and bronchial tree. A problem has been numerically solved as a unidimensional one in the quasi-steady-state formulation. It is shown that air conditioning occurs through the whole length of a respiratory tract. During inspiration bronchial walls are cooled, that in its turn induces a decrease of air temperature and water vapour content in time. That process depends on the intensity of lung blood circulation and character of air velocity changes during inspiration.

Nitrosamine formation from amines applied to the skin of mice after and before exposure to nitrogen dioxide.

Skin lipids of mice exposed to NO2 contain lipid-soluble nitrosating agent(s) (NSA) that react in vitro with amines to produce nitrosamines. To test whether this reaction occurs in skin, we exposed mice to 50 ppm NO2 for 4 h and, 20 h later, applied 25 mg morpholine or N-methylaniline to the skin, which was then analyzed for the corresponding nitrosamine. When morpholine was applied, mean N-nitrosomorpholine yield was only 0.3 nmol/mouse (not significant). When N-methylaniline was applied and mice were killed after 10-40 min, N-nitroso-N-methylaniline yield in the skin was 13-21 nmol/mouse of which 87% occurred in the hair. NSA formation when mice were exposed to 6.5 ppm NO2 was only 0.15% of that for exposure to 50 ppm NO2. NSA occurred mostly in surface lipids of the skin and its in vitro reaction to give nitrosamines was not inhibited by alpha-tocopherol. When morpholine was painted and mice were then exposed to 55 ppm NO2 for 30 min, the skins contained 19 nmol N-nitrosomorpholine/mouse, attributed to a direct reaction between NO2 and the amine. We concluded that nitrosamine formation in skin by this direct reaction may be more important than the reaction of amines with NO2-derived NSA.

Demonstration of in vivo formation of the nitrosamine N-nitroso-N-methylaniline from amyl nitrite.

Kaposi's sarcoma is associated with Acquired Immune Deficiency Syndrome (AIDS) in U.S. homosexuals. A possible explanation is that butyl nitrite, inhaled as a drug of abuse, initiates the tumor via the in vivo formation of N-nitroso compounds. To demonstrate that such a process can occur, we injected mice i.p. with the amine N-methylaniline (250 mg/kg), gavaged them 30 min later with amyl nitrite (AmNO2, 40 mg/kg), killed the mice after another 30 or 60 min, and analyzed the carcasses for N-nitroso-N-methylaniline (NMA). We obtained 480 +/- 130 (mean +/- S.E. for 6 mice killed after 30 min) and 380 +/- 40 (for 6 mice killed after 60 min) nmol NMA/mouse. Much lower yields were obtained when AmNO2 was injected i.p. and methylaniline was gavaged. Hence, relatively large amounts of at least one nitrosamine can be produced in vivo from simple nitrite esters.

Lipidic nitrosating agents produced from atmospheric nitrogen dioxide and a nitrosamine produced in vivo from amyl nitrite.

In studies on nitrosating agent(s) formed in skin of mice exposed to nitrogen dioxide, we showed that: (i) N-nitrosomethylaniline was produced in skin of mice exposed to nitrogen dioxide and then painted with N-methylaniline; (ii) a nitrosating precursor in methyl linoleate is associated with peroxidation products; (iii) cholesterol is a major nitrosating precursor in mouse skin, probably because it produces the nitrosating agent, cholesteryl nitrite; (iv) cholesteryl nitrite enhances autoxidation of lipids in vivo and on mouse skin and, like sodium nitrite, catalyses the autoxidation of iodide; (v) N-nitrosomethylaniline was produced in mice injected intraperitoneally with methylaniline and gavaged with amyl nitrite; and (vi) nitrosating agents may occur normally in human skin lipids.

[Mathematical model of the effect of mass transfer on heat exchange in the respiratory tract]. / Matematicheskaia model' vliianiia massoperenosa na teploobmen v respiratornom trakte.

On the base of the Weibel geometrical model of bronchial tree, a mathematical model of mass and heat transfer in the lungs was worked out. Mass transfer seems to play an important role in the heating of air.

[Simulation of a steady-state mass-heat exchange in the respiratory tract]. / Modelirovanie statsionarnogo massoteploobmenta v respiratornom trakte.

On the basis of Weibel respiratory tract model the mathematical model of mass and heat transfer in the lungs was solved for steady-state one-dimensional case. Coefficients of mass and heat transfer were taken from empirical expressions for canals. The model shows that independent water vapour or air heat saturation in the lungs occurs in 12-14 generations of the bronchial tree. The saturation site depends upon volume velocity of the air and functioning of the upper respiratory tract.