Entangling different degrees of freedom by quadrature squeezing cylindrically polarized modes.

Quantum systems such as, for example, photons, atoms, or Bose-Einstein condensates, prepared in complex states where entanglement between distinct degrees of freedom is present, may display several intriguing features. In this Letter we introduce the concept of such complex quantum states for intense beams of light by exploiting the properties of cylindrically polarized modes. We show that already in a classical picture the spatial and polarization field variables of these modes cannot be factorized. Theoretically it is proven that by quadrature squeezing cylindrically polarized modes one generates entanglement between these two different degrees of freedom. Experimentally we demonstrate amplitude squeezing of an azimuthally polarized mode by exploiting the nonlinear Kerr effect in a specially tailored photonic crystal fiber. These results display that such novel continuous-variable entangled systems can, in principle, be realized.

Orientational disorder as a function of temperature in the clathrate structure of hydroquinone and C60

In the compound [C(6)H(6)O(2)](3)C(60), hydroquinone (C(6)H(6)O(2)) forms a three-dimensional hydrogen-bonded network enclosing roughly spherical cages with point symmetry 3;m and a diameter of 13.2 A at 100 K. Although C(60) fits tightly into these cages, it shows threefold orientational disorder, the molecular site symmetry being 2/m. The disorder has been studied with single-crystal Mo Kalpha X-ray data at four temperatures, 100, 200, 293 and 373 K. In the refinement, C(60) was restrained to the icosahedral molecular symmetry m3;5; and to rigid-body translational and librational displacements including third- and fourth-order cumulants to account for curvilinear atomic movements, R(|F|) = 3.2-4.7%. At 100 K, bond lengths in C(60) refine to the expected values 1.450 (1) and 1.388 (1) A. The ratio of these values increases with increasing temperature, but the radius of the molecule remains constant at 3. 537 (2) A. The r.m.s. libration amplitudes of C(60) are relatively small (5.5 degrees at 373 K) and the probability function of orientations of C(60) inside the cage shows large values only at the refined positions, indicating that the energy barrier of reorientation is large. Refinement of an ordered twinned structure was unsuccessful; the orientations of neighboring C(60) appear to be uncorrelated.

Dynamics of molecules in crystals from multi-temperature anisotropic displacement parameters. II. Application To benzene (C6D6) and urea

The temperature evolution of atomic anisotropic displacement parameters (ADP's) of perdeuterobenzene and of urea in the temperature range between 12 and 123 K is investigated in terms of the model presented in paper I. For the benzene molecule, the temperature-dependent contributions to the ADP's are well described by three molecular librations and three molecular translations. For the urea molecule, the analysis revealed a low-frequency high-amplitude normal mode ( approximately 64 cm(-1)), which combines out-of-plane deformations of the NH(2) groups with molecular libration. The pyramidalization motion allows the hydrogen-bonding pattern to be retained quite well, whereas this pattern is heavily distorted in the higher-frequency molecular librations. The results presented for urea go a step beyond those obtainable in a conventional rigid-body or segmented-rigid-body analysis because they show how correlations of atomic displacements in molecular crystals can be determined from the temperature evolution of ADP's. For both molecules, the analysis reveals temperature-independent contributions to the ADP's accounting for the high-frequency internal vibrations. It is the first time that such contributions have been extracted directly from single-crystal diffraction data for light atoms like hydrogen and deuterium as well as for heavier atoms like carbon, nitrogen and oxygen. These contributions agree well with those calculated from independent spectroscopic information.

[Polyethylene content and cell size of foreign body giant cells in aseptic hip prosthesis loosening--a histomorphometric study]. / Polyethylenbeladung und Zellgrösse von Fremdkörperriesenzellen bei der aseptischen Hüftendoprothesenlockerung--Eine histomorphometrische Untersuchung.

INTRODUCTION: In aseptic loosening of cementless hip arthroplasty polyethylene particles are phagocytized by macrophages and foreign-body giant cells. This initiates an osteolytic cascade. In this study, the authors investigated if there are correlations between the size of foreign-body giant cells and the polyethylene loading and number of intracellular particles as determined by light microscopy. MATERIAL AND METHOD: Histological specimens were processed from tissues retrieved during revision surgery of 7 cases of cementless hip arthroplasty which had become aseptically loose. The specimens were analyzed by histolomorphology and histomorphometry. The cell size, polyethylene loading and intracellular particle number of 111 foreign-body giant cells were determined. A regression analysis was performed to investigate if there was a correlation between these variables. RESULTS: The mean cell size was 1417 +/- 487 micron 2, the mean polyethylene loading was 49 +/- 42 micron 2 and the mean intracellular particle number was 10.4 +/- 5.4. The cell size correlated with both the intracellular particle number (r = 0.25) and the polyethylene loading (r = 0.39). CONCLUSIONS: In the cellular reaction to polyethylene particles in aseptic loosening of cementless total hip arthroplasty, the size of foreign-body giant cells correlates with intracellular polyethylene loading and intracellular polyethylene particle number as determined by light microscopy. The presence of large foreign body giant cells might be associated with a high particle load of the tissue and a high osteolytic activity.

Plasma sterilization of selected ophthalmic instruments for combined intraocular surgery.

Plasma sterilization is a nontoxic fast procedure for thermolabile and thermostable microsurgical instruments. We report data on the microbicidal effectiveness for daily routine surgical instruments like steel scissors, trephination devices, microstripper and Vitro-Cat as well as irrigation/aspiration instruments. When these instruments were cleaned from blood and saline, and when H2O2 intensifiers (adapters) were applied where necessary plasma sterilization proved to be a microbiologically safe procedure with legally adequate reduction factors of > 6 log.

[H2O2 low temperature plasma sterilization. New possibilities for use with eye surgery instruments]. / H2O2-Niedrigtemperatur-Plasmasterilisation (NTP). Neue Möglichkeiten für den Einsatz augenchirurgischer Instrumente.

The H2O2-low-temperature-plasma-sterilization (STERRAD 100) works with a temperature below 50 degrees C (140 degrees F). This system is appliable for thermostabile materials as well as for thermolabile materials. The efficancy of this new system is shown by a biological test with Bacillus pumilus spores. 5 typical ophthalmic surgical instruments were contaminated. After sterilization the numerical reduction of the microorganisms had to be at least 6 log levels. Corrosion caused by hydrogene peroxide was excluded after exposing steal with a high quantity of this substrate. Electromicroscopy analysations of the surfaces of stainless steal after LTP, steam sterilization and hot-air sterilization are compared. Options and limitations of this new sterilization technique are discussed. A newly developed operating system with a complete instrumental box (OP-Set) will be introduced.

Medication education for children. Is it worthwhile?

Child psychiatric inpatients have little or no control over their treatment. Anxiety and fear are normal reactions to the hospitalization and treatment process. Pharmacotherapy is an intervention that the child often perceives as an indicator of pathology. This article presents various methodologies to teach children about their medication treatment. Puppetry, graphics, art, and discussion were techniques used in a peer group to impart knowledge and decrease anxiety, fear, and negativity.