Application of an F57 sequence-based real-time PCR assay for Mycobacterium paratuberculosis detection in bulk tank raw milk and slaughtered healthy dairy cows.

A light cycler-based real-time PCR assay that targets the F57 sequence was used to collect data on the prevalence of Mycobacterium avium subsp. paratuberculosis (MAP) in 100 bulk tank raw milk samples and in a population of 101 slaughtered dairy cattle. The assay's reproducible detection limit in total genomic DNA templates isolated from 10-ml samples of MAP-spiked raw milk was 100 cells per ml. Similarly, the evaluation of MAP-spiked bovine feces also demonstrated that the assay had a reproducible detection limit of 100 cells if they were contained within 200 mg of fecal sample material. Among the 100 bulk tank milk samples that were tested, we found 3 samples (3%) to be positive for MAP In the slaughterhouse part of the study, 8.9% (9 of 101) of the cows were positive for MAP DNA in fecal samples, 4.9% (5 of 101) in mesenteric lymph nodes, 0.9% (1 of 101) in ileum tissue, and 3.6% (3 of 84) in milk. Meanwhile, for 2.9% (3 of 101) of the culled cows, MAP DNA was detected in samples of diaphragmatic muscles.

MR imaging of calcification of the lateral collateral ligament of the knee: a rare abnormality and a cause of lateral knee pain.

OBJECTIVE: Our objective was to describe the radiologic appearances of calcification of the lateral collateral ligament (LCL) of the knee in four patients who presented with acute atraumatic lateral knee pain. This rare abnormality has not, to our knowledge, been previously shown on MR imaging. CONCLUSION: Calcification of the LCL of the knee is a rare cause of lateral knee pain and is thought to reflect underlying hydroxyapatite deposition. On MR imaging, calcification of the LCL may be associated with an aggressive appearance that can be mistaken for other knee abnormalities.

Highly functionalized dimeric tetraethynylethenes and expanded radialenes: strong evidence for macrocyclic cross-conjugation.

A selection of dimeric tetraethynylethenes (TEEs) and perethynylated expanded radialenes, containing different donor/acceptor substitution patterns, have been prepared and fully characterized. The first X-ray crystal structure of an expanded [6]radialene, with twelve peripheral 3,5-di(tert-butyl)phenyl substituents, is presented. This macrocycle, the all-carbon core of which is isomeric with fullerene C60, adopts a non-planar, "chair-like" conformation. Also a TEE dimer, carrying N,N-dimethylaniline donor substituents, has been subjected to an X-ray crystallographic analysis. The electronic properties were studied by UV/Vis spectroscopy and electrochemistry, providing fundamental insight into mechanisms of pi-electron delocalization in the acyclic and macrocyclic chromophores. Donor or donor-acceptor-substituted dimeric TEE derivatives show very strong absorptions extending over the entire UV/Vis region; their longest wavelength absorption bands have high charge-transfer character. Macrocyclic cross-conjugation in the expanded radialenes becomes increasingly efficient with increasing donor-acceptor polarization. A dual, strongly solvent-polarity-dependent fluorescence was observed for a tetrakis(N,N-dimethylaniline)-substituted dimeric TEE; this interesting emission behavior is explained by the twisted intramolecular charge-transfer (TICT) state model. Donor-substituted expanded radialenes display huge resonance-enhanced third-order nonlinear optical coefficients.

Pt-tetraethynylethene molecular scaffolding: synthesis and characterization of a novel class of organometallic molecular rods.

The series of monodisperse Pt-bridged TEE oligomers 3a-f was prepared by oxidative Glaser-Hay oligomerization of monomer 7 under end-capping conditions. These novel molecular rods extend in length from 3.3 nm (monomeric 3a) to 12.1 nm (hexameric 3 f). Their isolation was achieved by high performance gel permeation chromatography (GPC), and their purification was best monitored by analytical GPC in combination with matrix-assisted laser-desorption-ionization mass spectrometry (MALDI-TOF MS). The mass spectra of each oligomer revealed the molecular ion or its sodium complex as parent ion together with a clean, highly characteristic fragmentation pattern. Delayed addition of the end-capping reagent PhC(triple bond)CH to the oligomerization mixture afforded polymer 10 with an average of approximately 32 repeat units and a remarkably narrow molecular weight distribution (Mw/Mn=1.06), which is indicative of a living polymerization process. UV/Vis spectral data as well as measurements of the second hyperpolarizability gamma by third harmonic generation (THG) revealed a nearly complete lack of pi-electron delocalization along the oligomeric backbone. The Pt atoms act as true insulating centers, and the Pt-C(sp) bonds hardly possess any pi character. The synthesis of the molecular rods 3a-f provides another demonstration of the power of oxidative acetylenic homocouplings for the preparation of unusual nanoarchitecture.

Monodisperse poly(triacetylene) oligomers extending from monomer to hexadecamer: joint experimental and theoretical investigation of physical properties

A series of monodisperse Et3-Si-end-capped poly(triacetylene) (PTA) oligomers ranging from monomer to hexadecamer was prepared by a fast and efficient statistical deprotection-oxidative Hay oligomerization protocol. The PTA oligomers exhibit an increasingly deep-yellow color with lengthening of the pi-conjugated backbone, feature excellent solubility in aprotic solvents, and exhibit melting points up to > 22 degrees C for the hexadecameric rod. This new dramatically extended oligo(enediyne) series now enables to investigate the evolution of the physico-chemical effects in PTAs beyond the linear 1/n versus property regime into the higher oligomer region where saturation becomes apparent. We report the results of joint experimental and theoretical studies, including analysis of the 13C NMR spectra, evaluation of the linear (UV/ Vis) and nonlinear [third-harmonic generation (THG) and degenerate four-wave mixing (DFWM)] optical properties, and characterization of the redox properties with cyclic and steady-state voltammetry. Up to the hexadecameric rod, an increasingly facile one-electron reduction step is observed, showing at the stage of the dodecamer, a leveling off tendency from the linear correlation between the inverse number of monomer units and the first reduction potential. The effective conjugation length (ECL) determined by means of UV/Vis spectroscopy revealed a pi-electron-delocalization length of about n = 10 monomeric units, which corroborates well with the oligomeric length for which in the 13C NMR spectrum C(sp2) and C(sp) resonances start to overlap. Third-harmonic generation (THG) and degenerate four-wave mixing (DFWM) measurements revealed for the second-order hyperpolarizability gamma a power law increase gammma-alpha-n(a) for oligomers up to the octamer with exponential factors a= 2.46+/-0.10 and a=2.64+/-0.20, respectively, followed by a smooth saturation around n = 10 repeating units. The power law coefficient a calculated with the help of the valence effective Hamiltonian (VEH) method combined to a sum-over-states (SOS) formalism corroborates well with the values found by both THG and DFWM experiments. Up to the PTA heptamer, INDO (intermediate neglect of differential overlap)-calculated gas-phase ionization potentials and electron affinities obey a linear relationship as a function of the inverse number of monomer units displaying a strong electron-hole symmetry. The onset of saturation for the electron affinity is calculated to occur around the octamer, in accordance with experimentally obtained results from electrochemical measurements.

Synthesis and physical investigation of donor-donor and acceptor-acceptor end-functionalized monodisperse poly(triacetylene) oligomers.

Two series of monodisperse, terminally donor-donor [D-D, D=4-(dimethylamino)phenyl] and acceptor-acceptor [A-A, A=4-nitrophenyl] functionalized poly(triacetylene) (PTA) oligomers ranging from monomer to hexamer were synthesized by oxidative Hay oligomerization under end-capping conditions. The corresponding D-D and A-A end-substituted polymers with an average degree of polymerization (DP) of n approximately 18 and n approximately 12, respectively, were also prepared and served as reference points for the corresponding infinitely long polymers. These terminally functionalized PTA oligomers and polymers are yellow- to orange-colored compounds, displaying excellent solubility in aprotic solvents with melting points above 200 degrees C for the hexamers. For the 4-(dimethylamino)phenyl substituted compounds, a consistent first oxidation potential around +0.42 V versus Fc/Fc+ (ferrocene/ferricinium) was observed, whereas the 4-nitrophenyl functionalized systems underwent a reversible reductive two-electron transfer around -1.40V versus Fc/Fc+. The nature of the end-groups has a dramatic influence on the electronic absorption spectra. Saturation of the linear optical properties in the D-D series occurs at significantly shorter chain-length [effective conjugation length (ECL) of n approximately 4 monomer units] than in the A-A substituted or the previously reported Me3Si- and Et3Si-end-capped PTA oligomer series (ECL: n approximately 10 monomer units). Similar observations with respect to the ECL were made by measurement of the Raman-active v(C triple bound C) stretches. Third-harmonic generation (THG) and degenerate four-wave mixing (DFWM) experiments showed that shorter oligomers of terminally D-D or A-A functionalized PTAs display higher second hyperpolarizabilities gamma than the corresponding R3Si-end-capped series (R=alkyl). Moreover, they disclose a distinct peak of the nonlinearity per monomer unit at intermediate backbone lengths. In THG experiments, the second hyperpolarizabilities for long D/A-functionalized PTA oligomers attained the same saturation values as observed for the corresponding R3Si-end-capped rods. The nonlinearities measured by DFWM of the D-D and A-A substituted PTAs were found to be larger than for the silylated ones, which can be explained by the closeness of the two-photon resonance.

Cascaded contributions to degenerate four-wave mixing in an acentric organic crystal.

We show both theoretically and experimentally by degenerate four-wave mixing that the combined processes of optical rectification and the linear electro-optic effect contribute to the large effective third-order susceptibilities [14chi((3))(CS(2))] of the organic salt 4-N, N^- dimethylamino-4(?) -N(?) -methylstilbazolium toluene-p- sulfonate (DAST). Furthermore, the knowledge of the cascaded contributions was used to determine absolute values of the third-order susceptibilities as well as their sign.

Scaling law for second-order hyperpolarizability in poly(triacetylene) molecular wires.

Poly(triacetylenes) are rodlike molecules with electrons delocalized over a one-dimensional path. We show that they exhibit a power-law dependence of the second-order hyperpolarizability gamma on the monomer unit n for short molecules and a smooth saturation toward a linear increase in longer molecules. The power law of gamma?n(a) with a approximately 2.5 from dengenerate four-wave mixing and third-harmonic generation measurements is in good agreement with quantum-chemical calculations. The critical conjugation length for saturation in the three cases is shown to be approximately 60 carbon-carbon bonds, which indicates the upper boundary for the electron delocalization in such a one-dimensional molecular wire.

High-frequency response and acoustic phonon contribution of the linear electro-optic effect in DAST.

We present a simple method to measure the contribution from acoustic phonons to the linear electro-optic effect. A step voltage with a short rise time (600 ps) is applied to the sample, and the electro-optic response is measured in the time domain. For the organic salt 4-N, N-dimethylamino-4(?)-N(?)-methyl-stilbazolium tosylate (DAST), we obtained a negative contribution of r(a)(111) = -1.0 +/- 0.1 pm/V to the overall electro-optic coefficient of r(111) = 48 +/- 5 pm/V (lambda = 1535 nm). The electro-optic response was limited only by the rise time of the applied voltage, which corresponds to a frequency of 1 GHz.

Photorefractive effects observed in 4-N, N-dimethylamino-4'-N'-methyl-stilbazolium toluene-p-sulfonate.

We measured, for the first time to our knowledge, a net two-beam coupling gain in an organic crystal. Our photorefractive measurements were carried out in nominally pure organic crystals of 4-N, N-dimethylamino-4'-N'-methyl-stilbazolium toluene-p-sulfonate (DAST). Because of its large electro-optic coefficient, r(11) = 83 pm/V at lambda = 750 nm, and a photoconductivity of up to sigma = 6.7 x 10(-12) ?(-1) cm(-1) at intensity I = 570 mW/cm(2), DAST showed a gain of 2.2 cm(-1) for an absorption of alpha = 1.8 cm(-1). With grating buildup times below 1 s at light intensities of 300 mW/cm(2), DAST is a promising candidate for photorefractive applications in the near infrared.

High-repetition-rate femtosecond optical parametric oscillator based on KNbO(3).

A Ti:sapphire-pumped, high-repetition-rate, femtosecond optical parametric oscillator based on potassium niobate is described. Signal pulses as short as 90 fs have been recorded, and idler pulses as short as 105 fs have been measured. Tuning from 1.2 to 1.4 microm in the signal branch and from 1.76 to 2.2 microm in the idler branch has been achieved. Output powers as high as 300 mW have been measured at the signal wavelength.

Second-order cascading as the origin of large third-order effects in organic single-crystal-core fibers.

We have identified cascading of second-order nonlinear processes as the origin of previously reported, very large nonlinearities measured by self-phase-modulation experiments in organic single-crystal-core fibers of 4-(N,N-dimethylamino)-3-acetamidonitrobenzene.

[Music during gastroscopy]. / Musik bei der Gastroskopie.

As part of a project "Music therapy in internal medicine" we investigated 32 consecutive patients undergoing gastroscopy for various reasons. Patients were randomly assigned to two groups, regardless of sex, age or underlying disease. One group listened to music during gastroscopy, while the other did not. The choice of the type of music within the corresponding group was made with the patient and a trained music therapist in a short discussion prior to gastroscopy. The hormones ACTH and cortisol, as well as the catecholamines adrenalin and noradrenaline, were measured in both groups with three blood samples taken before, directly after and one hour after gastroscopy. Parallel measurements included blood pressure and pulse rate as well as questions about the patients' feelings during gastroscopy. The study showed the rise in the plasma levels of the stress hormones ACTH and cortisol to be significantly lower under the influence of music. The subjective feelings of the patients concerning "fear in general" and "fear about gastroscopy" paralleled these findings. Conversely, the plasma adrenalin and noradrenaline levels before and after gastroscopy were virtually unchanged in both groups, as were pulse rate and blood pressure. This study shows the influence of music on human biochemical parameters when used in the setting of a diagnostic procedure.

[Severe endocrine ophthalmopathy. A review with case reports]. / Schwere endokrine Ophthalmopathie. Eine Ubersicht mit Fallbeispielen.

The autoimmune pathogenesis of endocrine ophthalmopathy (EO) is only partly elucidated. About 40% of all patients with Graves' disease have clinically overt ophthalmopathy. 5% of all Graves' disease patients develop severe EO, independently of the treatment modality for thyrotoxicosis (radioiodine, surgery, antithyroid drugs) and require multidisciplinary treatment. In cases where glucocorticoid treatment is unsuccessful, orbital decompression, as described by Walsh and Ogura, should be considered.

Simultaneous utilization of methanol-glucose mixtures by Hansenula polymorpha in chemostat: Influence of dilution rate and mixture composition on utilization pattern.

The utilization of mixtures of methanol (C(1)) and glucose (C(6)) of different composition by the methylotrophic yeast Hansenula polymorpha was studied in carbon-limited chemostat culture. For all mixtures tested a similar utilization pattern was observed: At low dilution rates both carbon sources were utilized simultaneously, but at high dilution rates the cells used glucose only and the unutilized methanol accumulated in the culture medium. When grown with C(1) only, the cells exhibited a critical dilution rate D(c)(C(1)) of 0.19 h(-1), but when C(1)-C(6) mixtures were used as the carbon and energy substrate, the yeast was able to completely utilize C(1) at dilution rates considerably higher than D(c)(C(1)). The dilution rate at which the transition from C(1)-C(6) growth to C(6) growth occurred (D(t)) was strictly dependent on the composition of the C(1)-C(6) mixture in the feed, and D(t) increased with decreasing proportions of C(1) in the mixture. During mixed substrate growth the formation of biomass from the two substrates was additive. The results reported indicate that the utilization of C(1)-C(6) mixtures and hence D(t) in H. polymorpha are subject to two different regulatory regimes. When the cells were growing with C(1)-C(6) mixtures containing more than 60% C(1), the transition form C(1)-C(6) to C(6) growth was most probably influenced by the maximum C(1) oxidizing capacity of the cells, whereas for growth with mixtures containing less than 40% C(1), a growth rate of 0.28-0.30 h(-1) seemed to be the limiting barrier for the simultaneous utilization of the components of the binary carbon and energy substrate mixture.

[Application and results of biometry of the eye in implantation of intraocular lenses]. / Anwendung und Resultate der Biometrie des Auges bei der Implantation einer introakularen Linse.

Before extracapsular cataract surgery with implantation of a Binkhorst four-loop lens, keratometric readings were taken and anterior chamber depth was measured with a pachometer in 52 patients. The axial eye length was determined with A-scan echography using the Kretz technique 7200 MA unit with a 8 MHz probe and the immersion technique. The biometric control after surgery showed no change in the spherical equivalent of keratometric values. The mean anterior chamber depth was 3.19 mm (+/- 0.3 mm). No systematic correlation between anterior chamber depth before and after surgery was found. The dependence of the change in anterior chamber depth (DVK) on the cataract thickness (L) is described by the linear regression DVK = 2.22 mm - 0.47 L with a correlation coefficient as low as 0.68. The remaining refractive error after lens implantation, established by subjective testing, was compared with the calculated values. The calculated lenses were found to be more minus than the corrections required by the patients. We conclude that the calculated lens powers had been overestimated and were therefore myopizing in relation with the established length. If postoperative emmetropia had been aimed at on the basis of biometric data and conventional calculations, however, weaker lens powers would have been chosen with postoperative hypermetropia resulting.

[Endoscopy of the nose as an aid in lacrimal duct surgery]. / Endoskopie der Nase als Hilfe für die Tränenwegschirurgie.

Endoscopy of the nose is a recently-adopted supplementary procedure for examining the tear drainage system. This examination is performed under local anesthesia with the patient on the operating table. We use a Hopkins endoscope with 30 degrees and 70 degrees deflections, diameter 2.7 mm and 4 mm. Endoscopy prior to dacryocystorhinostomy enables the examiner to judge whether the nasal cavity is large enough for an osteotomy. The orifice of the nasolacrimal duct is visible directly through the endoscope, so that the dye test can be rendered fairly objective. Endoscopy also enables the course of healing of the nasal ostium after surgery to be studied. We observed complications, such as granular tissue and synechiae developing between the posterior flap of the nasal mucosa, the middle turbinate and the nasal septum. Granulation tissue may be removed under endoscopic control. If an intubation of the lacrimal system is attempted, it may be easier to find the end of the steel probe exiting into the nose under endoscopic observation. If the inferior turbinate is impacted with the nasal floor, it may be impossible to find the probe under the inferior turbinate without endoscopic control. Finally, during lacrimal duct probing in infants, one can check whether the probe is correctly sited. Perforations created by probing can be recognized and avoided.