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C Bosshard

Publications and source records attributed to C Bosshard.

At least 19 recordsLinked to original sources
PubMed2006

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.

Abattoirs↗
PubMed2003

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.

Adult↗
PubMed2001

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.

Journal Article↗
PubMed2001

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.

Journal Article↗
PubMed2000

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.

Journal Article↗
PubMed2000

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.

Journal Article↗
PubMed1993

[Music during gastroscopy].

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.

Adrenocorticotropic Hormone↗
PubMed1991

[Severe endocrine ophthalmopathy. A review with case reports].

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.

Combined Modality Therapy↗
PubMed1982

[Endoscopy of the nose as an aid in lacrimal duct surgery].

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.

Dacryocystorhinostomy↗
PubMed1982

[Application and results of biometry of the eye in implantation of intraocular lenses].

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.

Anterior Chamber↗
PubMed1981

[Lacrimal surgery].

Tear drainage may be disturbed due to the lack of a connection between the drainage system and the lacus lacrimalis or an obstruction within the drainage system. The connection to the drainage system may be reconstructed by surgery of the puncta. The one-snip and two-snip procedures described by L. T. Jones and the plasty of the punctum by Bangerter are mentioned. A torn canaliculus is repaired by internal splinting with silastic tubing which is inserted as a small, continuous loop. As the upper canaliculus may be of greater importance for the transportation of tears, a reconstruction of the upper canaliculus should also be attempted. Canalicular obstruction may be treated by intubation of the drainage system with silastic tubing. The following complications of this treatment have been observed: ulcera of the cornea and conjunctiva, slitting of the punctum, expression of the intubated silastic loop, closure of the nasal ostium after dacryocystorhinostomy as a result of a chronic irritation by the silastic tube. If reconstruction of the canalicular system is no longer possible, a direct anastomosis between conjunctiva, lacrimal sac and nose may be performed. The dacryocystorhinostomy remains the first choice operation for obstructions below the lacrimal sac. Treatment of the connatal lacrimal obstruction is performed in three steps: conservative treatment with compression of the lacrimal sac, hydraulic pressure flushing and probing.

Dacryocystorhinostomy↗
PubMed1980

[Plasmacytoma of the orbit].

Report on a 69-year-old woman with exophatalmos in the left eye caused by a plasma-cell tumor. The differential diagnosis of this tumor includes myelomatosis, solitary myeloma of bone and extramedullary plasmacytoma. The clinical features suggest an orbital involvement of myelomatosis. The results of physical examination and findings in axial computer tomography and ultrasonography are discussed.

Aged↗
PubMed1980

[Unusual course of Horton's arteritis (author's transl)].

It is generally accepted that the criteria for the diagnosis of temporal arteritis are increased blood sedimentation rate, advanced age and a generally poor state of health, accompanied by cephalalgia. However, as the case histories of three patients show, the absence of one or several of these criteria does not rule out the diagnosis.

Adult↗
PubMed1979

[Axial computerised tomography - answered and unanswered questions on the ophthalmologist (author's transl)].

The results of 67 examinations with computerized axial tomography are presented with reference to the indications. 15 examinations were performed in exophthalmos, 11 in unknown visual field defects, 9 in optic atrophy of unknown origin, 8 each in optic neuritis, papilledema and unclear visual disturbance. 8 furthur examinations were performed in different cases. The axial computerized tomography proved to be an efficient complementary examination technique if it is limited to well defined indications. The best results are obtained examining exophthalmos and visual field defects.

Brain Neoplasms↗
PubMed1978

[Metastasis from the colon to the choroid (author's transl)].

Various investigators have concluded that metastatic carcinoma is the most common malignant tumor of the eye. In about 70% of all cases the primary site is breast or lung. Metastasis from the colon to the choroid is found very seldom. The clinical course in our case is described and the elevated fashion of the right eye's metastatic carcinoma is shown. Usually cancerous tissue in the choroid spreads and produces a rather flat, diffuse lesion. Problems in making the diagnose are discussed. In choroidal metastasis radiation should be attempted, for adequate vision can sometimes be maintained for the remaining time of the patient's life.

Adenocarcinoma, Mucinous↗