Single-laser approach for fluorescence guidance of excimer laser angioplasty at 308 nm: evaluation in vitro and during coronary angioplasty

BACKGROUND AND OBJECTIVE: Spectroscopic guidance of laser angioplasty has been attempted using a diagnostic He-Cd laser in addition to the therapeutic laser system. This study evaluated a single-laser approach for simultaneous ablation and fluorescence excitation. STUDY DESIGN/MATERIALS AND METHODS: A spectroscopy system was coupled to a clinical XeCl excimer laser. Ablation of 162 human aortic samples in saline and blood with 45 mJ/mm2 per pulse yielded 676 fluorescence spectra validated histologically. The same equipment was used in 16 patients for angioplasty of 18 coronary stenoses applying 500 to 1,725 pulses with 45 to 60 mJ/mm2 under saline flushing. A total of 783 spectra were recorded and validated by intracoronary ultrasound (categories: atheroma, fibrous plaque, calcified lesion). RESULTS: In vitro, 5 types of spectra could be differentiated: (1) atheroma, (2) fibrous plaque, (3) calcified lesion in saline, (4) media, and (5) calcified lesion in blood. Discriminant analysis prospectively classified 576 validation spectra with the following sensitivity and specificity for each type: (1) 83.5 and 97.1%, (2) 85.7 and 96.8% (3) 100 and 98.5%, (4) 98.1 and 99.3%, (5) 98.9 and 100%, respectively. In vivo type 1, 2, 3, and 5 spectra were also observed, but not the media spectrum. The predominant sonographic category also prevailed in spectroscopy. Calcified lesions yielded type 3 and 5 as well as mixed spectra. CONCLUSIONS: Using an excimer laser for angioplasty allows combining ablation and fluorescence excitation without a diagnostic laser. Principal types of atherosclerotic lesions and the media can be differentiated spectroscopically with this approach.     

In situ FTIR spectroscopy on rhodium-exchanged NaX zeolite with different metal dispersion during syngas reaction

In situ FTIR spectroscopy has been applied to study the reason of the different selectivity behaviour of rhodium in the CO hydrogenation reaction in dependence on the different particle size. Several forms of molecularly adsorbed CO are observed, such as linearly- and bridgedbonded CO on metallic rhodium as well as dicarbonyl species with Rh(I) centres formed by oxidation of Rh(0) with protons in presence of CO. Furthermore, non-reactive formate, acetate, and carbonate species are produced as side products of the reaction. The higher selectivity to oxygenates, particularly to methanol, is explained by the existence of multiple-bonded CO present only on small rhodium crystallites. The multiple-bonded CO formed at low temperatures is converted at higher temperatures to the highly reactive formyl species, which is hydrogenated to methanol.     

Brief Overview of Recent Developments on Negative Phase–Velocity Mediums (alias Left–Handed Materials)

This brief overview covers a rapidly occurring development in the area of microwave composite materials: isotropic dielectric–magnetic mediums wherein the phase velocity vector and the time–averaged Poynting vector are oppositely directed. Such materials have also been inappropriately designated as left–handed materials. Ramifications for aberration–free lenses, homogenization approaches, and complex mediums are also presented.     

Differential osteoporosis diagnosis in the woman

Bone mineral density of a woman in the second half of her life depends on the amount of bone made during growth and its subsequent rate of loss. Although the rate of bone loss did receive more attention in the study of pathogenesis of osteoporosis, it is becoming increasingly clear that insufficient accumulation of skeletal mass by young adulthood predisposes a person to low bone mass and subsequently to fractures later in life as age related and menopause-related bone loss ensue. In this article we 1) explain the role of inadequate peak bone mass as a major risk factor for osteoporosis and 2) give an overview of factors leading to osteoporosis by decreasing bone mass. Special emphasis has been put on iatrogenic osteoporosis which is frequently neglected because of the fact that the responsible agents often are not known as to be deleterious to the skeleton: among others, glucocorticoids, thyroid hormones and antiepileptics adversely affect bone.     

Histochemical detection of lymphatic drainage pathways in the middle nasal meatus

AIM: Assessment of the antihypertensive effect of doxazosin, alpha-1 blocker, as well as its action on lipid and carbohydrate metabolism, microcirculation and platelet function in patients with non-insulin-dependent diabetes mellitus (NIDDM). MATERIALS AND METHODS: Doxazosin (tonocardin) treatment was given for 11 weeks to 33 NIDDM patients with concomitant hypertension. The clinical examination comprised evaluation of central hemodynamics, vessels of the fundus of eye, lipid and carbohydrate metabolism, renal function, platelet aggregation. RESULTS: Tonocardin produced a fall in the systolic blood pressure (BP) by 14%, in the diastolic BP--by 17%. The 24-h profile of BP, lipid and purine metabolism, microcirculation of the vessels of the fundus of eye also improved. Total peripheral vascular resistance, left ventricular myocardial mass and platelet aggregation. Carbohydrate metabolism remained unchanged. CONCLUSION: Monotherapy with tonocardin (2-8 mg/day) is effective and safe in the treatment of arterial hypertension in NIDDM patients.     

Untersuchungen an Caramel Curiepunkt-Pyrolyse von Caramelzuckersirupen und andere strukturspezifische Untersuchungen

Zusammenfassung Es wird über die Curiepunkt-Pyrolyse handelsüblicher Caramelzuckersirup-Proben und die Identifizerung von über 80 Pyrolysefragmenten durch kombinierte Capillargaschromatographie/ Massenspektrometrie berichtet. Mit dieser Methode sind die Proben untereinander and gegenüber Couleuren differenzierbar. Mittels Ultrafiltration wurden die Komponenten einer intensiv braunen Probe in Fraktionen unterschiedlicher Molekülmasse getrennt and nach Pyrolyse miteinander verglichen. In einer niedermolekularen Fraktion wurden nach Permethylierung Laevoglucosan, 1,6-Anhydro--d-glucofuranose, Trehalose, Cellobiose, Maltose, Isomaltose und Gentiobiose Bowie einige Difructosedianhydride nachgewiesen.

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Investigations of caramel. Curiepoint pyrolysis of caramel syrups and other investigations of structure

Summary A report is given on the investigation of commercial caramel syrups by Curiepoint pyrolysis and the identification of more than 80 pyrolysis products by capillary gas chromatography mass spectrometry. This method enables the differentiation between different caramel syrups and, additionally, between caramel syrups and caramel colours. Compounds of different molecular masses have been examined in the same manner after they have been isolated from an intense brown caramel sample by ultrafiltration. In a fraction consisting of compounds with low molecular masses laevoglucosan, 1,6-anhydro--d-glucofuranose, trehalose, cellobiose, maltose, isomaltose, gentiobiose and some difructosedianhydrides were identified by GC/MS after permethylation.

     

Comparison of different methods to determine the spreadability and firmness of processed cheese

Summary Current texture-measuring instruments and a recently developed measuring method (two-dimensional measuring of the force necessary to spread a sample) were compared in measuring the spreadability of processed cheese. How far subjective assessment by a qualified panel correlates with the instrumental results in determining spreadability and firmness was also investigated. Samples of processed cheese with various consistencies were measured by an Universal testing machine, a buttermeasuring instrument (DIN 10331), a rotational-type rheometer (oscillation mode) and a two-dimensional force measuring instrument. The evaluation of the results shows that an oscillating rheometer is most suitable to measure the spreadability of processed cheese; the correlation coefficient (r) between the dynamic Weissenberg number, calculated from parameters of the rheometer, and the subjective judgement by the panel wasr=0.91. For the determination of firmness the two-dimensional force measuring instrument is most suitable. The correlation coefficient between the parameter tangential energy (S _t) and the sensorially evaluated firmness wasr=0.95.

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Vergleich verschiedener Bestimmungsmethoden für die Streichfähigkeit und Festigkeit von Schmelzkäse

Zusammenfassung Verschiedene gebräuchliche Meßinstrumente und ein neu entwickeltes Gerät zur zweidimensionalen Messung der Kräfte, die zum Ausstreichen einer Probe erforderlich sind, wurden vergleichend zur Charakterisierung der Streichfähigkeit von Schmelzkäse erprobt. Dabei wurde auch geprüft, inwieweit die subjektiven Beurteilungen eines qualifizierten Prüferpanels mit den Meßwerten für Streichfähigkeit und Festigkeit korrelierten. Gemessen wurde mit einer Universalprüfmaschine, dem Butterprüfgerät (DIN 10331), einem Rotationsrheometer und mit dem zweidimensional registrierenden Kraftmeßgerät. Dabei zeigte sich, daß das Rheometer im oscillierenden Modus die Streichfähigkeit am besten zu charakterisieren vermag. Die Korrelation zwischen den Rheometerwerten, berechnet als dynamische Weissenbergzahl, und den sensorisch ermittelten Werten für die Streichfähigkeit betrugr=0,91. Zur Bestimmung der Festigkeit ist das zweidimensional registrierende Kraftmeßgerät am besten geeignet, was sich in einem Korrelationskoeffizienten vonr=0,95 zwischen dem ParameterS _t und den im Sensoriktest ermittelten Werten für dieFestigkeit ausdrückt.