Guided Photoluminescence from Integrated Carbon-Nanotube-Based Optical Waveguides.

Thin films and ridge waveguides based on large-diameter semiconducting single-wall carbon nanotubes (s-SWCNTs) dispersed in a polyfluorene derivative are fabricated and optically characterized. Ridge waveguides are designed with appropriate dimensions for single-mode propagation at 1550 nm. Using multimode ridge waveguides, guided s-SWCNT photoluminescence is demonstrated for the first time in the near-infrared telecommunications window.

Mechanistic analysis of PLGA/HPMC-based in-situ forming implants for periodontitis treatment.

In-situ forming implant formulations based on poly(lactic-co-glycolic acid) (PLGA), acetyltributyl citrate (ATBC), minocycline HCl, N-methyl pyrrolidone (NMP) and optionally hydroxypropyl methylcellulose (HPMC) were prepared and thoroughly characterized in vitro. This includes electron paramagnetic resonance (EPR), nuclear magnetic resonance ((1)H NMR), mass change and drug release measurements under different conditions, optical microscopy, size exclusion chromatography (SEC) as well as antibacterial activity tests using gingival crevicular fluid samples from periodontal pockets of periodontitis patients. Based on these results, deeper insight into the physico-chemical phenomena involved in implant formation and the control of drug release could be gained.

In-situ forming composite implants for periodontitis treatment: How the formulation determines system performance.

Periodontitis is the primary cause of tooth loss in adults and a very wide-spread disease. Recently, composite implants, based on a drug release rate controlling polymer and an adhesive polymer, have been proposed for an efficient local drug treatment. However, the processes involved in implant formation and the control of drug release in these composite systems are complex and the relationships between the systems' composition and the implants' performance are yet unclear.

In situ forming implants for periodontitis treatment with improved adhesive properties.

Novel in situ forming implants are presented showing a promising potential to overcome one of the major practical hurdles associated with local periodontitis treatment: limited adhesion to the surrounding tissue, resulting in accidental expulsion of at least parts of the implants from the patients' pockets. This leads to high uncertainties in the systems' residence times at the site of action and in the resulting drug exposure. In the present study, the addition of different types and amounts of plasticizers (acetyltributyl citrate and dibutyl sebacate) as well as of adhesive polymers (e.

Accelerated ketoprofen release from polymeric matrices: importance of the homogeneity/heterogeneity of excipient distribution.

Polymeric matrices loaded with 10-50% ketoprofen were prepared by hot-melt extrusion or spray-drying. Eudragit E, PVP, PVPVA and HPMC were studied as matrix formers. Binary "drug-Eudragit E" as well as ternary "drug-Eudragit E-PVP", "drug-Eudragit E-PVPVA" and "drug-Eudragit E-HPMC" combinations were investigated and characterized by optical macro/microscopy, SEM, particle size measurements, mDSC, X-ray diffraction and in vitro drug release studies in 0.

[Nuclear cardiology in the preoperative evaluation of the patient at risk of coronary disease; meta-analysis of the contribution of thallium dipyridamole scintigraphy].

Coronary disease may be assessed by several techniques of nuclear cardiology: classical thallium myocardial scintigraphy, position scintigraphy, left ventricular angioscintigraphy. These techniques measure the response of coronary flow, myocardial metabolism, or left ventricular contractility during a physical or pharmacologic stress test. Many studies have reported the interest of dipyridamole thallium scintigraphy in the assessment of the surgical risk for a coronary event.

[The concept of utility in decision strategies: application to diagnosis and treatment of renovascular hypertension].

To select a guideline in the management of diagnosis and treatment of renovascular hypertension, the clinician has to take into account many contradictory elements. He has to weight the invasive nature and the relative accuracy of the diagnostic tests, as well as the efficacy and drawbacks of medical and surgical treatments. The concept of utility in a decision making tree may lead to objective determination of best suited management for a given patient, according to the prior probability he had a renovascular hypertension.

Emission tomography for assessment of diffuse alcoholic liver disease.

A method of quantitative liver tomoscintigraphy (SPECT) was compared for accuracy with planar scintigraphy (PS) in a group of patients with diffuse alcoholic liver disease. SPECT sensitivity was also compared with that of transmission computed tomography (CT), US, aminopyrine breath test (ABT) and liver chemistries (LC). One hundred and fourteen alcoholic patients with proven liver disease and 17 patients free of liver disease were included.

Lack of cardiovascular side effects of the new tricyclic antidepressant tianeptine. A double-blind, placebo-controlled study in young healthy volunteers.

In a double-blind, placebo-controlled, crossover study, the effects of therapeutic doses of the new tricyclic antidepressant tianeptine on cardiovascular function were closely monitored in 21 healthy volunteers during a 2-week treatment period. Blood pressure measurements, ECG recording, 24-h Holter monitoring, and echocardiography were carried out at 1-week intervals. Isotopic ventriculography was measured twice under each treatment.

[Reliability of scintigraphic methods in the diagnosis of coronary insufficiency].

Some conceptual problems arise when applying the probability analysis to the scintigraphic diagnosis of coronary artery disease. Analysis with Bayes' rule considers disease to be present or absent, radionuclide test response to be positive or negative, sensitivity and specificity to be the same in all patients. In fact, disease can be graded in severity; test results can be analysed as continuous variables; sensitivity and specificity of our diagnostic procedures are not constants but depend of the population features.

Measurement of right ventricular volumes from ECG-gated steady-state krypton-81m angiocardiography.

The physical characteristics of krypton-81m makes it particularly suited for the study of right ventricular function, but its ultrashort half-life (13.3 s) precludes in vitro measurements of blood pool specific activity needed for count based determination of ventricular volumes. A combined geometric count based method was developed to measure absolute right ventricular volumes during steady state krypton-81m angiocardiography: background corrected ventricular count rates were converted to volumes using a count to volume calibration factor calculated in an 'internal reference ROI' located in the right ventricular outflow tract.

Evaluation of the accuracy of steady-state krypton-81m method for calculating right ventricular ejection fraction.

The accuracy of a steady-state 81mKr method for calculating the right ventricular ejection fraction (RVEF) has been examined in this study. Causes of errors using this method and their effects on the calculated RVEF were evaluated. The results suggested that mixing in the right ventricle during continuous infusion of 81mKr was homogenous, allowing for the calculation of ejection fraction using the count rate ratio.

Right ventricular ejection fraction: comparison of technetium-99m first pass technique and ECG-gated steady state krypton-81m angiocardiography.

Right ventricular ejection fraction (RVEF) calculated from ECG-gated steady-state 81mKr angiocardiography and from 99mTc first-pass studies were compared in 30 patients using a digital, single crystal, gamma-camera. Despite the two entirely different approaches RVEF values obtained by the two methods were comparable (r = 0.97): the mean absolute difference between the two techniques was 2.

Measurement of glomerular filtration rate by means of a 99Tcm-DTPA complex and a scintillation camera: a method based on the kinetics of the distribution volume of the tracer in the kidney area.

Glomerular filtration rate (GFR) may be computed using the kinetics of the renal distribution volume curve Vt = Rt/Pt and a power fit of the plasma curve Pt = Pot-B. It can be demonstrated that GFR = d(Vt)/d(t)(1-B). The method is largely independent of background subtraction, allowing nonequivocal renal function determination in all cases.

Measurement of left-ventricular volumes using an internal standard.

When performing equilibrium radionuclide angiocardiography with two successive acquisition views, absolute left-ventricular volumes can be calculated using an 'internal standard' generated by a computer in the left-ventricular cavity. The method is based on the computed ratio of maximum to global activity in the 40 degree-left-anterior-oblique view after background correction and on the measured depth of the left ventricle in almost-orthogonal, 30 degree-left-posterior-oblique Fourier first-harmonic images. The method does not require blood sampling or correction for self attenuation.

Tc-99m-MDP bone scanning detection of gastric calcification.

A 50-year-old man with hypercalcemia related to Cope syndrome was referred for bone scintigraphy. There was a clear accumulation of the technetium-phosphate complex in the stomach. The condition was reversible with treatment of the underlying cause.

Bacterial meningitis complicated by spinal arachnoiditis: diagnostic contribution of Tc-99m-inulin myeloscintigraphy.

Six cases of bacterial meningitis with myeloscintigraphic evidence of medullary arachnoiditis are reported. Four patients has tuberculous meningitis, another showed severe myelopathy, and the last was suspected to have hydrocephalus. Arachnoiditis is suspected when the earliest images show a sharp decrease of tracer concentration.