Relative Intensity Values Research Articles

Oxygen demand and energy cost of intense muscular activity in humans

Changes in the kinetics of aerobic and anaerobic metabolism were studied in 26 highly profiled athletes performing bicycle ergometer exercise. The different intensity exercise sessions included those with a critical intensity corresponding to the maximum oxygen consumption up to value of the maximum anaerobic intensity of about 10 MMR units. The maximal aerobic metabolism was maintained in the exercises with a relative intensity of 1.0 to 2.5 MMR units. At the higher values of the exercise relative intensity, the oxygen current consumption exponentially decreased. An increase in the rate of anaerobic glycolytic energy production, which was first recorded at the threshold of anaerobic metabolism (WAT = 0.5 MMR units), increased linearly with a further increase in the exercise relative intensity up to the level of the exhaustion intensity (Wex = 4.7 MMR units). A sharp increase in the rate of an alactic anaerobic process was found at the relative intensity values of 2.5 MMR units, and this increase grew linearly up to values of the maximal anaerobic intensity (Wmax = 9.5 MMR units).

SHG from centrosymmetric supermolecular crystal

Supermolecular crystal composed of p-nitrophenol, hexamethylenetetramine, phosphoric acid and water was obtained by supermolecular assembly. The crystal has a centrosymmetric structure with space group P21/c. The relative intensity and integral value of green frequency doubling of light from the crystal powder compared with that from KDP powder measured by pico-second Nd:YAG laser are 757.3 (KDP: 183.4) and 1771.7 (KDP: 423.98), respectively. In supermolecular crystal, due to the arrangement of centrosymmetric p-nitrophenol molecules in the inorganic-organic host framework formed by hexamethylenetetramine, phosphoric acid and water, the distances between the p-nitrophenol molecules with centrosymmetry are changed (N1A-O1A: 0.8158 nm, N1B’-O1B: 1.4450 nm, N1A-N1A’: 0.5837 nm, N1B’-N1B: 0.6898 nm), and the interaction between the dipoles becomes weak, which is easy for the ground state to turn into the excited state charge separated form, and generate the stable asymmetrical distribution of π-electron cloud density of quinonal structure, thus exhibiting SHG effect.

定量的キラル認識マススペクトロメトリーの進歩

The developments of our quantitative chiral recognition studies in the host-guest complexations between chiral crown ethers and chiral amino acid esters by FAB, ESI, and MALDI mass spectrometry have been described. Both the enantiomer labeled (EL)-guest method and the EL-host method, which had been previously proposed by us, were successfully advanced. The relative peak intensity (IRIS) values of the diastereomeric host-guest complex ions appeared in mass spectra were especially noted, and their use to chiral recognition was illustrated. Generally, the former method was used to chiral recognition ability-determination of a given host, and the latter one was used to enantiomeric excess (e.e.)-determination of a given guest. Through the manuscript, emphasis has been put on the finding that one can detect correctly the concentration ratio of the two diastereomeric host-guest complex ions formed in a matrix solution by FAB mass spectrometry and then, that FABMS is a powerful tool for detecting chiral host-guest interactions in the host-guest complexation systems. Recent ,e.e.-determination methods by ESI mass spectrometry etc. were also summarized.

Compositional characterization of encrustation on marble with laser induced breakdown spectroscopy

This study deals with the analysis of encrustation on marble by laser induced breakdown spectroscopy (LIBS), with the aim to obtain quick in-situ information on the in-depth profiling of the encrustation before advancing to conservation treatments. The encrustation examined is formed on exposed marble: (a) as products of the interaction between the stone surface and atmospheric pollutants (dendritic black and thin black encrustation, of approximately 300 and 200 μm thicknesses, respectively); (b) from deposition of soil–dust on marble surfaces (soil–dust crust, 300 μm thick); and (c) from treatments conducted in the past for aesthetic and/or protective purposes (patina samples, 300 μm thick). The crusts examined are multilayer encrustations on un-weathered marble, as revealed by studying cross sections with optical microscopy and scanning electron microscopy coupled with energy dispersive X-ray analysis. The elemental LIBS profiles of black encrustation based on relative spectral line intensity values show that the Fe, Si, Al and Ti content relative to Ca content decrease significantly with depth, expressing, thus, contamination decreasing within the alteration layers, since these elements originate from atmospheric pollution and deposition. In the cases of soil–dust encrustation and patina samples Si I and Al I emissions identified throughout the analyzed crust, indicate deposition of soil–dust and remnants of previous treatments, respectively. Therefore, LIBS, a micro-destructive technique can be used as an autonomous in-situ diagnostic technique to obtain in-depth elemental profiling of encrustation even in cases of highly in-homogeneous layered crusts, such those of un-weathered Pentelic marble.

Automated RIBATM HCV Strip Immunoblot Assay: A Novel Tool for the Diagnosis of Hepatitis C Virus Infection in Hemodialysis Patients

Hemodialysis (HD) patients remain a high-risk group for hepatitis C virus (HCV) infection. Serological assays (enzyme-linked immunosorbent assays, ELISAs) are the only tests currently approved by the Food and Drug Administration in the United States for the diagnosis of HCV. The RIBA^TM HCV Strip Immunoblot Assay (SIA) is an established method for supplemental testing of repeat reactive hepatitis C ELISA patients on HD. However, the current manual procedure is labor intensive, requiring subjective band scoring and result interpretation. Recently, the automated CHIRON^® RIBA^TM HCV Processor System has been designed to perform RIBA supplemental testing. The CHIRON RIBA HCV Processor System consists of a bench-top instrument that provides objective evaluation of the RIBA immunoblot strips, by measuring the light differentially reflected from the developed bands and white background, creating a density of reflectance. The CHIRON RIBA HCV Processor System assesses the intensity of each of the reactive bands in relation to the intensity of the internal control bands on each RIBA HCV strip. Comparison between processor and manual protocols was performed using a large (n = 200) cohort of ELISA 3.0 HCV negative and positive patients on maintenance HD. The test characteristics of RIBA HCV 3.0 SIA were identical with manual and automated runs. The relative intensity values of antigenic bands by the CHIRON RIBA HCV 3.0 Processor System between anti-HCV positive and negative patients were significantly different; only 15 of 784 (1.9%) antigenic bands had borderline reactivities. The correlation of test results between manual and automated runs was very high (kappa value 0.989). Among positive results by RIBA HCV 3.0 SIA, there was a strong concordance between manual and automated runs with regard to the pattern of reactivity (kappa value 0.943). The discordant results between manual and automated protocols were attributable to increased variability of antigen scores close to the cutoff value for both tests. In conclusion, the CHIRON RIBA HCV 3.0 Processor System is capable of performing RIBA HCV 3.0 SIA in the HD population accurately with minimal operator involvement. The test characteristics of RIBA HCV 3.0 SIA were identical by manual and automated runs. There was a strong correlation between the results of the manual and automated runs; the few discordant results between the two procedures were mostly due to increased variability of antigen scores close to the cutoff value for both tests. The Centers for Disease Control and Prevention in the USA have recently included chronic HD patients among those persons for whom routine HCV testing is recommended; HCV-infected patients on HD often have a high rate of indeterminate results by manual RIBA technology which is operator dependent for band scoring and result interpretation. The CHIRON RIBA HCV 3.0 Processor System may be very useful for supplemental anti-HCV testing of ELISA repeat reactive specimens in clinical practice within dialysis units.

Pixel analysis of MR perfusion imaging in predicting radiation therapy outcome in cervical cancer.

The purpose of this study was to assess heterogeneity of tumor microcirculation determined by dynamic contrast-enhanced magnetic resonance (MR) imaging and its prognostic value for tumor radiosensitivity and long-term tumor control using pixel-by-pixel analysis of the dynamic contrast enhancement. Sixteen patients with advanced cervical cancer were examined with dynamic contrast-enhanced MR imaging at the time of radiation therapy. Pixel-by-pixel statistical analysis of the ratio of post- to precontrast relative signal intensity (RSI) values in the tumor region was performed to generate pixel RSI distributions of dynamic enhancement patterns. Histogram parameters were correlated with subsequent tumor control based on long-term cancer follow-up (median follow-up 4.6 years; range 3.8-5.2 years). The RSI distribution histograms showed a wide spectrum of heterogeneity in the dynamic enhancement pattern within the tumor. The quantity of low-enhancement regions (10th percentile RSI < 2.5) significantly predicted subsequent tumor recurrence (88% vs. 0%, P = 0.0004). Discriminant analysis based on both 10th percentile RSI and pixel number (reflective of tumor size) further improved the prediction rate (100% correct prediction of subsequent tumor control vs. recurrence). These preliminary results suggest that quantification of the extent of poor vascularity regions within the tumor may be useful in predicting long-term tumor control and treatment outcome in cervical cancer. J. Magn. Reson. Imaging 2000;12:1027-1033.

Comparison of c-met Expression in Ovarian Epithelial Tumors and Normal Epithelia of the Female Reproductive Tract by Quantitative Laser Scan Microscopy

The transmembrane tyrosine kinase receptor c-met with its ligand, hepatocyte growth factor/scatter factor (HGF/SF), acts as a mitogen, motogen, and morphogen in many normal epithelia. HGF/SF-met signaling has also been implicated in neoplastic progression and metastasis. In this study, immunofluorescence staining and quantitative laser scanning confocal microscopy were used to measure c-met expression in ovarian surface epithelial tumors from 17 oophorectomy specimens. These specimens were from patients aged 25 to 81 (mean age, 52) and included 10 malignant tumors, 4 borderline tumors, and five benign tumors including a Brenner tumor. For comparison, c-met expression was measured in normal tissues from the same patients, including 4 ovarian surface epithelia, 4 fallopian tube epithelia, 2 endometria, and 3 endocervical epithelia, as well as 3 cases of endometriosis. Relative pixel intensity values of c-met expression ranged from 0.4 in a normal ovarian surface epithelium to 22.3 in a borderline serous tumor. Malignant tumors (mean, 9.6) and borderline tumors (mean, 12.9) had higher average c-met expression levels than normal tissues (mean, 3.6) and endometriosis (mean, 1.8). The expression levels of benign tumors were intermediate (mean, 7.9). Among the normal tissues, c-met expression in fallopian tubes (mean, 8.2; range, 3.4-12.9) was higher than that of the other normal epithelia (mean, 1.6; range, 0.4-4.3). In eight cases where both normal and malignant tissues were sampled, c-met expression was significantly greater in malignant than in normal epithelia (P = 0.01). These findings indicate that c-met plays a role in the biology of the normal tissues examined. They confirm that its expression increases in the malignant progression of ovarian surface epithelial tumors, and suggest that increases comparable to those in frankly malignant carcinomas have already been reached in borderline lesions, ie, early in the neoplastic process.

Trilateral intercomparison of photometric units maintained at NIST (USA), NPL (UK), and PTB (Germany)

A trilateral intercomparison of photometric units between NIST (USA), NPL (UK), and PTB (Germany) has been conducted to update the knowledge of the relationship between the photometric units disseminated in the three countries. The luminous intensity unit (cd), the luminous responsivity scale (A/lx), and the luminous flux unit (lm) maintained at each laboratory were compared by circulating transfer standard lamps and photometers. The results showed that the relative luminous intensity values, with respect to the average, measured by NIST, NPL, and PTB were 1.0014, 1.0021, and 0.9966; the relative inverse values of the luminous responsivity (corresponding to illuminance) were 1.0023, 1.0011, and 0.9965; the relative luminous flux values were 0.9994, 1.0034, and 0.9972, respectively. The results agreed within the stated uncertainties of the units maintained at the three laboratories.

Chiral recognition and the determination of optical purity of a-phenylethylamine using monosaccharide as a chiral selector under liquid secondary ion mass spectral conditions

Naturally available monosaccharides, D-mannose, D-galactose and D-glucose, have been used for the first time as chiral co-matrices for chiral recognition of α -phenylethylamine. The liquid secondary ion (LSI) mass spectra of a mixture of D-mannose and (R)- or (S)α -phenylethylamine in the presence of benzylamine as reference compound and glycerol as matrix showed [(mannose + (R)- / (S)-α phenylethylamine + H) – H2O] + (a) and [(mannose + benzylamine + H)–H2O] + (b) ions. The significant difference was observed in the relative peak intensity (RPI) values calculated from the ion abundances of ion a and b. The RPI values for (R)- and (S)-α phenylethylamine are RPIR = 0.79 and RPIS = 1.34, respectively. The efficiency of the chiral recognition property of D-mannose is demonstrated in estimating the enantiomeric excess of α -phenylethylamine.

ANALYSIS OF LASER‐INDUCED FLUORESCENCE LINE SHAPE OF INTACT LEAVES: APPLICATION TO UV STRESS DETECTION

Abstract— In vivo laser‐induced fluorescence spectra of intact leaves of healthy and UV‐irradiated Salvia splendens plants excited at 337 nm by a nitrogen laser were recorded using an optical multichannel analyzer system. The spectra showed the typical fluorescence bands centered around 450, 530, 685 and 730 nm. Exposure to UV radiation changed the relative intensity values of these bands and their peak positions. The analysis of the acquired spectra in terms of a linear combination of Gaussian bands was carried out to determine accurately the peak positions and the relative intensity contribution of the various bands to the laser‐induced fluorescence spectra on healthy and UV‐treated plants of different age.The results indicate that a curve‐fitting analysis of the measured fluorescence spectra is a useful and sensitive method to discriminate the various band contribution to the whole leaf fluorescence spectrum. The comparison among blue‐green and red‐far‐red fluorescence of leaves was also confirmed as an effective indicator of UV stress in plants.

Collisional transfer of vibrational energy in vapors of polyatomic molecules

Thc collisional transfer of vibrational energy has been the subject of much investigation l 1, 2 ], the results of which are of fundamental importance for the molecular physics of the gas phase and have numerous practical applications. However, the laws governing intermolecular vibrational relaxation in the quasi-continuum of vibrational states, which is characteristic of polyalomic molecules even at comparatively low levcls of vibrational excitation, have not rcceived sufficient study. This results from the limited number of direct expcrimenlal methods and from the absence of corresponding theoretical models. Experimental difficulties are responsiblc for the differences in the quantitative characteristics of collisional transfer as well as ira the laws governing their variation with an increase in the internal energy of the molecule. The diversity of the postulated means of deactivation of excited molecules and the complexity' of the energy spectrum and of the motion dynamics of polyatomic molecules make simulation of the process difficult and require new, original experimental works along these lines. As early as in the late fifties, B. S. Neporent and N. A. Borisevich [3 I demonstrated lhe high cfficiencv of luminescence methods as applied to the study of collisional transfer of vibrational energy. A new direct method of obsem'ing the process of collisional transfer and exchange of vibrational energy from the change in the rates of decay of the delayed fluorescence activated by the nonequilibrium vibrational laser excitation of triplet molecules was suggested in I4 1. In subsequent works 15-71 il was shown that the use of multiphoion excitalion (MPE) of triplet molecules by CO2-taser radiation permits onc to investigate the process at both low and high vibrational energies for molecules of differcnl degrees of complexity. In the present work the method is used Io investigatc the energy dependences of the characteristics of the collisional transfer of vibrational energy ira vapors of diacclvl and benzophenone and their mixtures with foreign gases. As noted earlier, the choice of objects for investigalion is based on the spectroscopic charactcristics of the molecules, which in the gas phase possess long-lived triplcl states, a low barrier to the activation of delayed fluorescence, resulting from efficicnt Tl----" SI interconversion, and the ability to absorb thc IR radiation of a CO2-1aser in the electron ground and tripleT, states. The characteristics of the collisional transfer of vibrational energy are estimated using dcpendences of {he intensities and rates of decay Kdc c of the fast, microsecond component of activated fluorescence on the pressures of the vapors and foreign gases. The pressure dependence of Kde c varies in the investigated range of pressures and energies of excitation. At a constant density of CO2-1ascr energy, the rate of decay Kde c increases linearly with the pressures of the vapors and foreign gases only in a limited range of pressures and then begins to decrease. It should be noted that such dependences in mixtures with foreign gases are obscrvcd when there is a noticeable increase in the range of the values of ECO 2 used to the higher side. Anomalous dependences manifesting themselves in a decrease of Kde c with pressure begin to dominate at low laser energy densities. The dependences of the instantaneous values of lhe relative intensity l(v, 0/lo (v, t), where l(v, 0 and lo(v, t) are the intensities of luminescence at the maximum of the pulse of the activated fluorescence and of the

Dynamic contrast-enhanced MR imaging assessment of vascularized free fibular grafts.

Magnetic resonance (MR) imaging may be a noninvasive method for assessing perfusion of vascularized bone grafts placed for treatment of avascular necrosis. One proximal femur of seven beagles was devascularized, with insertion of a vascularized fibular graft. MR imaging at 1 week (seven dogs) and 6 weeks (five dogs) after surgery included pre- and postcontrast spin-echo sequences, unenhanced two-dimensional time-of-flight (TOF) vascular imaging, and dynamic gradient-echo imaging during infusion of gadolinium. Relative signal intensity values of selected regions obtained from the dynamic gradient-echo images were plotted as percent enhancement versus time. In the operated hip, MR imaging did not show enhancement in six of seven femoral heads and greater trochanters at 1 week after surgery, with similar results after 6 weeks. MR imaging of fibular grafts 6 weeks after surgery showed an initial rapid increase in enhancement and a subsequent slower increase in five of five dogs, although no enhancement was seen in six of seven dogs at 1 week. These findings contrasted with a rapid initial increase in enhancement followed by slow decline in non-operated hips. Two-dimensional TOF imaging did not show the vascular pedicle of the graft in any dog. Findings of radionuclide bone scanning performed 1 week after surgery were consistent with devascularization of the operated femur and fibular graft. However, tetracycline distribution and histologic findings confirmed the viability of five of five grafts within the devascularized femurs 6 weeks after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Importance of Multiagent Chemotherapy Regimens in Ovarian Carcinoma: Dose Intensity Analysis

In the previous meta-analysis of dose intensity (dosage) of chemotherapy in advanced ovarian cancer, we analyzed data on cyclophosphamide, altretamine (hexamethylmelamine), doxorubicin, and cisplatin. Only cisplatin showed statistically significant association of complete and partial clinical response with dose intensity. This analysis updates the previous results and further characterizes response to cisplatin alone or in multiagent regimens. We analyzed data from 18 regimens containing platinum (cisplatin or carboplatin) that were used in nine new randomized trials, in addition to data from the 60 groups of patients in our previous study in which responses were reported. Relative dose intensity was calculated as a fraction of the dosage of a drug in the standard regimen of cyclophosphamide, altretamine, doxorubicin, and platinum (CHAP). We performed single and multiple regression analyses to determine the relationship between disease outcome and relative dose intensity for cyclophosphamide, platinum, and doxorubicin alone or in combination. The association between outcome and dose intensity for platinum alone or in multiagent regimens was statistically significant. This association was of borderline significance for cyclophosphamide alone but was not significant for this drug in multiagent regimens. There were insufficient data to test the relationship for doxorubicin as a single agent, but in multiagent regimens, the relationship was borderline (P = .05). Multiagent regimens containing platinum produced greater response rates than platinum alone for any fixed, planned relative dose intensity for platinum. Our results support other published findings that use of cyclophosphamide and doxorubicin increases the efficacy of single-agent platinum. Relative dose intensity values for cyclophosphamide used alone were larger than those used in multiagent regimens, which might explain why the relationship between relative dose intensity and outcome for cyclophosphamide was not significant for use in multiagent regimens. Similarly, none of the multiagent regimens incorporated doxorubicin at a relative dose intensity for which the drug is found to be effective as a single agent. Prospective clinical trials are required to test the effect of higher relative dose intensity for doxorubicin and cyclophosphamide added to platinum in advanced ovarian cancer. An important element in the design of prospective trials will be to test for the relative importance of dose intensity versus total dose. This testing is best achieved in a three-arm study design such as that reported in adjuvant treatment of stage II breast cancer conducted by the Cancer and Leukemia Group B.

Relative intensities of Lα1, Lβ1 and Lβ2,3,15 lines of gold: Electron beam excitation in the near‐threshold region of the L shell

AbstractVariations of the relative intensities of the Lα1, Lβ1 and Lβ2,3,15 lines of gold from an x‐ray tube with its operating voltage in the near‐threshold region of Au L subshells were studied. Large variations in the intensity ratios were observed for the lines originating from different subshells, which attain limiting values at high excitation overvoltages. These variations are primarily due to the variation with the electron beam energy of the realative numbers of initial ionizations created by the electron beam in different subshells. Attempts have been made to explain these variations by calculating the relative intensity values of these lines using various empirical expressions available.

The Use of Reference Intensity Ratios in X-Ray Quantitative Analysis

AbstractEach of the RIR based methods for carrying out quantitative X-ray powder diffraction analysis are described and a consistent set of notation is developed. The so called “standardless” analysis procedures are shown to be a special case of the internal-standard method of analysis where the normalizing assumption is used. All analytical methods, other than the Rietveld whole pattern matching procedure, require the use of explicitly measured standards, typically in the form of RIR values. However, if only semi-quantitative results can be tolerated, the standards may be obtained by using published RIR and relative intensity values. The exciting new techniques of whole pattern fitting and Rietveld constrained quantitative analysis are also described in RIR notation and shown also to be forms of the internal-standard method with the normalization assumption. The quantitative results obtained from Rietveld quantitative analysis are derived from computed standards in the form of computed, normalized, RIRN values. The normalization assumption in Rietveld analysis allows the exclusive use of computed standards and comes as close to a “standardless” analysis as one can achieve: relying on the absence of amorphous material and on the validity of the structural models. Relationships are given for obtaining quantitative analysis from these RIRN values obtainable from the least-squares scale factors.

Interactions between femtosecond solitons in optical fibers

Interactions between two femtosecond solitons or solitonlike pulses in single-mode optical fibers are studied. Because of Raman scattering, the total energy of the two input pulses is redistributed into two new solitons. The energy redistribution is controlled by various input parameters. The particular dependences on the initial values of relative phase, pulse separation, relative intensity, and wavelength separation are investigated. Numerical simulations are performed through a solution of the generalized nonlinear Schrodinger equation with the use of a modified version of the beam-propagation method. It is found that the interaction between the two pulses is determined by the interplay among the interpulse Raman scattering, the Raman self-frequency down-shift, the cross-phase modulation, and the walk-off effect. The energy redistribution between the two interacting pulses has potential applications to ultrafast switching devices and logic gates.

Introduction of a Nist Instrument Sensitivity Standard Reference Material for X-Ray Powder Diffraction

AbstractImprovements in sample preparation methods have resulted in increased accuracy in x-ray powder diffraction intensity measurements. This improvement has focused scrutiny on the instrument as a potential source of error. NIST Standard Reference Material, SRM, 1976 consists of a sintered α alumina, corundum, plate certified with respect to 12 relative intensity values from 25 to 145 degrees 2θ. Its function is to allow for standardization of powder diffraction intensity as a function of 2θ angle (instrument sensitivity). An increase in the accuracy of interlaboratory comparisons of diffraction intensity and related determinations will result. Utilization of the SRM requires the user to collect intensity data from the test instrument in a manner which conforms to that used in the certification. Graphical interpretation of the ratio of these data to those on the certificate will allow for appropriate judgment as to the condition of the test instrument. Discontinuities in the data indicate a malfunctioning or misaligned instrument. Systematic bias, introduced by design characteristics of the test instrument, manifests itself in terms of a pattern in the data other than a horizontal straight line with value of one. This bias may be removed with the calculation and application of a correction curve.

Search for reflection asymmetric structures in the A=145 mass region: Decays of 1.8-s 143Cs to levels of 143Ba and 4.1-s 147La to levels of 147Ce.

The level structures of {sup 143}Ba and {sup 147}Ce have been investigated by studying the {beta} decays of 1.8-s {sup 143}Cs and 4.1-s {sup 147}La to search for evidence of intrinsic reflection asymmetry in light rare-earth nuclei. Gamma-ray energies and relative intensity values, {gamma}-{gamma} coincidence intensities, and {gamma}-{gamma} angular correlation coefficients were measured. The parity doublets that characterize reflection asymmetric rotational structures in the light odd-{ital A} actinides were not readily identified in {sup 143}Ba or {sup 147}Ce. The observed level structures, combined with other data for these nuclides, suggest that weak deformation is present and that reflection asymmetric admixtures may play a significant role in driving that deformation.

Laser-induced autofluorescence of human arteries.

A new technique for imaging the intimal surface of arteries through optic fibers has been devised. With the aid of an optical multichannel analyzer, we recorded in real time fluorescence spectra during excitation of the arterial surface with an argon ion laser. Spectral parameters were used to detect atherosclerotic plaques and to discriminate normal tissue from lipid rich and calcified atheromas. By digitizing relative intensity values and the ratios of the peak at 550 nm to that at 520 nm into a gray scale, we generated pseudocolor maps of the arterial wall of 10 human aortas. Specific color distributions were congruent with the distribution of calcified tissue visualized by soft x-ray radiography and the distribution of lipid delineated by staining with Sudan IV. Thus, bidimensional maps obtained by laser spectroscopy can be used to identify the presence and composition of atherosclerotic lesions. Fluorescence imaging may prove to be an important application of laser techniques for the diagnosis and treatment of atherosclerosis.

Vertical turbulent mixing processes on ebb tides in partially mixed estuaries

Measurements of turbulent fluctuations of the horizontal and vertical components of velocity and of salinity in the region 1-1·25 m above the bed have been made in the Teign estuary during parts of three ebb tides of different tidal ranges. The turbulent mean flow field determined from vertical profiles of velocity and salinity varied from well mixed to partially mixed depending on the relative importance of the vertical gradient promoting effect of shear and longitudinal density gradient and of the mixing effect of bed-generated turbulence. The turbulence parameters showed regular temporal trends. The relative intensity values for the new and existing data for the velocity components are strongly dependent on relative depth but not generally affected by Richardson number. The intensity of the salinity fluctuations increased with the salinity gradients. The vertical transport of momentum and the vertical Reynolds flux correlation coefficients decreased with Richardson number. The horizontal Reynolds flux correlation coefficient increased with Richardson number. These effects are tentatively explained by the concept of turbulent fluctuations being replaced by wavelike fluctuations in stable conditions. Results for momentum and solute mixing lengths help to substantiate previously published values.