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Objectives: Carotid intima-media thickness (CIMT) is a surrogate marker of subclinical atherosclerosis and a predictor of cardiovascular events. Few studies in Africa have evaluated CIMT and its associations in people with type 2 diabetes mellitus. This study measured CIMT in a sample of mainly black South African patients with type 2 diabetes mellitus, and evaluated the association of demographic and clinical risk factors with CIMT.Design: Cross-sectional study.Setting: Kafalong Hospital, a large community hospital in Pretoria that mainly serves an urban black community.Subjects: Patients with type 2 diabetes mellitus.Outcome measures: We evaluated clinical, biochemical and CIMT ultrasound measurements in a standardised fashion.Results: In 185 patients, the univariate significant predictors of mean far-wall CIMT were age [beta 0.007 (standard error 0.001)], systolic blood pressure [beta 0.001 (standard error 0.000)] and inverse serum creatinine [beta -8.15 (standard error 3.23)]. Low-density lipo...

The present paper describes a model for frost assessment in mountainous areas in relation to forest management. Data were collected at 38 locations within a 625 km 2 region, which is characterised by a diverse topography and vegetation cover. Air temperature measurements were performed during the peak of the growing season. (July–August 1996) in the southern Swedish mountains at elevations between 500 and 1200 m a.s.l. The variation in nighttime minimum temperatures was analysed in relation to the prevailing weather and terrain type of the measuring sites. From the analysis of the temperature and weather conditions, i.e., wind and radiation, it was concluded that more than 90% of the frost situations, occurring during the study period, were of the radiation type. It was further concluded that the variation among the studied stations was closely related to the terrain type during these situations. Frost occurred most frequently in narrow valleys, then in concave and flat locations. Elevated and convex areas were found to have very few situations of radiation frost. Local terrain information was used together with a calculated frost index for assessment of the spatial variation in frost risk. Furthermore, a grid net was applied to the study area and the pixels were given a terrain form of the type convex, slope, flat, wide concave or narrow concave according to the dominating terrain curvature. For each pixel a frost index value was estimated from the recorded temperatures at the field stations. A cluster analysis was used to group the terrain types according to the index, whereby six obvious clusters were obtained each with clearly differentiated frost intensity. The analysis showed that this kind of treatment is a suitable method for assessing the spatial variation in frost risk.

Nonradiative excited-state relaxation via charge transfer induced twisting of N,N-dimethylaminobenzylidene-1,3-indandione (DMABI) in solution was investigated by means of picosecond transient absorption and femtosecond fluorescence spectroscopy.The analysis of the experimental data allows us to distinguish between different reaction stages of the molecular twisting in excited and ground states, as well as to consider the molecular dynamics along reactive (twisting) and nonreactive (solvation) coordinates. Quantum chemical calculations of the electronic structure of DMABI and its dependence on the molecular conformation are discussed in order to identify the bond(s) involved in the twisting reaction. It is found that such a twisting bond is the CC double bond, which is substantially weakened in the excited state.

The thermophilic hydrogen-oxidizing eubacterium, Hydrogenobacter thermophilus was grown with a semi-continuous gas feed in a 150 l fermentor, on different ratios of H 2 , O 2 (air) and CO 2 and on media of variable mineral salts composition. The best gas ratio during the exponential phase was approximately 0.5 :1.0 :0.03 atm of H 2 :air :CO 2 . Cell densities were increased by increasing the concentration of ammonium and phosphate in the medium. The maximum cell density obtained under the most favourable conditions was 2.62 g wet wt l -1 , corresponding to an absorption of 1.6 at 600 nm. The maximum specific growth rate (μ) was 0.44 h -1 .

International audience; Long nanowires formed by ca. 800 guanine tetrads (G4-wires) are studied in phosphate buffer containing sodium cations. Their room temperature optical properties are compared to those of the monomeric chromophore 2-deoxyguanine monophosphate (dGMP). When going from dGMP to G4-wires, both the absorption and the fluorescence spectra change. Moreover, the fluorescence quantum yield increases by a factor of 7.3 whereas the average fluorescence lifetime increases by more than 2 orders of magnitude, indicating emission associated with weakly allowed transitions. The behavior of G4-wires is interpreted in the light of a theoretical study performed in the frame of the exciton theory combining data from molecular dynamics and quantum chemistry. These calculations, carried out for a quadruplex composed of three tetrads, reveal the existence of various exciton states having different energies and oscillator strengths. The degree of delocalization of the quadruplex Franck−Condon excited states is larger than those found for longer duplexes following the same methodology. The slower excited-state relaxation in G4-wires compared to dGMP is explained by emission from exciton states, possibly limited on individual tetrads, whose coherence is reserved by the reduced mobility of guanines due to multiple Hoogsteen hydrogen bonds.

A new framework for deriving equations of motion for constrained quantum systems is introduced, and a procedure for its implementation is outlined. In special cases the framework reduces to a quantum analogue of the Dirac theory of constrains in classical mechanics. Explicit examples involving spin-1/2 particles are worked out in detail: in one example our approach coincides with a quantum version of the Dirac formalism, while the other example illustrates how a situation that cannot be treated by Dirac's approach can nevertheless be dealt with in the present scheme., Comment: 13 pages, 1 figure

Laser-induced fluorescence spectra of the C 3 Δ- X 3 Δ and B 3 Π- X 3 Δ transitions of TiO have been recorded at high resolution by Fourier transform spectroscopy. For the molecule production, a simple flame reaction device was used. This device was based on a titanium hollow cathode sputtering source used with O 2 or N 2 O as oxidant. Experimental data involving vibrational progressions up to v ″ = 6 have been fitted with standard Hamiltonian matrix models, allowing for an improved description of the ground state. Moreover, a merged fit combining new LIF-data and previous high-resolution emission data on the B - X band system has been performed, yielding the best set of ground state molecular constants for TiO available to this date.

There is currently no method to reliably diagnose the presence of ovarian tissue in inactive intact female cats except laparatomy which is an invasive procedure. All available tests require that the queen is in estrus. Obvious overt symptoms of estrus are, however, not always observed and some queens may have only 2 estrus periods/year. Therefore this study was designed to evaluate if it is possible to diagnose the presence of ovarian tissue by measurement of estradiol before and/or after stimulation with a GnRH-analogue. Twenty-two female cats were divided into two groups; 11 females that were known to have been ovariectomized and 11 females that were known to be intact. From each cat a heparinised blood sample was collected from the cephalic vein for resting estradiol and progesterone measurements. All cats were treated with a GnRH-analogue buserelin (Receptal ® , 0.4 μg/kg im). Two hours later a second blood sample was collected. Median estradiol increased after stimulation with buserelin in intact but not in ovariectomized females (11 range 5–21 vs. 20 range 12–41, P = 0.004 and 6 range 4–9 vs. 6 range 5–9 P = 0.8) and did not overlap between the two groups. The highest estradiol concentration post-GnRH in the ovariectomized group was 9 pmol/L while the lowest in the intact group was 12 pmol/L. Progesterone was basal in all cats except one both before and after GnRH-stimulation. In conclusion this study demonstrates that measurement of estradiol concentration in plasma 2 h after stimulation with a GnRH-analogue seems to be a reliable method to diagnose the presence of ovarian tissue in the female cat.

A general prescription for the treatment of constrained quantum motion is outlined. We consider in particular constraints defined by algebraic submanifolds of the quantum state space. The resulting formalism is applied to obtain solutions to the constrained dynamics of systems of multiple spin-1/2 particles. When the motion is constrained to a certain product space containing all of the energy eigenstates, the dynamics thus obtained are quasi-unitary in the sense that the equations of motion take a form identical to that of unitary motion, but with different boundary conditions. When the constrained subspace is a product space of disentangled states, the associated motion is more intricate. Nevertheless, the equations of motion satisfied by the dynamical variables are obtained in closed form., Comment: 11 pages

Geometric quantum mechanics aims to express the physical properties of quantum systems in terms of geometrical features preferentially selected in the space of pure states. Geometric characterisations are given here for systems of one, two, and three spin-1/2 particles, drawing attention to the classification of quantum states into entanglement types., 6 pages, 4 figures. Based on the talk presented at DICE 2006

This contribution describes the results of some recent studies concerning the excited state behavior of nucleic acid bases, where solvent and stacking effect are included. Our computational approach is based on PBE0 and TD‐PBE0 geometry optimizations, while bulk solvent effects are taken into account by the Polarizable Continuum Model, with the possible inclusion of the solvent molecules of the first solvation shell. This approach provides accurate absorption and emission spectra both for pyrimidine and purine bases and is able to explain solvent effect on the excited state lifetimes of uracil‐like molecules. Solvent indeed modulates the accessibility of an extra decay channel for the bright excited state, involving an underlying dark state. The effect of base stacking, investigated on 9‐methyl‐adenine stacked dimers and trimers, on the absorption and emission spectra is also fully reproduced by our calculations. Although light absorption leads to a state (SB) delocalized over different adenine molecules,...

The excited-state properties of uracil, thymine, and nine other derivatives of uracil have been studied by steady-state and time-resolved spectroscopy. The excited-state lifetimes were measured using femtosecond fluorescence upconversion in the UV. The absorption and emission spectra of five representative compounds have been computed at the TD-DFT level, using the PBE0 exchange-correlation functional for ground- and excited-state geometry optimization and the Polarizable Continuum Model (PCM) to simulate the aqueous solution. The calculated spectra are in good agreement with the experimental ones. Experiments show that the excited-state lifetimes of all the compounds examined are dominated by an ultrafast (< 100 fs) component. Only 5-substituted compounds show more complex behavior than uracil, exhibiting longer excited-state lifetimes and biexponential fluorescence decays. The S-0/S-1 conical intersection, located at CASSCF (8/8) level, is indeed characterized by pyramidalization and out of plane motion of the substituents on the C5 atom. A thorough analysis of the excited-state Potential Energy Surfaces, performed at the PCM/TD-DFT(PBE0) level in aqueous solution, shows that the energy barrier separating the local S-1 minimum from the conical intersection increases going from uracil through thymine to 5-fluorouracil, in agreement with the ordering of the experimental excited-state lifetime.

This chapter provides several interesting indications on the excited-state behavior of uracil derivatives in aqueous solution. The excited-state lifetimes of all the compounds examined, except 5-fluoro uracil, are dominated by a component shorter than 250 femtosecond. Calculations indicate that the relevant state for discussing the absorption and fluorescence spectra of uracil derivatives in aqueous solution is the ππ*. The key steps in the ultrafast internal conversion are the pyramidalization of C5 and the out of plane motion of C5 substituent, which explains why the excited-state lifetime depends mainly on the nature of the C5 substituent. The shape of the potential energy surface of the S 1 electronic states seems consistent with a very fast nonradiative decay. The result strongly supports the reliability of the general picture of the ultrafast ground state recovery of excited uracils in aqueous solution.

Available techniques for diagnosis and evaluation of right ventricular (RV) function are limited. In patients with arrhythmogenic right ventricular dysplasia (ARVD) it is of great importance to assess RV wall motion and function for diagnosis, prognosis and treatment. Contrast echocardiography and videodensitometry can be used to illustrate regional and global RV hemodynamics. The authors investigated patients with ARVD and healthy volunteers by this method. An off-line analysis system was used for calculation of time intervals and indices of contrast dynamics in different regions of the right ventricle. The data were also color-coded to illustrate, in one single image, the dynamic process of the contrast. The RV wall motion was also assessed by a visual score system. The patient group showed longer time intervals for the processing of the contrast in the right ventricle than the healthy group. The color pattern for the whole process showed regional disturbances in the patient group which corresponded to the wall motion abnormalities as compared to the normals. Color-coded contrast echocardiography with videodensitometry quickly and easily demonstrated disturbances in filling and elimination patterns as signs of abnormal RV function, both regional and global, in patients with ARVD compared to healthy controls.

Fluorescence spectroscopy is a powerful tool for the study of the reactivity of chemical and biological systems The fluorescence spectrum, the fluorescence quantum yield, and the fluorescence lifetime of a chromophore depend on its microenvironment and the solute-solvent interactions Fluorescence lifetimes also depend on the kinetics of possible chemical reactions Fluorescence measurements in the time domain thus provide detailed information about intraand inter-molecular photophysical and photochemical processes During the past 30 years the development of laser sources and ultrafast techniques has opened new ways for the study of the fluorescent excited states of molecules in the nano-, pico-, and femtosecond time range When analyzing the rise and the decay (often multi-exponential) of their fluorescence intensity as a function of time, the pre-exponential factors and the fluorescence time constants have to be determined accurately after a careful deconvolution using a computer-based algorithm Several techniques are used: phase modulation spectroscopy with a modulated laser pump source on a time scale comparable to the decay times of interest, time-correlated single photon counting under picosecond laser excitation (alternatively nanosecond flashlamp excitation), ultra-fast streak cameras designed for the conversion of time dependent light emission into distance dependent electron impact on a phosphor screen Because a sufficient resolution is not accessible with those techniques for the measurement of fast decays in the 50 fs-100 ps range, fluorescence up-conversion in nonlinear optical crystals is the technique of choice.

Background and Aim: Although both skeletal and cardiac muscles have a remarkable ability to take up and express plasmid DNA after intramuscular injection, gene expression has been reported to be lower in skeletal muscle. The aim of this study was to detect differences in plasmid uptake efficiency.

Pyranine or tsPyOH (8-hydroxy-1,3,6-trisulfonated pyrene) belongs to the family of aromatic alcohols which have been widely studied since Förster1 and Weller2. These molecules are known to undergo proton transfer (PT) both in the ground (GSPT) and singlet excited (ESPT) states, with Ka jump of seven orders of magnitude between the two processes. The dynamics of pyranine ESPT has been studied in various polar media 3-5. In all cases, ESPT was probed by observing the disappearance of the protonated species and the formation of the deprotonated form, using time resolved fluorescence techniques with picosecond or nanosecond time resolution. A long decay time (~100 ps) of tsPyOH*, correlated with the formation time of tsPyO-*, was found in aqueous solutions and ascribed to the ESPT time constant6. In contrast to these findings, Mataga's group, who probed ESPT of the related compound hydroxypyrene (PyOH) hydrogen-bonded to a strong base (triethylamine) in various non-polar and polar solvents, found a first, fast time constant (850 fs) followed by a slower one7. The first time constant, which is solvent independent, was ascribed to a fast ESPT, while the second one was assigned to the ion pair separation.

The aim of the present paper is to show that the LDS 751 unsymmetrical cyanine laser dye, highly polar in the ground state and nonpolar in the fluorescent excited singlet state, is a suitable solvent probe. Excitation of LDS 751 in a polar solvent with an ultrashort laser pulse suddenly annihilates the permanent dipole moment of the solute and suppresses the forces which orientate the nearby solvent molecules. The subpicosecond analysis of the Time‐Dependent Fluorescence Stokes Shift (TDFSS) of LDS 751 thus enables to probe the relaxation of polar solvent molecules which can be considered as free of solute‐solvent interactions.

SUMMARY Two computer- and image-analysis-based procedures for realignment of images of consecutive light micrographs of nerve tissue (cat motor cortex) have been developed. One procedure (CENT) was interactive, employing the subjective overall ‘best fit’ of two images to each other and the other (AUTOCENT) was based on an automatic comparison of two images (image thresholding and binary comparison). Images of light micrographs of several hundred consecutive sections were realigned using the interactive and the automatic methods. The interactive procedure was easy to use; realignment of an image took only a few minutes in the hands of an experienced operator and should be easy to implement on commercially available smaller computers like PCs and workstations, but the realignment was possibly disturbed by the operator's subjective expectancy of regular forms. The automatic procedure realigned 1–4 images per hour, might be implemented on smaller computers if the programming is made more efficient, was probably objective and restored the ‘true position of images’.

We give an overview of the two different methods that have been introduced in order to describe the dynamics of constrained quantum systems; the symplectic formulation and the metric formulation. The symplectic method extends the work of Dirac on constrained classical systems to quantum systems, whereas the metric approach is purely a quantum mechanical method having no immediate classical counterpart. Two examples are provided that illustrate the nonlinear motion induced by the constraint., Comment: 8 pages, 4 figures. Based on the talk presented at the DICE2008 conference in Castiglioncello, September 2008

A high-resolution absorption spectrum of gaseous BaCl in the wavelength region 10 000–12 500 cm −1 has been recorded using a Fourier transform spectrophotometer. A rotational analysis of the A 2 Π- X 2 Σ + transition is presented for v ′ = 0–2, and effective molecular constants for the A state are given. Also, an improved ground state description has been obtained by using the merged A - X and B - X data in a combined fit. Furthermore, an analysis of the strong interaction between the A 2 Π and B 2 Σ + states is presented, yielding deperturbed molecular constants for the A and B states, with an rms error of the fit equal to the experimental error.

New high-resolution LIF measurements on RbCs, using various Kr+ laser lines have been performed. Transitions to very high vibrational levels of the ground state were observed when using the 568·2nm line. These new data, together with already existing Ar+ LIF data, have made possible a detailed description of the ground state up to near dissociation. An accurate value of the ground state dissociation energy, De =3845±1 cm−1, has been obtained.

An optical-optical double-resonance (OODR) experiment with a Hitachi cw tunable diode laser (λ ≈ 830 nm) and a Coherent 699-29 Autoscan system (λ ≈ 570–580 nm) has been performed on gaseous BaCl. Selected B2Σ+ (v′, J′, e f ) levels were excited with the diode laser, while scanning the dye laser in the yellow spectral region. An excitation spectrum of the F2Σ+-B2Σ+ transition was recorded by detecting the undispersed UV fluorescence from the F-X deexcitation. Complementary information was collected by photographing the UV absorption spectrum of the F-X transition. A rotational analysis of the F2Σ+ state, based upon a weighted least-squares fitting of the merged OODR and UV absorption data, is presented.

A high-resolution absorption spectrum of the near-infrared B 2Σ-X 2Σ transition of BaCl has been recorded using a Fourier transform spectrophotometer. Complementary information regarding the assignment of individual rotational lines as well as a precise calibration of the spectrum has been obtained with the use of a commercial cw tunable diode laser. Rotational and vibrational constants for the B and X states are derived from 4600 assigned rotational lines belonging to 11 vibrational bands in the Δv = 0, ± 1 sequences with v' ≤ 5 and J ≤ 215.5.

A commercial low‐cost GaAlAs diode laser, operating at room temperature, was used as the tunable monochromatic light source in a high‐resolution laser spectrometer for the near‐infrared spectral region. This laser was found to have qualities fully comparable to those of the thousandfold more expensive single‐mode dye lasers commonly used in high‐resolution laser spectroscopy. Molecular spectra, obtained both in absorption and in laser‐induced emission, and optogalvanic atomic spectra clearly demonstrate the power of this extremely simple and cheap laser spectroscopic system.

Reports on postsplenectomy septicemia have led to a more conservative attitude to treatment of splenic trauma. A case of traumatic rupture of the spleen treated with splenic artery ligation is presented. In the 5-year follow-up the investigations included repeated scintigraphy. Alternative management of traumatized spleen is discussed.