Modified Mach-Zehnder interferometer for spatial coherence measurement.

Spatial coherence of light sources is usually obtained by using the classical Young's interferometer. Although the original experiment was improved upon in successive works, some drawbacks still remain. For example, several pairs of points must be used to obtain the complex coherence degree (normalized first-order correlation function) of the source. In this work, a modified Mach-Zehnder interferometer which includes a pair of lenses and is able to measure the spatial coherence degree is presented. With this modified Mach-Zehnder interferometer, it is possible to measure the full 4D spatial coherence function by displacing the incoming beam laterally. To test it, we have measured only a 2D projection (zero shear) of the 4D spatial coherence, which is enough to characterize some types of sources. The setup has no movable parts, making it robust and portable. To test it, the two-dimensional spatial coherence of a high-speed laser with two cavities was measured for different pulse energy values. We observe from the experimental measurements that the complex degree of coherence changes with the selected output energy. Both laser cavities seem to have similar complex coherence degrees for the maximum energy, although it is not symmetrical. Thus, this analysis will allow us to determine the best configuration of the double-cavity laser for interferometric applications. Furthermore, the proposed approach can be applied to any other light sources.

Accuracy and reproducibility of patient-specific hemodynamic models of stented intracranial aneurysms: report on the Virtual Intracranial Stenting Challenge 2011.

Validation studies are prerequisites for computational fluid dynamics (CFD) simulations to be accepted as part of clinical decision-making. This paper reports on the 2011 edition of the Virtual Intracranial Stenting Challenge. The challenge aimed to assess the reproducibility with which research groups can simulate the velocity field in an intracranial aneurysm, both untreated and treated with five different configurations of high-porosity stents. Particle imaging velocimetry (PIV) measurements were obtained to validate the untreated velocity field. Six participants, totaling three CFD solvers, were provided with surface meshes of the vascular geometry and the deployed stent geometries, and flow rate boundary conditions for all inlets and outlets. As output, they were invited to submit an abstract to the 8th International Interdisciplinary Cerebrovascular Symposium 2011 (ICS'11), outlining their methods and giving their interpretation of the performance of each stent configuration. After the challenge, all CFD solutions were collected and analyzed. To quantitatively analyze the data, we calculated the root-mean-square error (RMSE) over uniformly distributed nodes on a plane slicing the main flow jet along its axis and normalized it with the maximum velocity on the slice of the untreated case (NRMSE). Good agreement was found between CFD and PIV with a NRMSE of 7.28%. Excellent agreement was found between CFD solutions, both untreated and treated. The maximum difference between any two groups (along a line perpendicular to the main flow jet) was 4.0 mm/s, i.e. 4.1% of the maximum velocity of the untreated case, and the average NRMSE was 0.47% (range 0.28-1.03%). In conclusion, given geometry and flow rates, research groups can accurately simulate the velocity field inside an intracranial aneurysm-as assessed by comparison with in vitro measurements-and find excellent agreement on the hemodynamic effect of different stent configurations.

Two-dimensional quantification of the corrosion process in metal surfaces using digital speckle pattern interferometry.

The applicability of digital speckle pattern interferometry (DSPI) to the analysis of surface corrosion processes has been evaluated by studying the evolution of an Fe surface immersed in sulfuric acid. This work describes the analysis process required to obtain quantitative information about the corrosion process. It has been possible to evaluate the corrosion rate, and the results agree with those derived from the weight loss method. In addition, a two-dimensional analysis has been applied, showing that DSPI measurements can be used to extract information about the corrosion rate at any region of the surface.

[Anticoagulation in atrial fibrillation and antiplatelet in diabetes mellitus type 2. How do we do it?]. / Anticoagulación en fibrilación auricular y antiagregación en diabetes mellitus tipo 2. ¿Cómo lo hacemos?

BACKGROUND: In spite of evidence about the interest of anticoagulation in Atrial Fibrillation (AF) and antiplatelet to diabetics (DM) type 2, the national and international references describe a low level of assumption of those criteria in practice. Published studies on these aspects are unavailable in Navarre. METHODS: Cross-sectional study. POPULATION: primary care patients (1,600 people > 15 years). INCLUSION CRITERIA: patients diagnosed of AF / with diagnosis of DM type 2, over 40. VARIABLES: age and sex, criteria of AF with high embolic risk (>6% annual) and cardiovascular risk factors in DM2. DATA COLLECTION: in computerised registers of Organisation and Management Information. ANALYSIS: (population universe studied), results in absolute numbers and percentages. RESULTS: Twenty-five people with diagnosis of chronic FA (14 women and 11 men, average age 78.36 years); 22 (81.8%) show high embolic risk. There were counter-indications in 4 cases. Type 2 diabetics totalled 69 people (29 women and 40 men, average age 68.57 years). There are 16 (23.1%) in primary prevention (PP), 26 (37.3%) in secondary prevention (SP), and 27 (39.1%) do not follow antiplatelet therapy. There is counter-indication in 8 cases and 14 patients (20.2%) would be susceptible to intervention. CONCLUSIONS: The results of oral anticoagulant therapy (OAT) in high risk AF exceed the reviewed references. The PP with DM2 are similar figures to other studies; a area of improvement was detected. We must ask for the opinion of the patient and individualise these therapies. The family doctor has a significant responsibility in cardiovascular prevention of the patients affected by these problems.

Toxic epidermal necrolysis-like reaction secondary to colchicine overdose.

Colchicine is a microtubule-inhibiting drug used to treat gout, familial Mediterranean fever and many other skin diseases. Intoxication with colchicine affects multiple organs, often fatally. Cutaneous sequelae of colchicine toxicity are rare. We describe the clinical and histological features of a toxic epidermal necrolysis-like exanthem in a patient who lethally overdosed on colchicine.

Schizosaccharomyces pombe replication and repair proteins: proliferating cell nuclear antigen (PCNA).

Schizosaccharomyces pombe has a cell cycle progression with distinctive phases that serves as a perfect model system for investigating DNA replication and repair of eukaryotic cells. Here, we use proliferating cell nuclear antigen (PCNA) of S. pombe to demonstrate how the function of this protein in both DNA replication and repair can be assessed by genetic and biochemical approaches. We describe a method of introducing site-specific mutations into the fission yeast PCNA gene pcn1(+). The in vivo effects of these pcn1 mutants in a strain with a null pcn1 background are described and their in vitro biochemical properties are characterized. Mutants described here are those that are defective in enhancing processivity of DNA polymerase delta, show temperature-sensitive growth, and have increased sensitivity to hydroxyurea (HU), UV and gamma irradiation, and methyl methanesulfonate (MMS). Three mutants that show reduced growth rate in vivo and decreased capacity to enhance polymerase delta DNA synthetic activity and processivity in vitro-pcn1-1, pcn1-5, and pcn1-26-are described as examples of using a genetic approach to identify the biochemical function of replication proteins. One cold-sensitive growth allele, pcn1-3, that has a recessive cold-sensitive cdc phenotype and shows sensitivity to HU and UV and gamma irradiation is used as an example of using the genetic approach to reveal the function of replication proteins in repair. The power of combining both biochemical and genetic disciplines is emphasized. Methods for site-directed mutagenesis, in vitro analysis of mutant proteins, and in vivo characterization of mutants in response to UV or gamma irradiation, MMS, HU, and temperature, as well as genetic epistasis are described. Locations of functionally significant residues on the PCNA tertiary structure are summarized.

The C-terminal region of Schizosaccaromyces pombe proliferating cell nuclear antigen is essential for DNA polymerase activity.

Proliferating cell nuclear antigen (PCNA), the processivity factor (sliding clamp) of DNA polymerases (Pols), plays essential roles in DNA metabolism. In this report, we examined the functional role of the C-terminal region of Schizosaccaromyces pombe PCNA both in vitro and in vivo. The deletion or Ala substitution of the last 9 aa (252-260A), as well as Ala replacement of only 4 aa (252-255A) at the C terminus, failed to substitute for the wild-type PCNA protein for cell growth in S. pombe. Two other PCNA mutant proteins, A251V and K253E, exhibited cold-sensitive phenotypes. Several yeast strains harboring mutations, including those at the acidic C-terminal region, showed elevated sensitivity to DNA damage. The ability of the mutant PCNA proteins to stimulate DNA synthesis by Poldelta and Polepsilon also was studied in vitro. The mutant proteins that did not support cell growth and a mutant protein containing a single amino acid substitution at position 252, where Pro is replaced by Ala, stimulated Poldelta and Polepsilon activities poorly. All mutant PCNA proteins, however, were assembled around DNA by the clamp loader, replication factor C, efficiently. Thus, the C-terminal region of PCNA is important for interactions with both Poldelta and Polepsilon and for cell survival after DNA damage. The C terminus of sliding clamps from other organisms has been shown to be important for clamp loading as well as polymerase interactions. The relationship between the conserved sequence in this region in different organisms is discussed.

Digital speckle-pattern interferometry as a full-field fluid-velocimetry technique.

We present a novel fluid-velocimetry technique based on speckle interferometry. The light scattered from an illuminated plane is recorded with a CCD camera at the same time as a speckled reference beam. Substraction of two nonsimultaneous frames provides information about the velocity field for an out-of-plane component. An application to a Rayleigh-Bénard convective flow is given.

Mutant PCNA alleles are associated with cdc phenotypes and sensitivity to DNA damage in fission yeast.

Twenty-eight site-directed mutations were introduced into the fission yeast gene (pcn1+) that encodes proliferating cell nuclear antigen (PCNA) and their in vivo effects analyzed in a strain with a null pcn1 background. Mutants defective in enhancing processivity of DNA polymerase delta have previously been identified. In this study, we assessed all of the mutants for their sensitivities to temperature, hydroxyurea, UV irradiation and methyl methanesulfonate (MMS), and specific mutants were also tested for sensitivity to gamma irradiation. One cold-sensitive allele, pcn1-3, was characterized in detail. This mutant had a recessive cold-sensitive cdc phenotype and showed sensitivity to hydroxyurea, UV, and gamma irradiation. At the non-permissive temperature pcn1-3 protein was able to form homotrimers in solution and showed increased stimulation of both synthetic activity and processivity of DNA polymerase delta relative to the wild-type Pcn1+ protein. Epistasis analyses indicated that pcn1-3 is defective in the repair pathway involving rad2+ but not defective in the classical nucleotide excision repair pathway involving rad13+. Furthermore, pcn1-3 is either synthetically or conditionally lethal in null checkpoint rad backgrounds and displays a mitotic catastrophe phenotype in these backgrounds. A model for how pcn1-3 defects may affect DNA repair and replication is presented.

Schizosaccharomyces pombe proliferating cell nuclear antigen mutations affect DNA polymerase delta processivity.

We introduced nine site-directed mutations into seven conserved fission yeast proliferative cell nuclear antigen (PCNA) residues, Leu2, Asp63, Arg64, Gly69, Gln201, Glu259, and Glu260, either as single or as double mutants. Both the recombinant wild type and mutant PCNAs were able to form homotrimers in solution and to sustain growth of a null pcna strain (Deltapcna). Wild type Schizosaccharomyces pombe PCNA and PCNA proteins with mutations in Asp63, Gln201, Glu259, or Glu260 to Ala were able to stimulate DNA synthetic activity and to enhance the processivity of calf thymus DNA polymerase delta holoenzyme similar to calf thymus PCNA. Mutations of Leu2 to Val or Arg64 to Ala, either singly or as a double mutant, yielded PCNA mutant proteins that had reduced capacity in enhancing the processivity of DNA polymerase delta but showed no deficiency in stimulation of the ATPase activity of replication factor C. S. pombe Deltapcna strains sustained by these two mutant-pcna alleles had moderate defects in growth and displayed elongated phenotypes. These cells, however, were not sensitive to UV irradiation. Together, these in vitro and in vivo studies suggest that the side chains of Leu2 and Arg64 in one face of the PCNA trimer ring structure are two of the several sites involved in tethering DNA polymerase delta for processive DNA synthesis during DNA replication.

[Delegated prescription by specialists in primary care]. / Prescripción delegada por especialistas en atención primaria.

OBJECTIVES: To describe the qualitative-quantitative features of Primary Care prescriptions originated by specialists. DESIGN: A crossover descriptive study. SETTING: Txantrea Health Centre (Pamplona). PATIENTS AND OTHER PARTICIPANTS: All the prescriptions originated by out-clinic or hospital specialists over a two-month period, in three Health Centre clinics. MEASUREMENTS AND MAIN RESULTS: The number of prescriptions passed on to Primary Care was 3,009, costing 5,303,071 pesetas, which was 31.61% of the drugs prescribed and 38.08% of the pharmaceutical expenditure of the three clinics during the period under study. 65.88% of the prescriptions corresponded to out-clinic specialists and 34.11% to hospital specialists. They were not accompanied by a clinical note, the treatment and the length of treatment in 33.46%, 36.55% and 45.39% of cases, respectively. The group and sub-group with most prescriptions passed on were Cardiovascular Apparatus and Calcium antagonists. The commonest active principal was acetylsalicylic acid. 79.89% were taken orally, 88.20% were single drugs and 73.28% of the medicines had high intrinsic value. CONCLUSIONS: An important proportion of Primary Care's pharmaceutical expenditure was identified as originating with specialists. There was scant information given for following up the patients. Improvement of communication between different care levels on the basis of common procedures and objectives would be a useful step towards better quality of care.

Dual diode-laser fiber-optic diagnostic for water-vapor measurements.

We present a novel diode-laser diagnostic for water-vapor measurements based on absorption spectroscopy. Two InGaAsP diode lasers were used to record H(2)O absorption line shapes near 1395 nm at a 3-kHz repetition rate along a single path through a water-vapor flow field generated in a shock tube. The use of two lasers permits simultaneous line-shape measurements in different spectral regions and facilitates the selection of appropriate line pairs for thermometry. The wavelength tuning rate was determined by use of a fiber-optic device known as a ring interferometer. Flow-field conditions (1320 K, 0.3 atm) inferred from measured line shapes compared favorably with calculated values.

Diode-laser absorption technique for simultaneous measurements of multiple gasdynamic parameters in high-speed flows containing water vapor.

A distributed-feedback InGaAsP diode laser, emitting near 1.38 µm, was used to acquire spectrally resolved absorption profiles of H(2)O lines in the ν(1) + ν(3) band at a repetition rate of 10 kHz. The profiles were used for simultaneous measurements of flow parameters in high-speed, one-dimensional (1-D) transient flows generated in a shock tube. Velocity was determined from the Doppler shift, which was measured with a pair of profiles simultaneously acquired at different angles with respect to the flow direction. Temperature was determined from the intensity ratio of two adjacent lines. Pressure and density were found from the fractional absorption. From these primary gasdynamic variables, the mass and momentum fluxes were determined. Experiments were conducted with three different gas mixtures in the shock tube: pure H(2)O at initial pressures lower than 3 Torr, up to 6% of H(2)O in O(2) at initial pressures below 120 Torr, and up to 8% of H(2)O in O(2) at initial pressures below 35 Torr. In the third case, pyrolysis of H(2) /O(2) behind incident shocks produced known yields of H(2)O. With all three mixtures, results compare well with 1-D shock calculations. This H(2)O diagnostic strategy shows promise for applications in both ground and flight testing.

Absorption measurements of water-vapor concentration, temperature, and line-shape parameters using a tunable InGaAsP diode laser.

A tunable diode laser diagnostic based on spectrally resolved laser absorption has been developed to detect water vapor. The system uses a distributed feedback InGaAsP diode laser, emitting at ~ 1.38 µm. The diode laser is tuned in wavelength by modulation of the current, resulting in 1-cm(-1) tuning at 80-Hz repetition rate. The directly measured absorption spectra yield values for water-vapor concentration and temperature, as well as a collision-broadening line shape. To our knowledge, we accurately determined required data for H(2)O line strengths and self-broadening coefficients for several spectral lines in a static cell filled with pure water vapor. The temperature and concentration of the water vapor present in laboratory room air and in the postflame gases above a methane-air flat flame burner have also been measured. These results agree well with calculated values and independent measurements.

White-light speckle method of measurement of flow velocity distribution.

A white-light speckle technique for measurement of flow velocities is described. The speckle patterns are formed by incoherent light at the image plane of the fluid illuminated section. The convection flow generated in a rectangular cell filled with silicone oil is studied with this technique. The flow velocities are obtained as the result of a point-by-point analysis. Alternatively, an overall picture of their spatial distribution is obtained by means of a whole-field filtering technique. The accuracy of the two methods of analysis is studied.