981 research outputs found

    Ancestral self-compatibility facilitates the establishment of allopolyploids in Brassicaceae

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    Can the diagnosis of recurrent vulvovaginal candidosis be improved by use of vaginal lavage samples and cultures on chromogenic agar?

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    OBJECTIVE: To investigate if introital and vaginal flushing samples inoculated on chromogenic agar could increase the recovery rate and rapid identification of Candida and non-albicans species, as compared to culture of posterior vaginal fornix samples on Sabouraud agar and speciation of isolates by biochemical tests. METHODS: Samples from the introitus and the posterior vaginal fornix and vaginal lavage samples were collected from 91 women with a history suggestive of recurrent vulvovaginal candidosis (RVVC), and with a suspected new attack of the condition. The specimens were cultured on Sabouraud and CHROMagar. Speciation of yeast isolates was made on the chromogenic agar by API 32C kits and by an atomized system (Vitek). RESULTS: Forty-six (51%) women were positive for Candida from one or more of the samples. The introital cultures were positive in 43 (47%) women, both on Sabouraud and chromogenic agar. From the posterior vaginal fomix, 42 (46%) women were positive on the Sabouraud and 43 (47%) on chromogenic agar cultures, while the vaginal lavage cultures yielded Candida on those two media in 40 (44%) and 41 (45%) cases, respectively. Candida albicans was the most frequent species recovered, from 40 (87%) cases, followed by C. krusei in 4 (9%), C. glabrata in 2 (4%), and C. parapsilosis in one case. There was only one woman who had a mixed yeast infection, by C. albicans and C. krusei. There was only one discrepancy in the speciation as demonstrated by mean of chromogenic agar and API 32C kit. CONCLUSIONS: Neither cultures of introital nor of vaginal lavage samples increases the detection rate of Candida in RVVC cases as compared to cultures of posterior vaginal fornix samples. Use of chromogenic agar is a convenient and reliable means to detect colonization by Candida and differentiate between C. albicans and non-albicans species

    Temperature dependence of the electron spin g factor in GaAs

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    The temperature dependence of the electron spin gg factor in GaAs is investigated experimentally and theoretically. Experimentally, the gg factor was measured using time-resolved Faraday rotation due to Larmor precession of electron spins in the temperature range between 4.5 K and 190 K. The experiment shows an almost linear increase of the gg value with the temperature. This result is in good agreement with other measurements based on photoluminescence quantum beats and time-resolved Kerr rotation up to room temperature. The experimental data are described theoretically taking into account a diminishing fundamental energy gap in GaAs due to lattice thermal dilatation and nonparabolicity of the conduction band calculated using a five-level kp model. At higher temperatures electrons populate higher Landau levels and the average gg factor is obtained from a summation over many levels. A very good description of the experimental data is obtained indicating that the observed increase of the spin gg factor with the temperature is predominantly due to band's nonparabolicity.Comment: 6 pages 4 figure

    Optimal control of light pulse storage and retrieval

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    We demonstrate experimentally a procedure to obtain the maximum efficiency for the storage and retrieval of light pulses in atomic media. The procedure uses time reversal to obtain optimal input signal pulse-shapes. Experimental results in warm Rb vapor are in good agreement with theoretical predictions and demonstrate a substantial improvement of efficiency. This optimization procedure is applicable to a wide range of systems.Comment: 5 pages, 4 figure

    Risk factors for the preservation of morphological changes in the gastric mucosa after eradication therapy for Helicobacter pylori infection in children with chronic gastritis

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    We conducted a clinical, morphofunctional examination and standard treatment of 155 children with chronic gastroduodenitis associated with Helicobacter pylori (HP) infection. It was кevealed that after 6 months lymphoplasmacytic infiltration of the gastric mucosa (GM) preserved in 37% of cases, and unspecified atrophy - in 9%, increased C3 and C4 components of the compliment - in 19% of children, antroduodenal discoordination on the background of postprandial secretin and cholecystokinin level - in 25%, as well as disorders of the intestinal microbiot

    Precision spectral manipulation of optical pulses using a coherent photon echo memory

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    Photon echo schemes are excellent candidates for high efficiency coherent optical memory. They are capable of high-bandwidth multi-pulse storage, pulse resequencing and have been shown theoretically to be compatible with quantum information applications. One particular photon echo scheme is the gradient echo memory (GEM). In this system, an atomic frequency gradient is induced in the direction of light propagation leading to a Fourier decomposition of the optical spectrum along the length of the storage medium. This Fourier encoding allows precision spectral manipulation of the stored light. In this letter, we show frequency shifting, spectral compression, spectral splitting, and fine dispersion control of optical pulses using GEM
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