288 research outputs found

    Enhancement of Androgenesis and Plant Regeneration From Wheat Anther Culture by Seed Pre-Sowing Gamma Irradiation

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    Combination breeding and mutation breeding are widely used methods in plant breeding. Intensive studies are carried out on biotechnological methods that will allow obtaining homozygous lines in a short time in populations obtained with these two techniques. Numerous studies have been carried out by different researchers on mutation breeding in wheat. There are few studies on anther culture response in mutagen-treated genotypes. Two different bread wheat promising advanced lines were used as the material in the study, in which the possibilities of combining mutation breeding with anther culture through ionizing radiation in high quality wheat breeding were investigated. In the study, the responses of advanced bread wheat mutant lines to anther culture, to which eight different doses of gamma rays (0, 100, 150, 200, 250, 300, 350, 400 Gy) were applied, including the control, were investigated. There are significant differences between genotypes and irradiation doses for all traits studied. It has been shown that it is possible to decrease albinism and increase the response of anther culture with dose-dependent gamma irradiation depending on bread wheat varieties. In the multiple comparison test to classify the difference between doses; statistically, 150 gray dose 5.60 is in the first statistical class and in the first place with the number of transferred green plants. After that, it ranks second in the same class with the number of green plants transferred with a 300 gray dose of 5.21. In the total number of regenerated green plants excluding controls (888), 635 unit (71.5%) and 205 unit (23.1%) haploids and spontaneous double haploid plants were obtained, respectively. In the study integrated into the bread wheat breeding program, a total of 205 spontaneous double haploid mutant lines were produced. According to the data obtained, it was shown that the gamma ray doses of 150 and 200 Gy had a significant stimulation effect on all parameters studied and ultimately the success index of anther culture in bread wheat compared to control. © 2022 Namik Kemal University - Agricultural Faculty. All rights reserved

    Ascites as an initial presentation of spontaneously ruptured hydatid cyst

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    We describe the diagnosis of a 77-year-old woman admitted toour outpatient department with a 3-month history of abdominalbloating and distension. Abdominal computed tomographyrevealed a large cystic lesion in the posterior segment of the righthepatic lobe, with a separated germinal layer and widespreadascites with dense internal echoes and septal appearance. Theresult of a serum Echinococcus indirect haemagglutination testwas positive and findings were indicative of the spontaneousrupture of a hydatid cyst into the peritoneal cavity withouttrauma. Ascites is rarely seen in the course of hydatid disease,but can result from cyst rupture into the peritoneal cavity. Thisshould be considered in the differential diagnosis of ascites,especially in areas such as Turkey, where hydatid disease inendemic

    International multicentre study of candida auris infections

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    Background: Candida auris has emerged globally as a multi-drug resistant yeast and is commonly associated with nosocomial outbreaks in ICUs. Methods: We conducted a retrospective observational multicentre study to determine the epidemiology of C. auris infections, its management strategies, patient outcomes, and infection prevention and control practices across 10 centres from five countries. Results: Significant risk factors for C. auris infection include the age group of 61–70 years (39%), recent history of ICU admission (63%), diabetes (63%), renal failure (52%), presence of CVC (91%) and previous history of antibiotic treatment (96%). C. auris was commonly isolated from blood (76%). Echinocandins were the most sensitive drugs. Most common antifungals used for treatment were caspofungin (40%), anidulafungin (28%) and micafungin (15%). The median duration of treatment was 20 days. Source removal was conductedin 74% patients. All-cause crude mortality rate after 30 days was 37%. Antifungal therapy was associated with a reduction in mortality (OR:0.27) and so was source removal (OR:0.74). Contact isolation precautions were followed in 87% patients. Conclusions: C. auris infection carries a high risk for associated mortality. The organism is mainly resistant to most azoles and even amphotericin-B. Targeted antifungal therapy, mainly an echinocandin, and source control are the prominent therapeutic approaches

    Is rejection a diffuse or localized process in small-bowel transplantation?

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    Utilization of endoscopy to both visualize and selectively biopsy an intestinal allograft has become the standard for early recognition and treatment of intestinal allograft rejection. Despite the widespread acceptance of the need for selective mucosal biopsies, it has not been shown that the histological features of intestinal allograft rejection are either localized or occur as part of a more diffuse phenomenon within a tubular allograft. To resolve these issues, 88 ileoscopies were performed in 12 small-bowel allograft recipients and mucosal biopsy samples were obtained at 5, 10, and 15 cm, respectively, from the ileal stoma. Each mucosal biopsy was labeled, processed, and evaluated individually for the presence and severity of any evidence for allograft rejection. The data obtained suggest that intestinal allograft rejection is a diffuse process, and biopsies obtained randomly from an ileal graft are likely to demonstrate evidence of allograft rejection when such is present. © 1994 Springer-Verlag New York Inc

    Different methodological approaches to the assessment of in vivo efficacy of three artemisinin-based combination antimalarial treatments for the treatment of uncomplicated falciparum malaria in African children.

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    BACKGROUND: Use of different methods for assessing the efficacy of artemisinin-based combination antimalarial treatments (ACTs) will result in different estimates being reported, with implications for changes in treatment policy. METHODS: Data from different in vivo studies of ACT treatment of uncomplicated falciparum malaria were combined in a single database. Efficacy at day 28 corrected by PCR genotyping was estimated using four methods. In the first two methods, failure rates were calculated as proportions with either (1a) reinfections excluded from the analysis (standard WHO per-protocol analysis) or (1b) reinfections considered as treatment successes. In the second two methods, failure rates were estimated using the Kaplan-Meier product limit formula using either (2a) WHO (2001) definitions of failure, or (2b) failure defined using parasitological criteria only. RESULTS: Data analysed represented 2926 patients from 17 studies in nine African countries. Three ACTs were studied: artesunate-amodiaquine (AS+AQ, N = 1702), artesunate-sulphadoxine-pyrimethamine (AS+SP, N = 706) and artemether-lumefantrine (AL, N = 518).Using method (1a), the day 28 failure rates ranged from 0% to 39.3% for AS+AQ treatment, from 1.0% to 33.3% for AS+SP treatment and from 0% to 3.3% for AL treatment. The median [range] difference in point estimates between method 1a (reference) and the others were: (i) method 1b = 1.3% [0 to 24.8], (ii) method 2a = 1.1% [0 to 21.5], and (iii) method 2b = 0% [-38 to 19.3].The standard per-protocol method (1a) tended to overestimate the risk of failure when compared to alternative methods using the same endpoint definitions (methods 1b and 2a). It either overestimated or underestimated the risk when endpoints based on parasitological rather than clinical criteria were applied. The standard method was also associated with a 34% reduction in the number of patients evaluated compared to the number of patients enrolled. Only 2% of the sample size was lost when failures were classified on the first day of parasite recurrence and survival analytical methods were used. CONCLUSION: The primary purpose of an in vivo study should be to provide a precise estimate of the risk of antimalarial treatment failure due to drug resistance. Use of survival analysis is the most appropriate way to estimate failure rates with parasitological recurrence classified as treatment failure on the day it occurs

    General model with experimental validation of electrical resonant frequency tuning of electromagnetic vibration energy harvesters

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    This paper presents a general model and its experimental validation for electrically tunable electromagnetic energy harvesters. Electrical tuning relies on the adjustment of the electrical load so that the maximum output power of the energy harvester occurs at a frequency which is different from the mechanical resonant frequency of the energy harvester. Theoretical analysis shows that for this approach to be feasible the electromagnetic vibration energy harvester’s coupling factor must be maximized so that its resonant frequency can be tuned with the minimum decrease of output power. Two different-sized electromagnetic energy harvesters were built and tested to validate the model. Experimentally, the micro-scale energy harvester has a coupling factor of 0.0035 and an untuned resonant frequency of 70.05 Hz. When excited at 30 mg, it was tuned by 0.23 Hz by changing its capacitive load from 0 to 4000 nF; its effective tuning range is 0.15 Hz for a capacitive load variation from 0 to 1500 nF. The macro-scale energy harvester has a coupling factor of 552.25 and an untuned resonant frequency of 95.1 Hz and 95.5 Hz when excited at 10 mg and 25 mg, respectively. When excited at 10 mg, it was tuned by 3.8 Hz by changing its capacitive load from 0 to 1400 nF; it has an effective tuning range of 3.5 Hz for a capacitive load variation from 0 to 1200 nF. When excited at 25 mg, its resonant frequency was tuned by 4.2 Hz by changing its capacitive load from 0 to 1400 nF; it has an effective tuning range of about 5 Hz. Experimental results were found to agree with the theoretical analysis to within 10%

    The Role of Nonequilibrium Dynamical Screening in Carrier Thermalization

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    We investigate the role played by nonequilibrium dynamical screening in the thermalization of carriers in a simplified two-component two-band model of a semiconductor. The main feature of our approach is the theoretically sound treatment of collisions. We abandon Fermi's Golden rule in favor of a nonequilibrium field theoretic formalism as the former is applicable only in the long-time regime. We also introduce the concept of nonequilibrium dynamical screening. The dephasing of excitonic quantum beats as a result of carrier-carrier scattering is brought out. At low densities it is found that the dephasing times due to carrier-carrier scattering is in picoseconds and not femtoseconds, in agreement with experiments. The polarization dephasing rates are computed as a function of the excited carrier density and it is found that the dephasing rate for carrier-carrier scattering is proportional to the carrier density at ultralow densities. The scaling relation is sublinear at higher densities, which enables a comparison with experiment.Comment: Revised version with additional refs. 12 pages, figs. available upon request; Submitted to Phys. Rev.
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