23 research outputs found

    Producción de un genotipo superior a partir de un cultivo de papa agria mediante la variación somaclonal

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    Este estudio se realizó para producir un genotipo superior de la variedad de papa Agria usando variación somaclonal. Se utilizaron dos explantes de hojas y meristemas en combinación con cuatro dosis de 2,4-D (0, 2, 3 y 4 mg / l) para la inducción de callos en un modelo factorial basado en un diseño completamente al azar con 3 repeticiones. Los resultados mostraron que el explante de meristemo, junto con 3 mg de 2,4-D produjeron los callos más adecuados. En el medio de regeneración mencionado se regeneraron los mejores callos y se seleccionó uno de los genotipos regenerados, que era muy diferente al cultivar parental. El genotipo regenerado, se comparó con el genotipo materno (Agria) y un cultivar control (Sante), en un experimento de campo basado en un diseño de bloques completos al azar con 3 repeticiones. Los resultados mostraron que en términos de la mayoría de los rasgos estudiados, como peso del tubérculo por planta, longitud del estolón, porcentaje de materia seca y porcentaje de almidón, el nuevo genotipo fue superior, en comparación con la variedad parental y en términos de porcentaje de piel y madurez. fecha, el cultivar parental fue superior. Los resultados de la comparación molecular también mostraron que, según el marcador CBDP, tanto en términos de número de banda como de tamaño de banda, había diferencias entre el nuevo genotipo y el cultivar parental. En general, los resultados mostraron que la variación somaclonal puede ser un método eficaz para generar nuevos genotipos con características superiore

    La aplicación de nanoparticulas de SiO2 como pretratamiento disminuye el impacto de la sequía en la performance fisiológica de Prunus mahaleb (Rosaceae)

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    La aplicación de nanoparticulas de SiO2 como pretratamiento disminuye el impacto de la sequía en la performance fisiológica de Prunus mahaleb (Rosaceae). En este trabajo se estudiaron respuestas fisiológicas de Prunus mahaleb (Mahaleb) a la sequía luego de la aplicación de diferentes concentraciones de nanoparticulas de SiO2 (SNPs) por irrigación como pretratamientos. Se aplicaron 4 concentraciones de SNPs (0, 10, 50 and 100 mg L-1) durante 45 días y, a posteriori, las plantas fueron sujetas a tres regímenes hídricos que incluyeron control (300 mL cada 3 días), estrés hídrico moderado (150 mL cada 3 días) y estrés hídrico severo (sin riego) por 19 días. El intercambio de gases – fotosíntesis, conductancia estomática y transpiración –se redujo menos frente a la sequía en las plantas que recibieron pretratamientos con SNPs. El estado nutricional de las plantas tratadas con SNPs visto por la concentración de N, P y K se mantuvo bajo sequía moderada. Las plantas pretratadas con SNPs mantuvieron el largo de sus raíces y sufrieron menor impacto en su biomasa radical ante sequía. Se concluye que la aplicación de SNPs como pretratamiento podría ser una práctica agronómica para sitios propensos a déficit hídricos en épocas cercanas a la plantación.We studied the physiological responses of Prunus mahaleb (Mahaleb) seedlings to drought stress when previously irrigated (or not) with different concentrations of SiO2 nanoparticles (SNPs). SNPs were applied at four concentrations (0, 10, 50 and 100 mg L-1) for 45 days, and then seedlings were subjected to three watering treatments including low (300 mL water every 3 d), moderate (150 mL water every 3 d) and severe drought stress (no irrigation) for 19 days. Results showed that gas exchange ? photosynthesis, stomatal conductance, and transpiration rate ? were signifcantly less impacted by severe drought stress when seedlings were pretreated with SNPs at high concentrations. Benefcial effects of SNPs pretreatment were evident in the nutritional status of the plants as the concentration of N, P and K, were maintained at similar levels than in well-watered seedlings. Pretreated seedlings were able to maintain the root length and to reduce the impact of severe drought on root dry mass accumulation. Therefore, application of SNPs as pretreatment should be considered as a promising agronomic practice in sites prone to suffer from water defcitFil: Ashkavand, Peyman. Tarbiat Modares University; IránFil: Zarafshar, Mehrdad. Agricultural Research, Education and Extension Organization; IránFil: Tabari, Masoud. Tarbiat Modares University; IránFil: Mirzaie, Javad. University of Ilam; IránFil: Nikpour, Amirreza. Gorgan University; IránFil: Bordbar, Seyed Kazem. Ohio State University; Estados UnidosFil: Struve, Daniel. Department Of Horticulture And Crop Science; Estados UnidosFil: Striker, Gustavo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentin

    Izolati streptokoka grupe B u mokraći i njihova antimikrobna osjetljivost u skupini iranskih žena: učestalost i sezonske razlike

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    Streptococcus agalactiae is one of the uropathogens responsible for urinary tract infections (UTI ) in children, pregnant women, and elderly people with chronic underlying diseases. This study was performed to determine the prevalence of urinary tract isolates of group B streptococci (GBS) in a group of females referred to a referral University Hospital in Iran. In this retrospective cross-sectional study, urine analysis and urine culture results of all female subjects referred to the laboratory of the Rasoul-e-Akram Hospital, Tehran, Iran in 2010 were reviewed. Bacteriuria, colony count, pyuria and demographic data of patients were also evaluated. In this study, 10,256 females were investigated; 2061 (20.1%) of them had positive urine cultures. GBS was the isolated microorganism in 184 (8.92%) cases, yielding a prevalence of 1.79% in total study population. The mean age of subjects with positive GBS cultures was 48.24}18.8 years, with a higher prevalence recorded in the 51-60 and 21-30 age groups. The highest rates of cultures positive for GBS were seen in December and January. GBS was found to be sensitive to the following antibiotics: cephalothin (100%), norfloxacin (96.9%), ampicillin (96%), nitrofurantoin (95.5%), and vancomycin (95%). In this study, GBS showed greatest resistance to tetracycline (81.6%) and co-trimoxazole (68.9%). In conclusion, the prevalence of GBS in females with suspected UTI is relatively low; however, attention to the age and susceptibility pattern of antibiotic treatment for UTI caused by this microorganism is necessary.Streptococcus agalactiae je jedan od uropatogena odgovornih za infekcije mokraćnog sustava kod djece, trudnica i starijih osoba s kroničnim osnovnim bolestima. Cilj ove studije bio je utvrditi učestalost izolata streptokoka grupe B u mokraćnom sustavu skupine žena upućenih u referentnu Sveučilišnu bolnicu u Iranu. U ovoj retrospektivnoj studiji obrađeni su rezultati analize mokraće i kulture mokraće svih ženskih osoba upućenih u laboratorij Bolnice Rasoul-e-Akram u Teheranu, Iran tijekom 2010. godine. Obrađeni su i podaci o bakteriuriji, broju kolonija, piuriji, te demografski podaci svih bolesnica. Od ukupno 10.256 ispitanih žena pozitivna kultura mokraće utvrđena je u 2061 (20,1%) žene. Streptokok grupe B bio je izolirani mikroorganizam u 184 (8,92%) slučajeva, dok je njegova ukupna učestalost u čitavoj ispitivanoj populaciji bila 1,79%. Srednja dob žena s pozitivnom kulturom streptokoka grupe B bila je 48,24}18,8 godina, s većom učestalošću u dobnim skupinama od 51-60 i 21-30 godina. Najviše stope pozitivnih kultura streptokoka grupe B zabilježene su u prosincu i siječnju, a mikroorganizam je pokazao osjetljivost na slijedeće antibiotike: cefalotin (100%), norfloksacin (96,9%), ampicilin (96%), nitrofurantoin (95,5%) i vankomicin (95%). U ovoj studiji je streptokok grupe B pokazao najveću otpornost na tetraciklin (81,6%) i kotrimoksazol (68,9%). Zaključuje se kako je učestalost streptokoka grupe B kod žena sa sumnjom na infekciju mokraćnog sustava relativno niska, međutim, pozornost treba posvetiti dobi bolesnice i profilu osjetljivosti antibiotske terapije za infekciju mokraćnog sustava uzrokovanu ovim mikroorganizmom

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    Long-term results for post-interventional systemic heparinization following angioplasty of peripheral vessels

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    Objective: The long-term outcome of percutaneous transluminal angioplasties is mainly determined by restenoses, either by progression of the underlying disease or by intimal hyperplasia. Pharmacological substances on the one hand and the implantation of stents on the other have been developed with the intention of preventing precisely this complication. While patients are treated after PTA of peripheral vessels with different low-molecular-weight heparins, the indication for stent implantation is determined individually rather by experience. The aim of this study was to determine gender-specific risk factors of long-term outcome after percutaneous transluminal angioplasty (PTA) of peripheral vessels with or without stentimplantation. Methods: In the present study, we examined the long-term results of percutaneous transluminal angioplasty (PTA) of peripheral vessels. Between 2007 and 2017, in total, 3,276 patients underwent PTA with or without stent implantation in our clinic. All patients were treated postinterventionally for 48 hours with 25,000 IU heparin (Unfractionated Heparin (UFH), heparinsodium-Braun, 25,000 I.E./5 ml, 2 ml/h) monitored by the partial thromboplastin time and subsequently underwent a control investigation every 6 months. The endpoint of the study was determination of symptomatic stenosis larger than 50% that required reintervention. Results: 239 (68.2% with mean age 68.02 years) male patients and 111 female patients (31.71% with mean age 62.92 years) were evaluated with complete follow-up. A total of 470 PTAs were performed on male patients and 213 on female patients in multiple interventions. The majority of patients at the time of treatment were in stage IIb according to the classification of Fontaine (81.6% of male patients and 68% of females). In our sample, peripheral arterial disease stage III and IV according to Fontaine classification occurred twice as frequently in female patients as in male patients (stage III in 12.6% in female versus 6.1% in male, and stage IV in 18% in female versus 8.9% in males). In both groups, the femoral superficialis artery was most frequently dilated (64 cases, 30% in female and 155 cases, 32.9% in male), followed by the iliacal communis artery (46 cases in female and 99 cases in male, both with 21.5%). A balloon angioplasty of the tibialis anterior and posterior arteries was performed twice as frequently in female patients as in male patients (28 cases with 13.1% of tibialis ant. artery in female versus 32 cases with 6.8% in male patients, and in 17 cases with 7.9% of tibialis post. artery in female versus 16 cases with 3.4% in male patients). In this study, without consideration of gender, patency rates of 79% after 2.5 years, 67% after 5 years, 49% after 7.5 years and 37% after 10 years were determined for PTA without stent implantation. Between the 7th and 10th year in follow-up, the cumulative patency rates for stent implantation was 49%, whereas it was 31% for PTA alone. The results of this study show that the stent assisted PTA`s of comm. artery and external iliacal artery are significantly independent of risk factors better than the femoral vessels, and these in female patients better than in male patients. Male patients do not benefit significantly from stent implantation in the long term. As the COXI and II regression analyses show, gender-linked results are most evident for renal insufficiency and diabetes mellitus, and less pronounced also for the number of open lower leg vessels. Conclusion: Under consideration of gender and risk factors, while male patients with diabetes mellitus, renal insufficiency and/or poor run-off did not benefit from stent implantation in the long-term, female patients with similar risk factors showed higher patency rates after stent therapy. In addition, the long-term results after PTA of femoral superficialis artery and poplitea artery are significantly worse than PTA of the pelvic vessels in both genders

    Characterization of Barmejamal Spring Karst Aquifer Using Physico-Chemical Spring Responses

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    Barmejamal Spring is located in northeast of Ahwaz, Khuzestan Province, Iran. The catchment area of the spring consists of the northeast and southwest flanks of the Koh-e-Safid anticline, which is made up of karstic calcareous Asmari formations. There are sinkholes, caves, and other karst landforms in the catchment area. The existence of several faults has brecciaed Barmejamal spring karst aquifer that may have caused karstification to occur in parallel fracture systems. For the purposes of this study, pH and water temperature were measured on a weekly basis for a period of 12 months and water samples were analyzed for major anions and cations. Flow rate was measured on a daily basis during the recession, and weekly during the rest of the study period. Using the PHreeqc 2.6 computer model, the partial pressure of carbon dioxide and the saturation index of calcite and dolomite were also estimated. Three distinct periods belonging to three recession coefficients (α1, α2, α3) were observed in the hydrograph of the Barmejamal Spring. No considerable differences were observed between the first and second recession coefficients. Base flow for α1, α2 and α3 constituted 49%, 75.34%, and 100% of the total flow in the first and second recession periods and in the precipitation period, respectively. The variation of specific conductance, calcium and bicarbonate concentrations, and calcite saturation indices were not significant throughout the study period. The morphology and geology of the Barmejamal Spring catchment area and the data from hydrograph and chemographs show that the hydrologic system is of the diffuse-conduit flow type

    Preimplant ultrastructure and calcification tendency of various biological aortic valves

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    Background and aim of the study: In recent years a number of fixation and anti-calcification methods have been developed, but little is yet known about the calcification process of biological valves. The aims of this study were to: (i) perform a systematic ultrastructural investigation on various biological valves; and (ii) determine the extent of calcification of these valves in a subcutaneous rat model. Methods: The following porcine aortic prostheses were investigated: Toronto-SPV(R), Intact(R), Freestyle(R), Mosaic(R) and Hancock-IIB. Samples taken from the valve leaflets, and in the case of the Freestyle(R) and Toronto-SPV(R) valves also from the aortic wall, were examined ultrastructurally using scanning and transmission electron microscopy. Other samples were implanted subcutaneously in Wistar rats for 12 weeks. The calcium content of the samples was measured using atomic absorption spectrophotometry. Results: All valves examined showed a considerable loss of the endothelial cover. Significant changes in valve ultrastructure were also detected. With regard to calcium content, two valve groups could be distinguished (p 40 mg/g dry tissue); and (ii) those with low calcium content, e.g. Mosaic, Freestyle and Hancock-II (< 5 mg/g). Conclusion: Fixation methods have pronounced effects on the ultrastructural integrity of bioprostheses. The degenerative calcification of bioprostheses can be effectively inhibited by glutaraldehyde-free fixation and anti-calcification treatments

    Comparative analysis of different artificial neural networks for predicting and optimizing in vitro seed germination and sterilization of petunia.

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    The process of optimizing in vitro seed sterilization and germination is a complicated task since this process is influenced by interactions of many factors (e.g., genotype, disinfectants, pH of the media, temperature, light, immersion time). This study investigated the role of various types and concentrations of disinfectants (i.e., NaOCl, Ca(ClO)2, HgCl2, H2O2, NWCN-Fe, MWCNT) as well as immersion time in successful in vitro seed sterilization and germination of petunia. Also, the utility of three artificial neural networks (ANNs) (e.g., multilayer perceptron (MLP), radial basis function (RBF), and generalized regression neural network (GRNN)) as modeling tools were evaluated to analyze the effect of disinfectants and immersion time on in vitro seed sterilization and germination. Moreover, non‑dominated sorting genetic algorithm‑II (NSGA‑II) was employed for optimizing the selected prediction model. The GRNN algorithm displayed superior predictive accuracy in comparison to MLP and RBF models. Also, the results showed that NSGA‑II can be considered as a reliable multi-objective optimization algorithm for finding the optimal level of disinfectants and immersion time to simultaneously minimize contamination rate and maximize germination percentage. Generally, GRNN-NSGA-II as an up-to-date and reliable computational tool can be applied in future plant in vitro culture studies
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