80 research outputs found
Synthesis and Evaluation of Antibacterial and Antifungal Activities of 1,3-Disubstituted-4-thioxoimidazolidin-2-one Derivatives
1,3-Disubstituted-4-thioxoimidazolidin-2-one derivatives with various substituents at N1 and N3 were synthesized with high yields and excellent purity by the reaction of various N-arylcyanothioformamide derivatives with isocyanate derivatives. The activity of these products as antibacterial and antifungal agents was studied to through some light on structural activity relationship. Some of synthesized compounds showed significant antibacterial and antifungal activities. Most of the imidazole derivatives possess significant antifungal activity aginst S. cerevisiae (MIC 1–10 µg mL–1). As comparision with ketoconazole, most of the imidazole derivatives showed activity ranging from 50 % less activity to fourfold activity.
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Influence of Growth Regulators on Shedding of Broad Bean, Growth, Yield and Seed Quality
In order to study the effect of foliar spraying of growth regulators on growth,seed yield and seed quality, two field experiments were conducted at an extensive field during 2014/2015 and 2015/2016 seasons to determine following foliar spraying of Naphthalene Acetic Acid (NAA) concentrations, i.e. 0, 20, 40 and 60 ppm and Kinetin (Kin) concentrations, i.e. 0, 15, 30 and 45 ppm after 35 and 50 days from sown. Accumulative NAA levelsof to 60 ppm significantly increased total chlorophyll, plant height (cm),branches number/plant, number of shedding flowers, shedding %, pods and seeds number/plant,seedsnumber/pod, seed yield/plant, 100-seed weight (g), seed yield (ton/ha) and protein % in both seasons.Naphthalene Acetic Acid foliar spraying up to 60 ppm exceeded of total chlorophyll, plant height (cm), branchesnumber/plant, number of shedding flowers, podsnumber/plant, seedsnumber/pod, seedsnumber/plant, seed yield (g) /plant, 100-seed weight (g), seed yield (ton/ha) and protein % by 11.47, 23.92, 92.88, 20.53, 11.87, 23.48, 14.16, 24.91, 26.15 and 13.23%, respectively as the average of both seasons. But, reduced the shedding percentage by 11.91% as the average oftwo seasons. Kinetin (Kin) foliar spraying up to 45 ppm significantly increased total chlorophyll, plant height (cm), number of branches/plant, number of shedding flowers, shedding %, pods and seeds number/plant,number of seeds/pod, seed yield/plant, 100-seed weight (g), seed yield (ton/ha) and protein % in both seasons. It could be noticed that foliar spraying of Kinetin (Kin) concentrationsup to 45 ppm exceeded total chlorophyll, plant height (cm), branchesnumber/plant, number of shedding flowers, podsnumber/plant, seedsnumber/pod, seedsnumber/plant, seed yield /plant, 100-seed weight (g), seed yield (ton/ha) and protein % by 12.16, 19.39, 61.64, 5.60, 5.56, 6.96, 5.64, 18.75, 13.38 and 4.39%, respectively as average of both seasons. But, reduced the shedding % by 14.73 % as the average of both seasons.It could be recommended that foliar spraying of Naphthalene Acetic Acid up to 60 ppm and Kin of 45 ppm improved seed yield/ha by 38.2% compared without foliar application
Influence of antioxidants and salinity stress on seedling parameters of some rice cultivars
An investigation was conducted to study the response of antioxidants seed priming on rice cultivars and their effect on germination under salinity levels. The result indicated that the highest in shoot height (cm), root height (cm), seedling vigor index, and other related parameters, relative dry weight% were produced from Sakha 106 cultivar. The lowest seedling height reduction % was produced from Sakha 106 cultivar. An enhancement in salt concentration resulted a reduction in all studied parameters except seedling height reduction %. The results indicated the highest shoot height (cm), root height (cm),seedling vigor index, shoot fresh and dry weight (mg), root fresh and dry weight (mg), relative dry weight% and seedling height reduction % from which soaking, as pretreatment, in Humic acid at 500ppm. The interactions between cultivars, salinity concentration and antioxidants were insignificant on some traits. It could be concluded that to improve seedling parameters of rice cultivars under salinity stress; it could be recommended that soaking Sakha 106 cultivar seed in Humic acid at 500 ppm for 24 h. It can be used in breeding program to boost production in Egyptian territory
Effect of Horizontal DNA Transfer in Azospirillum and Azotobacter Strains on Biological and Biochemical Traits of Non-legume Plants
Abstract: Auxin production by Azospirillum and Azotobacter is believed to play a major role on promoting plant growth. Non legume plants inoculated with different genetically modified strains is significantly stimulated due to the contribution of Auxin biosynthesis by Azospirillum transconjugants affecting on root fresh weight of sugar beet above the plants fertilized with 50% of recommended dose. This study focuses the association between 2,4-D and Azospirillum which revealed significant increase in leaf area of top variety at the presence of 2,4-D above the plants fertilized with nitrogen recommended dose. At the absence of 2,4-D some of transconjugants significantly stimulate the leaf area of top variety above the plants fertilized with 50% of nitrogen recommended dose. The importance of horizontal gene transfer is an adaptive mechanism for bacteria, which may result in increased genetic variation by bringing together DNA from different genetic backgrounds. Furthermore, Azospirillum transconjugants (extra copy of DNA) were evaluated in field trail. Together, these results confirm the important role of IAA produced by transconjugants on stimulating root weight and illustrate the power of combining genetic tools and bioassays to elucidate the mechanism of a beneficial Azospirillum -plant interaction. The effects of biofertilizing by Azospirillum transconjugants on the technological parameters of sugar beet were studied. The better results were gained at variety Top (sugar %, potassium, sodium, quality) at the absence of 2,4-D under the effect of biofertilization, but variety dispery obtained better results of alphaamino-nitrogen under the effect of nitrogen recommended dose. When plant-growth promoting rhizobacteria (Azotobacter strains) were used as inoculants for biofertilization and phytostimulation of canola, some of the inoculants improving growth and yield parametres; leaf area, plant height, root dry weight and grain yield/plant above the plants fertilized with 50% of nitrogen recommended dose. In addition, chlorophyll b and grain yield/plant in Serw 6 variety was significantly affected by the addition of 2,4-D. Corn plants biofertilized with Azospirillum strains and their transconjugants appeared significant effect on ear length, plant height, grain content of carotene and leave content of cholorophyll pigments. This work describes the beneficial effect of genetic variations in rhizobacterium strains, which contains an active biological containment system affecting on their effectiveness of nitrogen fixation and auxin production. This leading to recommend to inoculate non -legume plants with selected rhizobacterial isolates to exhibit stimulatory effect on grain yield and root fresh weight (sugar beet). However, plantresponse was varied, due to plant varieties and genetic constitution of rhizobacterial strains as shown in this study. Field experiments conducted in this study on two varieties of sugar beet, canola and corn demonstrated an increase in root fresh and/or dry weight, shoot dry weight and grain yield of inoculated seedlings, above that in the plants fertilized with 50% of nitrogen recommended dose. Colonization of the non-legume plants by rhizobacteria have indirect and direct effects on plant growth and their developments. Direct effects include enhanced provision of nutrients and the production of phytohormones. Indirect effects involve aspects of biological control: the production of antibiotics and the induction of plant resistance mechanisms. It was concluded that the highest auxins-producing strains also caused a maximum increase of growth and yield of non-legume plants
How does study quality affect the results of a diagnostic meta-analysis?
Background: The use of systematic literature review to inform evidence based practice in diagnostics is rapidly expanding. Although the primary diagnostic literature is extensive, studies are often of low methodological quality or poorly reported. There has been no rigorously evaluated, evidence based tool to assess the methodological quality of diagnostic studies. The primary objective of this study was to determine the extent to which variations in the quality of primary studies impact the results of a diagnostic meta-analysis and whether this differs with diagnostic test type. A secondary objective was to contribute to the evaluation of QUADAS, an evidence-based tool for the assessment of quality in diagnostic accuracy studies. Methods: This study was conducted as part of large systematic review of tests used in the diagnosis and further investigation of urinary tract infection (UTI) in children. All studies included in this review were assessed using QUADAS, an evidence-based tool for the assessment of quality in systematic reviews of diagnostic accuracy studies. The impact of individual components of QUADAS on a summary measure of diagnostic accuracy was investigated using regression analysis. The review divided the diagnosis and further investigation of UTI into the following three clinical stages: diagnosis of UTI, localisation of infection, and further investigation of the UTI. Each stage used different types of diagnostic test, which were considered to involve different quality concerns. Results: Many of the studies included in our review were poorly reported. The proportion of QUADAS items fulfilled was similar for studies in different sections of the review. However, as might be expected, the individual items fulfilled differed between the three clinical stages. Regression analysis found that different items showed a strong association with test performance for the different tests evaluated. These differences were observed both within and between the three clinical stages assessed by the review. The results of regression analyses were also affected by whether or not a weighting (by sample size) was applied. Our analysis was severely limited by the completeness of reporting and the differences between the index tests evaluated and the reference standards used to confirm diagnoses in the primary studies. Few tests were evaluated by sufficient studies to allow meaningful use of meta-analytic pooling and investigation of heterogeneity. This meant that further analysis to investigate heterogeneity could only be undertaken using a subset of studies, and that the findings are open to various interpretations. Conclusion: Further work is needed to investigate the influence of methodological quality on the results of diagnostic meta-analyses. Large data sets of well-reported primary studies are needed to address this question. Without significant improvements in the completeness of reporting of primary studies, progress in this area will be limited
The impact of immediate breast reconstruction on the time to delivery of adjuvant therapy: the iBRA-2 study
Background:
Immediate breast reconstruction (IBR) is routinely offered to improve quality-of-life for women requiring mastectomy, but there are concerns that more complex surgery may delay adjuvant oncological treatments and compromise long-term outcomes. High-quality evidence is lacking. The iBRA-2 study aimed to investigate the impact of IBR on time to adjuvant therapy.
Methods:
Consecutive women undergoing mastectomy ± IBR for breast cancer July–December, 2016 were included. Patient demographics, operative, oncological and complication data were collected. Time from last definitive cancer surgery to first adjuvant treatment for patients undergoing mastectomy ± IBR were compared and risk factors associated with delays explored.
Results:
A total of 2540 patients were recruited from 76 centres; 1008 (39.7%) underwent IBR (implant-only [n = 675, 26.6%]; pedicled flaps [n = 105,4.1%] and free-flaps [n = 228, 8.9%]). Complications requiring re-admission or re-operation were significantly more common in patients undergoing IBR than those receiving mastectomy. Adjuvant chemotherapy or radiotherapy was required by 1235 (48.6%) patients. No clinically significant differences were seen in time to adjuvant therapy between patient groups but major complications irrespective of surgery received were significantly associated with treatment delays.
Conclusions:
IBR does not result in clinically significant delays to adjuvant therapy, but post-operative complications are associated with treatment delays. Strategies to minimise complications, including careful patient selection, are required to improve outcomes for patients
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