29 results on '"Alahmad S."'
Search Results
2. A toolkit to rapidly modify root systems through single plant selection
- Author
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Rambla, C, Van der Meer, S, Voss-Fels, KP, Makhoul, M, Obermeier, C, Rod, S, Ober, ES, Watt, M, Alahmad, S, Hickey, LT, Rambla, C, Van der Meer, S, Voss-Fels, KP, Makhoul, M, Obermeier, C, Rod, S, Ober, ES, Watt, M, Alahmad, S, and Hickey, LT
- Abstract
BACKGROUND: The incorporation of root traits into elite germplasm is typically a slow process. Thus, innovative approaches are required to accelerate research and pre-breeding programs targeting root traits to improve yield stability in different environments and soil types. Marker-assisted selection (MAS) can help to speed up the process by selecting key genes or quantitative trait loci (QTL) associated with root traits. However, this approach is limited due to the complex genetic control of root traits and the limited number of well-characterised large effect QTL. Coupling MAS with phenotyping could increase the reliability of selection. Here we present a useful framework to rapidly modify root traits in elite germplasm. In this wheat exemplar, a single plant selection (SPS) approach combined three main elements: phenotypic selection (in this case for seminal root angle); MAS using KASP markers (targeting a root biomass QTL); and speed breeding to accelerate each cycle. RESULTS: To develop a SPS approach that integrates non-destructive screening for seminal root angle and root biomass, two initial experiments were conducted. Firstly, we demonstrated that transplanting wheat seedlings from clear pots (for seminal root angle assessment) into sand pots (for root biomass assessment) did not impact the ability to differentiate genotypes with high and low root biomass. Secondly, we demonstrated that visual scores for root biomass were correlated with root dry weight (r = 0.72), indicating that single plants could be evaluated for root biomass in a non-destructive manner. To highlight the potential of the approach, we applied SPS in a backcrossing program which integrated MAS and speed breeding for the purpose of rapidly modifying the root system of elite bread wheat line Borlaug100. Bi-directional selection for root angle in segregating generations successfully shifted the mean root angle by 30° in the subsequent generation (P ≤ 0.05). Within 18 months, BC2F4:F5 introgr
- Published
- 2022
3. Effect of crack opening on carbon dioxide penetration in cracked mortar samples
- Author
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Alahmad, S., Toumi, A., Verdier, J., and François, R.
- Published
- 2009
- Full Text
- View/download PDF
4. Wheat root systems as a breeding target for climate resilience
- Author
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Ober, ES, Alahmad, S, Cockram, J, Forestan, C, Hickey, LT, Kant, J, Maccaferri, M, Marr, E, Milner, M, Pinto, F, Rambla, C, Reynolds, M, Salvi, S, Sciara, G, Snowdon, RJ, Thomelin, P, Tuberosa, R, Uauy, C, Voss-Fels, KP, Wallington, E, Watt, M, Ober, ES, Alahmad, S, Cockram, J, Forestan, C, Hickey, LT, Kant, J, Maccaferri, M, Marr, E, Milner, M, Pinto, F, Rambla, C, Reynolds, M, Salvi, S, Sciara, G, Snowdon, RJ, Thomelin, P, Tuberosa, R, Uauy, C, Voss-Fels, KP, Wallington, E, and Watt, M
- Abstract
In the coming decades, larger genetic gains in yield will be necessary to meet projected demand, and this must be achieved despite the destabilizing impacts of climate change on crop production. The root systems of crops capture the water and nutrients needed to support crop growth, and improved root systems tailored to the challenges of specific agricultural environments could improve climate resiliency. Each component of root initiation, growth and development is controlled genetically and responds to the environment, which translates to a complex quantitative system to navigate for the breeder, but also a world of opportunity given the right tools. In this review, we argue that it is important to know more about the 'hidden half' of crop plants and hypothesize that crop improvement could be further enhanced using approaches that directly target selection for root system architecture. To explore these issues, we focus predominantly on bread wheat (Triticum aestivum L.), a staple crop that plays a major role in underpinning global food security. We review the tools available for root phenotyping under controlled and field conditions and the use of these platforms alongside modern genetics and genomics resources to dissect the genetic architecture controlling the wheat root system. To contextualize these advances for applied wheat breeding, we explore questions surrounding which root system architectures should be selected for, which agricultural environments and genetic trait configurations of breeding populations are these best suited to, and how might direct selection for these root ideotypes be implemented in practice.
- Published
- 2021
5. MODIFIED DIFFERENTIAL TRANSFORMATION METHOD FOR SOLVING CLASSES OF NON-LINEAR DIFFERENTIAL EQUATIONS.
- Author
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ALAHMAD, S., ANAKIRA, N. R., MAMAT, M., SULAIMAN, I., and ALAHMAD, R.
- Subjects
NONLINEAR differential equations ,BOUNDARY value problems ,BACKLUND transformations - Abstract
In this research article, a numerical scheme namely modified differential transformation method (MDTM) is employed successfully to obtain accurate approximate solutions for classes of nonlinear differential equations. This scheme based on differential transform method (DTM), Laplace transform and Padé approximants. Validity and efficiency of MDTM are tested upon several examples and comparisons are made to demonstrate that. The results lead to conclude that the MDTM is effective, explicit and easy to use. [ABSTRACT FROM AUTHOR]
- Published
- 2022
6. Root System Architecture and Its Association with Yield under Different Water Regimes in Durum Wheat
- Author
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Hassouni, K., primary, Alahmad, S., additional, Belkadi, B., additional, Filali-Maltouf, A., additional, Hickey, L. T., additional, and Bassi, F. M., additional
- Published
- 2018
- Full Text
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7. Root System Architecture and Its Association with Yield under Different Water Regimes in Durum Wheat.
- Author
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Belkadi, B., Bassi, F. M., Hassouni, K. El, Filali-Maltouf, A., Alahmad, S., and Hickey, L. T.
- Subjects
DURUM wheat ,CROP yields ,PLANT root physiology - Abstract
Durum wheat (Triticum durum Desf.) is a major cereal crop grown globally, but its production is often hindered by droughts. Breeding for adapted root system architecture should provide a strategic solution for better capturing moisture. The aim of this research was to adapt low-cost and high-throughput methods for phenotyping root architecture and exploring the genetic variability among 25 durum genotypes. Two protocols were used: the "clear pot" for seminal root and the "pasta strainer" to evaluate mature roots. Analysis of variance revealed significant segregation for all measured traits with strong genetic control. Shallow and deep root classes were determined with different methods and then tested in yield trials at five locations with different water regimes. Simple trait measurements did not correlate to any of the traits consistently across field sites. Multitrait classification instead identified significant superiority of deep-rooted genotypes with 16 to 35% larger grains in environments with limited moisture, but 9 to 24% inferior in the drip irrigated site. Combined multitrait classification identified a 28 to 42% advantage in grain yield for the class with deeper roots at two environments where moisture was limited. Further discrimination revealed that yield advantage of 37 to 38% under low moisture could be achieved by the deepest root types, but that it also caused a 20 to 40% yield penalty in moisture-rich environments compared with the shallowest root types. In conclusion, the proposed methodologies enable low-cost and quick characterization of root behavior in durum wheat with significant distinction of agronomic performance. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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8. Effect of crack opening on carbon dioxide penetration in cracked mortar samples
- Author
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Alahmad, S., primary, Toumi, A., additional, Verdier, J., additional, and François, R., additional
- Published
- 2008
- Full Text
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9. On new properties of differential transform via difference equations
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Alahmad, S., Mamat, M., Rami Alahmad, Sulaiman, I. M., Ghazali, P. L., and Mohamed, M. A.
10. MODIFIED DIFFERENTIAL TRANSFORMATION METHOD FOR SOLVING CLASSES OF NON-LINEAR DIFFERENTIAL EQUATIONS
- Author
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Alahmad, S., Anakira, N. R., Mamat, M., Sulaiman Mohammed Ibrahim, and Alahmad, R.
11. Wheat root systems as a breeding target for climate resilience
- Author
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Michelle Watt, Marco Maccaferri, Samir Alahmad, Giuseppe Sciara, Roberto Tuberosa, Matthew J. Milner, Charlotte Rambla, Cristian Forestan, Kai P. Voss-Fels, Emma J. Wallington, Matthew P. Reynolds, Josefine Kant, Eric S. Ober, Emily C. Marr, James Cockram, Cristobal Uauy, Lee T. Hickey, Francisco de Assis de Carvalho Pinto, Silvio Salvi, Pauline Thomelin, Rod J. Snowdon, Ober E.S., Alahmad S., Cockram J., Forestan C., Hickey L.T., Kant J., Maccaferri M., Marr E., Milner M., Pinto F., Rambla C., Reynolds M., Salvi S., Sciara G., Snowdon R.J., Thomelin P., Tuberosa R., Uauy C., Voss-Fels K.P., Wallington E., and Watt M.
- Subjects
Crops, Agricultural ,0106 biological sciences ,Root (linguistics) ,Climate Change ,media_common.quotation_subject ,Review ,Agricultural engineering ,Biology ,Genes, Plant ,Plant Roots ,01 natural sciences ,Wheat, root, breeding, target, resilience ,03 medical and health sciences ,ddc:570 ,Genetics ,Plant breeding ,Triticum ,Selection (genetic algorithm) ,030304 developmental biology ,media_common ,0303 health sciences ,Food security ,business.industry ,General Medicine ,Climate resilience ,Genetic architecture ,Plant Breeding ,Phenotype ,Agriculture ,Psychological resilience ,business ,Agronomy and Crop Science ,010606 plant biology & botany ,Biotechnology - Abstract
In the coming decades, larger genetic gains in yield will be necessary to meet projected demand, and this must be achieved despite the destabilizing impacts of climate change on crop production. The root systems of crops capture the water and nutrients needed to support crop growth, and improved root systems tailored to the challenges of specific agricultural environments could improve climate resiliency. Each component of root initiation, growth and development is controlled genetically and responds to the environment, which translates to a complex quantitative system to navigate for the breeder, but also a world of opportunity given the right tools. In this review, we argue that it is important to know more about the ‘hidden half’ of crop plants and hypothesize that crop improvement could be further enhanced using approaches that directly target selection for root system architecture. To explore these issues, we focus predominantly on bread wheat (Triticum aestivum L.), a staple crop that plays a major role in underpinning global food security. We review the tools available for root phenotyping under controlled and field conditions and the use of these platforms alongside modern genetics and genomics resources to dissect the genetic architecture controlling the wheat root system. To contextualize these advances for applied wheat breeding, we explore questions surrounding which root system architectures should be selected for, which agricultural environments and genetic trait configurations of breeding populations are these best suited to, and how might direct selection for these root ideotypes be implemented in practice.
- Published
- 2021
- Full Text
- View/download PDF
12. Mapping quantitative trait loci for seminal root angle in a selected durum wheat population.
- Author
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Kang Y, Alahmad S, Haeften SV, Akinlade O, Tong J, Dinglasan E, Voss-Fels KP, Potgieter AB, Borrell AK, Makhoul M, Obermeier C, Snowdon R, Mace E, Jordan DR, and Hickey LT
- Subjects
- Phenotype, Genotype, Triticum genetics, Quantitative Trait Loci, Chromosome Mapping, Plant Roots genetics, Plant Roots anatomy & histology, Polymorphism, Single Nucleotide
- Abstract
Seminal root angle (SRA) is an important root architectural trait associated with drought adaptation in cereal crops. To date, all attempts to dissect the genetic architecture of SRA in durum wheat (Triticum durum Desf.) have used large association panels or structured mapping populations. Identifying changes in allele frequency generated by selection provides an alternative genetic mapping approach that can increase the power and precision of QTL detection. This study aimed to map quantitative trait loci (QTL) for SRA by genotyping durum lines created through divergent selection using a combination of marker-assisted selection (MAS) for the major SRA QTL (qSRA-6A) and phenotypic selection for SRA over multiple generations. The created 11 lines (BC
1 F2:5 ) were genotyped with genome-wide single-nucleotide polymorphism (SNP) markers to map QTL by identifying markers that displayed segregation distortion significantly different from the Mendelian expectation. QTL regions were further assessed in an independent validation population to confirm their associations with SRA. The experiment revealed 14 genomic regions under selection, 12 of which have not previously been reported for SRA. Five regions, including qSRA-6A, were confirmed in the validation population. The genomic regions identified in this study indicate that the genetic control of SRA is more complex than previously anticipated. Our study demonstrates that selection mapping is a powerful approach to complement genome-wide association studies for QTL detection. Moreover, the verification of qSRA-6A in an elite genetic background highlights the potential for MAS, although it is necessary to combine additional QTL to develop new cultivars with extreme SRA phenotypes., (© 2024 The Author(s). The Plant Genome published by Wiley Periodicals LLC on behalf of Crop Science Society of America.)- Published
- 2025
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13. Unveiling the Silent Threat: Exploring Hypertension Prevalence and Risk Factors Among University Students in Syria.
- Author
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Alahmad S, Samman A, and Al Kayali R
- Subjects
- Humans, Male, Female, Syria epidemiology, Cross-Sectional Studies, Prevalence, Universities, Adult, Risk Factors, Young Adult, Adolescent, Surveys and Questionnaires, Hypertension epidemiology, Students statistics & numerical data
- Abstract
Objective: The prevalence of hypertension has increased worldwide over the last decades. No data are available on the prevalence and correlates of hypertension and elevated blood pressure among young adults in Syria. This study aimed to measure the prevalence of hypertension and elevated blood pressure among university students and to identify the associated sociodemographic characteristics, and behavioral risk factors., Methods: This study was designed as a cross-sectional investigation with 1,100 subjects randomly selected from the students of Aleppo and Al-Wataniya universities. Risk factors, and measurement data were collected using a questionnaire. Hypertension was categorized according to ACC/AHA guidelines., Results: Out of 1,100 undergraduate university students, men made up 70.2% of the total respondents. The age of the participants ranged from 18 to 30 years with a mean age of 21 (±1.82). The prevalence of elevated blood pressure and hypertension was 27.7% and 15.9% respectively. The main common risk factors for elevated blood pressure and hypertension were sex, age, smoking, stress and BMI. Family history was only associated with hypertension., Conclusion: The prevalence of hypertension among undergraduate students was higher than in other countries which calls for urgent policy actions targeting this age group for early prevention of hypertension., Competing Interests: The authors declare that they do not have any conflicts of interest., (Copyright © 2025 Alahmad, Samman and Al Kayali.)
- Published
- 2025
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14. Stacking beneficial haplotypes from the Vavilov wheat collection to accelerate breeding for multiple disease resistance.
- Author
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Tong J, Tarekegn ZT, Jambuthenne D, Alahmad S, Periyannan S, Hickey L, Dinglasan E, and Hayes B
- Subjects
- Polymorphism, Single Nucleotide, Phenotype, Australia, Basidiomycota pathogenicity, Basidiomycota physiology, Ethiopia, Quantitative Trait Loci, Triticum genetics, Triticum microbiology, Haplotypes, Disease Resistance genetics, Plant Diseases genetics, Plant Diseases microbiology, Plant Diseases immunology, Plant Breeding
- Abstract
Key Message: We revealed the neglected genetic relationships of resistance for six major wheat diseases and established a haploblock-based catalogue with novel forms of resistance by multi-trait haplotype characterisation. Genetic potential to improve multiple disease resistance was highlighted through haplotype stacking simulations. Wheat production is threatened by numerous fungal diseases, but the potential to breed for multiple disease resistance (MDR) mechanisms is yet to be explored. Here, significant global genetic correlations and underlying local genomic regions were identified in the Vavilov wheat diversity panel for six major fungal diseases, including biotrophic leaf rust (LR), yellow rust (YR), stem rust (SR), hemibiotrophic crown rot (CR), and necrotrophic tan spot (TS) and Septoria nodorum blotch (SNB). By adopting haplotype-based local genomic estimated breeding values, derived from an integrated set of 34,899 SNP and DArT markers, we established a novel haplotype catalogue for resistance to the six diseases in over 20 field experiments across Australia and Ethiopia. Haploblocks with high variances of haplotype effects in all environments were identified for three rusts, and pleiotropic haploblocks were identified for at least two diseases, with four haploblocks affecting all six diseases. Through simulation, we demonstrated that stacking optimal haplotypes for one disease could improve resistance substantially, but indirectly affected resistance for other five diseases, which varied depending on the genetic correlation with the non-target disease trait. On the other hand, our simulation results combining beneficial haplotypes for all diseases increased resistance to LR, YR, SR, CR, TS, and SNB, by up to 48.1%, 35.2%, 29.1%, 12.8%, 18.8%, and 32.8%, respectively. Overall, our results highlight the genetic potential to improve MDR in wheat. The haploblock-based catalogue with novel forms of resistance provides a useful resource to guide desirable haplotype stacking for breeding future wheat cultivars with MDR., Competing Interests: Declarations. Conflict of interest: All authors declare that they have no conflicts of interest., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
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- 2024
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15. Epidemiology, biosafety, and biosecurity of Avian Influenza: Insights from the East Mediterranean region.
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Al-Eitan L, Khair I, Shakhatreh Z, Almahdawi D, and Alahmad S
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- Animals, Humans, Mediterranean Region epidemiology, Disease Outbreaks prevention & control, Disease Outbreaks veterinary, Influenza in Birds epidemiology, Influenza in Birds virology, Influenza in Birds prevention & control, Influenza in Birds transmission, Influenza, Human prevention & control, Influenza, Human epidemiology, Influenza, Human virology, Birds virology, Influenza A virus genetics, Influenza A virus physiology, Influenza A virus pathogenicity
- Abstract
The World Organization for Animal Health defines Avian Influenza Virus as a highly infectious disease caused by diverse subtypes that continue to evolve rapidly, impacting poultry species, pet birds, wild birds, non-human mammals, and occasionally humans. The effects of Avian influenza viruses have been recognised as a precursor for serious health concerns among affected birds, poultry, and human populations in the Middle East. Furthermore, low and high pathogenic avian influenza viruses lead to respiratory illness with varying severity, depending on the virus subtype (e.g., H5, H7, H9, etc.). Possible future outbreaks and endemics of newly emerging subtypes are expected to occur, as many studies have reported the emergence of novel mutations and viral subtypes. However, proper surveillance programs and biosecurity applications should be developed, and countries with incapacitated defences against such outbreaks should be encouraged to undergo complete reinstation and reinforcement in their health and research sectors. Public education regarding biosafety and virus prevention is necessary to ensure minimal spread of avian influenza endemic., (© 2024 John Wiley & Sons Ltd.)
- Published
- 2024
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16. Characterizing stay-green in barley across diverse environments: unveiling novel haplotypes.
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Brunner SM, Dinglasan E, Baraibar S, Alahmad S, Katsikis C, van der Meer S, Godoy J, Moody D, Smith M, Hickey L, and Robinson H
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- Environment, Photosynthesis genetics, Quantitative Trait Loci, Chromosome Mapping, Hordeum genetics, Hordeum growth & development, Haplotypes, Phenotype, Droughts, Plant Breeding
- Abstract
Key Message: There is variation in stay-green within barley breeding germplasm, influenced by multiple haplotypes and environmental conditions. The positive genetic correlation between stay-green and yield across multiple environments highlights the potential as a future breeding target. Barley is considered one of the most naturally resilient crops making it an excellent candidate to dissect the genetics of drought adaptive component traits. Stay-green, is thought to contribute to drought adaptation, in which the photosynthetic machinery is maintained for a longer period post-anthesis increasing the photosynthetic duration of the plant. In other cereal crops, including wheat, stay-green has been linked to increased yield under water-limited conditions. Utilizing a panel of diverse barley breeding lines from a commercial breeding program we aimed to characterize stay-green in four environments across two years. Spatiotemporal modeling was used to accurately model senescence patterns from flowering to maturity characterizing the variation for stay-green in barley for the first time. Environmental effects were identified, and multi-environment trait analysis was performed for stay-green characteristics during grain filling. A consistently positive genetic correlation was found between yield and stay-green. Twenty-two chromosomal regions with large effect haplotypes were identified across and within environment types, with ten being identified in multiple environments. In silico stacking of multiple desirable haplotypes showed an opportunity to improve the stay-green phenotype through targeted breeding. This study is the first of its kind to model barley stay-green in a large breeding panel and has detected novel, stable and environment specific haplotypes. This provides a platform for breeders to develop Australian barley with custom senescence profiles for improved drought adaptation., (© 2024. The Author(s).)
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- 2024
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17. Drug Metabolizing Enzymes: An Exclusive Guide into Latest Research in Pharmaco-genetic Dynamics in Arab Countries.
- Author
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Eitan LA, Khair IY, and Alahmad S
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- Humans, Middle East, Arabs genetics, Polymorphism, Genetic, Pharmaceutical Preparations metabolism, Glutathione Transferase genetics, Glutathione Transferase metabolism, Pharmacogenetics, Cytochrome P-450 Enzyme System genetics, Cytochrome P-450 Enzyme System metabolism, Glucuronosyltransferase genetics, Glucuronosyltransferase metabolism
- Abstract
Drug metabolizing enzymes play a crucial role in the pharmacokinetics and pharmacodynamics of therapeutic drugs, influencing their efficacy and safety. This review explores the impact of genetic polymorphisms in drug-metabolizing genes on drug response within Arab populations. We examine the genetic diversity specific to Arab countries, focusing on the variations in key drug-metabolizing enzymes such as CYP450, GST, and UGT families. The review highlights recent research on polymorphisms in these genes and their implications for drug metabolism, including variations in allele frequencies and their effects on therapeutic outcomes. Additionally, the paper discusses how these genetic variations contribute to the variability in drug response and adverse drug reactions among individuals in Arab populations. By synthesizing current findings, this review aims to provide a comprehensive understanding of the pharmacogenetic landscape in Arab countries and offer insights into personalized medicine approaches tailored to genetic profiles. The findings underscore the importance of incorporating pharmacogenetic data into clinical practice to enhance drug efficacy and minimize adverse effects, ultimately paving the way for more effective and individualized treatment strategies in the region., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)
- Published
- 2024
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18. The expression analyses of GSK3B, VEGF, ANG1, and ANG2 in human brain microvascular endothelial cells treated with the synthetic cannabinoid XLR-11.
- Author
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Al-Eitan L and Alahmad S
- Subjects
- Humans, Endothelial Cells metabolism, Angiopoietin-1 genetics, Angiopoietin-1 metabolism, Glycogen Synthase Kinase 3 beta genetics, Glycogen Synthase Kinase 3 beta metabolism, Vascular Endothelial Growth Factors metabolism, RNA, Messenger metabolism, Brain metabolism, Receptors, Cannabinoid metabolism, Angiopoietin-2 genetics, Angiopoietin-2 metabolism, Receptor, TIE-2 metabolism, Vascular Endothelial Growth Factor A metabolism, Cannabinoids pharmacology
- Abstract
The endocannabinoid system receptors, cannabinoid receptors type-1 (CBR-1) and -2 (CBR-2), are implicated in several behavioral and cognitive processes. Many studies have indicated a correlation between cannabinoid receptors and angiogenesis. The current study aims to reveal the possible molecular signaling involved in brain angiogenesis induced by the activation of CBR-1 and CBR-2. We investigated whether the synthetic cannabinoid XLR-11, an agonist of CBR-1 and CBR-2, influences the mRNA and protein expression of vascular endothelial growth factor (VEGF), angiopoietin-1 (ANG1) and -2 (ANG2) in human brain microvascular endothelial cells (hBMVEs). Furthermore, we determined the phosphorylation of glycogen synthase kinase 3 beta (GSK3B) expression. Treatment of hBMVEs cells with XLR-11 elevated the mRNA levels of VEGF, ANG1, and ANG2. The secretion of these proangiogenic factors was increased in the media. Furthermore, the intracellular expression of VEGF, ANG1, ANG2, and GSK3B was significantly increased. This current research provides a new possible approach by targeting the cannabinoid receptors to control and regulate brain angiogenesis for treating a variety of angiogenesis-related diseases. This could be achived by using different agonists or antagonists of the cannabinoid receptors based on the nature of the diseases., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)
- Published
- 2023
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19. Speed vernalization to accelerate generation advance in winter cereal crops.
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Cha JK, O'Connor K, Alahmad S, Lee JH, Dinglasan E, Park H, Lee SM, Hirsz D, Kwon SW, Kwon Y, Kim KM, Ko JM, Hickey LT, Shin D, and Dixon LE
- Subjects
- Crops, Agricultural genetics, Flowers, Gene Expression Regulation, Plant, Photoperiod, Plant Breeding, Triticum genetics, Edible Grain, Hordeum
- Abstract
There are many challenges facing the development of high-yielding, nutritious crops for future environments. One limiting factor is generation time, which prolongs research and plant breeding timelines. Recent advances in speed breeding protocols have dramatically reduced generation time for many short-day and long-day species by optimizing light and temperature conditions during plant growth. However, winter crops with a vernalization requirement still require up to 6-10 weeks in low-temperature conditions before the transition to reproductive development. Here, we tested a suite of environmental conditions and protocols to investigate whether the vernalization process can be accelerated. We identified a vernalization method consisting of exposing seeds at the soil surface to an extended photoperiod of 22 h day:2 h night at 10°C with transfer to speed breeding conditions that dramatically reduces generation time in both winter wheat (Triticum aestivum) and winter barley (Hordeum vulgare). Implementation of the speed vernalization protocol followed by speed breeding allowed the completion of up to five generations per year for winter wheat or barley, whereas only two generations can be typically completed under standard vernalization and plant growth conditions. The speed vernalization protocol developed in this study has great potential to accelerate biological research and breeding outcomes for winter crops., (Copyright © 2022 The Author. Published by Elsevier Inc. All rights reserved.)
- Published
- 2022
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20. Mining the Vavilov wheat diversity panel for new sources of adult plant resistance to stripe rust.
- Author
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Jambuthenne DT, Riaz A, Athiyannan N, Alahmad S, Ng WL, Ziems L, Afanasenko O, Periyannan SK, Aitken E, Platz G, Godwin I, Voss-Fels KP, Dinglasan E, and Hickey LT
- Subjects
- Disease Resistance genetics, Genome-Wide Association Study, Plant Diseases genetics, Basidiomycota, Triticum genetics
- Abstract
Key Message: Multi-year evaluation of the Vavilov wheat diversity panel identified new sources of adult plant resistance to stripe rust. Genome-wide association studies revealed the key genomic regions influencing resistance, including seven novel loci. Wheat stripe rust (YR) caused by Puccinia striiformis f. sp. tritici (Pst) poses a significant threat to global food security. Resistance genes commonly found in many wheat varieties have been rendered ineffective due to the rapid evolution of the pathogen. To identify novel sources of adult plant resistance (APR), 292 accessions from the N.I. Vavilov Institute of Plant Genetic Resources, Saint Petersburg, Russia, were screened for known APR genes (i.e. Yr18, Yr29, Yr46, Yr33, Yr39 and Yr59) using linked polymerase chain reaction (PCR) molecular markers. Accessions were evaluated against Pst (pathotype 134 E16 A + Yr17 + Yr27) at seedling and adult plant stages across multiple years (2014, 2015 and 2016) in Australia. Phenotypic analyses identified 132 lines that potentially carry novel sources of APR to YR. Genome-wide association studies (GWAS) identified 68 significant marker-trait associations (P < 0.001) for YR resistance, representing 47 independent quantitative trait loci (QTL) regions. Fourteen genomic regions overlapped with previously reported Yr genes, including Yr29, Yr56, Yr5, Yr43, Yr57, Yr30, Yr46, Yr47, Yr35, Yr36, Yrxy1, Yr59, Yr52 and YrYL. In total, seven QTL (positioned on chromosomes 1D, 2A, 3A, 3D, 5D, 7B and 7D) did not collocate with previously reported genes or QTL, indicating the presence of promising novel resistance factors. Overall, the Vavilov diversity panel provides a rich source of new alleles which could be used to broaden the genetic bases of YR resistance in modern wheat varieties., (© 2022. The Author(s).)
- Published
- 2022
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- View/download PDF
21. A toolkit to rapidly modify root systems through single plant selection.
- Author
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Rambla C, Van Der Meer S, Voss-Fels KP, Makhoul M, Obermeier C, Snowdon R, Ober ES, Watt M, Alahmad S, and Hickey LT
- Abstract
Background: The incorporation of root traits into elite germplasm is typically a slow process. Thus, innovative approaches are required to accelerate research and pre-breeding programs targeting root traits to improve yield stability in different environments and soil types. Marker-assisted selection (MAS) can help to speed up the process by selecting key genes or quantitative trait loci (QTL) associated with root traits. However, this approach is limited due to the complex genetic control of root traits and the limited number of well-characterised large effect QTL. Coupling MAS with phenotyping could increase the reliability of selection. Here we present a useful framework to rapidly modify root traits in elite germplasm. In this wheat exemplar, a single plant selection (SPS) approach combined three main elements: phenotypic selection (in this case for seminal root angle); MAS using KASP markers (targeting a root biomass QTL); and speed breeding to accelerate each cycle., Results: To develop a SPS approach that integrates non-destructive screening for seminal root angle and root biomass, two initial experiments were conducted. Firstly, we demonstrated that transplanting wheat seedlings from clear pots (for seminal root angle assessment) into sand pots (for root biomass assessment) did not impact the ability to differentiate genotypes with high and low root biomass. Secondly, we demonstrated that visual scores for root biomass were correlated with root dry weight (r = 0.72), indicating that single plants could be evaluated for root biomass in a non-destructive manner. To highlight the potential of the approach, we applied SPS in a backcrossing program which integrated MAS and speed breeding for the purpose of rapidly modifying the root system of elite bread wheat line Borlaug100. Bi-directional selection for root angle in segregating generations successfully shifted the mean root angle by 30° in the subsequent generation (P ≤ 0.05). Within 18 months, BC
2 F4 :F5 introgression lines were developed that displayed a full range of root configurations, while retaining similar above-ground traits to the recurrent parent. Notably, the seminal root angle displayed by introgression lines varied more than 30° compared to the recurrent parent, resulting in lines with both narrow and wide root angles, and high and low root biomass phenotypes., Conclusion: The SPS approach enables researchers and plant breeders to rapidly manipulate root traits of future crop varieties, which could help improve productivity in the face of increasing environmental fluctuations. The newly developed elite wheat lines with modified root traits provide valuable materials to study the value of different root systems to support yield in different environments and soil types., (© 2022. The Author(s).)- Published
- 2022
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22. Dissecting the Genetics of Early Vigour to Design Drought-Adapted Wheat.
- Author
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Vukasovic S, Alahmad S, Christopher J, Snowdon RJ, Stahl A, and Hickey LT
- Abstract
Due to the climate change and an increased frequency of drought, it is of enormous importance to identify and to develop traits that result in adaptation and in improvement of crop yield stability in drought-prone regions with low rainfall. Early vigour, defined as the rapid development of leaf area in early developmental stages, is reported to contribute to stronger plant vitality, which, in turn, can enhance resilience to erratic drought periods. Furthermore, early vigour improves weed competitiveness and nutrient uptake. Here, two sets of a multi-reference nested association mapping (MR-NAM) population of bread wheat ( Triticum aestivum ssp. aestivum L.) were used to investigate early vigour in a rain-fed field environment for 3 years, and additionally assessed under controlled conditions in a greenhouse experiment. The normalised difference vegetation index (NDVI) calculated from red/infrared light reflectance was used to quantify early vigour in the field, revealing a correlation ( p < 0.05; r = 0.39) between the spectral measurement and the length of the second leaf. Under controlled environmental conditions, the measured projected leaf area, using a green-pixel counter, was also correlated to the leaf area of the second leaf ( p < 0.05; r = 0.38), as well as to the recorded biomass ( p < 0.01; r = 0.71). Subsequently, genetic determination of early vigour was tested by conducting a genome-wide association study (GWAS) for the proxy traits, revealing 42 markers associated with vegetation index and two markers associated with projected leaf area. There are several quantitative trait loci that are collocated with loci for plant developmental traits including plant height on chromosome 2D (log
10 ( P ) = 3.19; PVE = 0.035), coleoptile length on chromosome 1B (-log10 ( P ) = 3.24; PVE = 0.112), as well as stay-green and vernalisation on chromosome 5A (-log10 ( P ) = 3.14; PVE = 0.115)., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Vukasovic, Alahmad, Christopher, Snowdon, Stahl and Hickey.)- Published
- 2022
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23. Effects of the synthetic cannabinoid XLR-11 on the viability and migration rates of human brain microvascular endothelial cells in a clinically-relevant model.
- Author
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Al-Eitan L, Alhusban A, and Alahmad S
- Subjects
- Brain cytology, Cannabinoids administration & dosage, Cell Movement drug effects, Cell Survival drug effects, Cells, Cultured, Dose-Response Relationship, Drug, Endothelial Cells cytology, Humans, Brain drug effects, Cannabinoids pharmacology, Endothelial Cells drug effects, Neovascularization, Physiologic drug effects
- Abstract
Background: Synthetic cannabinoids (SCs) are a group of newly-developed drugs that bind and activate endocannabinoid system receptors. Angiogenesis is a biological process in which new blood vessels are formed from preexistent blood vessels. It plays a vital role in tissue growth, wound healing, and embryogenesis. This study aims to investigate the effects of the synthetic cannabinoid XLR-11 on specific cellular functions such as viability and angiogenesis in vitro., Methods: Human brain microvascular endothelial cells (HBMECs) were cultured in DMEM/F12 medium supplemented with an endothelial cell growth kit. The MTT assay was used to investigate the viability of endothelial cells. An endothelial cell migration assay was used to investigate migration ability, while a tube formation assay was used to investigate the angiogenic capacity of the endothelial cells., Results: XLR-11 was found to enhance the viability of HBMECs. Moreover, the migration rate and angiogenic capacity significantly increased in the presence of various concentrations of XLR-11 compared to the control., Conclusion: The current study shows that XLR-11 increases the viability of human brain microvascular endothelial cells and enhances angiogenesis in the brain in vitro, suggesting that XLR-11 could potentially be used as a therapeutic angiogenic drug in human brain injury treatment.
- Published
- 2020
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24. Adaptive Traits to Improve Durum Wheat Yield in Drought and Crown Rot Environments.
- Author
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Alahmad S, Kang Y, Dinglasan E, Mazzucotelli E, Voss-Fels KP, Able JA, Christopher J, Bassi FM, and Hickey LT
- Subjects
- Chromosome Mapping, Crosses, Genetic, Dehydration genetics, Dehydration metabolism, Genome-Wide Association Study, Chromosomes, Plant genetics, Chromosomes, Plant metabolism, Quantitative Trait Loci, Triticum genetics, Triticum growth & development
- Abstract
Durum wheat ( Triticum turgidum L. ssp. durum ) production can experience significant yield losses due to crown rot (CR) disease. Losses are usually exacerbated when disease infection coincides with terminal drought. Durum wheat is very susceptible to CR, and resistant germplasm is not currently available in elite breeding pools. We hypothesize that deploying physiological traits for drought adaptation, such as optimal root system architecture to reduce water stress, might minimize losses due to CR infection. This study evaluated a subset of lines from a nested association mapping population for stay-green traits, CR incidence and yield in field experiments as well as root traits under controlled conditions. Weekly measurements of normalized difference vegetative index (NDVI) in the field were used to model canopy senescence and to determine stay-green traits for each genotype. Genome-wide association studies using DArTseq molecular markers identified quantitative trait loci (QTLs) on chromosome 6B ( qCR-6B ) associated with CR tolerance and stay-green. We explored the value of qCR-6B and a major QTL for root angle QTL qSRA-6A using yield datasets from six rainfed environments, including two environments with high CR disease pressure. In the absence of CR, the favorable allele for qSRA-6A provided an average yield advantage of 0.57 t·ha
-1 , whereas in the presence of CR, the combination of favorable alleles for both qSRA-6A and qCR-6B resulted in a yield advantage of 0.90 t·ha-1 . Results of this study highlight the value of combining above- and belowground physiological traits to enhance yield potential. We anticipate that these insights will assist breeders to design improved durum varieties that mitigate production losses due to water deficit and CR.- Published
- 2020
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25. A Major Root Architecture QTL Responding to Water Limitation in Durum Wheat.
- Author
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Alahmad S, El Hassouni K, Bassi FM, Dinglasan E, Youssef C, Quarry G, Aksoy A, Mazzucotelli E, Juhász A, Able JA, Christopher J, Voss-Fels KP, and Hickey LT
- Abstract
The optimal root system architecture (RSA) of a crop is context dependent and critical for efficient resource capture in the soil. Narrow root growth angle promoting deeper root growth is often associated with improved access to water and nutrients in deep soils during terminal drought. RSA, therefore is a drought-adaptive trait that could minimize yield losses in regions with limited rainfall. Here, GWAS for seminal root angle (SRA) identified seven marker-trait associations clustered on chromosome 6A, representing a major quantitative trait locus ( qSRA-6A ) which also displayed high levels of pairwise LD ( r
2 = 0.67). Subsequent haplotype analysis revealed significant differences between major groups. Candidate gene analysis revealed loci related to gravitropism, polar growth and hormonal signaling. No differences were observed for root biomass between lines carrying hap1 and hap2 for qSRA-6A , highlighting the opportunity to perform marker-assisted selection for the qSRA-6A locus and directly select for wide or narrow RSA, without influencing root biomass. Our study revealed that the genetic predisposition for deep rooting was best expressed under water-limitation, yet the root system displayed plasticity producing root growth in response to water availability in upper soil layers. We discuss the potential to deploy root architectural traits in cultivars to enhance yield stability in environments that experience limited rainfall.- Published
- 2019
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26. Speed breeding for multiple quantitative traits in durum wheat.
- Author
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Alahmad S, Dinglasan E, Leung KM, Riaz A, Derbal N, Voss-Fels KP, Able JA, Bassi FM, Christopher J, and Hickey LT
- Abstract
Background: Plant breeding requires numerous generations to be cycled and evaluated before an improved cultivar is released. This lengthy process is required to introduce and test multiple traits of interest. However, a technology for rapid generation advance named 'speed breeding' was successfully deployed in bread wheat ( Triticum aestivum L.) to achieve six generations per year while imposing phenotypic selection for foliar disease resistance and grain dormancy. Here, for the first time the deployment of this methodology is presented in durum wheat ( Triticum durum Desf.) by integrating selection for key traits, including above and below ground traits on the same set of plants. This involved phenotyping for seminal root angle (RA), seminal root number (RN), tolerance to crown rot (CR), resistance to leaf rust (LR) and plant height (PH). In durum wheat, these traits are desirable in environments where yield is limited by in-season rainfall with the occurrence of CR and epidemics of LR. To evaluate this multi-trait screening approach, we applied selection to a large segregating F
2 population (n = 1000) derived from a bi-parental cross (Outrob4/Caparoi). A weighted selection index (SI) was developed and applied. The gain for each trait was determined by evaluating F3 progeny derived from 100 'selected' and 100 'unselected' F2 individuals., Results: Transgressive segregation was observed for all assayed traits in the Outrob4/Caparoi F2 population. Application of the SI successfully shifted the population mean for four traits, as determined by a significant mean difference between 'selected' and 'unselected' F3 families for CR tolerance, LR resistance, RA and RN. No significant shift for PH was observed., Conclusions: The novel multi-trait phenotyping method presents a useful tool for rapid selection of early filial generations or for the characterization of fixed lines out-of-season. Further, it offers efficient use of resources by assaying multiple traits on the same set of plants. Results suggest that when performed in parallel with speed breeding in early generations, selection will enrich recombinant inbred lines with desirable alleles and will reduce the length and number of years required to combine these traits in elite breeding populations and therefore cultivars.- Published
- 2018
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27. Closing Gaps in Diabetes Care: From Evidence to Practice.
- Author
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Ba-Essa EM, Abdulrhman S, Karkar M, Alsehati B, Alahmad S, Aljobran A, Aldijwi A, and Alhawaj A
- Abstract
Background: Tracking progress in diabetes care may help in evaluating the quality of efforts and identifying gaps in the care., Objectives: To demonstrate that tracking important clinical indicators of diabetes mellitus can result in improved care as well as help identify and close gaps between evidence and practice in diabetes care., Subjects and Methods: The study is an observational, random audit of medical records of patients with diabetes who received care at the Diabetes Center, Dammam Medical Complex. Thirteen process and four outcome key performance indicators were studied using the quality improvement Plan-Do-Study-Act model, for the period between October 2012 and March 2016. Individual physician performance was also measured for the same duration. All data were benchmarked against peer organizations worldwide., Results: Urine examination for proteinuria, foot examination, annual influenza vaccination, aspirin prescription, structured education, personalized nutritional advice and self-monitoring of blood glucose significantly improved between baseline and the final observation of the study ( P < 0.001). The proportion of patients with hemoglobin A1c >9% decreased, and that of those who achieved the recommended levels of hemoglobin A1c (<7%), low-density lipoprotein cholesterol (<2.6 mmol/L) and blood pressure (<140/90 mmHg) significantly increased ( P < 0.001). Benchmarking against peer organizations worldwide showed comparable results overall, and better results for certain indicators., Conclusion: Quality improvement strategies and key performance indicators can be utilized to improve the quality of diabetes care delivered, and thus reduce gaps and barriers that exist between recommended diabetes care and practice., Competing Interests: There are no conflicts of interest.
- Published
- 2018
- Full Text
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28. Development and Validation of Chemometric Spectrophotometric Methods for Simultaneous Determination of Simvastatin and Nicotinic Acid in Binary Combinations.
- Author
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Alahmad S, Elfatatry HM, Mabrouk MM, Hammad SF, and Mansour FR
- Subjects
- Chemistry, Pharmaceutical instrumentation, Chemistry, Pharmaceutical methods, Drug Combinations, Niacin chemistry, Reproducibility of Results, Simvastatin chemistry, Spectrophotometry, Ultraviolet instrumentation, Spectrophotometry, Ultraviolet methods, Spectrophotometry, Ultraviolet standards, Chemistry, Pharmaceutical standards, Niacin analysis, Simvastatin analysis
- Abstract
Background: The development and introduction of combined therapy represent a challenge for analysis due to severe overlapping of their UV spectra in case of spectroscopy or the requirement of a long tedious and high cost separation technique in case of chromatography. Quality control laboratories have to develop and validate suitable analytical procedures in order to assay such multi component preparations., Methods: New spectrophotometric methods for the simultaneous determination of simvastatin (SIM) and nicotinic acid (NIA) in binary combinations were developed. These methods are based on chemometric treatment of data, the applied chemometric techniques are multivariate methods including classical least squares (CLS), principal component regression (PCR) and partial least squares (PLS). In these techniques, the concentration data matrix were prepared by using the synthetic mixtures containing SIM and NIA dissolved in ethanol. The absorbance data matrix corresponding to the concentration data matrix was obtained by measuring the absorbance at 12 wavelengths in the range 216 - 240 nm at 2 nm intervals in the zero-order. The spectrophotometric procedures do not require any separation step. The accuracy, precision and the linearity ranges of the methods have been determined and validated by analyzing synthetic mixtures containing the studied drugs., Conclusion: Chemometric spectrophotometric methods have been developed in the present study for the simultaneous determination of simvastatin and nicotinic acid in their synthetic binary mixtures and in their mixtures with possible excipients present in tablet dosage form. The validation was performed successfully. The developed methods have been shown to be accurate, linear, precise, and so simple. The developed methods can be used routinely for the determination dosage form., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)
- Published
- 2018
- Full Text
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29. Development and Validation of Chemometric-Assisted Spectrophotometric Methods for Simultaneous Determination of Phenylephrine Hydrochloride and Ketorolac Tromethamine in Binary Combinations.
- Author
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Elfatatry HM, Mabrouk MM, Hammad SF, Mansour FR, Kamal AH, and Alahmad S
- Subjects
- Chromatography, High Pressure Liquid, Least-Squares Analysis, Principal Component Analysis, Software, Spectrophotometry, Ultraviolet, Ketorolac Tromethamine analysis, Phenylephrine analysis
- Abstract
The present work describes new spectrophotometric methods for the simultaneous determination of phenylephrine hydrochloride and ketorolac tromethamine in their synthetic mixtures. The applied chemometric techniques are multivariate methods including classical least squares, principal component regression, and partial least squares. In these techniques, the concentration data matrix was prepared by using the synthetic mixtures containing these drugs dissolved in distilled water. The absorbance data matrix corresponding to the concentration data was obtained by measuring the absorbances at 16 wavelengths in the range 244-274 nm at 2 nm intervals in the zero-order spectra. The spectrophotometric procedures do not require any separation steps. The accuracy, precision, and linearity ranges of the methods have been determined, and analyzing synthetic mixtures containing the studied drugs has validated them. The developed methods were successfully applied to the synthetic mixtures and the results were compared to those obtained by a reported HPLC method.
- Published
- 2016
- Full Text
- View/download PDF
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