255 research outputs found
New norfloxacin/nitric oxide donor hybrids: Synthesis and nitric oxide release measurement using a modified Griess colorimetric method
No full textOximes and nitrate esters are considered as important nitric oxide (NO) donors with diverse biological activities. Herein, we report the synthesis and characterization of new oxime and nitrate ester derivatives of norfloxacin as potential NO donor hybrids with expected synergistic antimicrobial activity. The release of NO from those hybrids was measured by a modified Griess method in which p-nitroaniline was employed instead of sulfanilamide. The increased electrophilicity of the intermediate 4-nitroaniline diazonium salt accelerated the coupling process and shortened the overall assessment time. The improved detection limits and enhanced sensitivity would pave the way for the future application of this method in nitrite determination in biological or non-biological systems
A framework for enabling high-end high performance computing resources as a service
No full textIn an era of data explosion and analysis, researchers across the globe are trying to convert massive quantities of complex data into useful knowledge using Computational and Data-Enabled Science and Engineering (CDS&E) applications. CDS&E applications are gaining traction as an important dimension of Science, Technology, Engineering, and Mathematics research. These applications require powerful processors with fast interconnects, extreme large scale, and elastic resources. While high-end High Performance Computing (HPC) resources provide the necessary requirements, the complexity of such systems has grown exponentially. Furthermore, due to their high cost, limited availability, and high demand, the queue wait times to run applications on these systems is in the order of months. All of the above challenges prevent their adoption as a mainstream solution. On the other hand, Cloud computing is emerging as a dominant computing paradigm that offers many advantages. Consequently, early adopters have looked into using Clouds to solve the HPC model challenges. Initially, CDS&E applications were run on commodity Clouds, but this was found to be appropriate only for certain classes of applications. Other approaches explored complementing HPC resources with Clouds but failed to address all challenges in the HPC environment. Cloud providers also tried to provide HPC as a Cloud using small HPC clusters connected to form a larger Cloud but were hindered by small scale and limited performance. These approaches fall short of providing the high performance necessary for CDS&E applications. In this document, we propose a new approach to achieve the notion of HPC as a Service. This approach targets existing high-end HPC resources and investigates how a Cloud abstraction can be applied to provide a simple interface and support real-world applications. In particular, the application of Clouds to supercomputers is discussed, tested, and validated on an IBM Blue Gene/P supercomputer. The proposed framework transforms Blue Gene/P into an elastic cloud by bridging multiple systems to create HPC federated Clouds, supporting dynamic provisioning and efficient utilization, and maximizing ease-of-use through an as a Service abstraction. In order to effectively illustrate the benefits of such a concept, the proposed framework is demonstrated using a real-world ensemble application.M.S.Includes bibliographical referencesby Moustafa AbdelBak
New fluoroquinolones/nitric oxide donor hybrids: design, synthesis and antitubercular activity
No full textNew nitric oxide (NO) donating fluoroquinolones/nitrate ester hybrids were prepared and their structures were characterizedby various spectroscopic and analytical tools. The release of NO from the prepared nitrate esters was measured using the modified Griess colorimetric method. Evaluation of antitubercular activity showed that most of tested compounds exhibited comparable or higher activity than the parent fluoroquinolones. Compounds 2b, 3a, 4a, 5a, and 2d showed better activity than ciprofloxacin. Nevertheless, none of the new compounds were superior to the parent fluoroquinolones in terms of DNA cleavage stimulation in mycobacteria. The additional growth inhibition effect that is distinct from gyrase poisoning may be due to release of NO or enhancement of lipophilicity. These data are augmented by docking results where the docked compounds did not exert additional significant bindings over the parent fluoroquinolones
Synthesis and antimicrobial evaluation of new nitric oxide‐donating fluoroquinolone/oxime hybrids
No full textA new series of nitric oxide‐donating fluoroquinolone/oximes was prepared in this study. The nitric oxide release from the prepared compounds was measured using a modified Griess colorimetric method. The antitubercular evaluation of the synthesized compounds indicated that ketone derivatives 2b and 2e and oximes 3b and 3d exhibited somewhat higher activity than their respective parent fluoroquinolones. Mycobacterial DNA cleavage studies and molecular modeling of Mycobacterium tuberculosis DNA gyrase were pursued to explain the observed bioactivity. More important, antibacterial evaluation showed that oximes 3c–e are highly potent against Klebsiella pneumoniae, with minimum inhibitory concentration (MIC) values of 0.06, 0.08, and 0.034 µM, respectively, whereas ketone 2c and oxime 4c are more active against Staphylococcus aureus than ciprofloxacin (MIC values: 0.7, 0.38, and 1.6 µM, respectively). Notably, the antipseudomonal activities of compounds 2a and 4c were much higher than those of their respective parent fluoroquinolones
Guidelines for the Sustainable Intensification of Wheat Production in Egypt
No full textThis publication is a joint product of the International Center for Agricultural Research in Dry Areas (ICARDA) and Agriculture Research Center (ARC), Egypt. It is licensed for use under a Creative Commons Attribution - Non Commercial Share. The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatever on the part of the ICARDA and the legal status of any country, person, territory, city, or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. Where trade names are used, this does not
constitute endorsement of or discrimination against any product by ICARDA and ARC
Effect of chain length on the photophysical properties of pyrene-based molecules substituted with extended chains
No full textThe important role played by organic conjugated compounds in the ?elds of electronics and optoelectronics has led to a vast ?eld of research concerned with synthesizing various complex structures where π-π stacking plays a vital role. Pyrene-based molecules are examples of compounds which allow ef?cient charge transfer through π-π molecular stacking. Photophysical studies of such compounds have shown similar behavior as that of pyrene, even though they bear two additional conjugated rings and four long alkyl chains. Chain length may have played an effective role in in?uencing the π-π molecular stacking of such molecules. In continuation of our earlier work(Moustafa, R. M.; Degheili, J. A.; Patra, D.; Kaafarani, B. R. J. Phys. Chem. A 2008, 113, 1235-1243), we hereby synthesize and investigate the role of the chain lengths on the photophysical aspects of 2,11-di-tert-butyl-6,7,15,16- tetrakis(alkoxy-alkythio)quinoxaline-[2′,3′:9,10]phenanthro[4, 5-ab-c]phenazine, TQPP-[t-Bu]2-[XR]4(X O, S; R C nH2n+1). Various photophysical parameters such as Stokes shift, ?uorescence lifetime, ?uorescence quantum yield, and radiative and nonradiative rate constants are evaluated for TQPP-[t-Bu]2-[OR] 4 and TQPP-[t-Bu]2-[SR]4 in tetrahydrofuran. The variation of the Stokes shift, ?uorescence quantum yield, and lifetime are also correlated with the number of carbons in the alkyl chain R for TQPP-[t-Bu]2-[OR]4 and TQPP-[t-Bu]2-[SR] 4. © 2009 American Chemical Society.Anthony JE, 2008, ANGEW CHEM INT EDIT, V47, P452, DOI 10.1002-anie.200604045; Boden N, 1999, J MATER CHEM, V9, P2081, DOI 10.1039-a903005k; Chen MC, 2008, J MATER CHEM, V18, P1029, DOI 10.1039-b715746k; Chen ZH, 2006, ORG LETT, V8, P273, DOI 10.1021-ol0526468; Katsuhara M, 2005, SYNTHETIC MET, V149, P219, DOI 10.1016-j.synthmet.2005.01.005; Kumar S, 2006, CHEM SOC REV, V35, P83, DOI 10.1039-b506619k; Lakowicz J. R., 1999, PRINCIPLES FLUORESCE; Mitzi DB, 2004, J MATER CHEM, V14, P2355, DOI 10.1039-b403482a; MOUSTAFA RM, J PHYS CHEM A UNPUB; Naraso, 2005, J AM CHEM SOC, V127, P10142, DOI 10.1021-ja051755e; Oukachmih M, 2005, SOL ENERG MAT SOL C, V85, P535, DOI 10.1016-j.solmat.2004.05.012; Palilis LC, 2003, ORG ELECTRON, V4, P113, DOI 10.1016-j.orgel.2003.08.006; Parker C.A., 1968, PHOTOLUMINESCENCE SO; Petritsch K, 1999, SYNTHETIC MET, V102, P1776, DOI 10.1016-S0379-6779(98)01035-2; Ponomarenko SA, 2003, ADV FUNCT MATER, V13, P591, DOI 10.1002-adfm.200304363; Subuddhi U, 2006, PHOTOCH PHOTOBIO SCI, V5, P459, DOI 10.1039-b600009f; Sun YG, 2007, ADV MATER, V19, P1897, DOI 10.1002-adma.200602223; van de Craats AM, 1999, ADV MATER, V11, P1469, DOI 10.1002-(SICI)1521-4095(199912)11:171469::AID-ADMA14693.0.CO;2-K; WARIS R, 1988, APPL SPECTROSC, V42, P1525, DOI 10.1366-000370288442980513131
Nutrition Counselling in Pharmacy Practice in Australia
No full textPoor nutrition is considered the underlying cause of various chronic non-communicable preventable diseases such as type 2 diabetes and cardiovascular disease. These diseases impose a significant economic burden on Australian healthcare expenditure. Pharmacists are important members of the healthcare system and are highly accessible to patients. Counselling patients on medicines as well as lifestyle including nutrition, is part of their primary role in pharmacy practice. Pharmacists can play a prominent role in the provision of nutritional counselling, However, there are limited studies in Australia on the extent of nutritional counselling in pharmacy practice, including pharmacists’ attitude and confidence in this area
Design, synthesis and molecular docking of new N-4-piperazinyl ciprofloxacin-triazole hybrids with potential antimicrobial activity
No full textNew N-4-piperazinyl ciprofloxacin-triazole hybrids 6a-o were prepared and characterized. The in vitro antimycobacterial activity revealed that compound 6a experienced promising antimycobacterial activity against Mycobactrium smegmatis compared with the reference isoniazide (INH). Additionally, compound 6a exhibited broad spectrum antibacterial activity against all the tested strains either Gram-positive or Gram-negative bacteria compared with the reference ciprofloxacin. Also, compounds 6g and 6i displayed considerable antifungal activity compared with the reference ketoconazole. DNA cleavage assay of the highly active compounds 6c and 6h showed a good correlation between the Mycobactrium cleaved DNA gyrase assay and their in vitro antimycobactrial activity. Moreover, molecular modeling studies were done for the designed ciprofloxacin derivatives to predict their binding modes towards Topoisomerase II enzyme (PDB: 5bs8)
The Current State of Artificial Intelligence on Detecting Pulmonary Embolism via Computerised Tomography Pulmonary Angiogram: A Systematic Review.
No full textCopyright: © 2025 The Author(s).
https://creativecommons.org/licenses/by-nc/4.0/Pulmonary embolism (PE) is a life-threatening condition with significant diagnostic challenges due to high rates of missed or delayed detection. Computed tomography pulmonary angiography (CTPA) is the current standard for diagnosing PE, however, demand for imaging places strain on healthcare systems and increases error rates. This systematic review aims to assess the diagnostic accuracy and clinical applicability of artificial intelligence (AI)-based models for PE detection on CTPA, exploring their potential to enhance diagnostic reliability and efficiency across clinical settings. A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Excerpta Medica Database (EMBASE), Medical Literature Analysis and Retrieval System Online (MEDLINE), Cochrane, PubMed, and Google Scholar were searched for original articles from inception to September 2024. Articles were included if they reported successful AI integration, whether partial or full, alongside CTPA scans for PE detection in patients. The literature search identified 919 articles, with 745 remaining after duplicate removal. Following rigorous screening and appraisal aligned with inclusion and exclusion criteria, 12 studies were included in the final analysis. A total of three primary AI modalities emerged: convolutional neural networks (CNNs), segmentation models, and natural language processing (NLP), collectively used in the analysis of 341,112 radiographic images. CNNs were the most frequently applied modality in this review. Models such as AdaBoost and EmbNet have demonstrated high sensitivity, with EmbNet achieving 88-90.9% per scan and reducing false positives to 0.45 per scan. AI shows significant promise as a diagnostic tool for identifying PE on CTPA scans, particularly when combined with other forms of clinical data. However, challenges remain, including ensuring generalisability, addressing potential bias, and conducting rigorous external validation. Variability in study methodologies and the lack of standardised reporting of key metrics complicate comparisons. Future research must focus on refining models, improving peripheral emboli detection, and validating performance across diverse settings to realise AI's potential fully
Fame bias in editorial choice: Yes or No?
No full textRecently, Scientometrics has published a paper titled “Is there bias in editorial choice? Yes” (Moustafa 2015) in which some comments are given on our published paper in Nature titled “Is there fame bias in editorial choice?” (Mahian et al. 2015). Unfortunately, the author of above mentioned paper and many other readers might misunderstand the main aim of our correspondence. Here, we try to give some explanations to clarify the main goal of analysis presented in the paper
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