684 research outputs found
WinSyn: Jpeg and Raw data
No full textAleksandr Aleshkin, Angela Markoska, Artur Oliveira, Brian Benton, Chris West, Christopher Byrne, Elsayed Saafan, Florian Rist, George Iliin, Ignacio De Barrio, Jan Cuales, Kaitlyn Jackson, Kalina Mondzholovska, Kubra Ayse Guzel, Lukas Bornheim, Maria Jose Balestena, Michaela Nömayr, Mihai-Alexandru Filoneanu, Mokhtari Sid Ahmed Salim, Mussa Ubapa, Nestor Angulo Caballero, Nicklaus Suarez, Peter Fountain, Prem Chedella, Samantha Martucci, Sarabjot Singh, Scarlette Li, Serhii Malov, Simon Kelly, Stephanie Foden, Surafel Sunara, Tadiyos Shala, Susana Gomez, Tom Kelly, Vasileios Notis, and Yuan Yua
Correction: Guidelines for the prevention, detection and management of the renal complications of COVID-19 in Africa
No full textThe authors of the article ‘Guidelines for the prevention, detection and management of the renal complications of COVID-19 in Africa’ [1] wish to acknowledge the contribution of Professor Hussein El Fishawy. Our guidelines drew on various sources, including the Egyptian Ministry of Health guidelines, portions of which were adapted and reproduced with permission from the Egyptian Ministry of Health. Two of the authors of those guidelines, Professors Elsayed and Zaki, are also coauthors of our paper. Professor El Fishawy was the third author of the Egyptian guidelines and we would like to acknowledge his contribution to our review through this source, especially with respect to the treatment algorithms for patients with kidney transplants and those with acute kidney injury. Reference1. Elsayed HM, Wadee S, Zaki MS, Were AJO, Ashuntantang GE, Bamgboye EL, et al. Guidelines for the prevention, detection and management of the renal complications of COVID-19 in Africa. Afr J Nephrol. 2020; 23(1):109-126
Représentations littéraires du sacré dans le roman maghrébin de langue française
No full textThis interdisciplinary study explores how Driss Chraïbi’s L’Homme du Livre (1995), Assia Djebar’s Loin de Médine (1991), and Anissa Boumediène’s La fin d’un monde (1991) present accounts of particular historical moments in early Islam. This study explores the role of the imagination as well as freedom of invention when reconstructing historical events. It engages the novels through a study of the interplay between the literary text and the sources and traditions that impact and shape the text narrative. Gaining direct access to the original sources in Arabic serves to analyze how religious and early historical materials are considered in and reflected by the fictional texts. Because the sources tend to differ in both content and approach, this study examines their preoccupations in order to determine the criteria of selection applied by each novelist.Ph.D.Includes bibliographical referencesIncludes vitaby Hanan Elsaye
Intrathecal Drug Delivery Systems Survey: Trends in Utilization in Pain Practice [Corrigendum]
No full textAbd-Sayed A, Fiala K, Weisbein J, et al. J Pain Res. 2022;15:1305–1314.
The authors have advised there is an error in the author list on page 1305. The author name “Alaa Abd-Sayed” should read “Alaa Abd-Elsayed”.
The authors apologize for this error
Sabih Ailesi’nde Şiir: Araştırma ve Derleme
No full text"آل صبيح" أسرة من اسر ادبية اليت عاشت العصر العباسي، وهذه الدراسة مجعت شعر مخسة شعراء من هذه اسرة، كما درست شعرهم دراسةً فنية تكشف عن ظواهره الفنية، وهؤالء الشعراء هم: القاسم بن صبيح )عاش الشطر اول من القرن الثا اهلجري/ الثامن امليالدي(، وابنه يوسف بن القاسم )ت: 180هـ/ 796م(، وحفيداه: عبد هللا بن أمحد بن القاسم )عاش النصف اول من القرن الثالث اهلجري(، وأمحد بن أ سلمة املعروف أب بكر البغدادي )ت: 221هـ/835م(، وابن حفيده عبدهللا وامسه مد بن عبدهللا بن أمحد ويعرف أب الطيب اليوسفي )ت: 260 هــ/874م(.
وقد قسمت الدرسة إلى مخسة فصول يتقدمها مدخل وتعقبها خاتمة وثبت بالمصادر والمراجع، خصصت المدخل للحديث عن المصادر اليت وردت فيها أشعار آل صبيح المعنيني ومنهج الجمع الذي التزمت به مجع شعرهم، والفصل اول لرتمجة الشعراء، والثا غراض شعرهم، والثالث للظواهر الموسيقية واللغوية، والرابع للتصوير الف، واامس للمجموع الشعري مفردًا كل مبحث فيه بشعر شاعر من الشعراء امسة.
وأهم ما توصلت إليه الدراسة أن الشعراء امسة وردت أشعارهم مصادر معتبة كـ )اوراق(
بكر الصو )ت: 335ه/ 947م( و)معجم الشعراء( للمرزاب )ت: 384هـ/ 994م( وغريمها من المصادر، مما يجعلنا نثق بنسبة ما مجعناه من شعرهم إليهم، وأن هؤالء الشعراء عاشوا في البلاط العباسي وكان لكل واحد منهم مكانته عند اليفة الذي عاصره وعند رجال دولته، وأن شعرهم الذي أوردته المصادر مجعكثريا من الأغراض اليت تعرض لها الشعراء عبر عصور الشعر العري، ومال إلى الأوزن الطويلة والقوافي افيفة المعتمدة على حروف الروي سهلة المخرج، ووظفت فيه احملسنات اللفظية إلضفاء موسيقى داخلية تطرب لها الأذن وتتمايل لها الأمساع، كما وظفت فيه احملسنات المعنوية إلظهار المعا وبياهنا وإحداث الدهشة المطلوبة في الشعر عند المتلقي، كما وظفت فيه وسائل التصوير الف من تشبيه واستعارة وكناية إلبراز المعا واكاة الأشياء وتصويرها التصوير الدقيق الذي يطمئن له القلب وأتنس به الروح.“Al-i Sabîh” Abbasi döneminde yaşamış olan ailelerden biridir. Bu çalışma bu aileden beş şairin şiirini ele almış ve sanatsal açıdan özelliklerini alan bir özelliğe sahiptir. Bu beş şairin isimleri şöyledir: El-Kasım Bin Sabîh (Hicri 2. Yüzyılın başlarında/Miladi 8. yüzyılda yaşamıştır.), oğlu Yusuf bin El-Kasım (v. 180/796), iki torunu Abdullah bin Ahmed bin El-Kasım (Hicri 3. Yüzyılın ilk yarısında yaşamıştır.) ve Ebu Bekir El-Bağdadi olarak bilinen Ahmed bin Ebi Seleme (v. 221/835), torunu Abdullah’ın oğlu Ebu’t-Tayyib El-Yusufi olarak da bilinen Muhammed bin Abdullah bin Ahmed (v. 260/874).
Bu çalışma Giriş, 5 bölüm ve Sonuç kısımlarına ayrılır ve son olarak kaynakça bölümünden oluşur. Giriş bölümünü adı geçen Al-i Sabîh ailesi mensuplarının şiirlerinin geçtiği kaynaklar hakkında ve şiirlerini derlerken kullandığım yönetim hakkında konuşmaya ayırdım. Birinci bölümü şairlerin biyografilerine, ikinci bölümü şiir yazmadaki amaçlarına, üçüncü bölümü şiirlerindeki müziksel ve dilsel olgulara, dördüncü bölümü sanatsal betimlemeye, beşinci bölümü ise 5 şairden her birinin bir şiiri tek bir konuyu teşkil edecek şekilde düzenledim.
Araştırmamızın ulaştığı sonuçların en önemlisi, 5 şairin şiirlerinin Ebu bekir El-Savli’nin eseri olan (v. 335/947) “el-Evrak”, El-Merzebani’nin eseri olan (v. 384/994) “Mucemu’ş-Şuara” gibi güvenilir kaynaklarda geçmiş olmasının doğrulanmasıdır. Bu durum topladığımız şiirlerin onlara ait olduğuna dair güvenimizi güçlendirmektedir. Bu şairler Abbasi toprağında yaşamış ve hepsi zamanının Halifesi ve devlet adamları tarafından sevilirlermiş. Onların kaynaklarda geçen şiirleri Arapların tarih boyunca karşılaştığı birçok olayı içerir. Aynı zamanda şiirlerinde uzun vezinlere, telaffuzu kolay revî harflerine dayanan hafif kafiyelere yer verirler. Şiirlerinde kulağa hoş gelecek iç müzik ortaya çıkaran lafzî süsleme sanatları ve anlamları ortaya çıkarmak, açıklamak ve şiiri okuyan kişide istenilen hayreti bırakması için mânevî süsleme sanatları kullanılmıştır. Aynı şekilde anlamları daha iyi açıklamak, birtakım şeyleri birbirine benzetmek ve kalbin rahatlayacağı, ruhun hoşuna gidecek şekilde titiz betimleme için teşbih, istiare ve kinaye gibi betimleme araçları kullanılmıştır.The Sabeeh family is one of the literary families that thrived during the Abbasid era. This study compiles the poetry of five poets from this family and provides a detailed analysis of their artistic expressions. The featured poets are Al-Qasim bin Sabeeh (who lived in the first half of the 2nd century AH/8th century CE), his son Yusuf bin Al-Qasim (deceased 180 AH / 796 CE), and his grandsons: Abdullah bin Ahmed bin Al-Qasim, who lived in the first half of the 3rd century AH, Ahmed bin Abi Salama, also known as Abu Bakr Al-Baghdadi (deceased 213 AH/828 CE), and Abdullah's son, Muhammad bin Abdullah bin Ahmed, known as Abu Al-Tayyib Al-Yousefi (deceased 260 AH/874 CE).
The study is divided into five chapters, with an introduction and a conclusion, supported by references and sources. The introduction discusses the sources in which the poems of the Sabeeh family were found and the methodology used in collecting their poetry. The first chapter is dedicated to the biographies of the poets, while the second focuses on their poetic themes. The third chapter delves into the musical and linguistic aspects of their poetry, and the fourth explores their artistic imagery. The fifth chapter presents the entire poetic collection, with each section dedicated to the work of one of the five poets.
The most significant findings of this study are that the poems of these five poets were documented in reputable sources such as "Al-Awraq" by Abu Bakr Al-Souli (deceased 335 AH/947 CE) and "Mu'jam Al-Shu'ara" by Al-Marzubani (deceased 384 AH/994 CE), among others. This gives us confidence in attributing the collected poetry to them. Furthermore, these poets lived in the Abbasid court, and each of them held a special status among the caliph and his associates. Their poetry, as documented in these sources, encompasses a wide range of themes, many of which are common throughout various eras of Arabic poetry, and utilizes long meters and light rhymes based on easily pronounced letters, employing phonetic embellishments to create internal musicality that delights the ear and captivates the mind. Additionally, they employed semantic enhancements to convey and express meanings effectively, creating the desired impact in poetry when presented to the audience. They also employed various artistic techniques, such as simile, metaphor, and allegory, to illustrate and simulate objects with precise and detailed imagery that soothes the heart and resonates with the soul
Prevalence and Determinants of Symptomatic Dry Eye Disease Among Adult Urban Residents of High-Altitude Areas of Southwest Saudi Arabia – A Survey
No full textSaad Abbas Aldawsari,1 Nazih Alzaidi,2 Maram EA Abdalla Elsayed,3 Abdullah Ahmed Alhammadi,4 Hadeel Khaled Alharthi,1 Abdulrahman Alosaimi,5 Yahya Al-Najmi6 1Ophthalmology Department, King Faisal Medical Complex, Taif, Saudi Arabia; 2Ophthalmology Department, Alhada Military Hospital, Taif, Saudi Arabia; 3Ophthalmology Department, Jeddah Eye Hospital, Jeddah, Saudi Arabia; 4Ophthalmology Department, Asir Central hospital, Abha, Saudi Arabia; 5Ophthalmology Department, College of Medicine, Majmaah University, Majmaah, Saudi Arabia; 6Ophthalmology Department, Saggaf Eye Center, Jeddah, Saudi ArabiaCorrespondence: Yahya Al-Najmi, Ophthalmology Department, Saggaf Eye Center, Abdullah Salman St., Al Faiha’a Dist., P.O. Box: 31903, Jeddah, 21418, Saudi Arabia, Tel +966 564844281, Email [email protected]: To estimate the prevalence and determinants of Ocular Surface Disease Index (OSDI) score based dry eye disease (DED) among the adult urban population of four cities located at high altitudes in Southwest Saudi Arabia.Methods: This cross-sectional survey was held in 2023. OSDI questionnaire was used to collect the responses of the adult participants. The score was further graded into none, mild, moderate, and severe DED to estimate age-sex-adjusted DED prevalence. The OSDI score was correlated to demographic (age group, gender, education, occupation, city) and risk factors like smoking and co-morbidities.Results: Of the 401 adults, 388 (response rate of 97.8%) participated. The age-sex-adjusted prevalence of mild, moderate, and severe DED was 21.7%, 13.1%, and 32%, respectively. The median ODSI score was 22.9 [Interquartile range (IQR) 10.4; 47.9)]. The score was significantly higher in females (Mann–Whitney U-test P = 0.038), residents of Taif city (KW P = 0.05), those with primary/middle school education (Kruskal–Wallis P = 0.004), comorbidities like hypertension, asthma (KW P < 0.001) and risk factors like past refractive surgeries, arthritis (KW P = 0.013). Education status (P < 0.001) [B = − 9.0 95%] and presence of comorbidity (P = 0.022), [B = − 0.823] were significant predictors of DED.Conclusion: The prevalence of DED and severe grade was high. The level of education and presence of comorbidities significantly influenced DED in the adult urban Saudi population of cities at high altitudes.Keywords: dry eye disease, Ocular Surface Disease Inde
Degradation modeling of ink fading and diffusion of printed images
No full textColor printing plays an important role in the modern society. It is known that the color of printed images degrades gradually due to the fading and diffusion of the inks. Color degradation leads to a distortion or loss of the original information in printed images. Therefore, it is desirable to understand how the color of printed images changes over time. In this dissertation, we present degradation models to predict the characteristics of the ink fading and diffusion of printed images.
We begin by modeling the ink degradation from a physics-based perspective. Color images are printed by projecting small ink dots on medium, usually paper. This technique is called halftone printing. Halftone printing of color images results in a variety of ink mixtures and subsequently their potential catalytic fading. For the most commonly used Cyan-Magenta-Yellow-Black (CMYK) ink set, sixteen possible ink mixtures are generated during printing. A state transition diagram is then proposed for the ink fading in this multi-ink printing scenario. The ink area coverage is used as the performance indicator. Assuming constant fading and diffusion rates, we develop an ink fading model based on the differential equations according to the state transition diagram and an autoregressive ink diffusion model by discretizing the two-dimensional diffusion equation. The two models are then integrated into a single degradation model.
Further examination of the developed degradation models reveals that the fading or diffusion rate is equivalent to the hazard rate in reliability engineering. It is known that the hazard rate of the exponential failure time distribution is constant. Hence, the developed degradation model with constant fading and diffusion rates is equivalent to the multistate Markov process model with exponential transition time distribution. By using non-exponential transition time distributions, the fading and diffusion rates become time-varying and a more general semi-Markov process degradation model is developed accordingly.
Moreover, stochastic process models are investigated to provide stochastic area coverage prediction for the ink degradation. We first model the ink fading using the Hull-White/Vasicek (HWV) stochastic process. The HWV ink fading model considers that the variance of the ink area coverage shrinks as it approaches zero. Besides, spatial convolution is used to model ink diffusion. The two models are integrated into a spatio-temporal stochastic degradation model for the ink fading and diffusion of printed images. The cases of recurrent and non-recurrent time-varying fading and diffusion rates are investigated.
Inks on the paper degrade, so does the paper. The degradation of paper condition may in turn affect the degradation of the inks. Therefore, the investigation of the degradation modeling of ink fading and ink diffusion with ink-paper interactions is needed. Two aspects of the ink-paper interactions are considered, i.e., the effect of paper aging such as depolymerization and yellowing, and the fiber orientation of the paper.
The degradation process of printed images usually takes a very long time. An accelerated degradation model and the optimal design of accelerated degradation test planning is developed for accurate degradation prediction of printed images. The effects of three constant environmental stresses: temperature, humidity, and illumination (intensity), are investigated, and experimental data are used to validate the proposed model. The results show strong agreements between the proposed ink fading and ink diffusion prediction model and the actual experimental data.Ph.D.Includes bibliographical reference
Reliability estimation of balanced systems with multi-dimensional distributed units
No full textBalanced systems with multi-dimensional distributed units are emerging in a diverse range of industries. This includes Unmanned Aerial Vehicles (UAV) with multi-level of rotary wings, Spherical Unmanned Vehicles (SUV), Spherical Phased Array Antenna (SPAA), etc. In this dissertation, we present the reliability estimation for such systems. In particular, we consider two configurations: 1) balanced systems with units distributed circularly on multi-level and 2) balanced systems with units distributed spherically.
First, balanced systems with units distributed circularly on multi-level are generalized as (k₁, k₂)-out-of-(n, m) pairs: G balanced systems. We consider two scenarios: 1) all units perform the same function and 2) adjacent pairs perform complementary functions. For both scenarios, unbalanced system is considered as failed. When units fail and cause the system imbalance, we explore two approaches to rebalance the system: 1) forcing down units on other locations and 2) resuming units that are previously forced down (if any). When units in a system perform the same function, operational states are defined as balanced states with at least k₁ operating pairs and each operating pair has at least k₂ units on each side. The system reliability is obtained by enumerating all of the operational states and summing the probabilities of those states. For (k₁, k₂)-out-of-(n, m) pairs: G balanced systems with adjacent pairs performing complementary functions, in addition to maintaining system balance, the adjacent operating pairs are required to perform complementary functions. Thus, if a pair fails, one of the adjacent pairs is forced down. Similarly, the system reliability is obtained by enumerating all of the operational states. It becomes computational expensive when the number of units in each pair and/or the number of pairs are large. In that case, efficient algorithms are developed to obtain the reliability for such systems.
The balanced system with units distributed spherically is generalized as a spherical k-n-i: G balanced system. We consider two balancing requirements: 1) rotational balance is maintained so that the system is not rotating w.r.t. roll, yaw and pitch axes and 2) symmetrical balance is essential in improving the systems’ stability. We present mathematical approaches to determine the balance status of a system. Similarly, the unbalanced system is rebalanced by 1) forcing down units on other locations and 2) resuming previously forced-down units. The system reliability is obtained by the enumeration of operational states and calculation of operational states’ probabilities. We develop an efficient algorithm for reliability estimation when the number of units in the system is large.
Degradation models are developed for the (k₁, k₂)-out-of-(n, m) pairs: G balanced systems to further investigate the system reliability when degradation data are available. The degradation processes of units in the system are either stationary (inverse Gaussian process) or non-stationary (improved inverse Gaussian process). We propose a degradation balance mechanism in which the ‘most’ degraded units are forced down temporarily during the degradation process so that the system is less possible to fail due to imbalance. A closed-form lower bound reliability is presented when the balance mechanism is not applied. When it is applied, reliability is obtained by Monte Carlo simulation.
From the reliability study of the both configurations, it is observed that the reliability of a balanced system with multi-dimensional distributed units depends not only on the system’s total number of units and the least number of operating units, but also on the system configurations and balance requirements. Systems with more units do not necessarily provide a higher reliability since they are more likely to fail due to imbalance. Thus, optimal system design is key to maximize the system reliability which is investigated through numerical examples in this dissertation.Ph.D.Includes bibliographical reference
Master Thesis Entitled The Footnote of Bin Hamdoun on The Explanation Of Bahraq for The İbn Malik Lamiat
No full textتحمل هذه الدراسة عنوان "حاشية ابن حمدون على شرح بحرق على لامية ابن مالك، وهي موزعة على قسمين: الأول منهما تحدثت فيه عن ناظم اللامية: محمد بن عبد الله ابن مالك (ت. 672هـ)، وشارحها: محمد بن عمر الشهير بيحرق (ت 930هـ)، ومحشيها القاضي محمد الطالب بن حمدون ت (1273هـ)، ثم قمت بالتعريف باللامية والشرح الصغير، والحواشي عليه. ثم ختمت هذا القسم بالحديث عن حاشية ابن حمدون، فبينت اختلافات نسخها، وأهم مصادرها، وتعقبات المحشي على الناظم والشارح وعلى غيرهما من العلماء، وإضافات المحشي كالأجوبة عن الإيرادات والإشكالات وتحرير المسائل المستعصية والتنبيه على أوهام المخالفين والتقريرات الفقهية، والترجيحات، وختمته ببيان أهم النتائج التي توصلت إليها خلال الدراسة. أما القسم الثاني فخصصته لتحقيق الحاشية، وقدمت له بوصف النسخ المخطوطة، ثم منهج التحقيق وعملي فيه كتخريج الآيات والأحاديث، وعزو الأبيات مع بيان بحرها، والتعريف بالأعلام الواردة في الحاشية، والرموز والاختصارات.. ثم أتبعت ذلك بنص الحاشية مضبوطاً، ومفقرا، ومعنونا، ومنها ما فيه من أبيات، ومصحوبا بحواش فيها شرح الغريب وبيان المشكل منه، وعزو النقول إلى مصدرها، وفي أعلاه متن الشرح الصغير بخط أصغر من خط الحاشية.Bu araştırma "Hâşiyatü İbni Hamdün alâ Şarhi Bahrak alâ Lâmiyyeti İbni Mâlik başlığını taşımaktadır. İki kısma ayrılır: Birinci kısımda el-Lamiyye'yi derleyen kişiden bahsettim: Muhammed bin Abdullah İbni Malik ve onu şerh eden Bahrak ismiyle meşhur Muhammed bin Ömer ve ona haşiye yazan Kadı Muhammed bin Hamdun. Sonra Lamia'yı, küçük şerhi ve dipnotlarını tanıttım. Daha sonra İbn Hamdun'un haşiyesinden bahsederek, nüsha farklılıklarını, en önemli kaynaklarını, haşiyeyi derleyen ve şerh eden bu iki alim dışıdaki alimlerin tahkikatlarını, haşiyeye eklenen nakilleri, problemleri ve çözümü zor meseleleri, muhaliflerin yanılgılarını, fıkhi açıklamaları ve tercihleri açıkladım. Çalışma sırasında ulaştığım en önemli bulguları beyan ederek bölümü sonlandırdım.
İkinci bölüme gelince, onu haşiye incelemesine ayırdım ve yazma nüshaların bir tanıtımını sundum. sonra tahkik yöntemi, ayet ve hadis tahrici çalışması gibi, beyitleri ölçüleriyle inceleyerek haşiyede geçen işaretlerin, sembollerin ve kısaltmaların açıklamalarını yaptım. daha sonra haşiye metnini harekeli, paragraflı, başlıklı ve içindeki beyitlerle uyumlu şekilde, yabancı kelimeleri ve onunla ilgili problemleri dipnotlar eşliğinde açıklayıp, alıntıları kaynağına atfederek, üst kısımda haşiye hattından daha küçük bir hat ile metnin şerhini sundum.This study bears the title “Footnote of Bin Hamdoun on the explanation of Bahraq for the ibn Malik Lamiat.” (d. 672 AH), and its commentator: Muhammad bin Omar, the known also as Bahruq (d. 930 AH), and its commentator: Judge Muhammad al-Talib bin Hamdun (d. 1273 AH), then I introduced Lamyism and the small explanation, and footnotes to it. Then I concluded this section with talking about Ibn Hamdun’s footnote, so I showed the differences of its versions, its most important sources, the traced footnote for the author and the commentator and other scholars, and the additions to the footnote such as answers to questions and problems, editing intractable issues, alerting the delusions of violators, jurisprudential reports, and weightings, and concluded it with a statement of the most important results that i found during the study.
As for the second section, I devoted it to the investigation of the footnote, and I presented it with a description of the manuscript copies, then the investigation methodology and my work in it, I described the characteristics of the manuscript copies and explained the verses and hadiths mentioned in the gloss, as well as the couplets that the writer relied upon. I also provided descriptions of the symbols, marks, and abbreviations found in the gloss. Throughout the verses, I evaluated the conformity of Arabic diacritical marks and their placement. Additionally, I clarified the meanings of foreign words and explained the interpretations of ambiguous parts, and attributing it to it's sources. Moreover, I observed that the text of "Eş şerh ü sağir" was written in a smaller size above the gloss text, and I noted that the opinions in the gloss were based on references
Nanofiber composites containing N-heterocyclic carbene complexes with antimicrobial activity
No full textAhmed A Elzatahry1,4, Abdullah M Al-Enizi1, Elsayed Ahmed Elsayed2,5, Rachel R Butorac3, Salem S Al-Deyab1, Mohammad AM Wadaan2, Alan H Cowley31Petrochemical Research Chair, Department of Chemistry, 2Chair of Advanced Proteomics &amp; Cytomics Research, Faculty of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia; 3Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, TX, USA; 4Institute of Advanced Technology and New Materials, City for Scientific Research and Technology Applications, New Borg Alrab, Alexandria, Egypt; 5Natural &amp; Microbial Products Department, National Research Centre, Dokki, Cairo, EgyptAbstract: This report concerns nanofiber composites that incorporate N-heterocyclic carbenes and the use of such composites for testing antimicrobial and antifungal activities. The nanofiber composites were produced by electrospinning mixtures of the gold chloride or gold acetate complexes of a bis(imino)acenaphthene (BIAN)-supported NHC with aqueous solutions of polyvinyl alcohol (PVA). The products were characterized by scanning-electron microscopy, which revealed that nanofibers in the range of 250&ndash;300 nm had been produced. The biological activities of the nanofiber composites were tested against two Gram-positive bacteria, six Gram-negative bacteria, and two fungal strains. No activity was evident against the fungal strains. However, the gold chloride complex was found to be active against all the Gram-positive pathogens and one of the Gram-negative pathogens. It was also found that the activity of the produced nanofibers was localized and that no release of the bioactive compound from the nanofibers was evident. The demonstrated antimicrobial activities of these novel nanofiber composites render them potentially useful as wound dressings.Keywords: nanofiber, electrospinning, N-Heterocyclic carbene, biopolymer, antimicrobia
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