Corrosion evaluation of 316L stainless steel in CNT-water nanofluid: Effect of CNTs loading

Polarization resistance and potentiodynamic scan testing were performed on 316L stainless steel (SS) at room temperature in carbon nanotube (CNT)-water nanofluid. Different CNT loadings of 0.05, 0.1, 0.3 and 0.5 wt% were suspended in deionized water using gum arabic (GA) surfactant. Corrosion potential, Tafel constants, corrosion rates and pitting potential values indicated better corrosion performance in the presence of CNTs with respect to samples tested in GA-water solutions. According to Gibbs free energy of adsorption, CNTs were physically adsorbed into the surface of the metal, and this adsorption followed Langmuir adsorption isotherm type II. Samples tested in CNT nanofluid revealed a corrosion performance comparable to that of tap water and better than that for GA-water solutions. Among all samples tested in CNT nanofluids, the lowest corrosion rate was attained with 0.1 wt% CNT nanofluid, while the highest value was obtained with 0.5 wt% CNT nanofluid. At higher CNT concentrations, accumulated CNTs might form active anodic sites and increase the corrosion rate. SEM images for samples of higher CNT loadings were observed to have higher pit densities and diameters.This work was supported by Hamad Bin Khalifa University, College of Science and Engineering, Sustainable Development Division, Doha, Qatar. The publication of this article was funded by the Qatar National Library. Assistance provided by the Core Lab, HBKU is greatly appreciated. Special thanks to the Materials and Corrosion Laboratory at College of the North Atlantic-Qatar for their continuous support since the early stages of this research. Great gratitude is sent to Bruce Palmer for his guidance in this work.Scopu

Variability and host specificity of witchweed [Striga hermonthica (Del.) Benth.] populations on millet [Pennisetum glaucum (L.) R. Br.]

   Field surveys and greenhouse experiments were conducted during season 2009/10 in the Sudan to investigate variability and host specificity of witchweed [Striga hermonthica (Del.) Benth.] populations. Field surveys were conducted in S. hermonthica endemic areas in Gadarif, Gezira and Kordofan to collect seeds from Striga plants growing under their respective hosts. A total of fifteen S. hermonthica populations were collected. Twelve S. hermonthica populations, one each, were collected from under sorghum and three S. hermonthica populations, one each, were collected from under millet. A greenhouse experiment was undertaken at the horticulture nursery, Faculty of Agricultural Sciences, University of Gezira, Wad Medani, Sudan, to test the infectivity of seeds of witchweed populations on millet, cultivar Ashana, which is known for its differential response and to study virulence of parasitism on this cultivar. The fifteen S. hermonthica populations were arranged in a randomized complete block design with three replicates. Growth and harvest attributes on the parasite and crop were measured. Data were collected and transformed as necessary to √x+0.5 and subjected to the analysis of variance procedure. Means were separated for significance using Duncan's Multiple Range Test (at p £ 0.5). The greenhouse experiment showed that emergent S. hermonthica, capsules per plant and shoot dry weight were highest on the respective host. It is noteworthy that some of the Striga, sorghum populations, displayed limited emergence on millet and produced seeds. S. hermonthica populations significantly reduced growth and yield of millet. However, the magnitude of the damage attained, by each   population was highest on the respective host. These findings suggest the existence of inter-crop specialization. Moreover, the results confirmed the existence of two strains of S. hermonthica, one specific to sorghum and the other to millet. These findings showed clearly the complexity of obtaining millet cultivars with high and durable resistance across locations.      طفيل البُودا Striga hermonthica (Del.)، نبات متطفل إجبارياً على الجذور ينتمي للعائلة الهالوكية (Orobanchaceae)، يُهاجم محاصيل الغلال المهمة في أفريقيا. أدى وجود السلالات الفسيولوجية، التباينات الايكولوجية وعزلات الطفيل بالإضافة للتباين في حجم مخزون التربة من البذور، إلى عقبات جدية لتطوير وسائل تحكم بسيطة وفعالة. لذا أُجريت مسوحات حقلية وتجارب بيوت محمية خلال الموسم 2009/ 2010 في السودان لبحث التباين وتخصصية العائل في البُودا. المسوحات الحقلية أجريت في المناطق الموبؤة بالبُودا في القضارف والجزيرة وكردفان، لجمع البذور من نباتات البُودا النامية على عوائلها الخاصة. جمعت اثني عشر عشيرة للبُودا، واحدة لكل، من تحت الذرة الرفيعة، وجمعت ثلاث عشائر من تحت الدخن، واحدة لكل. أجريت تجربة البيوت المحمية بمشتل البساتين، كلية العلوم الزراعية، جامعة الجزيرة، ود مدني، السودان، لاختبار تلويث بذور عشائر البودا للدخن، الصنف عشانا، المعروف باستجابته التفضيلية، ولدراسة التباين في التطفل على هذا الصنف. وُضعت الخمسة عشر عشيرة للبُودا في تصميم قطاعات عشوائية كاملة بثلاث تكرارات. تم تحديد مقاييس النمو والحصاد بالنسبة للطفيل والمحصول. حُولت البيانات عند الضرورة (√x+0.5) وأُخضعت لتحليل التباين. تمت مقارنة المتوسطات بواسطة اختبار دنكن، عندما كان الاختبار معنويا. أوضحت نتائج تجارب البيوت المحمية أن قمة انبثاق نباتات البُودا في الأصيص، الكبسولات في النبات، الوزن الجاف للمجموع الخضري، عدد نباتات البُودا تحت سطح التربة في الأصيص والعدد الكلى لنباتات البُودا في الأصيص كانت أعلى على عوائلها الخاصة. الجدير بالملاحظة أن بعض نباتات البُودا، عشائر الذرة الرفيعة، أظهرت بزوغاً محدوداً على الدخن وأنتجت بذوراً. خفضت عشائر البُودا معنوياً نمو وإنتاج الذُرة والدُخن. ولكن تحققت أعلى مستويات الضرر لكل عشيرة من البُودا على عائلها الخاص. أوضحت نتائج هذا البحث وجود التخصصية بين وداخل نوع المحصول. كما أن النتائج تؤكد وجود سلالتان للبُودا واحدة متخصصة في الذُرة الرفيعة والأخرى في الدُخن. أظهرت هذه النتائج بوضوح التعقيد في الحصول على أصناف من الدخن ذات مقاومة عالية وعريضة في المناطق المختلفة

Molecular Characterization of Borrelia persica, the Agent of Tick Borne Relapsing Fever in Israel and the Palestinian Authority

The identification of the Tick Borne Relapsing Fever (TBRF) agent in Israel and the Palestinian Authority relies on the morphology and the association of Borrelia persica with its vector Ornithodoros tholozani. Molecular based data on B. persica are very scarce as the organism is still non-cultivable. In this study, we were able to sequence three complete 16S rRNA genes, 12 partial flaB genes, 18 partial glpQ genes, 16 rrs-ileT intergenic spacers (IGS) from nine ticks and ten human blood samples originating from the West Bank and Israel. In one sample we sequenced 7231 contiguous base pairs that covered completely the region from the 5′end of the 16S rRNA gene to the 5′end of the 23S rRNA gene comprising the whole 16S rRNA (rrs), and the following genes: Ala tRNA (alaT), Ile tRNA (ileT), adenylosuccinate lyase (purB), adenylosuccinate synthetase (purA), methylpurine-DNA glycosylase (mag), hypoxanthine-guanine phosphoribosyltransferase (hpt), an hydrolase (HAD superfamily) and a 135 bp 5′ fragment of the 23S rRNA (rrlA) genes. Phylogenic sequence analysis defined all the Borrelia isolates from O. tholozani and from human TBRF cases in Israel and the West Bank as B. persica that clustered between the African and the New World TBRF species. Gene organization of the intergenic spacer between the 16S rRNA and the 23S rRNA was similar to that of other TBRF Borrelia species and different from the Lyme disease Borrelia species. Variants of B. persica were found among the different genes of the different isolates even in the same sampling area

Analysis of the Chemical Components Found in The Volatile Oils of Thymus vulgaris and Lavandula angustifolia and Their Antiviral Properties: A Case Study of Russia

Herbal medicines are natural remedies derived from plants or plant extracts. They have been used for thousands of years in traditional medicine and are still widely used today as alternative treatments for various health conditions. In this study, the antiviral effects of the volatile oils of Thymus vulgaris and Lavandula angustifolia were examined separately after identifying the constituents of the volatile oils of these two plants. Two plants, Thymus vulgaris and Lavandula angustifolia, grown in the open air, were collected from the surrounding plains of Mirny and Ust-Ilimsk cities in Russia, respectively. Using a Clevenger apparatus, the oil was independently extracted from each plant by distillation with water. By using gas chromatography tandem mass spectrometry (GC-MS), the obtained volatile oil was examined. The antiviral effects of these two plants' essential oils were then studied independently on herpes simplex virus (HSV-1). These viruses can quickly multiply on HeLa or HEp-2 cancer cells and produce effects that specifically cause cytopathic effect. In the essential oil of the Lavandula angustifolia, 24 compounds including thymol, carvacrol, p-Cymene and caryophyllene were identified. In the essential oil of Thymus vulgaris, 27 substances including terpenin-4-L, p-cymene, γ-terpinene and sabinene were identified. Also, the antiviral effects of the volatile oil of these two plants were investigated separately with a concentration of 10-4 on HeLa cells infected with HSV-1, and the result was negative

Effects of Ketosis and Hypocalcemia on The Biochemical Parameters and Subsequent Postpartum Reproductive Performance in Buffaloes

Water buffaloes (Bubalus bubalis) are mainly distributed in tropical and subtropical countries that include the Indian sub-continent and some Mediterranean countries such as Egypt. The transition period is the most stressful period for buffaloes, and it is considered as a turning point in the productive cycle from one lactation to the next and includes different metabolic, physiological, and nutritional changes. Metabolic disorders are common causes of lower productivity in buffaloes. Of these metabolic disorders, ketosis and hypocalcemia are most prevalent. This study aimed to study the ketosis- and hypocalcemia-related biochemical changes during the transition period and their impacts on the postpartum reproductive fertility in Buffaloes. Out of 120 total number of examined buffaloes, 40 buffaloes were used in this study; control group (n=10), hypocalcemia-affected (n=15), and ketosis-affected group (n=15). All buffaloes were subjected to thorough clinical and gynecological examination. Both urine and blood samples were collected from all groups. The amounts of ketone bodies were detected in urine. Biochemical parameters were evaluated including concentrations of glucose, triglycerides, cholesterol, non-esterified fatty acids (NEFA), calcium, phosphorus, sodium, potassium, albumin, total protein, urea and progesterone hormone (P4) in blood the following time-points (2-weeks prepartum, 1-week prepartum, partum, 1-week postpartum, and 2-weeks postpartum). Both hypocalcemia- and ketosis affected buffaloes had lower glucose, phosphorus, sodium and albumin and higher NEFA than control group. Hypocalcemia-affected buffaloes showed lower calcium and higher total protein than control group, while, ketosis-affected buffaloes showed lower cholesterol and total protein than control group. Moreover, metabolic disorders negatively affected the reproductive performance. Both ketosis and hypocalcemia significantly prolonged the duration to first estrus, increased both the number of days-open and the number of services per conceptio

Rabies Virus Populations in Humans and Mice Show Minor Inter-Host Variability within Various Central Nervous System Regions and Peripheral Tissues

Rabies virus (RABV) has a broad host range and infects multiple cell types throughout the infection cycle. Next-generation sequencing (NGS) and minor variant analysis are powerful tools for studying virus populations within specific hosts and tissues, leading to novel insights into the mechanisms of host-switching and key factors for infecting specific cell types. In this study we investigated RABV populations and minor variants in both original (non-passaged) samples and in vitro-passaged isolates of various CNS regions (hippocampus, medulla oblongata and spinal cord) of a fatal human rabies case, and of multiple CNS and non-CNS tissues of experimentally infected mice. No differences in virus populations were detected between the human CNS regions, and only one non-synonymous single nucleotide polymorphism (SNP) was detected in the fifth in vitro passage of virus isolated from the spinal cord. However, the appearance of this SNP shows the importance of sequencing newly passaged virus stocks before further use. Similarly, we did not detect apparent differences in virus populations isolated from different CNS and non-CNS tissues of experimentally infected mice. Sequencing of viruses obtained from pharyngeal swab and salivary gland proved difficult, and we propose methods for improving sampling

First molecular analysis of rabies virus in Qatar and clinical cases imported into Qatar, a case report

Identifying the origin of the rabies virus (RABV) infection may have significant implications for control measures. Here, we identified the source of a RABV infection of two Nepalese migrants in Qatar by comparing their RABV genomes with RABV genomes isolated from the brains of a RABV infected camel and fox from Qatar

Selective Loss of Cysteine Residues and Disulphide Bonds in a Potato Proteinase Inhibitor II Family

Disulphide bonds between cysteine residues in proteins play a key role in protein folding, stability, and function. Loss of a disulphide bond is often associated with functional differentiation of the protein. The evolution of disulphide bonds is still actively debated; analysis of naturally occurring variants can promote understanding of the protein evolutionary process. One of the disulphide bond-containing protein families is the potato proteinase inhibitor II (PI-II, or Pin2, for short) superfamily, which is found in most solanaceous plants and participates in plant development, stress response, and defence. Each PI-II domain contains eight cysteine residues (8C), and two similar PI-II domains form a functional protein that has eight disulphide bonds and two non-identical reaction centres. It is still unclear which patterns and processes affect cysteine residue loss in PI-II. Through cDNA sequencing and data mining, we found six natural variants missing cysteine residues involved in one or two disulphide bonds at the first reaction centre. We named these variants Pi7C and Pi6C for the proteins missing one or two pairs of cysteine residues, respectively. This PI-II-7C/6C family was found exclusively in potato. The missing cysteine residues were in bonding pairs but distant from one another at the nucleotide/protein sequence level. The non-synonymous/synonymous substitution (Ka/Ks) ratio analysis suggested a positive evolutionary gene selection for Pi6C and various Pi7C. The selective deletion of the first reaction centre cysteine residues that are structure-level-paired but sequence-level-distant in PI-II illustrates the flexibility of PI-II domains and suggests the functionality of their transient gene versions during evolution

Antibiotic-induced release of small extracellular vesicles (exosomes) with surface-associated DNA

Recently, biological roles of extracellular vesicles (which include among others exosomes, microvesicles and apoptotic bodies) have attracted substantial attention in various fields of biomedicine. Here we investigated the impact of sustained exposure of cells to the fluoroquinolone antibiotic ciprofloxacin on the released extracellular vesicles. Ciprofloxacin is widely used in humans against bacterial infections as well as in cell cultures against Mycoplasma contamination. However, ciprofloxacin is an inducer of oxidative stress and mitochondrial dysfunction of mammalian cells. Unexpectedly, here we found that ciprofloxacin induced the release of both DNA (mitochondrial and chromosomal sequences) and DNA-binding proteins on the exofacial surfaces of small extracellular vesicles referred to in this paper as exosomes. Furthermore, a label-free optical biosensor analysis revealed DNA-dependent binding of exosomes to fibronectin. DNA release on the surface of exosomes was not affected any further by cellular activation or apoptosis induction. Our results reveal for the first time that prolonged low-dose ciprofloxacin exposure leads to the release of DNA associated with the external surface of exosomes