King Saud University

About: King Saud University is a education organization based out in Riyadh, Saudi Arabia. It is known for research contribution in the topics: Population & Adsorption. The organization has 22106 authors who have published 57908 publications receiving 1042234 citations. The organization is also known as: Riyadh University.

Box-Behnken Response Surface Design of Polysaccharide Extraction from Rhododendron arboreum and the Evaluation of Its Antioxidant Potential.

Abstract: In the present investigation, the ultrasound-assisted extraction (UAE) conditions and optimization of Rhododendron arboreum polysaccharide (RAP) yield were studied by a Box–Behnken response surface design and the evaluation of its antioxidant potential. Three parameters that affect the productivity of UAE, such as extraction temperature (50–90 °C), extraction time (10–30 min), and solid–liquid ratio (1–2 g/mL), were examined to optimize the yield of the polysaccharide percentage. The chromatographic analysis revealed that the composition of monosaccharides was found to be glucose, galactose, mannose, arabinose, and fucose. The data were fitted to polynomial response models, applying multiple regression analysis with a high coefficient of determination value (R2 = 0.999). The data exhibited that the extraction parameters have significant effects on the extraction yield of polysaccharide percentage. Derringer’s desirability prediction tool was attained under the optimal extraction conditions (extraction temperature 66.75 °C, extraction time 19.72 min, and liquid–solid ratio 1.66 mL/g) with a desirability value of 1 yielded the highest polysaccharide percentage (11.56%), which was confirmed through validation experiments. An average of 11.09 ± 1.65% of polysaccharide yield was obtained in optimized extraction conditions with a 95.43% validity. The in vitro antioxidant effect of polysaccharides of R. arboreum was studied. The results showed that the RAP extract exhibited a strong potential against free radical damage.

Genre Categorization of Web Pages

Abstract: With the increase of the number of web pages, it is very difficult to find wanted information easily and quickly out of thousands of web pages retrieved by a search engine. To solve this problem, many researches propose to classify documents according to their genre, which is another criteria to classify documents different from the topic. Most of these works assign a document to only one genre. In this paper we propose a new flexible approach for document genre categorization. Flexibility means that our approach assigns a document to all predefined genres with different weights. The proposed approach is based on the combination of two homogenous classifiers: contextual and structural classifiers. The contextual classifier uses the URL, while the structural classifier uses the document structure. Both contextual and structural classifiers are centroid-based classifiers. Experimentations provide a micro-averaged breakeven point (BEP) more than 85%, which is better than those obtained by other categorization approaches.

4-Hydroxybutyric aciduria

Abstract: The clinical findings in six patients from three families with 4-hydroxybutyric aciduria are described. The onset of disease was in early infancy in all cases. All infants presented with severe global delay and severe hypotonia, and all patients had seizure disorder. Eye findings included optic atrophy in two patients, and retinitis pigmentosa in one. Three patients had choreoathetosis, two had myoclonus and one had severe dystonia. The urine 4-hydroxybutyric acid was 300–1000 times that of normal, and other organic acids related to its further metabolism or to its inhibitory effect on β-oxidation were also increased. The administration of vigabatrine rapidly reduced the excretion of 4-hydroxybutyric acid promptly, and in the long-term its excretion could be kept at 80–200 times that of normal. However, the clinical course of the disease improved in only two, remained the same in two, and worsened in the remaining two patients.

Anemia among pregnant women in the Asir region, Saudi Arabia: an epidemiologic study.

Abstract: A cross sectional study was conducted during August 1992, on a representative sample of 6,539 pregnant women attending 69 primary health care centers in the Asir region, southwestern Saudi Arabia for the assessment of their hemoglobin level. The overall prevalence of anemia (Hb < 11 g/dl) was found to be 31.9%. It was found that the prevalence was affected by age (37.3% among those who were less than 20 years old), parity (34.9% among those who had 7 and more deliveries), inter-pregnancy spacing (35.2% among those whose birth spacing was less than 1 year), gestational age, and education (35.1% among illiterates). Health education programs at primary health care level in the region should be revised to stress the importance of balanced diet, compliance with iron medication and sufficient spacing between subsequent pregnancies.

Consensus recommendation for meningococcal disease prevention for Hajj and Umra pilgrimage/travel medicine.

Abstract: The Islamic Hajj to Makkah (Mecca) has been associated with outbreaks of invasive meningococcal disease and the global spread of Neisseria meningitidis serogroup W-135. For Hajj pilgrims the quadrivalent vaccination against serogroups A, C, W-135 and Y is a mandatory requirement. Novel conjugate vaccines may provide benefits for the community by reduction of carriage. With the introduction of the new generation of quadrivalent meningococcal conjugate vaccines (Menveo, Menactra, and others pending license) and their recent implementation in Saudi Arabia, experts from 11 countries in the Middle East region met at a Meningococcal Leadership Forum (MLF), in Dubai in May 2010 to exchange opinions on meningococcal disease and prevention strategies. These experts discussed the importance of introducing conjugate vaccines for pilgrims and travellers, and elaborated a consensus recommendation to support healthcare professionals and decision-makers.