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Several coumarin-containing substitute nitrogen heterocycles have recently received considerable importance due to their diverse pharmacological properties. One-pot and rapid synthesis of coumarin derivatives was achieved via reactions of acetyl-coumarin with p-chloro-benzaldehyde and malononitrile to provide compound 2-containing cyano-amine using conventional heating. Compound 2 was condensed with different carbon electrophiles triethyl orthoformate, phenyl isocyanate, carbon disulfide, benzoyl chloride, and acetyl chloride that afforded the corresponding chromene derivatives 3–17. All the newly synthesized compounds were characterized by elemental and spectroscopic evidences. All of the synthesized compounds were tested for antimicrobial activity against S. Pneumoniae, S. Epidermidis, S. Aureus, and E. coli as Gram + ve Bacteria, K. Pneumoniae, S. Paratyphi as Gram -ve Bacteria, P. Italicum, A. Fumigatus representative for Fungi. The preliminary screening results showed that most of the compounds had moderate to high activity against all tested organisms. The most potent four compounds were subjected to further investigation against E. Coli DNA gyrase and topoisomerase IV inhibitory activity, and the results showed that all of these derivatives inhibit DNA gyrase and thus cell division. Also, in silico studies were done for the most active compounds which showed good results.

Using wideband High Frequency (WBHF) communication has not been a luxury now due to the urgent need for the transfer of large files over long distances without the need for sophisticated infrastructure. The channel model helps in evaluating the performance of communications systems without the need for a real transmission. The existing HF ITU-R(International Telecommunication Union Radio) channel models are valid only for narrowband channels of bandwidth 3KHz and are valid up to 12KHz. Another channel model for WBHF with bandwidth up to 1MHz was given by Vogler yet, the model was mathematically intractable and allow no further analysis to take place. Noting that, WBHF demands channel bandwidth greater than 12KHz (e.g:24KHz). In this paper, we present a WBHF channel model that is both accurate and mathematically tractable laying the foundation for an informative comparison between different communication systems. The accuracy of the proposed model is first to cross verified against Vogler’s wideband model in terms of the channel impulse response, frequency response and channel scattering characteristics. This comparison leaves our model qualified to evaluate a newly developed standard of HF wideband Waveforms presented to support high data rates and link reliability requirements. Further, we establish a detailed comparison between OFDM and single carrier signaling schemes over the considered WBHF proposed ionospheric channel, under many parameters that affect the performance of both systems. We investigate the justification of using both systems under different channel conditions, we also derive the necessary rate formulas for each signaling scheme and provide simulation environment of both systems on selected samples of the ITU-R channel models for the HF ionospheric channel representing most of the channel conditions. It is coming up that in quiet channel conditions the OFDM outperforms SCCP, while in disturbed conditions SCCP shows more robustness against channel conditions than OFDM. Simulation results are shown that support our analytical results. In addition, we present a Software Defined Radio Hardware implementation of an OFDM wideband HF Transceiver. The developed implementation has been evaluated using an equivalent baseband channel model based on the ITU-R HF channel model.

Background Scientific studies require a well-prepared cascade of steps starting from the idea and formulating a research question passing through collecting data and analysis of the results to proper writing a good article and publication. The methodology section is the core of any scientific article. Main body Study designs in otolaryngology can be classified as “observational studies,” “experimental (interventional) studies,” and “meta-analysis—systematic review.” There may be a huge range in quality between kinds of studies. To standardize the method of reporting the quality of studies and include all important aspects in the evaluation process, a team of scientists created the reporting guidelines checklists. Conclusions In this article, we give a comprehensive review that can help authors to understand study designs in otolaryngology along with the appropriate reporting guidelines used in each study.

Background Allergic rhinitis is the most prevalent allergic disease, and the prevalence and sensitization patterns differ among countries. Identifying the most common inhalant allergen in each region plays a key role in the diagnosis and management of allergic rhinitis. There are no data available about the most prevalent aeroallergen among allergic rhinitis patients in Egypt. The aim of this study is to evaluate the prevalence of positive serum allergen-specific IGE to common inhalant allergens among allergic rhinitis patients in Egypt. A cross-sectional study was conducted on 354 allergic rhinitis patients, serum allergen-specific IGE was measured by using the Immuno CAP system to 16 common regional aeroallergens including (pollens, mite, molds, animal dander, and cockroach). Results The overall rate of sensitization to any allergen was 74.6%. Dermatophagoides pteronyssinus, birch pollens, and Dermatophagoides farina were the most prevalent allergens (29.7%, 23.7%, and 18.6%), respectively. Cladosporuim molds were the least prevalent individual allergens (1.7%). Conclusion Our data suggest that Dermatophagoides pteronyssinus and birch pollens were the predominant allergen sources among allergic rhinitis patient in Egypt.

Background Benign vocal fold lesions are a common cause for hoarseness of voice. Aim The aim of this work was to investigate the efficacy and safety of microdebrider and radiofrequency in excision of benign vocal fold lesions compared with the classic microlaryngosurgical (MLS). Patients and Methods This study included 30 patients, 22 male and eight female, diagnosed to have benign vocal fold lesions, who were divided into three groups: They were assessed preoperatively and 2 weeks postoperatively using the GRB scale for auditory perceptual assessment and computerized speech lab. Results Marked improvement of vocal functions with no statistically significant differences between the three groups was observed. Conclusion Radiofrequency and microdebrider could be used in the treatment of benign vocal fold lesions with nearly the same results of MLS.

Skin flap surgery is a cornerstone in plastic surgery. However, flaps may encounter postoperative partial or complete necrosis. Different modalities have been used to enhance skin flap survival. Adipose-derived stem cells (ASCs) can promote angiogenesis and improve skin flap survival. We aimed to investigate the appropriate timing of ASC administration to get the maximal angiogenic effect and better skin flap survival in rat model. Thirty-two male albino Wistar rats were used to study the role of ASCs on caudally based (2 × 8 cm) random pattern skin flap survival; the 32 male albino rats were equally divided into four groups according to timing of ASC injection. We applied the ASCs at three different timing, group A (local injection of ASCs along the flap axis simultaneously with flap elevation), group B (2 days preoperatively), and group C (7 days preoperatively). In the control group (group D), the flap was injected with phosphate buffered saline at the time of flap elevation. Skin flap survival was evaluated on the seventh postoperative day through percentage of flap survival, capillary density, and vascular endothelial growth factor (VEGF) expression. ASCs led to a statistically significant increase in skin flap viability when administered simultaneously with flap elevation or 2 days prior to flap elevation. This went along with significant increase in capillary density and VEGF expression. However, the ASCs had no effect on flap survival when injected 1 week prior to flap elevation. We demonstrate that the skin flap viability can be enhanced by local ASC administration simultaneously with flap elevation or 2 days prior to flap elevation. Their beneficial effect is attributed to paracrine secretion VEGF which enhanced the skin flap vascularity. The angiogenic effect of ASCs can be maximized when the ASCs are injected at the time of flap elevation. Level of Evidence: Not ratable

Objective The objective of the study was to translate the Sino-Nasal Outcome Test 22 (SNOT-22) into Arabic and to check its reliability and validity in Arabic-speaking patients. Patients and methods The study included 178 patients with confirmed chronic rhinosinusitis (CRS) and 95 asymptomatic individuals as a control group. All participants completed the Arabic SNOT-22 (A-SNOT-22) questionnaire. The scores of the two groups were compared for validity analysis. Eighty-two patients completed the questionnaire twice, 1 week apart, for test-to-test reliability analysis. The A-SNOT-22 scores of 60 CRS patients were correlated with Lund–Mackay scores for criterion validity analysis. The preoperative and postoperative scores of 73 patients were compared for responsiveness analysis. Results All participants completed the questionnaire with no or minimal assistance. Internal consistency (α=0.90) and test-to-test reliability (intraclass correlation=0.78) were good. The differences between the scores of CRS patients and asymptomatic individuals were significant (P

Background Tonsillectomy is one of the commonest otolaryngological procedures performed. Multiple reports have demonstrated the safety of ambulatory (outpatient) pediatric Tonsillectomy, however Post-tonsillectomy hemorrhage remains the most serious complication of tonsillectomy. Patients and methods In this work, we analyzed different parameters including patient’s age, gender, type of surgery “Tonsillectomy or Adenotonsillectomy”, technique “Cold dissection or Bipolar”, evidence of tonsillar bed infection and pre-operative hemoglobin level in two groups of patients indicated for tonsillectomy. One group of 80 patients didn’t suffer from posttonsillectomy bleeding as a control group; the other of 20 patients having secondary post-tonsillectomy bleeding. Results According to our statistical analysis and data, no significant difference between the two groups regarding the occurrence of secondary post-tonsillectomy in the following parameters: patient’s age, gender, type of surgery “Tonsillectomy or Adenotonsillectomy” and preoperative hemoglobin level. Conclusion However there was higher incidence of secondary post tonsillectomy bleeding in patients operated by bipolar scissors. Also evidence of tonsillar bed infection raises the possibility of secondary post-tonsillectomy bleeding occurrenc.

Background Calotropis procera is a wild plant species in the family Apocynaceae that is able to grow in harsh, arid and heat stressed conditions. Understanding how this highly adapted plant persists in harsh environments should inform future efforts to improve the hardiness of crop and forage plant species. To study the plant response to droμght and osmotic stress, we treated plants with polyethylene glycol and NaCl and carried out transcriptomic and metabolomics measurements across a time-course of five days. Results We identified a highly dynamic transcriptional response across the time-course including dramatic changes in inositol signaling, stress response genes and cytokinins. The resulting metabolome changes also involved sharp increases of myo-inositol, a key signaling molecule and elevated amino acid metabolites at later times. Conclusions The data generated here provide a first glimpse at the expressed genome of C. procera, a plant that is exceptionally well adapted to arid environments. We demonstrate, through transcriptome and metabolome analysis that myo-inositol signaling is strongly induced in response to drought and salt stress and that there is elevation of amino acid concentrations after prolonged osmotic stress. This work should lay the foundations of future studies in adaptation to arid environments. Electronic supplementary material The online version of this article (10.1186/s12870-017-1155-7) contains supplementary material, which is available to authorized users.

This paper presents the gas distribution analysis by injecting air fountain into the containment and simulations with the HYDRAGON code. Turbulence models of standard k-e (SKE), re-normalization group k-e (RNG) and a realizable k-e (RLZ) are used to assess the effects on the gas distribution analysis during a severe accident in a nuclear power plant. By comparing with experimental data, the simulation results of the RNG and SKE turbulence models agree well with the experimental data on the prediction of dimensionless density distributions. The results illustrate that the turbulence model choice had a small effect on the simulation results, particularly the region near to the air fountain source.

The role of the NS3 protease in HCV replication was demonstrated by the ability of a protease inhibitor cocktail (10 microg/ml) to abolish the induced cytopathic effect in RAW macrophages upon infection with Egyptian sera. The HCV protease gene was amplified from Egyptian sera by nested PCR and cloned downstream of the CMV promotor in a mammalian expression plasmid, which was then used to transform bacteria. Colonies carrying the gene in the correct orientation were subjected to large-scale plasmid purification followed by sequencing. Phylogenetic comparison of the sequence obtained with published sequences from different genotypes confirmed that our sequence belongs to genotype 4a. Of the other genotypes, the most closely related ones were from genotype 1. Multiple alignments of protease peptides showed that the catalytic triads and binding residues for substrate, Zn2+ and the NS4 cofactor are conserved among different isolates, including ours, and confirmed the closer homology between NS3 of genotypes 4 and 1. The HCV-protease-encoding construct was successfully transcribed in both mammalian cells and mice. Mouse antibodies produced against the protease-encoding-construct detected the 18-kDa enzyme in lysates of cells transfected with the construct by Western blotting, and in the media of infected cells by ELISA.

In an accelerator-driven subcritical system (ADS), a high-performance spallation neutron source is used to feed the subcritical reactor. Neutron generation depends on the proton beam intensity. If the beam intensity is increased by a given factor, the number of generated neutrons will increase. The mechanism yielding a high rate of neutron production per energy is the spallation process, and this mechanism produces a very high-energy deposition in the spallation target material. Producing a high rate of neutrons is accompanied by creation of problems of decay heat cooling and radiological protection. As a first step in designing a full-scale industrial ADS, a small-scale experimental ADS, which is similar to the European experimental ADS (XADS) is analysed. The analysis presented in this paper is based on lead–bismuth eutectic (LBE) cooled XADS-type experimental reactors, designed during the European experimental (PDS-XADS) project. Computational fluid dynamics analysis has been carried out for the spallation target. Steady state behaviour and shear stress transport turbulence model with the automatic wall treatment were applied in the present analysis.

Background Climate change is predicted to be a serious threat to agriculture due to the need for crops to be able to tolerate increased heat stress. Desert plants have already adapted to high levels of heat stress so they make excellent systems for identifying genes involved in thermotolerance. Rhazya stricta is an evergreen shrub that is native to extremely hot regions across Western and South Asia, making it an excellent system for examining plant responses to heat stress. Transcriptomes of apical and mature leaves of R. stricta were analyzed at different temperatures during several time points of the day to detect heat response mechanisms that might confer thermotolerance and protection of the plant photosynthetic apparatus. Results Biological pathways that were crosstalking during the day involved the biosynthesis of several heat stress-related compounds, including soluble sugars, polyols, secondary metabolites, phenolics and methionine. Highly downregulated leaf transcripts at the hottest time of the day (40–42.4 °C) included genes encoding cyclin, cytochrome p450/secologanin synthase and U-box containing proteins, while upregulated, abundant transcripts included genes encoding heat shock proteins (HSPs), chaperones, UDP-glycosyltransferase, aquaporins and protein transparent testa 12. The upregulation of transcripts encoding HSPs, chaperones and UDP-glucosyltransferase and downregulation of transcripts encoding U-box containing proteins likely contributed to thermotolerance in R. stricta leaf by correcting protein folding and preventing protein degradation. Transcription factors that may regulate expression of genes encoding HSPs and chaperones under heat stress included HSFA2 to 4, AP2-EREBP and WRKY27. Conclusion This study contributed new insights into the regulatory mechanisms of thermotolerance in the wild plant species R. stricta, an arid land, perennial evergreen shrub common in the Arabian Peninsula and Indian subcontinent. Enzymes from several pathways are interacting in the biosynthesis of soluble sugars, polyols, secondary metabolites, phenolics and methionine and are the primary contributors to thermotolerance in this species. Electronic supplementary material The online version of this article (doi:10.1186/s12870-016-0938-6) contains supplementary material, which is available to authorized users.