31 research outputs found

    Streaming multimedia over WMSNs: an online multipath routing protocol

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    Routing is a challenge to Wireless Multimedia Sensor Networks (WMSNs) for supporting multimedia applications due to nodes' energy constraints and computational capabilities, and the ways sensor nodes obtain forwarding information. In this paper, we propose an online multipath routing protocol that uses nodes' positions to make forwarding decisions at each hop. Real-time decisions are made without any need to have the entire network topology knowledge. The protocol achieves load-balancing and minimises nodes' energy consumption by utilizing: (a) smart greedy forwarding scheme for selecting next hop, and (b) walking back forwarding scheme to bypass network holes. Performance comparisons of the proposed protocol (schemes) are made with TPGF and GPSR. The results show that our schemes: (a) maximise the overall network lifespan by not draining energy from some specific nodes, (b) provide QoS delivery for video streams by using best nodes along the route, and (c) scale better in high density WMSN

    Effect of Exchange–correlation Functionals on Ground State Geometries, Optoelectronic and Charge Transfer of Triphenylamine-based Dyes

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    The importance of the Density Functional Theory (DFT) calculation approach lies in their ability to provide a highly accurate prediction of structural and optoelectronic properties. However, the traditional methods of DFT failed to predict optoelectronic properties satisfactorily. Therefore, it will be necessary to examine methods containing different percentages of Hartree-Fock exchange and correlation in order to find the most suitable functionals. DFT and Time-Dependent-DFT (TD-DFT) calculations was carried out using four different functionals approximations incorporating a different amount of Hartree Fock exchange (B3LYP, BHandHLYP, CAM-B3LYP and LCωPBE), in order to evaluate their accuracies to predict the geometrical, optoelectronic and charge transfer properties of four triphenylamine-based dyes for Dye-Sensitized Solar Cells (DSSCs) applications. The functional hybrid B3LYP was the best among adopted functional that reproduced the geometrical, optoelectronic and charge transfer properties. On the other hand, it has been shown that the Hartree-Fock exchange percentage for BHandHLYP, significantly improved TD-DFT results in the case of organic dyes. Moreover, the corrected long-range functionals (CAM-B3LYP and LC-wPBE) present valuable tools for giving results of comparable precision with experimental optical data. In terms of the choice of the most appropriate functional for computational calculation, the obtained results can be useful for future DSSC applications. DOI: http://dx.doi.org/10.17807/orbital.v14i1.168

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    www.elsevier.com/locate/comnet Service invocation admission control algorithm for multi-domain IP environment

    In vitro study of the antimitotic power and in vivo acute toxicity of aqueous and organic extracts of the aerial part of Haloxylon scoparium Pomel. and evaluation of the correlation between the chemical profile and their biological activities

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    The present study was conducted on the extracts from the aerial part of Haloxylon scoparium Pomel. The current research has focused on the evaluation of the antimitotic activity with the Lepidium sativum phytotest on aqueous (decocted, infused, macerated) and organic extracts (methanolic extract, methanolic macerated, ethyl acetate extract, chloroform extract and petroleum ether extract) extracts of the aerial portion of Haloxylon scoparium. In order to visualise the correlation between the content of chemical compounds in the aqueous and organic extracts with the results of the Lepidium sativum phytotest, we have used the principal component analysis (PCA). Then, we were interested in studying the acute in vivo toxicity of the methanolic extract and the decocted of Haloxylon scoparium. Antimitotic activity has shown that the methanolic extract exhibited high inhibition of Lepidium sativum germination (IC50=128.16±3.89 ”g/mL) than colchicine (IC50=474.66±1.86 ”g/mL). The decocted also showed high inhibition compared to the other aqueous extracts (IC50=1359.00±106.69 ”g/mL). The correlation study showed that there is a strong correlation between Lepidium sativum phytotest and total polyphenol (r=0.9453) and flavonoid (r=0.9884) composition. In addition, the MLD50 of the methanolic extract and the decocted was estimated at 2000 mg/kg. The present study shows that Haloxylon scoparium could be a potential antimitotic of low toxicity

    Inventory of poisonings and toxicological studies carried out on Atractylis gummifera L.: A review

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    Atractylis gummifera L. belongs to the family Asteraceae is widely used in traditional Moroccan medicine for its therapeutic effects (diuretic, purgative, emetic, abortive), but it causes serious and fatal poisonings, hence the objective of this work is to describe the current state of intoxication caused by A. gummifera in the Mediterranean and to summarize the toxicological studies carried out on this plant. The working methodology we adopted consisted in collecting data published in Arabic, French and English in specialized articles, books and on websites. Research results showed that the Centre Anti Poison and Pharmacovigilance of Morocco declared A. gummifera was in second place in the occurrence of poisonings in between January 1980 and December 2008. The synthesis of experimental work on plant toxicology showed that the lethal dose of A. gummifera varies according to the animal model used (rat or mouse), the route of administration (intraperitoneal, oral or intravenous) and the part of the plant used. The root has been found to be the most toxic part of the plant. The toxicity of A. gummifera is due to atractyloside and gummiferine, which are inhibitors of oxidative phosphorylation that prevent the formation of ATP from ADP in intracellular organelles. This study shows the interest in raising public awareness of the toxicity of A. gummifera and in rationalizing its use in traditional medicine

    Effect of Exchange–correlation Functionals on Ground State Geometries, Optoelectronic and Charge Transfer of Triphenylamine-based Dyes

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    The importance of the Density Functional Theory (DFT) calculation approach lies in their ability to provide a highly accurate prediction of structural and optoelectronic properties. However, the traditional methods of DFT failed to predict optoelectronic properties satisfactorily. Therefore, it will be necessary to examine methods containing different percentages of Hartree-Fock exchange and correlation in order to find the most suitable functionals. DFT and Time-Dependent-DFT (TD-DFT) calculations was carried out using four different functionals approximations incorporating a different amount of Hartree Fock exchange (B3LYP, BHandHLYP, CAM-B3LYP and LCωPBE), in order to evaluate their accuracies to predict the geometrical, optoelectronic and charge transfer properties of four triphenylamine-based dyes for Dye-Sensitized Solar Cells (DSSCs) applications. The functional hybrid B3LYP was the best among adopted functional that reproduced the geometrical, optoelectronic and charge transfer properties. On the other hand, it has been shown that the Hartree-Fock exchange percentage for BHandHLYP, significantly improved TD-DFT results in the case of organic dyes. Moreover, the corrected long-range functionals (CAM-B3LYP and LC-wPBE) present valuable tools for giving results of comparable precision with experimental optical data. In terms of the choice of the most appropriate functional for computational calculation, the obtained results can be useful for future DSSC applications. DOI: http://dx.doi.org/10.17807/orbital.v14i1.168

    In vivo anti-diabetic effect of aqueous and methanolic macerated extracts of Atractylis gummifera

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    The anti-diabetic effect of Atractylis gummifera (plant used in traditional Moroccan medicine) has been evaluated in type 2 diabetic mice model. The mice were divided into five groups: Normal control, diabetic control, diabetic treated with aqueous macerate (500 mg/kg), diabetic treated with methanol macerate (500 mg/kg) and diabetic treated with metformin (300 mg/kg). The treatment of the mice was performed by daily gastric gavage for 5 weeks. The monitoring of the mice was carried out weekly by fasting glucose and measurement of biochemical parameters at the end of treatment. The aqueous macerate of A. gummifera was most effective that reduced the fasting blood glucose with 62.7%. In addition, this extract restored the biochemical parameters of diabetic mice to normal

    Phytochemical screening and in vitro evaluation of alpha amylase, alpha glucosidase and beta galactosidase inhibition by aqueous and organic Atractylis gummifera L. extracts

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    Diabetes is a chronic condition which is increasingly progressing throughout the world. To treat it, several methods are used, among which is medicinal plants that still have an unknown mechanism of action. The objective of this work is to evaluate the in vitro hypoglycemic effect of the extracts of the underground part of Atractylis gummifera, a member of Asteraceae used in traditional Moroccan medicine. A phytochemical study of the aqueous extracts (decocted, infused and macerated) and organic extracts (methanol, methanol macerate, chloroformic, ethyl acetate and petroleum ether), and a phytochemical screening of the different secondary metabolites was done. The antidiabetic power of the extracts of A. gummifera by testing the inhibitory activity of ?-amylase, ?-glucosidase and ?-galactosidase, which are enzymes responsible for the digestion of polysaccharides was determined. The extracts of A. gummifera are very rich in flavonoids and tannins, and are inhibitory to?-amylase and ?-glucosidase, mainly the macerate of methanol with IC50 values of 0.557 ± 0.013 and 0.743 ± 0.017 mg / mL respectively. Higher ?-galactosidase inhibitory potential than quercetin was observed for aqueous macerates and methanol with IC50 values of 2.23 ± 0.012 and 2.443 ± 0.071 mg / mL respectively. The extracts of A. gummifera possess a significant inhibitory activity of the alpha amylase and alpha glucosidase and beta-galactosidase enzymes, in particular the macerate of methanol followed by the aqueous macerate, among the eight extracts tested

    Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

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    Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≀0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

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    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
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