362 research outputs found

    Molecular interactions of arbuscular mycorrhizal fungi with mycotoxin-producing fungi and their role in plant defense responses

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    Les trichothécènes de Fusarium appartiennent au groupe des sesquiterpènes qui sont des inhibiteurs la synthèse des protéines des eucaryotes. Les trichothécènes causent d’une part de sérieux problèmes de santé aux humains et aux animaux qui ont consommé des aliments infectés par le champignon et de l’autre part, elles sont des facteurs importants de la virulence chez plantes. Dans cette étude, nous avons isolé et caractérisé seize isolats de Fusarium de la pomme de terre infectée naturellement dans un champs. Les tests de pathogénicité ont été réalisés pour évaluer la virulence des isolats sur la pomme de terre ainsi que leur capacité à produire des trichothécènes. Nous avons choisi F. sambucinum souche T5 comme un modèle pour cette étude parce qu’il était le plus agressif sur la pomme de terre en serre en induisant un flétrissement rapide, un jaunissement suivi de la mort des plantes. Cette souche produit le 4,15-diacétoxyscirpénol (4,15-DAS) lorsqu’elle est cultivée en milieu liquide. Nous avons amplifié et caractérisé cinq gènes de biosynthèse trichothécènes (TRI5, TRI4, TRI3, TRI11, et TRI101) impliqués dans la production du 4,15-DAS. La comparaison des séquences avec les bases de données a montré 98% et 97% d'identité de séquence avec les gènes de la biosynthèse des trichothécènes chez F. sporotrichioides et Gibberella zeae, respectivement. Nous avons confrenté F. sambucinum avec le champignon mycorhizien à arbuscule Glomus irregulare en culture in vitro. Les racines de carotte et F. sambucinum seul, ont été utilisés comme témoins. Nous avons observé que la croissance de F. sambucinum a été significativement réduite avec la présence de G. irregulare par rapport aux témoins. Nous avons remarqué que l'inhibition de la croissance F. sambucinum a été associée avec des changements morphologiques, qui ont été observés lorsque les hyphes de G. irregulare ont atteint le mycélium de F. sambucinum. Ceci suggère que G. irregulare pourrait produire des composés qui inhibent la croissance de F. sambucinum. Nous avons étudié les patrons d’expression des gènes de biosynthèse de trichothécènes de F. sambucinum en présence ou non de G. irregulare, en utilisant le PCR en temps-réel. Nous avons observé que TRI5 et TRI6 étaient sur-exprimés, tandis que TRI4, TRI13 et TRI101 étaient en sous-exprimés en présence de G. irregulare. Des analyses par chromatographie en phase-gazeuse (GC-MS) montrent clairement que la présence de G. irregulare réduit significativement la production des trichothécènes par F. sambucinum. Le dosage du 4,15-DAS a été réduit à 39 μg/ml milieu GYEP par G. irregulare, comparativement à 144 μg/ml milieu GYEP quand F. sambucinum est cultivé sans G. irregulare. Nous avons testé la capacité de G. irregulare à induire la défense des plants de pomme de terre contre l'infection de F. sambucinum. Des essais en chambre de croissance montrent que G. irregulare réduit significativement l’incidence de la maladie causée par F. sambucinum. Nous avons aussi observé que G. irregulare augmente la biomasse des racines, des feuilles et des tubercules. En utilisant le PCR en temps-réel, nous avons étudié les niveaux d’expression des gènes impliqué dans la défense des plants de pommes de terre tels que : chitinase class II (ChtA3), 1,3-β-glucanase (Glub), peroxidase (CEVI16), osmotin-like protéin (OSM-8e) et pathogenèses-related protein (PR-1). Nous avons observé que G. irregulare a induit une sur-expression de tous ces gènes dans les racines après 72 heures de l'infection avec F. sambucinum. Nous avons également trové que la baisse provoquée par F. sambucinum des gènes Glub et CEVI16 dans les feuilles pourrait etre bloquée par le traitement AMF. Ceci montre que l’inoculation avec G. irregulare constitut un bio-inducteur systémique même dans les parties non infectées par F. sambucinum. En conclusion, cette étude apporte de nouvelles connaissances importantes sur les interactions entre les plants et les microbes, d’une part sur les effets directs des champignons mycorhiziens sur l’inhibition de la croissance et la diminution de la production des mycotoxines chez Fusarium et d’autre part, l’atténuation de la sévérité de la maladie dans des plantes par stimulation leur défense. Les données présentées ouvrent de nouvelles perspectives de bio-contrôle contre les pathogènes mycotoxinogènes des plantes.Fusarium trichothecenes are a large group of sesquiterpenes that are inhibitors of eukaryotic protein synthesis. They cause health problems for humans and animals that consume fungus-infected agricultural products. In addition some of Fusarium trichothecenes are virulence factors of plant pathogenesis. In this study, sixteen Fusarium strains were isolated and characterized from naturally infected potato plants. Pathogenicity tests were carried out to evaluate the virulence of these isolates on potato plants and their trichothecene production capacity. We chose F. sambucinum strain T5 as a model for this study because it was the most aggressive strain when tested on potato plants. It induces a rapid wilting and yellowing resulting in plant death. This strain produced 4,15-diacetoxyscirpenol (4,15-DAS) when grown in liquid culture. We amplified and characterized five trichothecene genes (TRI5, TRI4, TRI3, TRI11, and TRI101) involved in the production of 4,15-DAS. Nucleotide BLAST search showed 98% and 97% sequence identity with trichothecene biosynthetic genes of F. sporotrichioides and Gibberella zeae, respectively. We used F. sambucinum to determine if trichothecene gene expression was affected by the symbiotic arbuscular mycorrhizal fungus (AMF) Glomus irregulare. We found that the growth of F. sambucinum was significantly reduced in the presence of G. irregulare isolate DAOM-197198 compared with controls that consisted of carrot roots without G. irregulare or F. sambucinum alone. Furthermore, inhibition of the growth F. sambucinum was associated with morphological changes, which were observed when G. irregulare hyphae reached F. sambucinum mycelium, suggesting that G. irregulare may produce compounds that interfere with the growth of F. sambucinum. Using real-time qRT-PCR assays, we assessed the relative expression of trichothecene genes of F. sambucinum confronted or not with G. irregulare. When G. irregulare was confronted with F. sambucinum, TRI5 and TRI6 genes were up-regulated, while TRI4, TRI13 and TRI101 were down-regulated. We therefore used GC-MS analysis to determine whether G. irregulare affects trichothecene production by F. sambucinum. We found that the production of 4,15-DAS trichothecene was significantly reduced in the presence of G. irregulare compared with controls that consisted of carrot roots without G. irregulare or F. sambucinum alone. Interestingly, 4,15-DAS pattern was reduced to 39 μg/ml GYEP medium by G. irregulare compared to 144 μg/ml GYEP with F. sambucinum grown with carrot roots or F. sambucinum alone respectively. We tested the AMF capacity to induce defense responses of potato plants following infection with F. sambucinum. The response of AMF-colonized potatoes to F. sambucinum was investigated by tracking the expression of genes homologous with pathogenesis-related proteins chitinase class II (ChtA3), 1,3-β-glucanase (gluB), peroxidase (CEVI16), osmotin-like protein (OSM-8e) and pathogenesis-related protein (PR-1). We found that the AMF treatment up-regulated the expression of all defense genes in roots at 72 hours post-infection (hpi) with F. sambucinum. We also found that a decrease provoked by F. sambucinum in gluB and CEVI16 expression in shoots could be blocked by AMF treatment. Overall, a differential regulation of PR homologues genes in shoots indicates that AMF are a systemic bio-inducer and their effects could extend into non-infected parts. In conclusion, this study provides new insight into on the interactions between plants and microbes, in particular the effects of AMF on the growth and the reduction of mycotoxins in Fusarium. It also shows that AMF are able to reduce the disease severity in plants by stimulating their defense. The data presented provide new opportunities for bio-control against mycotoxin-producing pathogens in plants

    Novel control strategy for the global model of wind turbine

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    This paper presents a new nonlinear control for the overall model of a three-blade horizontal axis variable speed wind turbine (VSWT) including mechanical and electrical parts, with the aim of improving its performance and making it more profitable. The proposed control is an extension of the classical sliding mode control (SMC) by converting its sliding surface into a sliding sector. The classical SMC approach is widely used for nonlinear systems due to its stability against parameter variation, it is robustness against modeling uncertainties, its good results against external disturbances, and its ease of implementation in real time. Unfortunately, the SMC has a major drawback related to the chattering phenomenon. This phenomenon is due to the utility of a higher switching gain in the case of large uncertainties, it causes high-frequency oscillations once the sliding regime is reached, and it can cause a loss of accuracy by influencing the input control variables. This is the reason that aims to develop a new control law to eliminate the chattering and to guarantee stability, which is demonstrated by the Lyapunov theory. The effectiveness of the developed control is compared with the SMC and is illustrated by numerical simulations using MATLAB toolboxes

    Experimental Investigation of the Performance and Exhaust Emissions of a Spark-Ignition Engine Operating with Different Proportional Blends of Gasoline and Water Ammonia Solution

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    This paper aims to investigate the impact of water ammonia solution (WAS)-gasoline fuel (GF) blends on SI engine exhaust emission and engine performance characteristics and compare the obtained results with those using base gasoline. This investigation used a single-cylinder, four-stroke, air-cooled, and SI engine coupled with an AC generator to achieve this experimental work. Water ammonia solution fuel was blended with neat gasoline in volume rates of 5, 10,15,20, and 25%. The experimental investigation was conducted at an off-road engine under a constant engine speed of 3000 rpm and different load conditions. The results show that the use of ammonia solution as an addition to gasoline fuel increase the overall thermal efficiency, and G75Was25 blend obtained the maximum increase ratio of overall efficiency by 38.96% at maximum load condition in comparison to neat gasoline and reduce the specific fuel consumption compared with that of gasoline fuel. This alteration results in an elevation in CO, HC, and NOx emissions

    Non-Tensile Tunica Albuginea Plication for the Correction of Penile Curvature

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    Objective: To evaluate the efficacy of non-tensile tunica albuginea plication (NTTAP) using nonabsorbable sutures for the correction of congenital and acquired penile curvature and to determine the key points for a successful outcome of this procedure. Patients and Methods: From June 2004 to July 2007, 43 patients with penile curvature (35 congenital and 8 secondary to Peyronie’s disease) underwent surgical correction by NTTAP. The indications were difficult or impossible vaginal penetration, and a cosmetically unacceptable penis. For tunica albuginea plication (TAP) we applied the 16 dot procedure using non-absorbable sutures (Tycron® 2/0 polyester fiber).Results: After a mean follow-up period of 18 months, successful results with respect to penile straightening, normal erection, penetration and sensation, confirmed both subjectively and objectively, were achieved in all patients. Post-operative penile shortening of less than 1.5 cmwas present in 50% of the cases, but did not affect intercourse. Post-operative complications were mild and reversible; they consisted of penile skin necrosis after circumcising incisions and post-operative pain upon nocturnal erection that subsided after a few weeks with the frequent use of ice compresses. The overall satisfaction rate was nearly 100% (35/43 very satisfied and 8/43 satisfied).Conclusion:NTTAP is a simple and effective method for the correction of congenital and acquired penile curvature. The key points for successful outcomes are: clear identification of the line of maximum curvature, adequate pre-operative evaluation, counseling of the patient to setappropriate expectations, and careful discussion of the location of the suture sites. There is no need for mobilization of the urethra or neurovascular bundle, which adds a great advantage to this easy and simple technique. Cutting through the tunica albuginea, which may prevent postoperative erectile dysfunction, is not necessary. A disadvantage of this procedure is that it cannot correct hour-glass deformity

    Prevalence of Body Dysmorphic Disorder (BDD) among the Lebanese University students: Associated risk factors and repercussion on mental health

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    Background: Body Dysmorphic Disorder (BDD) is a psychological illness characterized by persistent and intrusive preoccupation with an imagined or slight defect in appearance. For individuals with BDD, these perceived defects are significant and prominent, leading to emotional distress, depression, anxiety, and impairment in daily functioning. Despite its impact, no prior studies have explored the prevalence of BDD among Lebanese university students. Objectives: This study aimed to determine the prevalence of BDD and investigate its association with mental health status (depression and anxiety), religiosity, eating disorder risk, and self-esteem among Lebanese University students.  Methodology: A cross-sectional study was conducted in March 2020, involving students from the Lebanese University. Data were collected using the dysmorphic concern questionnaire (DCQ), Rosenberg self-esteem scale (RSE), religiosity scale, patient health questionnaire (PHQ-9), generalized anxiety disorder assessment (GAD-7), Eating Attitude test-26 scale (EAT-26). Results: A total of 6448 participants were enrolled in our study. The overall prevalence of BDD among university students was (6.4%).Our results showed that Lebanese students with BDD were more likely to have anxiety ORadj 1.3 (95% CI:1.2-1.7) p-value 0.001, depression ORadj 1.2 (95% C:1.15-1.5) p-value 0.007, and eating disorder (Bulimia & Food preoccupation ORadj 1.06 (95% CI:1.03-1.2) P-value 0.0, and oral control ORadj 1.09 (95% CI:1.05-1.1)  P-value < 0.001) compared to those with no BDD. We also found that students with BDD had Lower Self-esteem ORadj 0.88 (95%CI: 0.78-0.9) P-value <0.001), and less likely to be religious ORadj 0.88 (95%CI: 0.82-0.9) P-value 0.02) compared to those with no BDD. Conclusion: This pioneering study in Lebanon sheds light on the prevalence of BDD among Lebanese university students and its associated factors. BDD was found to be significantly linked to elevated levels of depression, anxiety, and eating disorders, along with lower levels of self-esteem and religiosity. These findings underscore the importance of early detection of BDD during adolescence and young adulthood, necessitating timely psychological intervention to prevent chronicity and complications. Moreover, promoting widespread awareness through various social media and public platforms is essential to address this psychological issue effectively

    Effect of Modifying Mechanical Ventilator Trigger Sensitivity on Arterial Blood Gases in ICU Patients

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    Background: Despite the fact that mechanical ventilation is an essential part in management of critically ill patients, mechanically ventilated patients have a higher risk of complications, which can lead to increased morbidity and mortality. Objective: This study aimed to study the effect of training inspiratory muscle through modifying mechanical ventilator (MV) trigger sensitivity on arterial blood gases in mechanically ventilated patients. Patients and Methods: Sixty adult patients diagnosed with acute respiratory failure, needed to be intubated and connected to mechanical ventilated. They were from both gender and their ages ranged from 50 to 70 years. The patient were chosen from Intensive Care Unit (ICU), Department of Chest Diseases, Cairo University Hospitals. They were randomly assigned into two equal groups. Group (A): included thirty patients who received training for inspiratory muscle through modifying MV trigger sensitivity plus usual physical therapy. Group (B): included thirty patients who received usual physical therapy only. Results: The results showed a significant increase in partial arterial pressure (PaO2) in both groups, this increasing was significantly higher in  patients who received training for the inspiratory muscle plus the usual chest physical therapy than patients who only received usual chest physical therapy (P-value < 0.001). The results showed no significant change in neither power of hydrogen (pH) nor partial pressure of carbon dioxide (PaCO2). Conclusion: Training to inspiratory muscles in mechanically ventilated patient through modifying mechanical ventilator trigger sensitivity can produce a significant increase in partial arterial pressure (PaO2). Although it has no effect in pH nor PaCO2

    Impact of a Designed Nursing Intervention Protocol about Preoperative Liver transplantation Care on Patients’ Outcomes at A University Hospital in Egypt

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    Background: Literature review cited that, Liver transplantation is now considered as the gold standard for treatment of patients with end-stage liver diseases and early liver tumors in cirrhotic livers. Patient education is vital to the safety and success of a transplant. Aim: the aim is to assess the impact of a designed nursing intervention protocol about preoperative liver transplantation care on patient’s outcomes as indicated by: patients` knowledge & practice mean scores, and complications developed. To fulfill the aim of this study, the following hypothesis was formulated: patients undergoing liver transplantation who will be exposed to the designed nursing intervention protocol about preoperative liver transplantation care will show better outcomes. Material and Methods: A convenient sample of 14 adult male and female patients admitted to Liver Transplant Unit at El Manial University Hospital were included, three of them were died with an attrition rate of 21.4%. Four tools were formulated to collect data pertinent to the study. 1- Sociodemographic and medical data sheet; 2- Pre/Post knowledge assessment questionnaire sheet, 3- Observational checklists, & 4- Complications assessment sheet. Structured interview, reviewing medical records, direct observation and physical examination were utilized for data collection. Results: a  significant statistical difference was found in relation to the total and subtotal mean knowledge and practice scores during different assessment periods  with P values (0.00 for both); as well, 45.5 %  of patients developed respiratory complications (pleural effusion) compared to 53.8 % of their correspondence who developed respiratory complications (pleural effusion, chest infection, and others), in addition, 9.1% of the studied subjects developed  rejection, and ascites as compared to (1.9 %, 5.7%) of their correspondence over the last consecutive three years respectively. Conclusion: Liver transplantation patients showed a positive improvement in their knowledge and practice in relation to breathing, coughing, & using respirometer exercises and range of motion. Replication of this study on a larger sample selected from different geographical areas is highly recommended. Key wards: liver transplantation, designed nursing intervention protocol, preoperative liver transplantation care, knowledge, complications, and patient`s outcome

    Knowledge and Attitude towards Monkeypox among the Lebanese Population and their Attitude towards Vaccination

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    Monkeypox is a currently re-emerging disease in the world and several cases have been detected in Lebanon. For this reason, an assessment of the knowledge and attitude of the Lebanese population towards monkeypox and smallpox or monkeypox vaccines had to be done. A cross-sectional study was conducted using a questionnaire developed from previous literature among a sample of Lebanese residents. It recorded the sociodemographic characteristics and comorbidities of the participants and analyzed the patterns of knowledge and attitudes in Lebanon. Among 493 participants, it was found that there is a generally low knowledge of and an average attitude toward monkeypox. However, knowledge is better with higher educational levels, COVID-19 vaccination, and residency in the south of Lebanon and poorer with marriage and residency in Beirut. Attitude is better in females but poorer with higher educational levels. Several other effectors have been devised too. As for vaccination, taking the smallpox vaccine as a proactive measure is predicted with previous COVID-19 vaccination and better attitude but not in the residents of the north of Lebanon and married Lebanese residents. Higher educational levels and a better attitude were positive predictions of taking the monkeypox vaccine whenever it is developed. This study provided insights into the level of knowledge and attitude towards monkeypox and its vaccines, which can be a rich resource when proactive measures are developed

    Synthesis, reactions and antimicrobial activity of benzothiazoles

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    Benzothiazoles have been proven to be potent antimicrobial agents. In this study, 3-(5,6-dimethoxy-2-oxo-1,3-benzothiazol-3(2H)-yl)propanohydrazide has been utilized as a scaffold for synthesis of pyrrole, indolylidene, pyrazoles, mercaptotriazole, oxadiazole, triazole and oxothiazolidine derivatives. Structures of the synthesized compounds were elucidated on the basis of elemental analyses and spectral data. All the synthesized compounds were screened for their antimicrobial activity

    Knowledge, attitude and practice of long acting reversible hormonal contraception (LARHC) among women in urban upper Egypt

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    Background: The current study aims to assess the knowledge, attitude and practice of long acting reversible hormonal contraception (LARHC) among women in urban upper Egypt.Methods: A cross sectional study which included 902 married women, in the reproductive age, attending the outpatient clinics (Gynecology and family planning) of: 1-Assiut University Maternity Hospital, 2- Sohag University Hospital, and 3-Gehina General Hospital (MOH hospital) with current or previous use of any method of LARHC methods. A Questionnaire file was designed to assay knowledge attitude and practice of clients towards contraceptive methods. All data collected from clients reviewed separately to assess knowledge, attitude and practice of women towards contraceptive methods.Results: The most popular contraceptive method is COCs followed by IUD then DMPA. 99% of studied sample heard with good description about different types of LARHC. 54.9% of studied sample most popular/famous LARHC DMPA, most sources of information on LARHC were, Hospital, Relative/friends and health workers. 94.24% of the studied sample were in favor to use of LARHC, 94.2% of them agree to take a space between births, about 55.4% of them were health child and 61% comfortable lifestyle benefit from birth spacing, 33% of studied sample were maternal health, 68% of them were think/prefer to use implants, 64.5% of them didn’t pregnant while breastfeeding. 11% of sample women never used any contraception before and most reasons for not using contraception are fear of side effects, desire for more children, irregular sexual relationship, and husband opposition. Only 16.6 % of studied sample used LARHC before and most of them used DMPA, however 3 women who used DMPA get pregnant while using it.Conclusions: There is a good level of knowledge between upper Egypt women about LARHC methods
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