296 research outputs found
ANTIBACTERIAL, ANTIFUNGAL, ANTITUMOR AND TOXICITY OF ESSENTIAL OILS OF SALVIA OFFICINALIS, THYMUS VULGARIS, EUGENIA CARYOPHYLLATA AND ARTEMISIA ABSINTHIUM
Essential oils are aromatic and volatile liquids extracted from plants. The chemicals in essential oils are secondary metabolites, which play an important role in plant defense as they often possess antimicrobial properties. In this study, essential oils of four plants were investigated for their antimicrobial activity against eight bacterial pathogens and seven fungal strains. The used plants were Salvia officinalis, Thymus vulgaris, Eugenia caryophyllata and Artemisia absinthium.
All of plants essential oils showed antibacterial and antifungal activities. Zones of inhibition against pathogenic bacteria ranged from 10 to 28 mm and MIC from 25 to 150 µg/ml, while zones of inhibition against fungal strains ranged from 10 to 26 mm and MIC from 25 to 150 µg/ml. Cytotoxicity against Artimia salina and antitumor activity against Ehrlich ascites carcinoma and Lymphoma cell line were investigated. A. absinthium showed the best antitumor activity on Lymphoma cell line with moderate cytotoxic effect on Artimia salina. Analysis of A. absinthium essential oil by GC-MS discovered two major compounds; camphor and fenchone which may be involved in the biological activity of the plant extrac
ANTIMICROBIAL ACTIVITIES OF SOLANUM INCANUM, ELETTARIA CARDAMOMUM AND ZINGIBER OFFICINALE, USED TRADITIONALLY TO TREAT PATHOGENIC MICROBES
The use and search for antibiotics derived from plants have been accelerated in recent years. Three plants, used traditionally as medicine and as food additives were collected and extracted with hot water, methanol, diethyl-ether, ethyl acetate and chloroform. The used plants were Solanum incanum, Elettaria cardamomum and Zingiber officinale. The plant extracts were screened for their inhibitory effects on eight bacterial and seven fungal pathogens using agar well diffusion method. It was shown that methanol extract was more effective as compared to hot water, diethyl-ether, ethyl acetate and chloroform extracts. Inhibition zone diameters of the methanol extracts of the used plants ranged from 10 to 29 mm and minimum inhibitory concentrations (MIC) from 50 to 150 μg/ml. No toxicity was found using Artimia salina as test organism. Antitumor activity against Ehrlich ascites carcinoma and Lymphoma cell line was recorded only for S. incanum extrac
THE POWER OF INTEGRATION TOWARDS SUSTAINABLE PERFORMANCE: A MODEL TO MINIMIZE TECHNOSTRESS AMONG FRONTLINE RESTAURANT EMPLOYEES BY COMBINING JOB AND EMPLOYEE RESOURCES
To develop a model that integrates restaurant and employee resources to overcome technostress and achieve
sustainable performance. This qualitative study is based on twenty-two semi-structured interviews with restaurant managers
and frontline employees (FLEs) to comprehensively understand how restaurant resources and personnel can be employed to
combat technostress and achieve sustainable performance. Restaurant FLEs experience technostress from multiple sources,
including unclear work-life boundaries, complex new systems, job insecurity, and the frequent use of new technologies. In
addition, restaurant managers and FLEs concur that integrating restaurant and FLE resources is an effective model for
reducing technostress and achieving FLEs' sustainable performance. The study expands the JD-R model to address the
challenges faced by FLEs in managing technology-induced job demands, offering a comprehensive solution that benefits
restaurants and employees. This approach considers the role of both employers and employees in managing technostress,
leading to a supportive work environment and improved sustainable performance
The Effect of Hotel Employees’ Emotional Labour on Interpersonal Counterproductive Work Behaviours
This research aims to shed light on the effect of hotels’ employees' emotional labour with its three levels (surface acting, deep acting and genuine emotions) on interpersonal counterproductive work behaviours. To achieve this aim, a questionnaire was designed for Egyptian hotels’ employees which was structured to cover three main parts: (1) demographic characteristics of employees, (2) employees' emotional labour and (3) interpersonal counterproductive work behaviours. Structural equation modelling (SEM) was used involving (smart- PLS)
software, IBM, version 4. The results show that the hotels’ employees' emotional labour with its three levels (surface acting, deep acting and genuine emotions) affects interpersonal counterproductive work behaviours with its two types (task focused and person focused) as there is a positive effect of surface acting on interpersonal counterproductive work behaviour. Employees' emotional labour must be seriously handled within the hospitality industry as it is a very important element affecting task-focused or person-focused ICWBs in the hotel. As both
surface acting and genuine emotions increase task-focused or person-focused ICWBs, deep acting decreases task-focused or person-focused ICWBs
Ninety-day complication rate based on 532 Latarjet procedures in Dutch hospitals with different operation volumes
Background: In this study, we aimed to provide insight into the 90-day complication rates following the Latarjet procedure. Data from 2015 were collected from multiple hospitals in the Netherlands, with different volumes of Latarjet procedures. Our second aim was to examine which patient and surgical factors were associated with complications.Methods: We conducted a retrospective chart review of 13 hospitals between 2015 and 2022. Data regarding complications within 90 days of Latarjet procedures were extracted. The effect of sex, age, body mass index (BMI), smoking, previous shoulder operations, fixation material, hospital volume, screw size, and operation time on the complication rate was assessed by multivariable logistic regression analysis.Results: Of the 532 included patients, 58 (10.9%) had complications. The most common complications were material failure (n = 19, 3.6%) and nerve injury (n = 13, 2.4%). The risk of complications was lower for male patients than for female patients (odds ratio, 0.40; 95% confidence interval, 0.21-0.77; P = .006). Age, BMI, smoking, previous shoulder operations, type of fixation material, hospital volume, screw size, and operation time were not associated with complications.Conclusion: The 90-day complication rate after the Latarjet procedure was 10.9% and was higher in female patients than in male patients. Age, BMI, smoking, previous shoulder operations, type of fixation material, hospital volume, screw size, and operation time did not affect complication rates. We advise setting up a national registry to prevent under-reporting of complications.</p
Agronomic Management of Indigenous Mycorrhizas
Many of the advantages conferred to plants by arbuscular mycorrhiza (AM) are associated to the ability of AM plants to explore a greater volume of soil through the extraradical mycelium. Sieverding (1991) estimates that for each centimetre of colonized root there is an increase of 15 cm3 on the volume of soil explored, this value can increase to 200 cm3 depending on the circumstances. Due to the enhancement of the volume of soil explored and the ability of the extraradical mycelium to absorb and translocate nutrients to the plant, one of the most obvious and important advantages resulting from mycorrhization is the uptake of nutrients. Among of which the ones that have immobilized forms in soil, such as P, assume particular significance. Besides this, many other benefits are recognized for AM plants (Gupta et al, 2000): water stress alleviation (Augé, 2004; Cho et al, 2006), protection from root pathogens (Graham, 2001), tolerance to toxic heavy metals and phytoremediation (Audet and Charest, 2006; Göhre and Paszkowski, 2006), tolerance to adverse conditions such as very high or low temperature, high salinity (Sannazzaro et al, 2006), high or low pH (Yano and Takaki, 2005) or better performance during transplantation shock (Subhan et al, 1998). The extraradical hyphae also stabilize soil aggregates by both enmeshing soil particles (Miller e Jastrow, 1992) and producing a glycoprotein, golmalin, which may act as a glue-like substance to adhere soil particles together (Wright and Upadhyaya, 1998).
Despite the ubiquous distribution of mycorrhizal fungi (Smith and Read, 2000) and only a relative specificity between host plants and fungal isolates (McGonigle and Fitter, 1990), the obligate nature of the symbiosis implies the establishment of a plant propagation system, either under greenhouse conditions or in vitro laboratory propagation. These techniques result in high inoculum production costs, which still remains a serious problem since they are not competitive with production costs of phosphorus fertilizer. Even if farmers understand the significance of sustainable agricultural systems, the reduction of phosphorus inputs by using AM fungal inocula alone cannot be justified except, perhaps, in the case of high value crops (Saioto and Marumoto, 2002). Nurseries, high income horticulture farmers and no-agricultural application such as rehabilitation of degraded or devegetated landscapes are examples of areas where the use of commercial inoculum is current. Another serious problem is quality of commercial available products concerning guarantee of phatogene free content, storage conditions, most effective application methods and what types to use. Besides the information provided by suppliers about its inoculum can be deceiving, as from the usually referred total counts, only a fraction may be effective for a particular plant or in specific soil conditions. Gianinazzi and Vosátka (2004) assume that progress should be made towards registration procedures that stimulate the development of the mycorrhizal industry.
Some on-farm inoculum production and application methods have been studied, allowing farmers to produce locally adapted isolates and generate a taxonomically diverse inoculum (Mohandas et al, 2004; Douds et al, 2005). However the inocula produced this way are not readily processed for mechanical application to the fields, being an obstacle to the utilization in large scale agriculture, especially row crops, moreover it would represent an additional mechanical operation with the corresponding economic and soil compaction costs.
It is well recognized that inoculation of AM fungi has a potential significance in not only sustainable crop production, but also environmental conservation. However, the status quo of inoculation is far from practical technology that can be widely used in the field. Together a further basic understanding of the biology and diversity of AM fungi is needed (Abbott at al, 1995; Saito and Marumoto, 2002).
Advances in ecology during the past decade have led to a much more detailed understanding of the potential negative consequences of species introductions and the potential for negative ecological consequences of invasions by mycorrhizal fungi is poorly understood. Schwartz et al, (2006) recommend that a careful assessment documenting the need for inoculation, and the likelihood of success, should be conducted prior to inoculation because inoculations are not universally beneficial.
Agricultural practices such as crop rotation, tillage, weed control and fertilizer apllication all produce changes in the chemical, physical and biological soil variables and affect the ecological niches available for occupancy by the soil biota, influencing in different ways the symbiosis performance and consequently the inoculum development, shaping changes and upset balance of native populations. The molecular biology tools developed in the latest years have been very important for our perception of these changes, ensuing awareness of management choice implications in AM development.
In this context, for extensive farming systems and regarding environmental and economic costs, the identification of agronomic management practices that allow controlled manipulation of the fungal community and capitalization of AM mutualistic effect making use of local inoculum, seem to be a wise option for mycorrhiza promotion and development of sustainable crop production
Rare Earth Group Separation after Extraction Using Sodium Diethyldithiocarbsamate/Polyvinyl Chloride from Lamprophyre Dykes Leachate
This study presents the first application of sodium diethyldithiocarbamate/polyvinyl chloride (DdTC/PVC) as a novel adsorbent for rare earth element (REE) sorption from leach liquors. DdTC/PVC has higher adsorption properties than other sorbents, the synthesis of DdTC/PVC is more accessible than other resins, and it is considered a more affordable sorbent. The three-liquid-phase extraction technique (TLPE) was applied to separate REEs into light, middle, and heavy rare earth elements as groups. The TLPE is an excellent achievable technique in the separation of REEs. DdTC/PVC was prepared as a sorbent to sorb rare-earth ions in chloride solution. It was described by XRD, SEM, TGA, and FTIR. The factors pH, initial rare-earth ion concentration, contact time, and DdTC/PVC dose were also analyzed. The ideal pH was 5.5, and the ideal equilibration time was found to be 45 min. The rare-earth ion uptake on DdTC/PVC was 156.2 mg/g. The rare-earth ion sorption on DdTC/PVC was fitted to Langmuir and pseudo-2nd-order models. The rare-earth ions’ thermodynamic adsorption was spontaneous and exothermic. In addition, rare-earth ion desorption from the loaded DdTC/PVC was scrutinized using 1 M HCl, 45 min time of contact, and a 1:60 S:L phase ratio. The obtained rare earth oxalate concentrate was utilized after dissolving it in HCl to extract and separate the RE ions into three groups—light (La, Ce, Nd, and Sm), middle (Gd, Ho, and Er), and heavy (Yb, Lu, and Y)—via three-liquid-phase extraction (TLPE). This technique is simple and suitable for extracting REEs. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.The authors express their gratitude to the Princess Nourah bint Abdulrahman University Researchers Supporting Project (PNURSP2022R2), Princess Nourah bint Abdulrahman University, Riyadh, Saudi ArabiaAcknowledgments: The authors express their gratitude to the Princess Nourah bint Abdulrahman University Researchers Supporting Project (PNURSP2022R2), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
Adsorption of Yttrium Ions on 3-Amino-5-Hydroxypyrazole Impregnated Bleaching Clay, a Novel Sorbent Material
In this work, spent bleaching clay (SBC) was treated with ethyl acetate and impregnation with 3-amino-5-hydroxypyrazole (AHIBC) that utilized as economical sorbent material. The uptake of yttrium ions from aqueous solution using AHIBC was studied under batch process as a function of pH of the solution, contact time, adsorbent dosage, Yttrium ions concentration, and ambient temperature. The adsorption equilibrium was achieved at the value of pH = 6.0 and agitation time of 60 min at room temperature. The utmost adsorption capacity of Y(III) ions on AHIBC was 171.32 mg·g−1 . Kinetic, isotherm, and thermodynamic models were applied to the experimental data obtained. Adsorption follows a pseudo–second–order kinetic model, while the adsorption isotherm fits the Langmuir model. A negative value of Gibbs free energy ∆G◦ revealed that the adsorption of the Y ions on the AHIBC adsorbent was spontaneously in nature. In addition, the electrostatic interaction process between the metal ions and AHIBC was favorable. The negative value of ∆H◦ states that Y ions adsorption was an exothermic process. Desorption efficiency reduced from 97% to 80% after eight consecutive rounds. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.This study was funded by Taif University Researchers Supporting Project number (TURSP2020/157), Taif University Taif, Saudi Arabia
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