1,077 research outputs found
Jan Surman. Universities in Imperial Austria, 1848–1918. A Social History of a Multilingual Space
This article review:  Jan Surman. Universities in Imperial Austria, 1848–1918. A Social History of a Multilingual Space. Indiana: PurÂdue University Press, 2019, 458 pp
Comparative cytotoxicity study of nicotine and cotinine on MRC-5 cell line
Nicotine has several health hazards regarding carcinogenic potential. It also imparts increased risk for respiratory, cardiovascular, and gastrointestinal disorders. Several mechanisms have been proposed for the carcinogenic potential, including effects on cell proliferation, inducing oxidative stress, DNA mutation, or inhibition of apoptosis. The cotinine metabolite is generally thought to have effects similar to nicotine in some experimental systems. The purpose of this study was to assess the nicotine and cotinine cytotoxicity on MRC-5 lung fibroblasts. The pulmonary fibroblasts were treated with various concentrations of nicotine or cotinine (in the range 1 µM – 2 mM) for 24 or 48 h and analyzed for cell viability by MTT test. The results indicated that high nicotine concentrations (2 mM) induced marked cell death (about 50%) in MRC-5 cell line. Cotinine showed lower toxicity than nicotine on the MRC-5 cells. In contrast to nicotine treatment, cells treated with cotinine continued to proliferate after the 48h incubation period
HPTLC assay of nicotine and cotinine in biological samples
This study presents the development of a simple high-performance thin layer chromatography (HPTLC) method for the determination of nicotine and its metabolite cotinine in human plasma and urine.
The following mobile phases: methanol: ammonia (100:1.5, v:v), chloroform: acetone: ammonia (48.75: 48.75: 2.5, v:v:v), methanol: chloroform: ammonia (48.75: 48.75: 0.5, v:v:v) and glass plates precoated with silicagel 60 F254 (20x20) as a stationary phase were used. Densitometric scanning was performed at 263 nm. Two different extraction procedures have been applied: liquid-liquid extraction using dichloromethane at alkaline pH and solid-phase extraction using C18 cartridges.
Preliminary tests in order to establish the system of solvents for development, as well as the range of linearity, were conducted. The best separation of nicotine and cotinine was obtained by using methanol: chloroform: ammonia (48.75: 48.75: 0.5, v:v:v) as the mobile phase. The liquid-liquid extraction technique led to better results than solid phase extraction. The regression curves were linear (with a corresponding correlation coefficient higher than 0.99) in the quantities range of 200 ng–1000 ng/spot for both nicotine and cotinine. The UV spectra confirm the identification of nicotine and cotinine both in the standards and in the extracts after liquid-liquid extraction.
The proposed method can be applied for the simultaneous evaluation of nicotine and cotinine in biological samples at toxic/lethal levels. Thus, the method may be applicable in lethal nicotine intoxication cases in forensic toxicological analysis
Integrating Ecosystem Services in Historically Polluted Areas: Bioremediation Techniques for Soils Contaminated by Heavy Metals
Bioremediation of soils contaminated by heavy metals is based on the use of specially selected plants able to reduce the hazards of toxic metals. Depending on the mode of action on the heavy metals existing in the soil and the place where the action takes place, the following mechanisms for soil phytoremediation are distinguished: phytostabilization, phytoextraction, phytoimobilization, rhizofiltration, or evapotranspiration. These mechanisms are complex and include the plant ability to reduce the mobility and bioavailability of heavy metals and other pollutants, to extract large amounts of heavy metals from the soil or to evaporate water together with various pollutants already reached in the rhizosphere. Decontamination of polluted soils by using bioaccumulative plants is proposed as an environmental-friendly alternative to the traditional physicochemical methods, being a sustainable method with a great potential in the terms of environmental protection and cost management
Comparative cytotoxicity study of nicotine and cotinine on MRC-5 cell line
Nicotine has several health hazards regarding carcinogenic potential. It also imparts increased risk for respiratory, cardiovascular, and gastrointestinal disorders. Several mechanisms have been proposed for the carcinogenic potential, including effects on cell proliferation, inducing oxidative stress, DNA mutation, or inhibition of apoptosis. The cotinine metabolite is generally thought to have effects similar to nicotine in some experimental systems. The purpose of this study was to assess the nicotine and cotinine cytotoxicity on MRC-5 lung fibroblasts. The pulmonary fibroblasts were treated with various concentrations of nicotine or cotinine (in the range 1 µM – 2 mM) for 24 or 48 h and analyzed for cell viability by MTT test. The results indicated that high nicotine concentrations (2 mM) induced marked cell death (about 50%) in MRC-5 cell line. Cotinine showed lower toxicity than nicotine on the MRC-5 cells. In contrast to nicotine treatment, cells treated with cotinine continued to proliferate after the 48h incubation period
Validation study for the Academic Maladjustment Questionnaire on a Romanian sample
IntroductionThe problem of academic dropout in the first year of studies represents an important issue for higher education, in that it accounts for an important indicator of quality but also for the negative consequences it produces on individual, institutional and social level. The main aim of the study is to validate and evaluate a robust measure of overall academic maladjustment.MethodThe participants were 809 first-year students from various Romanian universities.ResultsThe results showed a reliable version of the instrument with a factorial structure that did not deviate significantly from the authors’ initial model. The exploratory and confirmatory factor analysis revealed a unified score including six dimensions, procrastination, dishonesty – unethical behavior, test anxiety, machiavellian attitude, neuroticism, and somatization. Our results confirmed that besides academic achievement, personal factors are important indicators of adjustment, showing that personal resources management, emotional and behavioral strategies are components of adjustment. Our study revealed a medium and positive correlation between overall maladjustment and academic dropout intention, procrastination seemed to be the most relevant predictor of dropout intention.DiscussionAcademic adjustment acts as a safeguard against dropping out, and it is crucial to acknowledge that most students enter college with the intention of completing their studies
Methadone Treatment for Heroin Dependence
In substitution therapy for treatment of heroin addiction, methadone is the synthetic opioid agonist of first choice. Methadone doses vary depending on addict profile established by repeated evaluation. It studied a group of 82 patients both male and female, aged between 19 and 47Â years, residing in Bucharest, with diagnosis of heroin addiction. They were voluntarily submitted in the methadone substitution treatment at a specialized treatment center for addiction in Bucharest. The study group was characterized in detail, taking into account demographic, comorbid and addiction characteristics, heroin use history, treatment history, and clinical and paraclinical evaluation. The outcomes resulting from the study design on 82 heroin addict patients enrolled into a methadone maintenance program highlighted: lowering of the onset age of heroin use, HVC infection comorbidity, and the extension of the treatment period due to the relapses. The results obtained by clinical, laboratory, and psychological complex evaluations in a correlative approach is essential both in initiating methadone treatment and monitoring the detox period but also in the supervision of methadone maintenance treatment
HPTLC assay of nicotine and cotinine in biological samples
This study presents the development of a simple high-performance thin layer chromatography (HPTLC) method for the determination of nicotine and its metabolite cotinine in human plasma and urine.
The following mobile phases: methanol: ammonia (100:1.5, v:v), chloroform: acetone: ammonia (48.75: 48.75: 2.5, v:v:v), methanol: chloroform: ammonia (48.75: 48.75: 0.5, v:v:v) and glass plates precoated with silicagel 60 F254 (20x20) as a stationary phase were used. Densitometric scanning was performed at 263 nm. Two different extraction procedures have been applied: liquid-liquid extraction using dichloromethane at alkaline pH and solid-phase extraction using C18 cartridges.
Preliminary tests in order to establish the system of solvents for development, as well as the range of linearity, were conducted. The best separation of nicotine and cotinine was obtained by using methanol: chloroform: ammonia (48.75: 48.75: 0.5, v:v:v) as the mobile phase. The liquid-liquid extraction technique led to better results than solid phase extraction. The regression curves were linear (with a corresponding correlation coefficient higher than 0.99) in the quantities range of 200 ng–1000 ng/spot for both nicotine and cotinine. The UV spectra confirm the identification of nicotine and cotinine both in the standards and in the extracts after liquid-liquid extraction.
The proposed method can be applied for the simultaneous evaluation of nicotine and cotinine in biological samples at toxic/lethal levels. Thus, the method may be applicable in lethal nicotine intoxication cases in forensic toxicological analysis
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