432 research outputs found
The Impact of Big Data Analytics Implementation on Data Analysts Behavior: The Role of Stress and Psychological Capital
Recently the application of big data analytics (BDA) technology has become a trend in improving business outcomes to capture valuable insights that were not achievable previously. Despite the positive impacts expected by the implementation of these technologies, the results show inconsistencies. This study uses the transactional theory of stress to elaborate on the role of implementation of BDA in such seemingly contradictory results. Specifically, we propose that depending on their psychological capital, data analysts may perceive such technological change either as inspirational or impeding. Analysts who can cope with the difficulties inherent to the new technology may be more motivated to learn analytical skills. In contrast, given the inability to manage their negative, stressful feelings, less psychologically competent data analysts would resist BDA implementation. The potential contributions to theory and practice will also be discussed
Naltrexone Removal from Aqueous Media by Multi-Walled Carbon Nanotubes
Background: Extensive researches with different techniques are being carried out for removal of pharmaceuticals from aqueous media. The aim of this study was to use multi-walled carbon nanotubes (MWCNTs) to remove naltrexone as a pollutant of the aquatic environment and to investigate the mechanism of absorption and factors affecting it.
Methods: In this experimental study, different amounts of MWCNTs were added to different concentrations (200 to 400 mg/L) of naltrexone and adsorption at various conditions including temperature, pH, and time of adsorption was studied. Adsorption on multi-walled carbon nanotubes was adopted on isotherm model equations to estimate the adsorption mechanism.
Results: Optimum conditions to remove 90% of naltrexone from 20 ml of its 400mg/ml solution were at adsorbent amount of 0.1g and time of 20 to 30 minutes. Temperature and pH had no effect on adsorption in the examined ranges. The drug can be absorbed as one layer and according to the Langmuir isotherm, on carbon nanotubes.
Conclusion: Naltrexone removal by MWCNTs, due to higher surface area and therefore more efficient adsorption properties, is more efficient than by activated carbon and requires no specific conditions in regard to pH, temperature, and concentration. Substances with similar structures, like morphine, compete with naltrexone on adsorption
The Use of Subconjunctival Erythropoietin Injection to Treat Avascular Bleb after Trabeculectomy: A Case Report
Purpose: To report a patient with avascular bleb after trabeculectomy who showed promising results after subconjunctival erythropoietin injection.
Case Report: A 45-year-old woman with the diagnosis of primary open-angle glaucoma and history of trabeculectomy three years prior was admitted to our center. The corrected distance visual acuity (CDVA) was 20/20 in both eyes. Her ocular examination revealed an avascular and cystic bleb in the right eye. Seidel test was negative while bleb sweating was observed after fluorescein staining of the bleb area. Intraocular pressure (IOP) was 5 mmHg in the right eye. Erythropoietin (2000 unit in 0.1 ml) was injected subconjuctivally around the bleb area in the temporal quadrant. Six weeks after the injection, the bleb area just superior to the conjunctiva showed an increased fibrosis formation while the IOP remained the same as before injection.
 
Evaluation of offspring sex ratio, sex hormones and antioxidant enzymes following exposure to methyl tertiary butyl ether in adult male Sprague-Dawley rats
Methyl tertiary butyl ether (MTBE) is an oxygenated fuel additive which has been used widely in many parts of the world. This experiment was performed to determine the effect of MTBE on offspring sex ratio, sex hormones and antioxidant enzymes. A total of 20 adult Sprague-Dawley male rats were divided into four groups and received 0, 400, 800 and 1600 mg/kg/day MTBE by gavages for 30 consecutive days. At the end of the experiment, blood samples were taken for determination of sex hormones and antioxidant enzymes. Then, male rats were mated with healthy unexposed female rats and sex of offspring was determined after birth. Sex ratio was 0.48, 0.50, 0.43 and 0.50 in 0, 400, 800 and 1600 mg/kg/day MTBE groups, respectively (P = 0.91). There was significant decreasing trend for luteinizing hormone (LH) and testosterone in experimental groups (rs = -0.50, P = 0.030 and rs = -0.67, P = 0.002, respectively). No changes were observed for superoxide dismutase. However, decrease in glutathione peroxidase (GPX) was observed in all treatment groups compared with control which was significant in 400 mg/kg/day MTBE group (P = 0.016). The present study showed that paternal exposure to oral MTBE has no effect on offspring sex ratio; while, MTBE exposure could exert dose-dependent changes in serum testosterone and LH in treatment groups. The results of the present study, need to be clarified in the future studies
Lightweight Rubberized Concrete Slabs for Sustainable Road Pavements Serving Non-Auto Traffic
Non-auto transportation infrastructure, such as bicycle lanes and sidewalks, serves as an efficient means of public mobility. Improving the sustainable design and construction of the concrete slabs that compose such roads promotes environmental and economic benefits, spanning the usage of green sources of materials and reduced maintenance costs. In this study, an investigation into the application of recycled tires, also known as tire-derived aggregate (TDA), combined with rotary-kiln produced expanded clay (EC) as coarse aggregates in concrete, as well as their life-cycle cost assessment, are presented. The mechanical properties of concrete specimens with three different mix designs, i.e.,100% EC (MIX A or control mix), a mixture of 20% EC – 80% TDA (MIX B), and 100% TDA (MIX C) as coarse aggregates, were first derived through experimental tests. Impact-fatigue tests were then conducted on concrete slabs of MIX A, B, and C to evaluate their sustainability under several cycles of bicycle loads. The results showed that the TDA concrete has lower compressive and flexural strength, but it is more ductile than concrete with zero rubber content. Also, the results of impact-fatigue tests combined with a life-cycle cost analysis indicated the long-term benefits of constructing green and durable infrastructure using TDA on future investments in transportation
Defective mitosis-linked DNA damage response and chromosomal instability in liver cancer.
Abstract Hepatocellular carcinoma (HCC), the most common form of liver cancer, represents a health problem in hepatic viruses-eradicating era because obesity, type 2 diabetes, and nonalcoholic steatohepatitis (NASH) are considered emerging pathogenic factors. Metabolic disorders underpin mitotic errors that lead to numerical and structural chromosome aberrations in a significant proportion of cell divisions. Here, we review that genomically unstable HCCs show evidence for a paradoxically DNA damage response (DDR) which leads to ongoing chromosome segregation errors. The understanding of DDR induced by defective mitoses is crucial to our ability to develop or improve liver cancer therapeutic strategies
Optimization and Validation of a novel Nebulizer-assisted Liquid Phase Microextraction Followed by HPLC-DAD for Diazinon Analysis in Plasma Samples
Background: Diazinon is among the most prevalently used broad-spectrum organophosphates insecticides. Diazinon toxicity depends on its blood concentration. The current study aimed to extract and determine diazinon in plasma samples using a new Nebulizer -Assisted Liquid-Phase Microextraction followed by High-Performance Liquid Chromatography with Diode-Array Detection (NALPME-HPLC-DAD).Methods: Several effective parameters, including the type and volume of extracting solvent, pH, surfactant, salt amount, and nebulizing, were evaluated and optimized to find the best condition for the extraction and determination of diazinon in plasma samples using High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD). Additionally, the Plackett-Burman design was employed in preliminary experiments to screen the most appropriate parameters. Furthermore, we selected a central composite design to determine the best experimental conditions in NALPME-HPLC-DAD. Results: In an optimum condition, 412 μL of toluene (as extracting solvent) and nebulizing with nitrogen gas as dispersing and emulsification, sodium lauryl sulfate (2.8% w/v) and 100μL sodium chloride (1.5% w/v) in pH 8.1 were selected. The standard calibration curves for diazinon were linear with the concentration range of 0.5–4 µg/mL with a correlation coefficient of 0.9992. The Limit Of Detection (LOD) and Limit Of Quantification (LOQ) for diazinon were 0.123 µg/mL and 0.372 µg/mL, respectively.Conclusion: The proposed method was simple, accurate, precise, and sensitive for analyzing diazinon in the plasma samples. This method can be used for analyzing plasma diazinon concentrations in acute poisoning cases in clinical and forensic toxicology analyses
Disperzivna tekućinsko-tekućinska mikroekstrakcija temeljena na eksperimentalnom centralnom kompozitnom dizajnu u svrhu određivanja diazinona u ljudskoj mokraći: razvoj i validacija metode
Diazinon poisoning is an important issue in occupational, clinical, and forensic toxicology. While sensitive and specific enough to analyse diazinon in biological samples, current methods are time-consuming and too expensive for routine analysis. The aim of this study was therefore to design and validate a simple dispersive liquid-liquid microextraction (DLLME) for the preparation of urine samples to be analysed for diazinon with high performance liquid chromatography with diode-array detector (HPLC-DAD) to establish diazinon exposure and poisoning. To do that, we first identified critical parameters (type and volume of extraction and disperser solvents, pH, surfactant, and salt concentrations) in preliminary experiments and then used central composite design to determine the best experimental conditions for DLLME-HPLC-DAD. For DLLME they were 800 μL of methanol (disperser solvent) and 310 μL of toluene (extraction solvent) injected to the urine sample rapidly via a syringe. The sample was injected into a HPLC-DAD (C18 column, 250×4.6 mm, 5 μm), and the mobile phase was a mixture of acetonitrile and buffer (63:37 v/v, pH 3.2; flow rate: 1 mL/ min). Standard calibration curves for diazinon were linear with the concentration range of 0.5–4 μg/mL, yielding a regression equation Y=0.254X+0.006 with a correlation coefficient of 0.993. The limit of detection and limit of quantification for diazinon were 0.15 μg/mL and 0.45 μg/mL, respectively. The proposed method was accurate, precise, sensitive, and linear over a wide range of diazinon concentrations in urine samples. This method can be employed for diazinon analysis in routine clinical and forensic toxicology settings.Trovanje diazinonom važan je problem za medicinu rada te kliničku i forenzičnu toksikološku praksu. Premda su postojeće metode njegova utvrđivanja u biološkim uzorcima dovoljno osjetljive i specifične, njihova je primjena za rutinske analize preskupa i dugotrajna. Zbog toga je cilj ovoga istraživanja bio razviti i validirati jednostavnu metodu disperzivne tekućinsko-tekućinske mikroekstrakcije (engl. dispersive liquid-liquid microextraction, krat. DLLME) kojom bi se uzorci ljudske mokraće pripremili za analizu diazinona tekućinskom kromatografijom visoke djelotvornosti s detektorom s nizom fotodioda (engl. high performance liquid chromatography with diode-array detector, krat. HPLC-DAD) radi utvrđivanja izloženosti i trovanja diazinonom. U tu smo svrhu u preliminarnim eksperimentima prvo odredili ključne parametre: vrstu i volumen ekstrakcijskoga i disperzijskoga otapala, pH, površinski aktivne tvari (surfaktanta) te koncentraciju soli. Zatim smo s pomoću eksperimentalnoga centralnoga kompozitnoga dizajna utvrdili optimalne eksperimentalne uvjete za DLLME-HPLC-DAD. Za DLLME oni su bili 800 μL metanola (kao disperzijskoga otapala) te 310 μL toluena (kao ekstrakcijskoga otapala) za brzu injekciju uzorka mokraće. Uzorak je injektiran u HPLC-DAD (5-mikrometarski analitički stupac C18, 250×4,6 mm), a mobilna je faza bila mješavina acetonitrila i pufera (63:37 v/v, pH 3.2; protok: 1 mL/min). Standardne su kalibracijske krivulje za diazinon bile linearne s rasponom koncentracija diazinona od 0,5 do 4 μg/mL, a regresijska jednadžba Y=0,254X+0,006 s koeficijentom korelacije 0,993. Granice detekcije odnosno kvantifikacije diazinona bile su 0,15 μg/mL odnosno 0,45 μg/mL. Ova se metoda pokazala točnom, preciznom, osjetljivom i linearnom u širokom rasponu koncentracija diazinona u uzorcima mokraće, stoga se može koristiti za njegovu rutinsku analizu u kliničkoj i forenzičnoj toksikološkoj praksi
مقایسه دور گردن و دور کمر در پیشگویی اختلالات کاردیومتابولیک در افراد مراجعه کننده به مطب های خصوصی غدد شهر قزوین(فایل دفاع نهایی)
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