106 research outputs found
Studying the Conformational Landscape of Biomolecules Using Single Molecule Fluorescence Spectroscopy
Proteins have many important functions in living system. They are produced from ribosomes as unstructured polypeptide chains of amino acids and then either fold by themselves or with the help of chaperones into their functional, three dimensional structures. However, the details for some proteins conformational changes and how it relates to their function, is still one of the unsolved questions in modern biophysics. Many techniques such as X-ray, NMR and single-molecule Förster Resonance Energy Transfer (smFRET) and multiparameter fluorescence detection techniques can get information about the protein conformational changes, structure, and also dynamic exchange and the equilibrium between different native protein states. Thus, providing insight into how those bio molecular machines really work. The focus of this thesis will therefore deal with: (1) protein structure and conformational changes (2) Fluorescence methods to study the protein conformational changes. (3) N-methyl-D-aspartate (NMDA) receptor that is, one member of the ionotropic glutamate receptor family, which requires a co-agonist such as glycine or D-serine for channel activation. Using fluorescence methods we studied the conformational changes of the ligand binding domain of this receptor in the presence of different co-agoinst to understand agonism
Long-term exposure to low frequency electro-magnetic fields of 50- and 217-Hz leads to learning and memory deficits in mice
Electromagnetic field (EMF) radiation affects cellular and brain chemistry and function, resulting in deleterious effects such as free radicals formation, impaired DNA repair, reduced melatonin and blood brain barrier protection, and defects on learning and memory and other higher brain functions. In this paper the effects of low frequency EMF of 50- and 217 Hz, ranges often associated with common electronic devices such as televisions and cell phones were examined on learning and memory in adult male mice. Five groups (n=10 mice/group) of mice (1 control and 4 experimental) were initially trained for the passive avoidance (PA) test. They were then placed in devices creating EMF radiation with varying intensities (0.5 to 2 milli-Tesla, mT) and frequencies (50- and 217-Hz) for 2-weeks (16 hrs/day). Control mice received no radiation. Learning and memory was tested by the PA test and evaluated based on the following parameters: mean step through latency (STL), number of crossing (Cr#) and time in dark compartment (TDC). Results showed significant deficiencies in learning and memory in the EM-exposed mice compared to controls: mean STL decreased significantly (p<0.001) in the 50 Hz group (1 and 1.5 mT intensities). In the 217 Hz group, STL also decreased in the 0.5 and 2 mT groups (p< 0.05). There was a notable increase in mean Cr# for both groups and TDC for 50 Hz group. Results confirm that long-term exposure to EMF radiation of 50 and 217 Hz, imparts significant harmful changes on memory and learning, reiterating the need for preventive measures against such exposures
Factors influencing medication errors according to nurses’ decisions to do self-report
Background: There are many factors associated with medication errors. These errors are mainly related to nursing care, including error in medication administration and omission. Nurses make up the largest group of health workers. Hence, quality of health care depends to a great extent to nurses. Nurses who work in hospitals with inadequate human resources and have more working hours are more likely to commit errors. This study aimed at determining the incidence of medication errors and factors affecting it according to nurses’ self-report.Methods: This is a descriptive analytical study in which 100 nurses in beast hospital in Sanandaj, Iran were selected randomly from different shifts. The questionnaire consisted of 2 sections. The first section consisted of 17 questions on demographic information including age, sex, type of activity, duration of service, hospital ward and location, error during the years of service, reporting or non-reporting of mistakes and type of mistake. The second part of the tool consisted of 25 items rated to 1-to-5 likert scale, which checked out medical errors in 5 domains. For ethical issues, anonymous questionnaires were distributed with bar codes. Then the data were entered into SPSS version 16 and analyzed.Results: All the participants in this study had a history of medication error in the previous year. In 12% of the cases, association between workload and medication error were too high, 22% was high, 54% was average and 6% was low.Conclusions: The results of this study showed that the most important factors affecting the incidence of errors include workplace stress, working in the intensive care units, tiredness due to work load, and inappropriate nurse physician relationship. Hence, identification of these factors helps nurses to reduce errors and helps reduce other medical consequences and improve in the quality of patient care and patient safety. Regarding the importance of patient safety it is necessary to improve positive relationship between nurse managers and nursing staff. Therefore, an environment of close collaboration, in-service training for new nurses regarding medication errors, and creating a reporting system is necessary
Optimization and Modeling of Ammonia Removal from Aqueous Solutions by Using Adsorption on Single-walled Carbon Nanotubes
Due to the health effects of ammonia as an environmental pollutant, such as its odor, corrosion, algae phenomenon, etc., a method should be adopted to remove it from wastewater. In this study, removal of ammonia from hypothetical wastewater was investigated using adsorption on SWCNTs. The Design-Expert software was used to design the experiments and optimize the parameters that are effective in the adsorption performance of carbon nanotubes (CNTs), such as contact time, adsorbent dosage, pH, temperature, and ammonia concentration. The results revealed that the maximum adsorption with a performance of 90% was attained at a pH of 9.5. In addition, the adsorption performance was enhanced by increasing adsorption time and adsorbent dosage. Furthermore, increasing the temperature and the adsorbate quantity led to a decrease in the adsorption performance
Biomarker Profiling (Erbb2, P53, and PR) for Stage I of Breast Cancer
Breast cancer (BC) accounts for one of the major health problems around the world. Since the diagnosis process can have great effect on therapy outcomes, we studied the biomarkers specific to breast tumors stage I based on examining different Iranian patients. Cases from different stages were examined to discover their highly expressed proteins. In addition, pathologic evaluations were performed as the diagnosis procedure. Considering positive percentage of over-expressed protein in different stages in the population, it is guessed that over-expression of ErBb2 and PR are positively correlated, while P53 is in negative correlation with them. Therefore, these molecules can probably account for stage I biological marker. This study suggests that alterations in over-expression of specific biomarkers in different stages may be associated to the stage classification, and can help achieve more effective therapies of this malignancy
Discourse Analysis of Teaching Persian Language and Literature: A Model For the Expansion of Cultural Diplomacy
Discourse analysis is one of the interdisciplinary trends in linguistics, sociology, anthropology, psychology, and so on. This tendency has two main perspectives: first, it evaluates the formation of meaning and message in relation to the intricacies (including the physiological and structural aspects of language) and, in the second perspective, examines the exogenous factors (the relationship between language and all external features that include the knowledge of sociology, culture, etc.) Discourses are considered as the open language of power relations, and since language teaching concepts are also manifestations of cultural power, the authors of this paper have sought to criticize the concepts of second language teaching based on the second view of discourse analysis. The most important findings show that in meaning-based approaches, the reliance is on common prominent figures, for example, between Iran and Turkmenistan (Abu Saeed Abul-Khair, Abulfazl Sarakhsi, ...), Iran and Uzbekistan (Rudaki Samarghandi, Amir Ali Shirnava’i, Attar Neishabouri, and ...). Community-based approaches identify target communities by examining linguistic geography to transform communicative potentiality to communicative action. A culture-based approach which identifies common roots in literature, art, and language, and the obvious examples of which are the customs of Nowruz celebrations, Welcoming Spring and Seven Sin between Iran and its neighbors such as Azerbaijan, Pakistan, Turkmenistan and ..., refers to the creation of common cultural themes for the teaching of language learners. The psychology-based approach deals with the use of mystical literature, as well as its link with the concepts of participatory learning such as improvement of attitude in Hafez poetry and self-esteem in Saeb
Ispitivanje značajka domova djece s alergijskim rinitisom i astmom
The prevalence of allergic diseases, especially asthma and allergic rhinitis, has dramatically increased during the last decades. Mite and cockroach, which are the most common allergens in house dust, are the major indoor allergens in asthmatic and allergic rhinitis patients. The aim of this study was to compare the association between age of dwelling and some other home characteristics in asthmatic and allergic rhinitis children, who had positive skin prick test to mite and cockroaches, with allergic patient with negative skin test. Thirty-six asthmatic and allergic rhinitis children with positive skin prick test to mite and cockroach allergens, and 34 allergic rhinitis and asthmatic children with negative skin prick test to these allergens were enrolled in this study. Data on home characteristics, including age of homes, kind of carpeting, floor of home and number of rooms in the building, were collected by telephone questionnaire. The mean age of buildings was higher in the group of children sensitive to mite and cockroach (22.4±12.9 vs. 16.3±13.9 years), but the difference was not significant. However, when patients sensitive to mite only were compared to control patients, the difference was significant (p=0.025). There was no significant difference in the number of floor, rooms, kind of carpet and other features of building between the case and control group. There was a significant relationship between mite allergy and building age, which could be important for the policy of allergy control in the society. However, further studies are needed to clarify the association between more specific home characteristics and allergy diseases.Učestalost alergijskih bolesti, poglavito astme i alergijskog rinitisa, bilježi znatan porast posljednjih desetljeća. Grinje i žohari kao najčešći alergeni u kućnoj prašini glavni su alergeni na koje nailaze osobe s alergijom i alergijskim rinitisom u zatvorenom prostoru. Cilj ovoga istraživanja bio je usporediti povezanost starosti objekta i neke druge značajke domova kod djece s astmom i alergijskim rinitisom te s pozitivnim kožnim testom na grinje i žohare s vrijednostima istih kod djece s astmom i alergijskim rinitisom, ali s negativnim kožnim testom na grinje i žohare. U studiju je bilo uključeno 36 djece s astmom i alergijskim rinitisom te s pozitivnim kožnim testom na grinje i žohare i 34 djece s astmom i alergijskim rinitisom, ali s negativnim kožnim testom na grinje i žohare. Podatci o značajkama doma uključujući starost zgrade, vrst zidne obloge, kat i broj soba u zgradi prikupljeni su telefonskim anketiranjem roditelja. Srednja starost zgrade u kojoj žive bila je veća kod djece osjetljive na grinje i žohare nego u djece koja nisu pokazala osjetljivost na ove alergene (22,4±12,9 prema 16,3±13,9 years), ali razlika nije bila značajna. Međutim, kad su s kontrolnom skupinom uspoređena djeca osjetljiva samo na grinje, tada je razlika bila značajna (p=0,025). Nije bilo nikakve razlike između dviju skupina u odnosu na kat, broj soba, vrst zidne obloge i druge značajke zgrade. Dakle, utvrđena je značajna povezanost alergije na grinje i starosti zgrada, što bi moglo biti važno u planiranju aktivnosti za suzbijanje alergije u društvu. Potrebna su daljnja ispitivanja kako bi se pojasnila udruženost nekih specifičnih značajka zgrada i alergijskih bolesti
Potential Effect of Human Platelet Lysate on in vitro Expansion of Human Corneal Endothelial Cells Compared with Y-27632 ROCK Inhibitor
Purpose: Corneal endothelial cell (CEC) therapy can be used as a promising therapeutic option for patients with various corneal endothelial dysfunctions. In this study, we compared the proliferative effect of human platelet lysate (HPL), as a xeno-free medium supplement, with Y-27632 Rho/rho-associated protein kinase (ROCK) inhibitor, as a wellknown proliferative and adhesive agent for CECs, and fetal bovine serum (FBS) as the control, in the culture medium of human corneal endothelial cells (HCECs).
Methods: We isolated HCECs from human donors and treated the cells as three different treatment groups including 20% HPL only, 10 μM Y-27632 ROCK inhibitor, combination of 20% HPL and 10 μM Y-27632 ROCK inhibitor, and 20% FBS as the control group. ELISA cell proliferation assay and cell counting was performed on the treated cells. Finally, HCECs were characterized by morphology and immunocytochemistry (ICC).
Results: There was no significant proliferative effect of HPL on cell proliferation compared with the cells treated with Y-27632 ROCK inhibitor or the combination of HPL and Y-27632 ROCK inhibitor, but all the respected treatments had significant inducible effect on cell proliferation as compared with FBS-treated cells. The cells grown in all three treatment groups exhibited CEC morphology. Also, there was a higher expression of Na+/K+-ATPase and ZO-1, as CEC characteristic markers, in the culture of HCECs treated with HPL as compared with FBS.
Conclusion: HPL offers a xeno−free and affordable medium supplement for CEC expansion that can be used in clinical applications
Gene sets involved in prostate cancer based on differential expression
Prostate cancer is the second most common cancer in men. In spite of on-going researches in this filed, the specific causes of prostate cancer are so far unknown. In this study, we used two methods of Gene Set Analysis to improve the biological interpretation of the observed expression patterns in prostate cancer. The Gene Set Analysis is a computational method to discover gene sets whose expression is associated with a phenotype of interest. In addition, we used these methods to search gene sets defined by KEGG and BioCarta. Although, our results showed that most of the gene sets were associated with prostate cancer in the Category and Hotelling’s T2 methods, the power of the Hotelling’s T2 was more than Category method in either KEGG or BioCarta gene sets. The concordance between the results of Pubmed articles and KEGG gene sets was more than the results of Pubmed articles and BioCarta gene sets
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