299 research outputs found

    The effect of 6 weeks decreased activity in the form of spinal cord ligation on CDK5 expression in sciatic nerve of Wistar male rats with neuropathic pain

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    چکیده مقدمه: درد نوروپاتیک به صورت درد ناشی از آسیب یا بیماری سیستم عصبی حسی- پیکری تعریف می‌شود. نورون‌ها به کاهش و افزایش فعالیت به لحاظ بیوشمیایی سازگار می‌شوند که چنین تغییرات بیوشمیایی می‌تواند در حفظ و بقای نورون‌ها اثر گذار باشد، با توجه به نقش تنظیمی CDK5 در عملکرد و ساختار اعصاب هدف از انجام پژوهش حاضر بررسی تاثیر شش هفته فعالیت کاهش یافته به شکل درد نوروپاتیک بر بیان CDK5 در عصب سیاتیک رت های نر دارای درد نوروپاتیک بود. مواد و روش‌ها: 10سر موش صحرایی نر نژاد ویستار با میانگین وزن 20±250 گرم به 2 گروه کنترل سالم(5n=) و گروه فعالیت کاهش یافته (SNL) (5n=) تقسیم شدند. طی شش هفته آینده آزمون‌های رفتاری درد نوروپاتیک در گروه‌های پژوهشی به طور مستمر انجام شد. در پایان 6 هفته تغییرات بیان ژن CDK5 در عصب سیاتیک با تکنیک Real time اندازه‌گیری و با روش 2-ΔΔCT محاسبه شد. نتایج: پس از 6 هفته وزن عضله نعلی در گروه لیگاتوربندی شده به طور معناداری نسبت به گروه کنترل کاهش داشت(05/0 ≤ P). در آزمون‌های رفتاری درد نوروپاتیک آلودنیای مکانیکی و هایپرآلژزنیای حرارتی نشان داده شد در گروه لیگاتور بندی آستانه تحریک درد نسبت به گروه کنترل به طور معناداری کمتر بود(05/0 ≤ P). میزان بیان ژن CDK5 در عصب سیاتیک در گروه لیگاتور بندی شده به طور معناداری (پاتولوژیک) نسبت به گروه کنترل افزایش نشان داد(05/0 ≤ P). بحث و نتیجه‌گیری: به نظر می‌رسد در پی یک دوره فعالیت کاهش یافته با مدل SNL ، افزایش پاتولوژیک بیان ژن CDK5 منجر به اثرات مخرب بر سیستم عصب و عضله، و ظهور نشانه‌های پاتولوژیکی نظیر، آتروفی عضلانی، عصبی، تسریع روند آپوپتوز و تخریب عصبی می‌گردد

    Photochemical reduction of silver nitrate to nano silver using stannous chloride, ctab and daylight irradiation

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    Silver nanoparticles (NPs) were synthesized and stabilized by a simple method in aqueous solution, by the reduction of silver nitrate with stannous chloride (SnCl2.2H2O) and cetyl trimethyl ammonium bromide (CTAB)through day light irradiation. Thereby, the silver nanoparticles were colloidally stabilized by CTAB as a surfactant. The synthesis of silver NPs with different size were possible by changing the reaction conditions such as reagent ratio. The silver NPs were characterized by Dynamic Light Scattering (DLS) and UV-visible spectroscopy. A very strong plasmon resonance peak at 400-500 nm in the UV-visible spectra is a clear consequence of the silver NPs production. The synthesized silver NPs showed good stability by using CTAB. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2063

    Surface roughness and wettability of wool fabrics loaded with silver nanoparticles: Influence of synthesis and application methods

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    Hydrophilization of wool fabrics was performed by silver nanoparticles with different surface charge using three different methods: exhausting, pad–dry–cure and in situ synthesis. Dynamic wetting measurements and surface topography analysis were used to evaluate surface changes on wool fabrics. The wool samples in situ loaded revealed the highest fabric roughness and porosity, while the use of the pad–dry–cure method leads to the lowest fabric porosity, and its roughness values approximately were the same as those for samples loaded with the exhaustion method. The results revealed that loading silver nanoparticles with high surface charges onto wool fabrics via the exhaustion method can significantly improve the hydrophilicity of wool fibre surface. The possible reasons for this improvement are discussed

    Evaluation of methylation pattern in promoter region of E-cadherin gene and its relation to tumor grade and stage in breast cancer

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    The epithelial cadherin gene (CDH1) has been identified as a tumor suppressor gene located within the 16q22.1 region. The CDH1 gene encodes a transmembrane glycoprotein involved in cell to cell adhesion and loss of CDH1 expression contributes to increased proliferation, invasion and metastasis in breast carcinoma. No mutation in CDH1 have been identified in invasive ductal carcinoma (IDC), suggesting that, other inactivation mechanisms are responsible for IDC oncogenesis. In order to analyze the role of promoter methylation in CDH1 gene inactivation in breast cancer, the CpG methylation status of Ecadherin promoter region by bisulfite sequencing PCR (BSP) was investigated. 10 CpG sites [nucleotide (nt) 863, 865, 873, 879, 887, 892, 901, 918, 920 and 940] in the promoter region were screened for methylation. The CDH1 methylation was detected in 94% (47 to 50) of breast tumors which was associated with higher tumor grade (p = 0.035), tumor stage (p = 0.000) and tumor metastasis (p = 0.000). There was also a significant correlation between tumor stage, grade and metastatic status with sites of methylation (p = 0.000). The data indicate that CDH1 promoter methylation might be a potential mechanism for epigenetic silencing of CDH1 in primary breast cancer suggesting a valuable molecular marker for detection of breast cancer progression.Key words: Breast cancer, E-cadherin, methylation pattern, tumor stage, tumor grade

    Assessment of students' perceptual readiness for e-learning in Iranian Universities

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    Background and Objectives: The current generation of academic learners is considered "digital natives" because of their ease of use and familiarity with networking technologies; However, there are ambiguities about the readiness of students to study in an e-learning environment. In particular, Iranian students' lack of motivation for e-learning, despite much infrastructure investment over the past two decades, has been a major challenge that has recently attracted the attention of higher education planners to e-learning readiness, especially from a perceptual perspective. This study investigated the perceptual readiness level of Iranian students for e-learning. Therefore, the current state of perceptual readiness of Iranian students to participate in the e-learning environment beyond the presumption of "existence" or "lack" of this preparation is such that their actual readiness is determined in a number of important universities. Methods: This research is philosophically placed in the positivism paradigm and the logic of deductive reasoning is used. Its macro-targeting is applied, and the survey research strategy is used to collect first-hand data using a questionnaire tool. The survey data were collected between April 2018 and February 2019. In addition, two complementary approaches have been used to formulate and weigh the indicators and criteria for assessing students' e-learning readiness: first, the use of indicators and criteria developed in previous research, and second, and the use of subject matter experts in the country. The use of data from other researches makes it possible to compare the results with the findings of other researchers, and the use of expert opinion causes the localization of indicators and criteria with the requirements and context of higher education in the country. The students' perceptual readiness was measured by the following four scales: Attitude, Perceived usefulness, Willingness and Perceived self-efficacy; Then, the weight of each scale and measure will be calculated. Finally, based on the rating results, the students' perceptual readiness at the number of comprehensive universities and specialized universities will be estimated. Findings: The average perceptual readiness of students for e-learning in 15 selected Iranian universities is 4.9 out of 10, which indicates the situation at the "average" level. Also, the findings show that about 35% of the students' readiness measures are below the "good" level, and the average of all readiness measures is at the "medium" level. Also, considering students' relative perceptual readiness for e-learning, especially in "perceived self-efficacy" and "attitudes" scales, the deans of universities should focus on the two main activities of "enhancing students' self-efficacy through e-learning" and "providing an appropriate e-learning environment”. Conclusion: Considering the decrease in the number of e-learning Iranian students, the results of this study show that one of the important reasons for the failure of e-learning systems in Iranian universities can be students' lack of perceptual readiness. At the same time, considering the lower than average level of students' readiness in the "willingness" and "perceived usefulness" scales, there is a need to focus on awareness and education of students in this regard. Besides, relying on students 'relative readiness to understand self-efficacy and attitude indicators, universities should put two main activities on their agenda: 1) further strengthening students' self-efficacy through e-learning, and 2) providing a suitable environment. For e-learning for students. ===================================================================================== COPYRIGHTS©2021 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers. ====================================================================================

    Utjecaj glutaraldehida na svojstva želatinskih filmova

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    In this work gelatin film was prepared from cow\u27s bone. In order to increase mechanical stability of the prepared transparent film as well as decrease its swelling, glutaraldehyde (GTA) was used. Different mass fractions of GTA were utilized. It was observed that at w = 0.18 % of GTA the load at break of the film is δ= 53.7 N and the solubility decreased. The solubility of the film was measured as a dependant parameter of the swelling behavior. In this case it was decreased from 389 % to 156 % at 5 min for gelatin films without GTA and with 0.18 % GTA, respectively. FTIR spectroscopy results showed a peak for crosslinked gelatin at ΰ = 1650 cm-1. It means the crosslinking between gelatin and GTA has taken place. SEM micrographs confirm the porosity has decreased by increasing the GTA fraction, which is an indication of higher strength.U ovom je radu pripremljen želatinski film od kravlje kosti. Da bi se povećala mehanička stabilnost pripremljenog transparentnog filma kao i smanjilo njegovo bubrenje, upotrijebljen je glutaraldehid (GTA). Upotrijebljeni su različiti maseni udjeli mase GTA. Uočeno je da kod 0,18 % GTA prekidna sila filma iznosi 53,7 N i da se povećala topljivost. Topljivost filma izmjerena je kao parametar ovisan o ponašanju pri bubrenju. U ovom slučaju smanjio se s 389 % na 156 % kod 5 minuta za želatinske filmove bez GTA odn. s 0,18 % GTA. Rezultati spektroskopije FTIR pokazali su maksimum za umreženu želatinu kod 1650 cm-1. To znači da je došlo do umrežavanja između želatine i GTA. Mikroskopske slike SEM potvrđuju da se poroznost smanjila povećanjem dijela GTA, što je pokazatelj veće čvrstoće

    Osteopetrosis: A Case Report and Review of the Literature

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    Osteopetrosis or marble bone disease is a rare heritable skeletal disorder that the bones becoming denser, caused by aberrant osteoclast-mediated bone resorption. This condition reveals a spectrum of heterogeneity of genetic defects. This metabolic disorder has an unequal balance between new bone formation and old bone resorption. Thus the result is increased bone density on radiographs. Presented here is a 25 years-old Persian female presented to our clinic with the chief complaint of low back pain and limping. She explained that her problem had been present for a long time. There were no other significant findings in past medical history and her parents and three siblings did not have any disorder of note, however, the parents were first cousin. No specific laboratory abnormalities found in the initial evaluation. On physical examination, an antalgic gait is noted. A Bone biopsy from proximal medial tibia revealed increased density of the cortex and part of medullary canal with hematopoietic marrow and irregular and thickened bone trabeculae. These factors suggested osteopetrosis disease. Osteopetrosis should be kept in mind as a rare cause of low back pain and limping and should be mentioned as a differential diagnosis of fluorosis, Paget’s disease, malignancies (lymphoma, osteoblastic cancer metastases) and myelosclerosis.Keywords: Osteopetrosis, marble bone disease, bone trabeculae, Iran

    Report of a new mutation and frequency of connexin 26 gene (GJB2) mutations in patients from three provinces of Iran

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    Autosomal recessive and sporadic non-syndromic hearing loss (ARSNSHL) is the major form of hereditary deafness. Mutations in the GJB2 gene encoding the gap-junction protein Connexin 26 have been identified to be highly associated with ARSNSHL. In this study we have analyzed 196 deaf subjects from 179 families having one or more deaf children in 3 proviences of Iran, including Kordestan, Khuzestan and Golestan. The nested PCR prescreening strategy and direct sequencing technique were used to detect the mutations in coding exon of the gene. Altogether 3 GJB2 recessive mutations including 35delG, 167delT and V27I+E114G, were identified in 23 of 179 families (12.8). Fourteen of 179 families were observed to have GJB2 mutation in both alleles (7.8). A novel variant (R159H) also was found in a deaf family from Khuzestan. Four polymorphisms V27I, E114G, S86T and V153 I also were detected in 7 families. A polymorphism(S86T) was seen in the whole population studied. Our data indicated that the rate of connexin 26 mutations is different in this three Irainian population and is lower than the high frequency of 35delG (26) reported from Gilan province in the north of Iran
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