488 research outputs found
Characterization and prediction of cracks in coated materials: direction and length of crack propagation in bimaterials
No full textThe behaviour of materials is governed by the surrounding environment. The contact area between the material and the surrounding environment is the likely spot where different forms of degradation, particularly rust, may be generated. A rust prevention treatment, like bluing, inhibitors, humidity control, coatings, and galvanization, will be necessary. The galvanization process aims to protect the surface of the material by depositing a layer of metallic zinc by either hot-dip galvanizing or electroplating. In the hot-dip galvanizing process, a metallic bond between steel and metallic zinc is obtained by immersing the steel in a zinc bath at a temperature of around 460°C. Although the hot-dip galvanizing procedure is recognized to be one of the most effective techniques to combat corrosion, cracks can arise in the intermetallic layer. These cracks can affect the life of the coated material and decrease the lifetime service of the entire structure. In the present paper the mechanical response of hot-dip galvanized steel submitted to mechanical loading condition is investigated. Experimental tests were performed and corroborative numerical and analytical methods were then applied in order to describe both the mechanical behaviour and the processes of crack/cracks propagation in a bimaterial as zinc-coated material
Numerical simulation in coated materials: model of crack propagation bi-material
No full textFrom the simple device to complex assembly, protection against corrosion is the most important treatment. As well as known, this treatment could be done in different varieties in the function of available resources and depending on economic price. Most of the time, protection is made with the use of one material, that holds the highest anti-corrosion characteristics, through a form of a thin film layer.
Among various materials, zinc may be considered as one. Zinc could be applied under the thin layer during the hot dip galvanized steel process. During this procedure of steel coating, some cracks are initiated in the intermetallic layer δ and spread in the layered surface of the zinc coating. For the simulation of this process we use the finite element method (FEM). The realization of modelling is done in the bi-material steel-zinc model, using the computer software application Abaqus 6.10.1
A Hypothesis about the Author of Aja’ib al-Dunya
No full textAja’ib al-Dunya is one of the most famous Books of Wonders in Persian which has had a great impact on later works. Some scholars reject the attribution of this book to Abol-moayyed Balkhi, but identifying the author is a question that has so far remained unanswered. In the book Aja’ib Va Ghara’ib, Azari Esfarayeni referred to this book 14 times. In one of them, he attributed the book to Naser Khosrow. In this research, the author seeks to verify the accuracy of this attribution. The study demonstrates that the quotations made by Azari are available in the mentioned sources, and we can trust his honesty. Comparing those 14 stories shows that Azari used the same Aja’ib al-Dunya which is now available. Additionally, the examination of biographies and Naser Khosrow's works shows that he was probably interested in this branch of knowledge in an episode of his life. Therefore, it can be concluded that Azari Esfrayeni's statement is probably true and the book Aja’ib al-Dunya may have been composed by Naser Khosrow before converting to the Isma’ili thought and being entitled “Hojjat of Khorasan Island”
Anticancer biomaterials: A special design for precision medicine
No full textDespite prominent progress in cancer detection and therapy, critical challenges still remain and need to be addressed. In this sense, several innovative biomaterials have been designed and produced using different types of biocompatible materials like metals, and polymers, as well as glasses and glass-ceramics. Currently, more precise treatments can be achieved based on the tissue type, the stage of the cancer, and other patient-specific factors, resulting in improved cancer diagnosis and treatment. Indeed, the integration of interdisciplinary research areas, including tissue engineering, regenerative medicine, biomaterials science, nanotechnology, and pharmacology has led to a move forward toward cancer precision medicine. In this sense, precision biomaterials have emerged as promising approaches for more efficient modeling, detection, and treatment of cancers. In this chapter, we will discuss the recent advances and potential applications of precision biomaterials for personalized cancer treatment and try to summarize future directions according to the available data in the literature
Spaces of contestation: the everyday experiences of ten African migrants in Cape Town
No full textIncludes bibliographical references.Xenophobia in South Africa is so overt that it has take a covert form. The 'xenocide' events that took place in 2008 were called xenophobic acts. It is the recurrent denialism of xenophobia on an everyday basis that this project has explored through the narrative accounts of ten African migrants in Cape Town. The lived everyday experiences of ten African migrants have brought forward the central argument of this thesis. From the data, it is evident that as a reponse to everyday pressures of prejudices and xenophobia in social and physical spaces, African migrants have developed mutable, unsettled and vagrant identities in order to cope with everyday low level violence. This argument emerged as four key stressors have been identified as the components of a more substantial explanation of xenophobia in South Africa. The four key components are: the enforcement of identity (national and group), the demarcation of spaces of belonging, the experiences of economic insecurity, and lastly a 'culture of violence' in South Africa. This thesis argues that these four stressors are the result of an on-going active process of xenophobic attitudes
Islamska teokracija šiitskih dvanajstnikov v Iranu
No full textThe paper introduces the concept of Velayat-e faqih (Guardianship of the
Jurist) as actual political system in Iran. The Farsi concept transfers the authority, political
and religious, to the Shia clergy called ruling faqih (ruling jurist). It means that the religious
leader (Vali-e faqih) is in fact the supreme leader in Iran. He gets his authority from God
and he has already been appointed by the Hidden Imam and he would just be discovered
by Maraj-e taghlid. Shia Islam knows a particular meaning of the concept Velayat-e faqih,
started by Islamic Revolution in 1979. The paper presents the interpretation of the doctrine
formulated by the dissident Iranian cleric Ayatollah Ruhollah Khomeini. The presentation
is based on his book Islamic Government: Governance of the Jurist. The paper compares
different views of Velayat-e faqih and it describes the relation of the actual Iranian understanding of Velayat-e faqih with traditional Shia custom and practice. This paper is written
in English but it is based on the Farsi bibliography and is supported by the life experience
of the political system.Članek predstavlja koncept Velayat-e faqih (Pravnikovo skrbništvo) kot trenutno
politično ureditev v Iranu. Perzijski koncept izroča politično in versko oblast šiitskemu duhovniku, ki se imenuje vladajoči faqih (vladajoči pravnik). To pomeni, da je verski voditelj
(Vali-e faqih) v resnici vrhovni voditelj v Iranu. Bog mu je dal avtoriteto in Skriti imam ga je
imenoval, neposredno pa ga je odkril Maraj-e taghlid. Šiitski islam pozna poseben pomen
izraza Velayat-e faqih, ki ga je začela islamska revolucija leta 1979. Prispevek predstavlja
interpretacijo doktrine, ki jo je oblikoval disidentski iranski klerik ajatola Ruholah Homeini.
Članek temelji na njegovi knjigi Islamska vlada: vladanje pravnika, ki je bila prvič natisnjena
leta 1970. Avtorja primerjata različne poglede na Velayat-e faqih in opišeta razmerje sedanjega iranskega razumevanja koncepta s tradicionalnimi šiitskimi običaji in prakso. Članek
je napisan v angleščini, vendar temelji na iranski bibliografiji in je podprt z življenjskimi
izkušnjami političnega sistem
Deprivation to destruction? : a look at Reich, Azari and the Iranian Revolution
No full textIn 1933 Wilhelm Reich wrote The Mass Psychology of fascism to psychologically explain the attraction of Hitler to the people of Germany, claiming that the combination of sexual suppression, religiosity and authoritarian parenting prevalent in Germany was the cause. In 1983 Farah Azari, in Women in Iran, endorsed his opinion, by suggesting that these factors accounted for the success of the Islamic regime in the Iranian Revolution.
Wilhelm Reich has not been endorsed by the mainstream psychological fraternity and acquired a bad reputation for his use of a particular "sexual therapy". This thesis examines the contentions Reich makes in Mass Psychology considering modern psychological and affiliated findings, attempting to sort the gold from the dross in his theories.
The thesis further examines Farah Azari's reasons for agreeing with Reich by looking at the Shia Karbala paradigm and its attendant beliefs and rituals, plus formal religious prescription, and social attitudes prevailing in Iran to see if she is correct in her assumptions.
Broadly, the thesis finds that both Reich and Azari are more right than wrong, but sometimes err in their emphases. The author looks too for other areas of influence, and suggests that gendered socialisation plays a much larger part than sexual suppression itself in the formation of Iranian character tendencies.
The thesis concentrates on negative character types, and therefore is not a balanced look at either Iranian society or Islamic religion. Reich correctly noted that "authoritarianism" is a pervasive worldwide character trait and therefore elucidation of the psychological mechanisms which "cause" or enhance it are of value to our own society, as well as helping us to understand that of others
Zinc- and Copper-Doped Mesoporous Borate Bioactive Glasses: Promising Additives for Potential Use in Skin Wound Healing Applications
No full textIn this study, zinc (Zn)- and copper (Cu)-doped 13-93B3 borate mesoporous bioactive glasses (MBGs) were successfully synthesized using nitrate precursors in the presence of Pluronic P123. We benefited from computational approaches for predicting and confirming the experimental findings. The changes in the dynamic surface tension (SFT) of simulated body fluid (SBF) were investigated using the Du Noüy ring method to shed light on the mineralization process of hydroxyapatite (HAp) on the glass surface. The obtained MBGs were in a glassy state before incubation in SBF. The formation of an apatite-like layer on the SBF-incubated borate glasses was investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The incorporation of Zn and Cu into the basic composition of 13-93B3 glass led to changes in the glass transition temperature (Tg) (773 to 556 °C), particle size (373 to 64 nm), zeta potential (−12 to −26 mV), and specific surface area (SBET) (54 to 123 m2/g). Based on the K-means algorithm and chi-square automatic interaction detection (CHAID) tree, we found that the SFT of SBF is an important factor for the prediction and confirmation of the HAp mineralization process on the glasses. Furthermore, we proposed a simple calculation, based on SFT variation, to quantify the bioactivity of MBGs. The doped and dopant-free borate MBGs could enhance the proliferation of mouse fibroblast L929 cells at a concentration of 0.5 mg/mL. These glasses also induced very low hemolysis (<5%), confirming good compatibility with red blood cells. The results of the antibacterial test revealed that all the samples could significantly decrease the viability of Pseudomonas aeruginosa. In summary, we showed that Cu-/Zn-doped borate MBGs can be fabricated using a cost-effective method and also show promise for wound healing/skin tissue engineering applications, as especially supported by the cell test with fibroblasts, good compatibility with blood, and antibacterial properties
Stem cell-mediated angiogenesis in skin tissue engineering and wound healing
No full textThe timely management of skin wounds has been an unmet clinical need for centuries. While there have been several attempts to accelerate wound healing and reduce the cost of hospitalisation and the healthcare burden, there remains a lack of efficient and effective wound healing approaches. In this regard, stem cell-based therapies have garnered an outstanding position for the treatment of both acute and chronic skin wounds. Stem cells of different origins (e.g., embryo-derived stem cells) have been utilised for managing cutaneous lesions; specifically, mesenchymal stem cells (MSCs) isolated from foetal (umbilical cord) and adult (bone marrow) tissues paved the way to more satisfactory outcomes. Since angiogenesis plays a critical role in all four stages of normal wound healing, recent therapeutic approaches have focused on utilising stem cells for inducing neovascularisation. In fact, stem cells can promote angiogenesis via either differentiation into endothelial lineages or secreting pro-angiogenic exosomes. Furthermore, particular conditions (e.g., hypoxic environments) can be applied in order to boost the pro-angiogenic capability of stem cells before transplantation. For tissue engineering and regenerative medicine applications, stem cells can be combined with specific types of pro-angiogenic biocompatible materials (e.g., bioactive glasses) to enhance the neovascularisation process and subsequently accelerate wound healing. As such, this review article summarises such efforts emphasising the bright future that is conceivable when using pro-angiogenic stem cells for treating acute and chronic skin wounds
Periodontal condition in rats with experimental diabetes mellitus after orthodontic surgery
No full textAzari Mehrdad Mohammad Ali. Periodontal condition in rats with experimental diabetes mellitus after orthodontic surgery. Journal of Education, Health and Sport. 2019;9(10):246-252. eISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.3522313
http://ojs.ukw.edu.pl/index.php/johs/article/view/7610
The journal has had 7 points in Ministry of Science and Higher Education parametric evaluation. Part B item 1223 (26/01/2017).
1223 Journal of Education, Health and Sport eISSN 2391-8306 7
© The Authors 2019;
This article is published with open access at Licensee Open Journal Systems of Kazimierz Wielki University in Bydgoszcz, Poland
Open Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author (s) and source are credited. This is an open access article licensed under the terms of the Creative Commons Attribution Non commercial license Share alike.
(http://creativecommons.org/licenses/by-nc-sa/4.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited.
The authors declare that there is no conflict of interests regarding the publication of this paper.
Received: 03.10.2019. Revised: 08.10.2019. Accepted: 29.10.2019.
UDK 616.31:615.37:616.179:379:008
PERIODONTAL CONDITION IN RATS WITH EXPERIMENTAL DIABETES MELLITUS AFTER ORTHODONTIC SURGERY
Azari Mehrdad Mohammad Ali
Odessa National Medical University
[email protected]
Abstract
Background. Determine periodontal condition in rats with experimental diabetes mellitus after orthodontic surgery.
Methods. In rats, type 1 diabetes mellitus (DM1) was reproduced with aloxane (100 mg / kg, intraperitoneally) once. Orthodontic surgery was performed by fixing the spring, starting from the 12th day. Animal euthanasia was performed on the 35th day of the experiment. The activity of urease, lysozyme, catalase, elastase, as well as the content of malondialdehyde (MDA) and hyaluronic acid were determined in the gum homogenate. In the alveolar bone homogenate, the activity of alkaline phosphatase (AlP) and acid phosphatase (AcP) and elastase was determined, as well as the content of calcium and protein. The antioxidant-prooxidant index (API) was calculated by the ratio of catalase activity and MDA content, and the degree of dysbiosis according to A. P. Levitsky was calculated by the ratio of the relative activities of urease and lysozyme. The mineralizing activity (MA) was calculated by the ratio of the activity of alkaline phosphatase (AlP) and AcP in the bone tissue and the mineralization (MD) degree was calculated by the ratio of the concentration of calcium, and protein.
Results. In rats with DM1, the level of elastase, urease, MDA and the degree of dysbiosis increase in the gum, however, the level of lysozyme, hyaluronic acid, and the API index decrease. In the bone tissue of the periodontium of rats with type 1 diabetes, the level of alkaline phosphatase and MA decreases, but the level of AC increases. Orthodontic surgery significantly reduces the degree of dysbiosis in the gums and shows a tendency to increase API and decrease elastase activity. After orthodontic surgery, rats significantly increase the level of alkaline phosphatase and MA.
Conclusion. With type 1 diabetes, periodontitis, dysbiosis develops and the mineralizing activity of periodontal bone tissue decreases. Orthodontic surgery tends to improve periodontal conditions.
Keywords: periodontium; diabetes mellitus; orthodontics; dysbiosis; inflammation; mineralizing activity
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