Isolation and purification of rat islet cells by flow cytometry     

Azim Akbarzadeh  Dariush Norouzian  Ali Farhangi  Mohammad Reza Mehrabi  Shirin Jamshidi  Davood Zare  Morvarid Shafiei 《Indian journal of clinical biochemistry : IJCB》2008,23(1):57-61

Flow cytometry has been employed as a method to study homogeneity of isolated islet subpopulations. After collagenase digestion of rat pancreas and elutriation of tissue fragments, islets were isolated and dissociated, and cells were analyzed and sorted according to their low forward angle light scattering properties by using automated flow cytometry. A standardized procedure was developed for the preparation of rat islet cell grafts for purification of islet cells. In this process, after collagenase digestion of pancreas, islets were isolated, dissociated, identification by dithizone method and then with enzymatic procedure by DNase and trypsin, the islet cells changed into single cells and beta cells were identified by immunofluorescence method and then assayed by flow cytometry. Methods have been developed for the preparation of suspension of viable rat pancreatic islet cells and their analysis and sorting in the fluorescence activated cell sorter (FACC IV, Becton Dickinson, Sunnyvale, Ca). Flow cytometry of these cells indicated that there were 91% of beta cells in cell suspension. Most of the exocrine particles were lost during digestion. Purified endocrine islet cell grafts were prepared by pure beta-cells, without endocrine non-beta cells. The purified aggregates were devoid of endocrine non-beta cells and damaged cells.  相似文献   

Non-Descender and All-Cap Arabic Writing     

Mohammad Ali Yaghan 《Al-Masaq: Islam & the Medieval Mediterranean》2018,30(2):166-190

Contrary to the common belief of Arabic language users that the Arabic writing system has descenders as an inherent quality, some historical examples demonstrate that there were some artistic attempts to create non-descender, all-cap calligraphic systems, but they have never been studied as a phenomenon. This article draws attention to the existence of these examples, and analyses and classifies them according to their form.

The article begins with an analysis of the current Arabic writing system in terms of descenders, differentiating between artistic and functional writing, defining the need for harmonious balance in artistic writing, and demonstrating that descenders do disrupt the balance in Arabic writing, which could be considered as an ascender-system.

Then, historical examples of the non-descender system are introduced, categorised into four visual stages, and the descender handling for each stage is described; all-capital letter examples are then introduced.

Finally, some historical texts describing the beauty of calligraphy in this specific system of writing are analysed.

Abbreviations: MET: The Metropolitan Museum of Art, www.metmuseum.org; LACMA: The Los Angeles County Museum of Art, www.lacma.org; No. : Accession Number  相似文献   

The Uses and Gratifications of Language in Social Media among the Indian Subcontinental Diaspora in the U.S.     

Mohammad Delwar Hossain  Aaron S. Veenstra 《Journal of Intercultural Communication Research》2017,46(5):478-496

This study examines the uses and gratifications of language in social media among the Indian subcontinental diaspora in the United States, based on data collected from an online survey of 535 adult immigrants following a snowballing technique. Results showed the use of native language is related to the use of home country media, while the use of English language is related to emotional adjustment. This study contributes to the literature on social media, community, and language preference by opening avenues for conducting further research on the usage of language in social media among the Indian subcontinental diaspora in the United States. The findings of this study contribute to an understanding of the influence of social media on language preference.  相似文献   

Improving teacher prediction of children at risk for reading failure     

Jane M. Flynn  Mohammad Hossein Rahbar 《Psychology in the schools》1998,35(2):163-172

Whether screening tests or teacher ratings best predict children at risk for reading failure continues to be an area of disagreement in the early identification literature. Our early studies confirmed low positive identification rates (30%) when kindergarten teachers were asked to predict future reading achievement using a traditional rating scale, while a project-developed, theory-based screening battery correctly identified 81% of poor readers. Construction of a teacher rating scale of current skill levels on research-validated precursors to reading improved prediction in the current study, although results were still inferior to the screening test (64% and 80% valid positives, respectively). Combining test results and teacher ratings resulted in 88% identification of those who failed in first, second, or third grade, suggesting that both teacher ratings and screening tests should be used to identify the largest number of those who will later fail in reading. © 1998 John Wiley & Sons, Inc.  相似文献   

Livelihoods and informal trade at the Bangladesh border     

Mohammad Jalal Uddin Sikder  Barun Kumar Sarkar 《Inter-Asia Cultural Studies》2013,14(3):432-445

Abstract

Cross‐border informal trade is one of the most important issues between India and Bangladesh. It takes place between people who live a short distance apart, but who find themselves separated by an international boundary. The people of international border areas believe that cross‐border informal trade is a process to maintain a sustainable livelihood because it provides a livelihood to the unemployed. This research has analysed the nature and impact of informal border trade between India and Bangladesh. It has highlighted the sources of security and insecurity through the process of informal border trade. It also analyses the different socio‐economic conditions of informal border trade in border trade prone areas. This research argues that although informal border trade is considered illegal, it is necessary for the maintenance of the livelihood for the poor in the bordering areas. The state failures in fulfilling the needs of the poor force them to involve themselves in informal border trade.  相似文献   

A commentary on “determining the level of inquiry in teachers' questions”     

Mohammad N. Siddiqi  Hans O. Anderson  George T. Ladd 《科学教学研究杂志》1973,10(2):179-181

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Chip morphology predictions while machining hardened tool steel using finite element and smoothed particles hydrodynamics methods     

Usama Umer  Jaber Abu Qudeiri  Mohammad Ashfaq  Abdulrahman AL-Ahmari 《浙江大学学报(A卷英文版)》2016,17(11):873-885

Chip morphology predictions in metal cutting have always been challenging because of the complexity of the various multiphysical phenomena that occur across the tool-chip interface. An accurate prediction of chip morphology is a key factor in the assessment of a particular machining operation with regard to both tool performance and workpiece quality. Although finite element (FE) models are being developed over the last two decades, their capabilities in modeling correct material flow around the tool tip with shear localization are very limited. FE models with an arbitrary Lagrangian Eulerian (ALE) approach are able to simulate correct material flow around the tool tip. However, these models are unable to predict any shear localization based on material flow criteria. On the other hand, FE models with a Lagrangian formulation can simulate shear localization in the chip segments; they need to make use of a mesh-based chip separation criterion that significantly affects material flow around the tool tip. In this study a mesh-free method viz. smoothed particles hydrodynamics (SPH) is implemented to simulate shear localization in the chip while machining hardened steel. Unlike other SPH models developed by some researchers, this model is based on a renormalized formulation that can consider frictional stresses along the tool-chip interface giving a realistic chip shape and material flow. SPH models with different cutting parameters are compared with the traditional FE models and it has been found that the SPH models are good for predicting shear localized chips and do not need any geometric or mesh-based chip separation criteria.  相似文献   

A comparative study of conventional and supercritical fluid extraction methods for the recovery of secondary metabolites from <Emphasis Type="Italic">Syzygium campanulatum</Emphasis> Korth     

Abdul Hakeem Memon  Mohammad Shahrul Ridzuan Hamil  Madeeha Laghari  Fahim Rithwan  Salman Zhari  Mohammed Ali Ahmed Saeed  Zhari Ismail  Amin Malik Shah Abdul Majid 《Journal of Zhejiang University. Science. B》2016,17(9):683-691

Syzygium campanulatum Korth is a plant, which is a rich source of secondary metabolites (especially flavanones, chalcone, and triterpenoids). In our present study, three conventional solvent extraction (CSE) techniques and supercritical fluid extraction (SFE) techniques were performed to achieve a maximum recovery of two flavanones, chalcone, and two triterpenoids from S. campanulatum leaves. Furthermore, a Box-Behnken design was constructed for the SFE technique using pressure, temperature, and particle size as independent variables, and yields of crude extract, individual and total secondary metabolites as the dependent variables. In the CSE procedure, twenty extracts were produced using ten different solvents and three techniques (maceration, soxhletion, and reflux). An enriched extract of five secondary metabolites was collected using n-hexane:methanol (1:1) soxhletion. Using food-grade ethanol as a modifier, the SFE methods produced a higher recovery (25.5%?84.9%) of selected secondary metabolites as compared to the CSE techniques (0.92%?66.00%).  相似文献   

Phytoremediation of heavy metal polluted soils and water：Progresses and perspectives   总被引：4，自引：0，他引：4  

Lone MI  He ZL  Stoffella PJ  Yang XE 《Journal of Zhejiang University. Science. B》2008,9(3):210-220

Environmental pollution affects the quality of pedosphere, hydrosphere, atmosphere, lithosphere and biosphere. Great efforts have been made in the last two decades to reduce pollution sources and remedy the polluted soil and water resources. Phytoremediation, being more cost-effective and fewer side effects than physical and chemical approaches, has gained increasing popularity in both academic and practical circles. More than 400 plant species have been identified to have potential for soil and water remediation. Among them, Thlaspi, Brassica, Sedum alfredii H., and Arabidopsis species have been mostly studied. It is also expected that recent advances in biotechnology will play a promising role in the development of new hyperaccumulators by transferring metal hyperaccumulating genes from low biomass wild species to the higher biomass producing cultivated species in the times to come. This paper attempted to provide a brief review on recent progresses in research and practical applications of phytoremediation for soil and water resources. Project supported by the Higher Education Commission, Government of Pakistan for the faculty training under the R & D Project “Strengthening Department of Soil Science and Soil and Water Conservation” at the University of Florida, USA, a grant from the St. Lucie River Water Initiative (SFWMD contract No. OT060162), USA, in part, and the Program for Changjiang Scholars and Innovative Research Team in University (No.IRT0536), China  相似文献   

From “chalk and talk” to “guide on the side”: A cross‐cultural analysis of pedagogy that drives customised teaching for personalised learning     

Mohammad Reza Sarkar Arani  Bruce Lander  Yoshiaki Shibata  Christine Kim‐Eng Lee  Hiroyuki Kuno  Andrew Lau 《European Journal of Education》2019,54(2):233-249

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