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Author(s): 

سرافراز حسین

Issue Info: 
  • Year: 

    1390
  • Volume: 

    -
  • Issue: 

    1
  • Pages: 

    141-160
Measures: 
  • Citations: 

    1
  • Views: 

    608
  • Downloads: 

    0
Keywords: 
Abstract: 

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    1386
  • Volume: 

    18
Measures: 
  • Views: 

    382
  • Downloads: 

    0
Keywords: 
Abstract: 

مقدمه: کشت های قطعات نخاع می توانند برای مطالعه مکانیسم های مسوول بقا و مرگ سلول های عصبی مورد استفاده قرار گیرند. با این وجود، قطعات نخاع گرفته شده از جانوران بالغ به سختی در محیط های کشت باقی مانده و سریعا ازبین می روند. در این تحقیق ما کشت های قطعات نخاع از موش بالغ را مورد استفاده قرار دادیم تا مکانیسم های دخیل در مرگ سلولی موتورنورونها را مورد بررسی قرار دهیم.روشها: بخش سینه ای نخاع به قطعاتی با ضخامت 500 میکرون بریده و در محیط کشت حاوی MEM %50،  25%سرم اسب، 25% محلول نمکی Hanks،25  میلی مولار HEPES و پنی سیلین-استرپتومایسین با pH=7 قرار گرفتند. این کشت ها سپس در دمای 37 درجه سانتی گراد و  CO2 %5برای 6 ساعت انکوبه شدند. موتورنورونها بوسیله خصوصیات مورفولو ژیکی (اجسام سلولی و هسته بزرگ)، موقعیتشان در شاخ های شکمی نخاع و رنگ آمیزی آنها باآنتی بادی  Choline acetyl transferase (ChAT)مورد شناسایی قرار گرفتند. مرگ سلولی در موتورنورونها با استفاده ازرنگ های فلئورسنت مثل propidium iodide و Hochest33342 و نیز ظهور فراگمنت های نوکلئوزومی DNA بر روی ژل آگارز مورد ارزیابی قرار گرفت.نتایج: بعد از 6 ساعت در محیط کشت، بیشتر موتورنورونها مشخصه هایapoptosis ، شامل متراکم شدن هسته وکروماتین و ظهور فراگمنت های نوکلئوزومی DNA را نشان دادند. در این زمان، بیشتر موتورنورونها همچنین ایمیونوریکتیویتی را نسبت به آنتی بادی calpain II، هم در سیتوپلاسم و هم در هسته نشان دادند. بعد از 6 ساعت در محیط کشت، هم calpain inhibitor VI و هم EGTA ظهور هسته های اپوپتوتیک را مهار نموده در حالی که یک مهار کننده عمومی (Z-VAD.fmk) caspase فاقد اثر بود.نتیجه گیری: مطالعه حاضر پیشنهاد می کند که calpain برای apoptosis موتورنورونها در قطعات نخاع جانور بالغ ضروری و اینکه این apoptosis بصورت غیر وابسته به فعالیت caspase عمل می نماید.

Yearly Impact:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    0
  • Volume: 

    1
  • Issue: 

    1
  • Pages: 

    96-103
Measures: 
  • Citations: 

    1
  • Views: 

    749
  • Downloads: 

    0
Keywords: 
Abstract: 

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 749

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Issue Info: 
  • Year: 

    2020
  • Volume: 

    14
  • Issue: 

    1
  • Pages: 

    149-174
Measures: 
  • Citations: 

    0
  • Views: 

    442
  • Downloads: 

    0
Abstract: 

The increasing rate of construction activities in urban areas is accompanied by excavation in the vicinity of existing structures and urban utilities. This issue has highlighted the importance of constructing protecting structures in order to control displacements and prevent damage to structures and their neighboring area. Among the important widely used wall stabilization techniques, one can name nailing and grouted anchors. However, these methods suffer some drawbacks such as annoying noise and vibration during the drilling, implementation difficulties below the water table, grouting problem, installation of strands and bars in the borehole in porous and collapse soils, and long curing time for the grout of post-tension anchors. Since the helical anchor method lacks many of the mentioned problems, it is now widely used in many applications. In the present work, a laboratory model of helical anchor stabilized wall is presented and evaluated. For this purpose, four types of anchors at 20° back slope are designed in a sandy soil and the effect of helix configuration (in term of its diameter and number of blades) is investigated. Considering the laboratory scale of the designed model, the results obtained using helical anchor were compared with numerical results of soil nailing wall by applying the particle image velocimetry (PIV) analyses. Material and methods: The test box designed in this work is made of a metal plate with a thickness, length, width, and depth of 1. 5 mm, 100 cm, 60 cm, and 30 cm, respectively, and a Plexiglas in its opposing side with a thickness of 50 mm. The soil used in the experiments was the dry sand of Soufian region in east Azerbaijan province of Iran. The soil is classified as SP according to USCS classification. The helical anchors were fabricated by welding the helical pitches to a metal shaft. The end part of the shafts is screw threaded such that to fasten a bolt to them. To start the experiment, the empty box was completely cleaned using the detergents to remove any pollution or soil on the Plexiglas and metal surface. Afterward, the sandy soil was poured on the wall floor and the facing was placed inside the box vertically. Again, the sandy soil was poured from both sides of the facing up to the installation height of the helices. Helices were installed in the assigned holes and their angle was adjusted through the pre-fabricated stencils. The soil height was increased up to the next row assigned for helices installation. These steps were repeated until reach the wall crest. After preparation of the physical model, its behavior during the preparation must be modeled. We first filled both sides of the model and then modeled the stability behavior of the helical anchor wall through excavating its facing opposed side. Overall, the wall was built through eight excavation steps. Results and discussion: The maximum displacement is related to the anchor type 1, which does not have enough bearing capacity under surcharge conditions. By changing the anchor type and increasing the number of helices, shear strains and their expansion in the wall back decline. The decrease in displacement rate by changing the anchor from type 1 to type 2 is 18%, which is due to the low bearing capacity of type 2 anchor compared to the type 1 anchor. Increasing the number of pitches from one to two (changing the type 1 anchor to type 3 anchor) showed a considerable decrease (i. e., 43%) in displacement rate. Increasing the number of pitches from 1 to 3 (changing the anchor from type 1 to type 3) resulted in a 62% decrease in wall crest displacement. This displacement decrease rate seems to decline with an increase in the number of helixes. The displacement rate for all four anchors is almost similar in two excavation steps, which probably is because of the need for displacement for activation of the anchors. One strategy to deal this issue in the sensitive projects and control the displacement is to apply post-tension helical anchors. Then, in stages 4 to 6, the displacement was almost constant due to four main reasons including wall rigidity, the presence of reinforcements, formation of pre-step displacement-induced tension force, and enough capacity of anchors to face with more displacement. In stages 6 to 8, type 1 and 2 anchors showed growing displacements due to the reduction and ending the wall rigidity and lower bearing capacity. In type 3 and 4 anchors, the maximum displacement was related to 4 initial stages. In type 1 and 2 anchors, which have two helical plates, almost a similar behavior was observed until stage 6 of excavation, but eventually type 3 anchors showed better performance because of higher bearing capacity to overall displacement. Conclusion: In the present study, a physical model was designed to investigate the effect of helical anchors’ geometry on displacement rate of helical anchor wall and compare it with a nail wall. Overall, comparing the results obtained by conducting these experiments on a helical anchor stabilized wall and a nail wall revealed that:-Wall crest displacement is affected by the diameter and number of helices and decreases by an increase in bearing capacity.-The increase in the number of pitches from one to two (single-pitch to double-pitch anchor) has a higher effect on displacement control compared to the case of changing the double-pitch to triple-pitch anchor. So, it can be stated that a further increase in the number of anchor pitches results in a declined performance of the anchors.-All anchors need a slight displacement for activation. This issue cannot be resolved by changing the type of helical anchors. Hence, when the displacement required for activation of the anchors exceeds the allowable wall crest displacement, use of post-tensioned helical anchors is recommended.-A comparison between nailing and helical anchor results revealed that the relative density of the wall stabilized with the helical anchor is less than that of the nail wall; and wall crest displacement in the helical anchor wall was very lower than that of nail wall. Thus, the helical anchor wall stabilization is preferred when other economic and technical requirements are met.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    1391
  • Volume: 

    17
Measures: 
  • Views: 

    257
  • Downloads: 

    0
Abstract: 

شواهد اخیر نشان می دهد که سلولهای بنیادی سوماتیک نامحدود کاندید مناسب تری برای سلول درمانی میباشد.با این وجود مکانیسم های سیگنالینگ کنترل کننده آنها برای تمایز به دودمانهای مختلف سلولی هنوز شناسایی نشده است.هدف از این مطالعه، بررسی نقش مسیر اصلی Wnt در تمایز سلولهای بنیادی سوماتیک نامحدود به سلولهای استخوانی است...

Yearly Impact:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Issue Info: 
  • Year: 

    2012
  • Volume: 

    3
  • Issue: 

    2
  • Pages: 

    113-119
Measures: 
  • Citations: 

    0
  • Views: 

    1313
  • Downloads: 

    0
Abstract: 

Aim: Expression of aquaporin5 (AQP5), a member of aquaporins family of water channel proteins, in the early stage of colon cancer suggests that AQP5 is probably a driving force in colon carcinogenesis. We hypothesized that curcumin can reduce the level of AQP5 protein in hct116 colon cancer cells.Material and methods: hct116 colorectal cancer cells were cultured in DMEM, divided into three groups, nontreated control group, vehicle-treated and drug-treated. Cells were just exposed to medium, vehicle-treated (sham) cells received ethanol (as the solution of curcumin) and drug-treated cells were treated with different concentrations (10, 20, 30, 50, 80, 160 mM) of curcumin for 24 and 48h. Cell viability measured by MTT assay. Then cells were treated with 50 mM (IC50) of curcumin. immunocytochemistry performed to examine the effect of curcumin on the expression of AQP5.Results: MTT assay indicated that curcumin decreased cell viability and proliferation in a time and dose dependent manner. Immunocytochemistry showed that the amount of AQP5 protein decreased in treated cell by curcumin.Conclusion: our results suggested that curcumin inhibits the expression of AQP5 in human hct116 colon cancer cell line. In this article, for the first time, the effect of curcumin in inhibition of AQP5 investigated. Inhibition of AQP5 expression may provide a novel therapeutic target in colon cancer treatment and prevention.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Author(s): 

Issue Info: 
  • Year: 

    0
  • Volume: 

    2
  • Issue: 

    10
  • Pages: 

    0-0
Measures: 
  • Citations: 

    0
  • Views: 

    707
  • Downloads: 

    0
Keywords: 
Abstract: 

لطفا برای مشاهده متن کامل این مقاله اینجا را کلیک کنید.

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Author(s): 

متقی ابراهیم

Issue Info: 
  • Year: 

    1386
  • Volume: 

    5
  • Issue: 

    6
  • Pages: 

    81-111
Measures: 
  • Citations: 

    1
  • Views: 

    319
  • Downloads: 

    0
Keywords: 
Abstract: 

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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Author(s): 

بهارستان ح.

Journal: 

پیک سلامت

Issue Info: 
  • Year: 

    1383
  • Volume: 

    5
  • Issue: 

    11
  • Pages: 

    12-14
Measures: 
  • Citations: 

    2
  • Views: 

    464
  • Downloads: 

    0
Keywords: 
Abstract: 

Yearly Impact: مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

View 464

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Issue Info: 
  • Year: 

    1383
  • Volume: 

    1
Measures: 
  • Views: 

    801
  • Downloads: 

    0
Keywords: 
Abstract: 

انتقال باراز میل مهار یه سنگ یکی از پارامترهای اساسی از رفتار سیستم تقویتی سنگ می باشد که بایستی به منظور بدست اوردن پایداری کامل حفریات سطی و زیرزمینی به طور عمیق بررسی و فهمیده شود. در بررسی وضعیت انتقال بار پارامترهایی از قبیل پروفیل های مختلف میل مهار، که رل مهمی را در انتقال بار ازمیل مهار به سنگ ایفا می کند و مقاومت سنگ در بر گیرنده و فشار محصور کننده در سطح درزه برشی که به صورت پیش تنیدگی در میل مهار اعمال شده است مورد بررسی قرار گرفته اند. و همچنین پارامترهای ذکر شده در بررسی انتقال بار با استفاده از شبیه شازی های سه بعدی مورد ارزیابی قرار گرفتند. نتایج حاصل از این تحقیق نشان داده است که مقاومت سنگ در برگیرنده، پروفیل میل مهار و پیش تنیدگی میل مهار تاثیر مهمی در انتقال بار بهتر ایفا می کنند.

Yearly Impact:   مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

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