وبلاگ شخصی سید سعید میرقاسمی

وبلاگ شخصی سید سعید میرقاسمی

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ایجاد عدسی گرانشی توسّط سیاهچاله ی شوارز شیلد

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ماه سپتامبر،آزمایشگاه Argonne فنّاوری جدیدی را برای بهبود فرایند داروسازی رونمایی کرد.

آن ها با استفاده از امواج صدا،قطرات مجزّا را معلّق می کنند و مانع ایجاد کریستال در مایع می شوند که محصول آن داروی بی شکل است که

بدن آن را به طور موثّرتری جذب می کند.در نتیجه شما به دوز کمتری برای همان میزان اثر نیاز دارید.


ویدیوی معلّق سازی:

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حجم: 9.11 مگابایت




It’s not a magic trick and it’s not sleight of hand – scientists really are using levitation to improve the drug development process, eventually yielding more effective pharmaceuticals with fewer side effects.

Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have discovered a way to use sound waves to levitate individual droplets of solutions containing different pharmaceuticals. While the connection between levitation and drug development may not be immediately apparent, a special relationship emerges at the molecular level.

At the molecular level, pharmaceutical structures fall into one of two categories: amorphous or crystalline. Amorphous drugs typically are more efficiently taken up by the body than their crystalline cousins; this is because amorphous drugs are both more highly soluble and have a higher bioavailability, suggesting that a lower dose can produce the desired effect.

“One of the biggest challenges when it comes to drug development is in reducing the amount of the drug needed to attain the therapeutic benefit, whatever it is,” said Argonne X-ray physicist Chris Benmore, who led the study.

“Most drugs on the market are crystalline – they don’t get fully absorbed by the body and thus we aren’t getting the most efficient use out of them,” added Yash Vaishnav, Argonne Senior Manager for Intellectual Property Development and Commercialization.

Getting pharmaceuticals from solution into an amorphous state, however, is no easy task. If the solution evaporates while it is in contact with part of a vessel, it is far more likely to solidify in its crystalline form.  “It’s almost as if these substances want to find a way to become crystalline,” Benmore said.    

In order to avoid this problem, Benmore needed to find a way to evaporate a solution without it touching anything. Because liquids conform to the shape of their containers, this was a nearly impossible requirement -- so difficult, in fact, that Benmore had to turn to an acoustic levitator, a piece of equipment originally developed for NASA to simulate microgravity conditions.

Levitation or “containerless processing” can form pristine samples that can be probed in situ with the high-energy X-ray beam at Argonne’sAdvanced Photon Source. “This allows amorphization of the drug to be studied while it is being processed,” said Rick Weber, who works on the project team at the synchrotron.

The acoustic levitator uses two small speakers to generate sound waves at frequencies slightly above the audible range – roughly 22 kilohertz. When the top and bottom speakers are precisely aligned, they create two sets of sound waves that perfectly interfere with each other, setting up a phenomenon known as a standing wave.

At certain points along a standing wave, known as nodes, there is no net transfer of energy at all. Because the acoustic pressure from the sound waves is sufficient to cancel the effect of gravity, light objects are able to levitate when placed at the nodes.

Although only small quantities of a drug can currently be “amorphized” using this technique, it remains a powerful analytical tool for understanding the conditions that make for the best amorphous preparation, Vaishnav explained.

Argonne researchers have already investigated more than a dozen different pharmaceuticals, and the laboratory’s Technology Development & Commercialization Division is currently pursuing a patent for the method. Technology Development & Commercialization is also interested in partnering with the pharmaceutical industry to develop the technology further as well as to license it for commercial development.

After adapting the technology for drug research, the Argonne scientists teamed up with Professors Stephen Byrn and Lynne Taylor at the Department of Industrial and Physical Pharmacy at Purdue University and Jeffery Yarger of the Department of Chemistry and Biochemistry atArizona State University. The group is now working on identifying which drugs the levitation instrumentation will impact most strongly.

Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation's first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America's scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy'sOffice of Science.

DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time.  For more information, please visit science.energy.gov.

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نور لبه ی خورشید نسبت به نور مرکز 2 ثانیه بیشتر طول می کشد تا به زمین برسد.

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Supercooled Water or 'snap-freezing' - Is cooling the water to a temperature below its freezing point, fairly pure water left unagitated, has nothing for the ice to easily form around. Then you pick it up and agitate it, voilà ice.





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حجم: 4.33 مگابایت

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نیل آرمسترانگ اوّلین انسانی است که پا به ماه گذاشت و یکی از 12 فردی است که پا به ماه گذاشته است.





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چرخش ایستگاه فضایی بین المللی به طور اتّفاقی به فضانوردان اجازه داد از این زاویه فوران آتش فشان Sarychev( در جزایر Kuril

در شمال شرقی ژاپن)را در مراحل اوّلیّه ی فوران ببینند.(تاریخ 12 ژوئن2009)

آتش فشان Sarychev فعّال ترین آتش فشان در محموعه جزایر Kuril است و انتهای شمال غربی جزیره ی Matua قرار دارد.

قبل از 12 ژوئن آخرین فوران در سال 1989 اتفاق افتاد.همچنین در سال های 1986-1976-1954-1946 در حال تولید گدازه بود.

خاکستر فعالیت چند روزه ی آن 2407 کیلومتر در جنوب شرقی آن و 926 کیلومتر شمال غربی آن یافت شده است و خطوط هواپیمایی این ناحیه

برای جلوگیری از آسیب به موتور هواپیما به دلیل خاکستر آتشفشان به حال تعلیق در آمده است.



A fortuitous orbit of the +International Space Station allowed the astronauts this striking view of Sarychev Volcano (Kuril Islands, northeast of Japan) in an early stage of eruption on June 12, 2009. Sarychev Peak is one of the most active volcanoes in the Kuril Island chain, and it is located on the northwestern end of Matua Island. Prior to June 12, the last explosive eruption occurred in 1989, with eruptions in 1986, 1976, 1954, and 1946 also producing lava flows. Ash from the multi-day eruption has been detected 2,407 kilometers east-southeast and 926 kilometers west-northwest of the volcano, and commercial airline flights are being diverted away from the region to minimize the danger of engine failures from ash intake.

This detailed astronaut photograph is exciting to volcanologists because it captures several phenomena that occur during the earliest stages of an explosive volcanic eruption. The main column is one of a series of plumes that rose above Matua Island on June 12. The plume appears to be a combination of brown ash and white steam. The vigorously rising plume gives the steam a bubble-like appearance.

In contrast, the smooth white cloud on top may be water condensation that resulted from rapid rising and cooling of the air mass above the ash column. This cloud, which meteorologists call a pileus cloud, is probably a transient feature: the eruption plume is starting to punch through. The structure also indicates that little to no shearing wind was present at the time to disrupt the plume. (Satellite images acquired 2-3 days after the start of activity illustrate the effect of shearing winds on the spread of the ash plumes across the Pacific Ocean.)

By contrast, a cloud of denser, gray ash—probably a pyroclastic flow—appears to be hugging the ground, descending from the volcano summit. The rising eruption plume casts a shadow to the northwest of the island (image top). Brown ash at a lower altitude of the atmosphere spreads out above the ground at image lower left. Low-level stratus clouds approach Matua Island from the east, wrapping around the lower slopes of the volcano. Only about 1.5 kilometers of the coastline of Matua Island (image lower center) are visible beneath the clouds and ash.

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