Scanning electron microscope (SEM) image of quantum dots fabricated through electron beam lithography
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SEM image of a micron sized trench in a Cu/SiO2/Si multilayer
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SEM image of a work sample on a magnesium oxide surface using FIB. The diameter of the hole measures approximate. 4 µm.
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Tiny spaces have formed inside titanium dioxide nanocrystals, as shown in this SEM image.
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Gold-manganese nanoparticles for targeted diagnostic and imaging. @nanotech1
Gold-manganese nanoparticles for targeted diagnostic and imaging
(Nanowerk Spotlight) Imagine the possibility of non-invasive, non-radiation based Magnetic Resonance Imaging (MRI) in combating cardiac disease. Researchers at the Savannah River National Laboratory (SRNL) are developing a process that would use nanotechnology in a novel, targeted approach that would allow MRIs to be more descriptive and brighter, and to target specific organs.
An MRI is a non-invasive procedure that uses a superconducting magnet to align the hydrogen protons in the body. Magnetic resonance imaging is one of the most powerful imaging and diagnostic techniques used to visualize the internal structure of the body. Contrast agents, or dyes, are used to help provide different signals and improve the captured magnetic image. Of the contrast agents, one can be extremely toxic, while overexposure to another can lead to Parkinson’s disease. A third agent has limitations that can create “black holes” in the image.
By using nanoparticle-based MRI positive contrast agents, you can specifically target different tissues or organs, you can control active component loading, and you can generate bright or hyperintense anatomical view of the tissue.
Researchers at SRNL have discovered a way to use multifunctional metallic gold-manganese nanoparticles to create a unique, targeted positive contrast agent (Journal of Nanoparticle Research, "Manganese–gold nanoparticles as an MRI positive contrast agent in mesenchymal stem cell labeling"). SRNL Senior Scientist, Dr. Simona Hunyadi Murph, first thought of using nanoparticles for cardiac disease applications after learning that people who have survived an infarct exhibit have up to a 15 times higher rate of developing chronic heart failure, arrhythmias and/or sudden death compared to the general population.
Read more: Gold-manganese nanoparticles for targeted diagnostic and imaging
http://www.nanowerk.com/spotlight/spotid=41828.php
(Nanowerk Spotlight) Imagine the possibility of non-invasive, non-radiation based Magnetic Resonance Imaging (MRI) in combating cardiac disease. Researchers at the Savannah River National Laboratory (SRNL) are developing a process that would use nanotechnology in a novel, targeted approach that would allow MRIs to be more descriptive and brighter, and to target specific organs.
An MRI is a non-invasive procedure that uses a superconducting magnet to align the hydrogen protons in the body. Magnetic resonance imaging is one of the most powerful imaging and diagnostic techniques used to visualize the internal structure of the body. Contrast agents, or dyes, are used to help provide different signals and improve the captured magnetic image. Of the contrast agents, one can be extremely toxic, while overexposure to another can lead to Parkinson’s disease. A third agent has limitations that can create “black holes” in the image.
By using nanoparticle-based MRI positive contrast agents, you can specifically target different tissues or organs, you can control active component loading, and you can generate bright or hyperintense anatomical view of the tissue.
Researchers at SRNL have discovered a way to use multifunctional metallic gold-manganese nanoparticles to create a unique, targeted positive contrast agent (Journal of Nanoparticle Research, "Manganese–gold nanoparticles as an MRI positive contrast agent in mesenchymal stem cell labeling"). SRNL Senior Scientist, Dr. Simona Hunyadi Murph, first thought of using nanoparticles for cardiac disease applications after learning that people who have survived an infarct exhibit have up to a 15 times higher rate of developing chronic heart failure, arrhythmias and/or sudden death compared to the general population.
Read more: Gold-manganese nanoparticles for targeted diagnostic and imaging
http://www.nanowerk.com/spotlight/spotid=41828.php
Nanowerk
Gold-manganese nanoparticles for targeted diagnostic and imaging
Imagine the possibility of non-invasive, non-radiation based Magnetic Resonance Imaging (MRI) in combating cardiac disease. Researchers are developing a process that would use nanotechnology in a novel, targeted approach that would allow MRIs to be more descriptive…
Spiders point the way to make better adhesives for high-humidity environments
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Spiders point the way to make better adhesives for high-humidity environments
(Nanowerk Spotlight) Scientists have long been fascinated by spider silk – a unique biopolymer that combines mechanical strength and elasticity to make it one of the toughest materials known. In addition, the silk threads are coated with an adhesive which ranks among the strongest biological glues.
Spiders are one of the most diverse species on the planet. Currently, there are about 45,000 known species of spiders living in a variety of habitats and environments. About 1/6th of these species use webs to catch prey.
The capture silk used in these webs consists of axial fiber coated with glue droplets at regular intervals. The spider glue has a unique property that its adhesion is humidity responsive such that for some species the adhesion keeps on increasing up to 100% relative humidity.
This is unlike synthetic adhesives that fail under humid conditions. From a polymer science perspective, researchers are interested in understanding the principle behind humidity responsive adhesion of spider glue to create adhesives that work in high humidity conditions.
"Adhesion in high humidity environment is a fundamental challenge for synthetic and natural adhesives; yet, some spider species that are active in highly humid environments use glue that is the stickiest in almost 100% humidity conditions," Ali Dhinojwala, H.A. Morton Professor in the Department of Polymer Science at the University of Akron, tells Nanowerk. "We find that the spider glue from five different species, living in diverse habitats, is maximally adhesive at the humidity where the spider hunts for prey. This is intuitive but beautiful to observe in data."
Previously, Dhinojwala's group had worked on understanding the mechanism of spider glue adhesion at a particular humidity ("Ubiquitous distribution of salts and proteins in spider glue enhances spider silk adhesion").
A new paper just published in ACS Nano ("Spiders Tune Glue Viscosity to Maximize Adhesion") discusses the mechanism of humidity responsive adhesion of spider glue.
"We observed that the glue extensibility increased dramatically with an increase in humidity," says Gaurav Amarpuri, a PhD student in Dhinojwala's group and the paper's first author. "We used high speed imaging to quantify the spreading of glue and further used spreading power law to measure the glue viscosity."
Read more: Spiders point the way to make better adhesives for high-humidity environments
http://www.nanowerk.com/spotlight/spotid=41816.php
(Nanowerk Spotlight) Scientists have long been fascinated by spider silk – a unique biopolymer that combines mechanical strength and elasticity to make it one of the toughest materials known. In addition, the silk threads are coated with an adhesive which ranks among the strongest biological glues.
Spiders are one of the most diverse species on the planet. Currently, there are about 45,000 known species of spiders living in a variety of habitats and environments. About 1/6th of these species use webs to catch prey.
The capture silk used in these webs consists of axial fiber coated with glue droplets at regular intervals. The spider glue has a unique property that its adhesion is humidity responsive such that for some species the adhesion keeps on increasing up to 100% relative humidity.
This is unlike synthetic adhesives that fail under humid conditions. From a polymer science perspective, researchers are interested in understanding the principle behind humidity responsive adhesion of spider glue to create adhesives that work in high humidity conditions.
"Adhesion in high humidity environment is a fundamental challenge for synthetic and natural adhesives; yet, some spider species that are active in highly humid environments use glue that is the stickiest in almost 100% humidity conditions," Ali Dhinojwala, H.A. Morton Professor in the Department of Polymer Science at the University of Akron, tells Nanowerk. "We find that the spider glue from five different species, living in diverse habitats, is maximally adhesive at the humidity where the spider hunts for prey. This is intuitive but beautiful to observe in data."
Previously, Dhinojwala's group had worked on understanding the mechanism of spider glue adhesion at a particular humidity ("Ubiquitous distribution of salts and proteins in spider glue enhances spider silk adhesion").
A new paper just published in ACS Nano ("Spiders Tune Glue Viscosity to Maximize Adhesion") discusses the mechanism of humidity responsive adhesion of spider glue.
"We observed that the glue extensibility increased dramatically with an increase in humidity," says Gaurav Amarpuri, a PhD student in Dhinojwala's group and the paper's first author. "We used high speed imaging to quantify the spreading of glue and further used spreading power law to measure the glue viscosity."
Read more: Spiders point the way to make better adhesives for high-humidity environments
http://www.nanowerk.com/spotlight/spotid=41816.php
Nanowerk
Spiders point the way to make better adhesives for high-humidity environments
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کانال نانوتکنولوژی: کتاب،مقالات،مطالب و عکس های مرتبط با حوزه های مختلف نانو @nanotech1 شیمی-فیزیک-مواد-پزشکی-مدلسازی
Nano-Explosions Color-enhanced scanning electron micrograph of an overflowed electrodeposited magnetic nanowire array (CoFeB), where the template has been subsequently completely etched. It’s a reminder that nanoscale research can have unpredicted consequences at a high level.
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Bamboos for Vibration Control Ni-Mn-Ga melt-extracted fibers with an approximate diameter of 100 µm showing a bamboo-type structure (imaged with a backscattered electron detector in an FEG-SEM). Melt-extraction is a unique and novel method to prepare single-crystalline particles for magnetic shape memory composites.
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کاربرد گرافن در آنتن ها: فرصت ها و چالش ها از مایکروویو تا تراهرتز
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استفاده از گرافن برای آنتنها و سایر وسایل الکترومغناطیسی میتواند مزایای بسیاری همچون کوچک سازی زیاد ، ادغام یکپارچه با نانوالکترونیک گرافن RF، تنظیم پویای کارآمد و حتی شفافیت و انعطاف پذیری مکانیکی را داشته باشد . اگرچه کارهای تئوریکی و نظری بسیار متفاوتی در این حوزه انجام شده است اما کاربردهای بسیار کمی پیشنهاد شده و در واقعیت مورد ارزیابی قرار گرفته است . در این مقاله در مورد خواص گرافن و کاربردهای تجربی و تئوری آن صحبت خواهیم کرد . سپس در مورد تعدادی از کاربردهای بالقوه آنتن از مایکروویو تا تراهرتزبحث خواهیم کرد و ارزیابی های ضروری در هر کدام را به همراه مزایا، محدودیت ها و مسائل مربوط به آن در کاربردهای واقعی را بیان میکنیم. در این جا خلاصه ای از دستگاههای مختلف و توسعههای مرتبط با آن که شامل آنتن های گرافنی و آرایه های انعکاسی در مایکروویو و تراهرتز،سوئیچ های پلاسمونیک و متاسطوح همسانگرد و ناهمسانگرد است را فراهم می کنیم .
برگرفته شده از nano-mag.ir
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استفاده از گرافن برای آنتنها و سایر وسایل الکترومغناطیسی میتواند مزایای بسیاری همچون کوچک سازی زیاد ، ادغام یکپارچه با نانوالکترونیک گرافن RF، تنظیم پویای کارآمد و حتی شفافیت و انعطاف پذیری مکانیکی را داشته باشد . اگرچه کارهای تئوریکی و نظری بسیار متفاوتی در این حوزه انجام شده است اما کاربردهای بسیار کمی پیشنهاد شده و در واقعیت مورد ارزیابی قرار گرفته است . در این مقاله در مورد خواص گرافن و کاربردهای تجربی و تئوری آن صحبت خواهیم کرد . سپس در مورد تعدادی از کاربردهای بالقوه آنتن از مایکروویو تا تراهرتزبحث خواهیم کرد و ارزیابی های ضروری در هر کدام را به همراه مزایا، محدودیت ها و مسائل مربوط به آن در کاربردهای واقعی را بیان میکنیم. در این جا خلاصه ای از دستگاههای مختلف و توسعههای مرتبط با آن که شامل آنتن های گرافنی و آرایه های انعکاسی در مایکروویو و تراهرتز،سوئیچ های پلاسمونیک و متاسطوح همسانگرد و ناهمسانگرد است را فراهم می کنیم .
برگرفته شده از nano-mag.ir
محققان دانشگاه بازل، تکنیک جدیدی را گسترش داده اند که از نانو بادی ها استفاده میکند.با به کارگیری مورفوترپ (Morphotrap )، توزیع مورفوژن DPP که نقش مهمی در توسعه و گسترش بال دارد را می توان به صورت انتخابی دستکاری کرد و برای اولین بار در مگس میوه مورد تجزیه و تحلیل قرار داد. در آینده این ابزار می تواند برای تحقیقات مختلفی در مورد رشد اندام ها مورد استفاده قرار گیرد . نتایج این تحقیق در شماره اخیر مجله Nature منتشر شده است.
دو فرآیند اصلی که می تواند توسعه و گسترش اندام ها را کنترل کند شامل تنظیم رشد و الگوهای فضایی است . تیم تحقیقاتی پرفسور مارکوس آفولتر (Markus Affolter) در دانشگاه بازل ، هم اکنون روش جدیدی به نام مورفوترپ برای مطالعه ی توسعه و رشد بال در مگس میوه را گسترش داده اند. نتایج آنها نشان می دهد که سیگنالینگ مولکول DPP ، به اصطلاح یک مورفوژن ، رشد در مرکز دیسک خیالی(imaginal disc ) باله را تحت تاثیر قرار می دهد اما تاثیری در نواحی محیطی ندارد . این اولین باری است که از یک نانو بادی ضد GFP برای چنین تحقیقاتی استفاده می شود . این ابزار می تواند برای مطالعه ی رشد ارگان ها در آینده بسیار امیدوار کننده باشد .
برگرفته شده از nano-mag.ir
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دو فرآیند اصلی که می تواند توسعه و گسترش اندام ها را کنترل کند شامل تنظیم رشد و الگوهای فضایی است . تیم تحقیقاتی پرفسور مارکوس آفولتر (Markus Affolter) در دانشگاه بازل ، هم اکنون روش جدیدی به نام مورفوترپ برای مطالعه ی توسعه و رشد بال در مگس میوه را گسترش داده اند. نتایج آنها نشان می دهد که سیگنالینگ مولکول DPP ، به اصطلاح یک مورفوژن ، رشد در مرکز دیسک خیالی(imaginal disc ) باله را تحت تاثیر قرار می دهد اما تاثیری در نواحی محیطی ندارد . این اولین باری است که از یک نانو بادی ضد GFP برای چنین تحقیقاتی استفاده می شود . این ابزار می تواند برای مطالعه ی رشد ارگان ها در آینده بسیار امیدوار کننده باشد .
برگرفته شده از nano-mag.ir
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