<a href="https://www.jove.com/video/4189">LabVIEW-operated Novel Nanoliter Osmometer for Ice Binding Protein Investigations</a>
Ido Braslavsky1, 2, Ran Drori1 1Institute of Biochemistry, Food Science, and Nutrition, The Robert H. Smith Faculty of Agriculture, Food, and Environment, The Hebrew University of Jerusalem, 2Department of Physics and Astronomy, Ohio University
Ice binding proteins (IBPs), also known as antifreeze proteins, inhibit ice growth and are a promising additive for use in the cryopreservation of tissues. The main tool used to investigate IBPs is the nanoliter osmometer. We developed a home-designed cooling stage mounted on an optical microscope and controlled using a custom-built LabVIEW routine. The nanoliter osmometer described here manipulated the sample temperature in an ultra-sensitive manner.

<a href="https://www.jove.com/video/50022">Origami Inspired Self-assembly of Patterned and Reconfigurable Particles</a>
Shivendra Pandey1, Evin Gultepe1, David H. Gracias1, 2 1Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, 2Department of Chemistry, The Johns Hopkins University
We describe experimental details of the synthesis of patterned and reconfigurable particles from two dimensional (2D) precursors. This methodology can be used to create particles in a variety of shapes including polyhedra and grasping devices at length scales ranging from the micro to centimeter scale.

<a href="https://www.jove.com/video/50225">Rapid Colorimetric Assays To Qualitatively Distinguish RNA And DNA In Biomolecular Samples</a>
Jennifer Patterson, Cameron Mura Department of Chemistry, University of Virginia
A suite of colorimetric assays is described for rapidly distinguishing protein, RNA, DNA, and re-ducing sugars in potentially heterogeneous biomolecular samples.

<a href="https://www.jove.com/video/4323">Preparation and Use of Samarium Diiodide (SmI2) in Organic Synthesis: The Mechanistic Role of HMPA and Ni(II) Salts in the Samarium Barbier Reaction</a>
Dhandapani V. Sadasivam, Kimberly A. Choquette, Robert A. Flowers II Department of Chemistry, Lehigh University
A straightforward procedure for the preparation of samarium diiodide (SmI2) in THF is described. The role of two main additives namely hexamethylphosphoramide (HMPA) and Ni(acac)2 in Sm mediated reactions is demonstrated in the Sm-Barbier reaction.

<a href="https://www.jove.com/video/50021">Bringing the Visible Universe into Focus with Robo-AO</a> 
Christoph Baranec1, 2, Reed Riddle1, Nicholas M. Law3, A.N. Ramaprakash4, Shriharsh P. Tendulkar2, Khanh Bui1, Mahesh P. Burse4, Pravin Chordia4, Hillol K. Das4, Jack T.C. Davis1, Richard G. Dekany1, Mansi M. Kasliwal5, Shrinivas R. Kulkarni1, 2, Timothy D. Morton2, Eran O. Ofek6, Sujit Punnadi4 1Caltech Optical Observatories, California Institute of Technology, 2Department of Astronomy, California Institute of Technology, 3Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 4Inter-University Centre for Astronomy &#38; Astrophysics, 5Observatories of the Carnegie Institution for Science, 6Benoziyo Center for Astrophysics, Weizmann Institute of Science
Light from astronomical objects must travel through the earth's turbulent atmosphere before it can be imaged by ground-based telescopes. To enable direct imaging at maximum theoretical angular resolution, advanced techniques such as those employed by the Robo-AO adaptive-optics system must be used.

<a href="https://www.jove.com/video/50130">Trajectory Data Analyses For Pedestrian Space-time Activity Study</a>
Feng Qi1, Fei Du2 1School of Environmental and Life Sciences, Kean University, 2Department of Geography, University of Wisconsin-Madison
A suite of spatiotemporal processing methods are presented to analyze human trajectory data, such as that collected using a GPS device, for the purpose of modeling pedestrian space-time activities.

<a href="https://www.jove.com/video/4416">Murine Fetal Echocardiography</a>
Gene H. Kim Department of Medicine, Section of Cardiology, Institute for Cardiovascular Research, University of Chicago
Fetal and perinatal death is a common feature when studying genetic alterations affecting cardiac development. High-frequency ultrasound imaging has improved 2-D resolution and can provide excellent information on early cardiac development and is an ideal method to detect the impact on cardiac structure and function prior to death.

No conflicts of interest declared.

february 2013: this month in jove

Here's a look at what's coming up in the February 2013 issue of Journal of Visualized Experiments (JoVE).
Since JoVE's first issue, biomedical research has comprised the predominate fraction of our content, and we've got sections for Neuroscience, Clinical and Translational Medicine, Bioengineering, and Immunology. In July 2012, we branched out to the physical sciences with the launch of JoVE Applied Physics. This month, we are pleased to release the first video-articles in JoVE Chemistry, which features subjects ranging from complex biochemistry, to assay development, to chemical engineering, and organic synthesis.
In the chemical engineering department, Pandey et al. combine planar lithography with self-folding methods to create 3-dimensional structures inspired by the art of origami. Through exposure to heat or magnetic fields, these microstructures can be induced to fold over objects, and can be used to excise tissue - an application that could translate to taking nanoscale biopsies in vivo.
Moving on to biochemistry, Braslavsky and Drori present an experiment designed to measure the effects of ice-binding proteins on ice crystal formation. Through video microscopy and subsequent video analysis, thermal hysteresis-the difference between freezing and melting temperatures-can be determined in the presence of antifreeze proteins, which protect many organisms like bacteria and plants from freezing temperatures.
In JoVE Applied Physics, Baranec et al. aim for the stars in our very first astronomy article, which brings the visible universe into focus with the Robo-AO laser adaptive optics system. With the help of a high-power laser beam, this system corrects the incoming light waves that get distorted by atmospheric turbulence so objects in the sky can be seen with high resolution. The authors plan to use this technique to find planets beyond our Solar System, and make precise observations of astronomical phenomena.
Looking back at Earth, Qi and Du examine how human movements in spatial and temporal dimensions can be used to study disease transmission. GPS-enabled devices can be used to automatically collect human trajectory data, which the authors process using a novel interactive interface. The trajectories can also be animated in Google Earth. These methods can help detect "hot spots" for the transmission of infectious diseases, such as influenza.
In JoVE Clinical and Translational Medicine, Kim presents a non-invasive method for imaging fetal mouse hearts in utero using high-frequency ultrasonography. This procedure, also called echocardiography, can be used to study normal heart structure and function as well as the mechanisms of cardiovascular disease. It can even be used for the early diagnosis of heart defects, making this a powerful tool with many scientific and clinical applications.
From visualizing the far reaches of space, to analyzing human movements in space and time, you've just caught a glimpse of JoVE's new content for February 2013. Like the universe, we continue to expand, and this month marks our arrival at a new frontier with the launch of Chemistry in JoVE: The Journal of Visualized Experiments.

Watch this Scientific Journal Video about February 2013: This Month in JoVE at JoVE.com

February 2013: This Month in JoVE

Here's a look at what's coming up in the February 2013 Issue of Journal of Visualized Experiments (JoVE).

Here's a look at what's coming up in the February 2013 issue of Journal of Visualized Experiments (JoVE).
Since JoVE's first issue, biomedical research ...

Research

JoVE Journal

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8.9K vues.  Massachusetts Eye and Ear. Voici un aperçu de ce qui s'en vient en Février 2013 dans la Revue des expériences visualisées (JoVE).

Vidéo: February 2013: This Month in JoVE

August 2012: This Month in JoVE

Traditional microscopy requires lens objectives to magnify specimens, and can involve numerous optical components like additional objectives, filters, and mirrors to refract and direct light to optical sensors. The August 2012 issue of JoVE (Journal of Visualized Experiments) is marked by the third publication from the Ozcan Lab (University of California, Los Angeles) on their lens free lens-free "on-chip" microscopy platform, which they have pioneered.
Back in 2009, the Ozcan lab published their first article, which demonstrated the use of a lens-free imaging platform that could image cells within whole blood. This imaging technique involves placing a sample directly on an optoelectric sensor array, like the CCD or CMOS chips found in the standard camcorder. Then, LED illumination from above the sample casts shadows on the chip, which are recorded as digital holograms that can be subjected to image processing. Not only does this lensless imaging system allow for an extremely large field of view (FOV of 0.6-8 cm2), the lack of bulky optical components makes it excellent for microfluidic applications. The Ozcan group demonstrates this in their follow-up 2011 JoVE article, in which fluorescently labeled white blood cells are imaged within a microfluidic chip.
This August in JoVE, the Ozcan group demonstrates further advancements to their lens-free microscopy platform by applying it to tomographic imaging of the nematode, C. elegans. By changing the angle of illumination, using a motorized rotation stage, the Ozcan group shows how multiple holographic slices may be generated for a sample-which, following processing, can be combined into tomograms. The Ozcan group confirms that their 3D reconstruction of the worm is successful by citing that the pharyngeal tube, a 5-micron-thick structure, is only visible in a single slice and in a 3D reconstructed cross section.
The compact and inexpensive nature of the lens-free imaging systems - designed and assembled by the Ozcan group - make them well suited for point-of-care diagnostic applications, or even cell phone based microscopy that can be performed in the field.
At the Ernest Gallo Clinic and Research Center at University of California, San Francisco JoVE learns how to visualize morphological changes in single cells using three-dimensional fluorescence microscopy and computer analysis. In this procedure, cells are given agonist, antagonist plus agonist, or no treatment, and prepared for immunofluorescence microscopy. Three-dimensional images are acquired with the help of a two-photon laser system, and the fluorescence data are processed on the computer using Imaris and Matlab.
To demonstrate the power of this technique, our authors quantify single-cell phenotypic changes in transfected HEK293 cells. Three-dimensional morphometric analysis shows dramatic changes in cells treated with agonist. These changes are not always apparent when using conventional 2D analysis. This technique allows morphological changes in single cells to be quantified and characterized in response to pharmacologic stimuli, offering a powerful new assessment tool to the arsenal of drug discovery research.
This month, in JoVE Applied Physics, we travel to South Carolina to visit the School of Materials Science and Engineering at Clemson University. Here, researchers show us how to construct lithium batteries for laboratory research.
The basic components of a lithium coin cell are the working electrode, the lithium electrolyte, and a lithium foil counter electrode. The different components of the coin cell are carefully assembled and sealed with a crimping machine. The finished coin cell can then be characterized in a battery tester. Using their homemade coin cells, our researchers can experiment with using different materials to make the cathodes of lithium coin cells.
This month in JoVE Immunology and Infection, we head to Basel, Switzerland to witness two techniques for diagnosing helminth infections. We also see how investigators perform the shuttle run test in children, in order to assess the effects of these infections on physical fitness.
Helminths are parasitic worms that can live inside humans and animals. Many species infect the intestinal tract, and may be transmitted through soil. Our authors demonstrate the Kato-Katz technique, which is used for diagnosing several common soil-transmitted helminths. They also demonstrate the Baermann technique, which uses light to stimulate the migration of certain types of phototactic helminths out of sample preparations. The various types of helminth species can subsequently be determined based on morphology.
Our authors then demonstrate how to set up and perform a 20-meter shuttle run test for children, and to measure the impact of helminth infections on physical fitness. This method can help determine the true burden of soil-transmitted helminth infections on overall health.
This brief summary highlights but a few notable video-articles that will be released in August. We'll also feature articles that demonstrate how to express genes in the midbrain of the chick embryo, study neutrophil transmigration in parallel flow chambers lined with endothelial cells, and precisely measure proteolytic degradation of the extracellular matrix.

Traditional microscopy requires lens objectives to magnify specimens, and can involve numerous optical components like additional objectives, filters, and mirrors to refract and direct light to optical sensors. The August 2012 issue of JoVE (Journal of Visualized Experiments) is marked by the third publication from the Ozcan Lab (University of California, Los Angeles) on their lens-free "on-chip" microscopy platform, which they have pioneered.

Traditional microscopy requires lens objectives to magnify specimens, and can involve numerous optical components like additional objectives, filters, and ...

2012: A Year In Review

Here's a look at some of the milestones and highlights of the year 2012 in Journal of Visualized Experiments (JoVE).
At the start of 2012, JoVE reached a major milestone by publishing our 1500th article. In this publication, in JoVE Bioengineering, Yu et al. described a method for analyzing the free radical composition of cigarette smoke. This method simulated cigarette puffing with a single-port smoking device, and combined it with electron spin resonance (ESR) spectroscopy to measure the degree to which antioxidant compounds can scavenge free radicals in cigarette smoke. A possible outcome of this research is the creation of less harmful cigarettes.
JoVE Bioengineering also contained the most-viewed article of 2012. Owczarczak et al. described a method for hacking a standard inkjet printer, loading ink cartridges with a cell-suspension "bioink," and printing lines of live cells onto glass slides. The thermal inkjet printing process creates temporary pores in the cell membrane, visualized by the incorporation of fluorescently labeled actin monomers. This concept, called "bioprinting," has many potential applications in cell and tissue engineering.
Also in 2012, JoVE Bioengineering featured a protocol by Hsia et al. for isolating and purifying spider silk protein, spinning it into fibers, and assessing the fiber strength. This protocol for laboratory-scale production of spider silk, which is stronger than tensile steel, can potentially be extended to large-scale manufacturing.
In JoVE Clinical and Translational Medicine, we featured a number of articles related to stroke, one of which. In one article, M&ouml;bius-Winkler et al. demonstrated placement of the WATCHMAN left atrial appendage occlusion device from Boston Scientific. This device is designed to prevent strokes by trapping clots within the left atrial appendage of the heart before they exit. Our authors demonstrated how to insert the guide wire through the femoral artery into the heart, advance the device into the left atrium, and deploy the device in the left atrial appendage.
Another article focused on stroke, Hamel et al. described the use of a driving simulator to study how patients compensate for visual field defects following stroke. By analyzing the compensatory gaze behavior of patients as they navigated through virtual driving courses with varying degrees of complexity, our authors see great potential for the use of driving simulators in stroke rehabilitation.
In JoVE Immunology and Infection, we published an article by Keyel et al. describing the real-time kinetics of immune cell responses to bacterial toxins using live cell microscopy. Combined with high-speed 3D confocal microscopy, this technique can also visualize the cellular repair response.
Also in JoVE Immunology and Infection, we featured an article by Yap et al. describing methods for diagnosing helminth infections in children. Helminths are parasitic worms that can infect the intestinal tract of humans and animals, and may be distinguished based on their morphology. The same article demonstrated how to measure the impact of helminth infections on physical fitness in children, which is a measure of overall health.
In JoVE Neuroscience, we featured a method by Hoffmann et al., who used tiny headphones to alter the auditory feedback in songbirds, and analyzed the computational and neurophysiological basis of vocal learning in birds when they adjust their singing in response to altered acoustic signals.
Also in JoVE Neuroscience, we moved from birds to bees with a method that assesses associative and non-associative tactile learning in honeybees. This method, by Mujagi&#263; et al., allowed bees to scan different metal surfaces with their antennae, then conditioned them to expect sugar water when their antennae touched particular surfaces, and analyzed the corresponding changes in antennal movement.
In 2012, we launched a brand-new section: JoVE Applied Physics, which features articles on subjects ranging from plasma physics to material science. The Applied Physics section also contained JoVE's 2000th video article, filmed in a synchrotron radiation facility, where Borisenko et al. showed how to determine the electronic structure of complex materials using angle-resolved photoemission spectroscopy.
In the JoVE General section, we published an article by Artioli et al. demonstrating the use of a portable gas analyzer to measure oxygen consumption during complex exercise - such as judo. By analyzing oxygen consumption and collecting blood for measuring plasma lactate concentration, this method can determine the relative contributions of different energy systems to specific aspects of complex exercise.
Finally, JoVE followed Dolhi et al. to a permanently ice-covered saline lake in Antarctica. There, scientists drilled through the ice to study single-celled microorganisms called protists that live in the harsh conditions of Antarctica.
This Year in Review was just a brief glimpse of a few of over 600 video articles that JoVE offered in 2012. Browse the JoVE archives to see thousands of other videos, and stay tuned for what's coming up this year in JoVE: The Journal of Visualized Experiments.

Here's a look at some of the milestones and highlights of the year 2012 in Journal of Visualized Experiments (JoVE).

 
 
Here's a look at some of the milestones and highlights of the year 2012 in Journal of Visualized Experiments (JoVE).
At the start of 2012, JoVE ...