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Zinc Fingers: Motifs in DNA- and RNA-binding proteins whose amino acids are folded into a single structural unit around a zinc atom. In the classic zinc finger, one zinc atom is bound to two cysteines and two histidines. In between the cysteines and histidines are 12 residues which form a DNA binding fingertip. By variations in the composition of the sequences in the fingertip and the number and spacing of tandem repeats of the motif, zinc fingers can form a large number of different sequence specific binding sites.
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Photoelectric Effect

JoVE 10413

Source: Yong P. Chen, PhD, Department of Physics && Astronomy, College of Science, Purdue University, West Lafayette, IN

Photoelectric effect refers to the emission of electrons from a metalwhen light is shining on it. In order for the electrons to be liberated from the metal, the frequency of the light needs to be sufficiently high such that the photons in the light have sufficient energy. This energy is proportional to the light frequency.The photoelectric effect provided the experimental evidence for the quantum of light that is known as photon. This experiment will demonstrate the photoelectric effect using a charged zinc metal subject to either a regular lamp light, or ultraviolet (UV) light with higher frequency and photon energy.The zinc plate will be connected to an electroscope, an instrument that can read the presence and relative amount of charges. The experiment will demonstrate that the UV light, but not the regular lamp, can discharge the negatively charged zinc by ejecting its excess electrons.Neither light source, however, can discharge positively charged zinc, consistent with the fact that electrons that are emitted in photoelectric effect.


 Physics II

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Pelvic Exam III: Bimanual and Rectovaginal Exam

JoVE 10163

Source:

Alexandra Duncan, GTA, Praxis Clinical, New Haven, CT

Tiffany Cook, GTA, Praxis Clinical, New Haven, CT

Jaideep S. Talwalkar, MD, Internal Medicine and Pediatrics, Yale School of Medicine, New Haven, CT

A bimanual exam is a thorough check of a patient's cervix, uterus, and ovaries. It can tell an experienced provider a great deal, as it may lead to the discovery of abnormalities, such as cysts, fibroids, or malignancies. However, it's useful even in the absence of such findings, as it allows the practitioner to establish an understanding of the patient's anatomy for future reference. Performing the bimanual exam before the speculum exam can help relax patients, mentally and physically, before what is often perceived as the "most invasive" part of the exam. A practitioner already familiar with the patient's anatomy can insert a speculum more smoothly and comfortably. However, lubrication used during the bimanual exam may interfere with processing certain samples obtained during the speculum exam. Providers must be familiar with local laboratory processing requirements before committing to a specific order of examination. This demonstration begins


 Physical Examinations II

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Rodent Handling and Restraint Techniques

JoVE 10221

Source: Kay Stewart, RVT, RLATG, CMAR; Valerie A. Schroeder, RVT, RLATG. University of Notre Dame, IN 

It has been demonstrated that even minimal handling of mice and rats is stressful to the animals. Handling for cage changing and other noninvasive procedures causes an increase in heart rate, blood pressure, and other physiological parameters, such as serum corticosterone levels. Fluctuations can continue for up to several hours. The methods of restraint required for injections and blood withdrawals also cause physiological changes that can potentially affect scientific data. Training in the proper handling of mice and rats is required to minimize the effects to the animals.1 Mice and rats can be restrained manually with restraint devices, or with chemical agents. Manual methods and the use of restraint devices are covered in this manuscript. All restraint methods include the process of lifting the animals from their home cage.


 Lab Animal Research

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Pelvic Exam I: Assessment of the External Genitalia

JoVE 10144

Source:
Alexandra Duncan, GTA, Praxis Clinical, New Haven, CT
Tiffany Cook, GTA, Praxis Clinical, New Haven, CT
Jaideep S. Talwalkar, MD, Internal Medicine and Pediatrics, Yale School of Medicine, New Haven, CT

The pelvic exam can feel invasive to patients, so it is important to do everything possible to make patients feel comfortable and empowered, rather than vulnerable. Clinicians should be aware of how they are communicating, both verbally and nonverbally, and should give their patients control whenever possible. There are many ways to do this, from how the exam table is positioned to how the patient is engaged throughout the exam. As many as 1 in 5 patients may have experienced sexual trauma; therefore, it is important to avoid triggering those patients, but it's not always possible to know who they are. The exam in this video demonstrates neutral language and techniques that can be employed with all patients to create the best experience possible. It's important to keep the patient covered wherever possible and to minimize extraneous contact. A clinician should be careful to tuck fingers that aren't being used to examine the patient to avoid accidental contact with the clitoris or anus. Before performing the pelvic e


 Physical Examinations II

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Wrist and Hand Examination

JoVE 10242

Source: Robert E. Sallis, MD. Kaiser Permanente, Fontana, California, USA

The wrist is a complex joint made up of 8 carpal bones and their numerous articulations and ligaments. Overlying the wrist are the tendons and muscles of the hand and fingers. The hand is made up of 5 metacarpal bones, and the tendons that run to the hand overlie these bones. Finally, the fingers consist of 14 phalanges with their articulations held together by collateral ligaments and volar plates. Common mechanisms of both acute and chronic wrist injury include impact, weight bearing (which can occur in gymnastics), twisting, and throwing. Osteoarthritis of the hand commonly affects distal interphalangeal (DIP) and proximal interphalangeal (PIP) joints, while rheumatoid arthritis (RA) is seen in the metacarpophalangeal (MCP) and PIP joints. It is important to compare the injured wrist or hand to the uninvolved side. Key aspects of the wrist and hand exam include inspection, palpation for tenderness or deformity, testing the range of motion (ROM) and strength, neurovascular assessment, ligaments and tendon testing, and the special tests.


 Physical Examinations III

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Determining the Solubility Rules of Ionic Compounds

JoVE 10197

Source: Laboratory of Dr. Neal Abrams — SUNY College of Environmental Science and Forestry

An ionic compound's solubility can be determined via qualitative analysis. Qualitative analysis is a branch of analytical chemistry that uses chemical properties and reactions to identify the cation or anion present in a chemical compound. While the chemical reactions rely on known solubility rules, those same rules can be determined by identifying the products that form. Qualitative analysis is not typically done in modern industrial chemistry labs, but it can be used easily in the field without the need of sophisticated instrumentation. Qualitative analysis also focuses on understanding ionic and net ionic reactions as well as organizing data into a flow chart to explain observations and make definitive conclusions. Many cations have similar chemical properties, as do the anion counterparts. Correct identification requires careful separation and analysis to systematically identify the ions present in a solution. It is important to understand acid/base properties, ionic equilibria, redox reactions, and pH properties to identify ions successfully. While there is a qualitative test for virtually every elemental and polyatomic ion, the identification process typically begi


 General Chemistry

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Dispersion of Nanomaterials in Aqueous Media: Towards Protocol Optimization

1School of Geography, Earth and Environmental Sciences, University of Birmingham, 2Analytical Science, National Physical Laboratory, 3INAC-LCIB, Université Grenoble Alpes, 4CEA, INAC-SyMMES, 5NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 6Chemical, Medical and Environmental Science, National Physical Laboratory, 7BAM Division 6.1 'Surface Analysis and Interfacial Chemistry', BAM Federal Institute for Materials Research and Testing, 8Fraunhofer Institute for Ceramic Technologies and Systems

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JoVE 56074


 JoVE In-Press

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Comprehensive Breast Exam

JoVE 10118

Source:
Alexandra Duncan, GTA, Praxis Clinical, New Haven, CT
Tiffany Cook, GTA, Praxis Clinical, New Haven, CT
Jaideep S. Talwalkar, MD, Internal Medicine and Pediatrics, Yale School of Medicine, New Haven, CT

Breast exams are a key part of an annual gynecological exam and are important for all patients, no matter their sex or gender expression. One out of every 8 women will be diagnosed with breast cancer; male breast cancer, though less common, has a lifetime incidence of 1 in 1000. Breast exams can feel invasive to patients, so it is important to do everything possible to make the patients feel comfortable and empowered, rather than vulnerable. Examiners should be aware of what they are communicating, both verbally and non-verbally, and give their patients control wherever possible (for instance, always allowing them to remove their own gowns). Examiners may choose to utilize chaperones for the patients' (as well as their own) comfort. Some institutions require the use of chaperones. While it is always important to avoid overly clinical language, certain colloquial words can cross the line from caring to overly intimate in this exam. It is helpful to avoid the words "touch" and "feel" in this exam, as this lan


 Physical Examinations II

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Determining the Density of a Solid and Liquid

JoVE 10082

Source: Laboratory of Dr. Michael Evans — Georgia Institute of Technology

The ratio of the mass of a substance to its volume is known as the mass density or, simply, the density of the substance. Density is expressed in units of mass per volume, such as g/mL or kg/m3. Because the density of a substance does not depend on the amount of substance present, density is an “intensive property”. To measure the density of a sample of material, both the mass and volume of the sample must be determined. For both solids and liquids, a balance can be used to measure mass; however, methods for determining volume are different for solids and liquids. As liquids can flow and take the shapes of their containers, glassware such as a graduated cylinder or volumetric flask can be used to measure the volume of a liquid. The volume of an irregularly-shaped solid can be measured by submersion in a liquid — the difference in volume caused by addition of the solid is equal to the volume of the solid. This demonstration illustrates the methods for measuring the density of solids and liquids. Using a volumetric flask and an analytical balance, the density of ethanol can be determined. Using a graduated cylinder, analytical balance, and water as the displaced


 General Chemistry

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Abdominal Exam III: Palpation

JoVE 10089

Source: Alexander Goldfarb, MD, Assistant Professor of Medicine, Beth Israel Deaconess Medical Center, MA

Abdominal palpation, if performed correctly, allows for examination of the large and relatively superficial organs; for a skilled examiner, it allows for assessment of the smaller and deeper structures as well. The amount of information that can be obtained by palpation of the abdominal area also depends on the anatomical characteristics of the patient. For example, obesity might make palpation of internal organs difficult and require that additional maneuvers be performed. Abdominal palpation provides valuable information regarding localization of the problem and its severity, as abdominal palpation identifies the areas of tenderness as well as presence of organomegaly and tumors. The specific focus of palpation is driven by the information collected during history taking and other elements of the abdominal exam. Palpation helps to integrate this information and develop the strategy for subsequent diagnostic steps.


 Physical Examinations II

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Essential Metal Uptake in Gram-Negative Bacteria: X-Ray Fluorescence, Radioisotopes, and Cell Fractionation

1Graduate Biomedical Sciences Microbiology Theme, University of Alabama at Birmingham, 2Department of Radiology, University of Alabama at Birmingham, 3Office of the Provost, University of Alabama at Birmingham, 4Department of Pharmacology and Toxicology, University of Alabama at Birmingham

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JoVE 57169


 JoVE In-Press

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Preparation of Authigenic Pyrite from Methane-bearing Sediments for In Situ Sulfur Isotope Analysis Using SIMS

1School of Earth Sciences and Engineering, Sun Yat-sen University, 2School of Marine Sciences, Sun Yat-sen University, 3Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, 4South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, 5Institut für Geologie, Universität Hamburg, 6Institut für Geologie und Paläontologie, Westfälische Wilhelms-Universität Münster, 7Guangzhou Marine Geological Survey

JoVE 55970


 Environment

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Central Venous Access Device Dressing Change

JoVE 10311

Source: Madeline Lassche, MSNEd, RN and Katie Baraki, MSN, RN, College of Nursing, University of Utah, UT

Central venous access devices (CVAD), commonly known as central lines or central catheters, are large-bore intravenous (IV) catheters that are introduced into the central circulation. Typically, CVADs terminate in the superior vena cava, just outside of the right atrium of the heart, but they may also terminate in any one of the great veins (i.e., aorta, inferior vena cava, brachiocephalic vein, pulmonary artery, internal iliac vein, or common femoral vein). Patients may need a CVAD for any number of reasons. CVADs allow for the rapid infusion of fluids to treat significant hypovolemia or shock. They are also beneficial when administering vasoactive medications, highly concentrated medications, total parenteral nutrition (TPN), or chemotherapy, because the increased blood volume in these areas allows for the hemodilution of these potentially caustic or reactive agents. Patients who must receive multiple non-compatible IV medications, those that require long-term IV medications, or those with limited vascular access may also require the placement of a CVAD. These devices may be tunneled (i.e., inserted into a vein at one location and tunneled under the skin to emerge through the skin at another site)


 Nursing Skills

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Seeded Synthesis of CdSe/CdS Rod and Tetrapod Nanocrystals

1Department of Chemical Engineering, UC Berkeley, 2Department of Materials Science and Engineering, UC Berkeley, 3Department of Chemistry, UC Berkeley, 4Materials Sciences Division, Lawrence Berkeley National Laboratory, 5Department of Chemistry, University of Chicago, 6Center for Nanoscale Materials, Argonne National Laboratory

JoVE 50731


 Chemistry

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Elbow Exam

JoVE 10207

Source: Robert E. Sallis, MD. Kaiser Permanente, Fontana, California, USA

The elbow is a hinged joint that involves the articulation of 3 bones: the humerus, radius, and ulna. It is a much more stable joint than the shoulder, and because of that, the elbow has less range of motion. The elbow and its structures are prone to significant injuries, particularly with repetitive motion. Lateral and medial epicondylitis (also called tennis elbow and golfer's elbow) are two common diagnoses and often occur as a result of occupational activities. When examining the elbow, it is important to remove enough clothing so that the entire shoulder and elbow can be inspected. It is important to compare the injured elbow to the uninvolved side. A systematic evaluation of the elbow includes inspection, palpation, range of motion (ROM) testing, and special tests, including maneuvers to evaluate ligamentous stability and stretch tests to accentuate pain caused by epicondylitis.


 Physical Examinations III

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Aerosol-assisted Chemical Vapor Deposition of Metal Oxide Structures: Zinc Oxide Rods

1Instituto de Microelectrónica de Barcelona (IMB-CNM, CSIC), 2SIX Research Centre, Brno University of Technology, 3Institute of Physics of Material, Academy of Science of Czech Republic, 4Institute of Physical Engineering and Central European Institute of Technology, Brno University of Technology

JoVE 56127


 Chemistry

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Synthesis Of A Ti(III) Metallocene Using Schlenk Line Technique

JoVE 10428

Source: Tamara M. Powers, Department of Chemistry, Texas A&M University 

Inorganic chemists often work with highly air- and water-sensitive compounds. The two most common and practical methods for air-free synthesis utilize either Schlenk lines or gloveboxes. This experiment will demonstrate how to perform simple manipulations on a Schlenk line with a focus on solvent preparation and transfer. Through the synthesis of a reactive Ti(III) metallocene complex, we will demonstrate a new, simple method to degas solvent as well as how to transfer solvent by cannula and by syringe on a Schlenk line. The synthesis of a Ti(III) metallocene compound 3 is shown in Figure 1.1 Compound 3 is highly reactive with O2, (see oxidation of compound 3 to Ti(IV) metallocene 4 shown in Figure 1). Therefore, it is important to run the synthesis under anaerobic conditions. The synthesis of target compound 3 can be monitored visually and progresses through one additional color change before arriving at the desired product, which is blue in color. If during the experiment there is an observed color change from blue to yellow (or green = blue + yellow), this is an indication that O2 entered the flask and that undesired oxidation of compound 3 to


 Inorganic Chemistry

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Compound Administration I

JoVE 10198

Source: Kay Stewart, RVT, RLATG, CMAR; Valerie A. Schroeder, RVT, RLATG. University of Notre Dame, IN

As many research protocols require that a substance be injected into an animal, the route of delivery and the amount of the substance must be accurately determined. There are several routes of administration available in the mouse and rat. Which route to use is determined by several factors of the substance to be injected: the pH of the solution, the volume required for the desired dosage, and the viscosity of the solution. Severe tissue damage can occur if a substance is administered incorrectly. This video looks at the various restraint methods and technical details for the most commonly used injection routes.


 Lab Animal Research

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Motor Exam I

JoVE 10052

Source:Tracey A. Milligan, MD; Tamara B. Kaplan, MD; Neurology, Brigham and Women's/Massachusetts General Hospital, Boston, Massachusetts, USA

Abnormalities in the motor function are associated with a wide range of diseases, from movement disorders and myopathies to strokes. The motor assessment starts with observation of the patient. When the patient enters the examination area, the clinician observes the patient's ability to walk unassisted and the speed and coordination while moving. Taking the patient's history provides an additional opportunity to observe for evidence of tremors or other abnormal movements, such as chorea or tardive dyskinesia. Such simple but important observations can yield valuable clues to the diagnosis and help to focus the rest of the examination. The motor assessment continues in a systematic fashion, including inspection for muscle atrophy and abnormal movements, assessment of muscle tone, muscle strength testing, and finally the examination of the muscle reflexes and coordination. The careful systematic testing of the motor system and the integration of all the findings provide insight to the level at which the motor pathway is affected, and also help the clinician to formulate the differential diagnosis and determine the course of the subsequent evaluation and treatment.


 Physical Examinations III

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Basic Life Support Part II: Airway/Breathing and Continued Cardiopulmonary Resuscitation

JoVE 10232

Source: Julianna Jung, MD, FACEP, Associate Professor of Emergency Medicine, The Johns Hopkins University School of Medicine, Maryland, USA

High-quality cardiopulmonary resuscitation (CPR) and defibrillation are the most important interventions for patients with cardiac arrest, and should be the first steps that rescuers perform. This is reflected in the American Heart Association's new "CAB" mnemonic. While rescuers were once taught the "ABCs" of cardiac arrest, they now learn "CAB" - circulation first, followed by airway and breathing. Only once CPR is underway (and defibrillation has been performed, if a defibrillator is available) do we consider providing respiratory support. This video will describe the correct technique for providing respiratory support to a patient in cardiac arrest, and how to continue basic life support over the period of time until help arrives. This video assumes that all the steps described in "Basic Life Support Part I: Cardiopulmonary Resuscitation and Defibrillation" have already been completed. This video does NOT depict the initial steps taken when arriving at the scene of a cardiac arrest.


 Emergency Medicine and Critical Care

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Preparing and Administering IV Push Medications

JoVE 10262

Source: Madeline Lassche, MSNEd, RN and Katie Baraki, MSN, RN, College of Nursing, University of Utah, UT

Intravenous (IV) push is the rapid administration of a small volume of medication into a patient's vein via a previously inserted IV catheter. Preparations for IV push administration are commonly provided in vials or ampules for withdrawal into a syringe. This method is used when a rapid response to a medication is required, or when the medication cannot be administered via the oral route. For instance, medications commonly administered via IV push are the ones used to treat moderate or severe pain. Before administrating IV push, it is important to confirm the correct placement of the IV catheter, because the push medication can cause irritation and damage to the lining of the blood vessel and to surrounding tissues. Since IV push medications act quickly, the patients need to be closely monitored after the drug has been administered, and any error can be especially dangerous. It is imperative that the nurse adheres to the five "rights" and three checks of safe medication administration and is knowledgeable about the medication purpose and adverse effects. The nurse should determine the appropriate medication dose, based upon the medication concentration in the container. If


 Nursing Skills

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Imaging Metals in Brain Tissue by Laser Ablation - Inductively Coupled Plasma - Mass Spectrometry (LA-ICP-MS)

1Elemental Bio-imaging Facility, University of Technology Sydney, 2Florey Institute of Neuroscience and Mental Health, The University of Melbourne, 3Department of Pathology, The University of Melbourne, 4School of Earth Sciences, The University of Melbourne, 5Research School, Ruhr University, 6Department of Physiology, Monash University, 7ESI Ltd., Bozeman, 8Agilent Technologies, Mulgrave

JoVE 55042


 Medicine

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