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Silver Nitrate: A silver salt with powerful germicidal activity. It has been used topically to prevent Ophthalmia neonatorum.

Nucleophilic Substitution

JoVE 10465

Source: Vy M. Dong and Daniel Kim, Department of Chemistry, University of California, Irvine, CA

Nucleophilic substitution reactions are among the most fundamental topics covered in organic chemistry. A nucleophilic substitution reaction is one where a nucleophile (electron-rich Lewis base) replaces a leaving group from a carbon atom.

SN1 (S = Substitution, N = Nucleophilic, 1 = first-order kinetics) SN2 (S = Substitution, N = Nucleophilic, 2 = second-order kinetics) This video will help to visualize the subtle differences between an SN1 and SN2 reaction and what factors help to speed up each type of nucleophilic substitution reaction. The first section will focus on reactions that will help to better understand and learn about nucleophilic substitution reactions. The second section will focus on a real-world example of a substitution reaction.


 Organic Chemistry II

Establishment of a Valuable Mimic of Alzheimer's Disease in Rat Animal Model by Intracerebroventricular Injection of Composited Amyloid Beta Protein

1Institute of Traditional Chinese Medicine, Chengde Medical College, 2Shijiazhuang Obstetrics and Gynecology Hospital, 3Hebei Province Key Research Office of Traditional Chinese Medicine Against Dementia, 4Hebei Province Key Laboratory of Traditional Chinese Medicine Research and Development, 5Institute of Basic Medical Research of Basic Medical School

JoVE 56157


 Behavior

Fluorescent Silver Staining of Proteins in Polyacrylamide Gels

1Ming Wai Lau Centre for Reparative Medicine, Karolinska Institutet, 2Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Institute of Molecular Functional Materials, State Key Laboratory of Neuroscience, Division of Biomedical Engineering, and Division of Life Science, Hong Kong University of Science and Technology

Video Coming Soon

JoVE 58669


 JoVE In-Press

Le Châtelier's Principle

JoVE 10138

Source: Laboratory of Dr. Lynne O'Connell — Boston College

When the conditions of a system at equilibrium are altered, the system responds in such a way as to maintain the equilibrium. In 1888, Henri-Lewis Le Châtelier described this phenomenon in a principle that states, "When a change in temperature, pressure, or concentration disturbs a system in chemical equilibrium, the change will be counteracted by an alteration in the equilibrium composition." This experiment demonstrates Le Châtelier's principle at work in a reversible reaction between iron(III) ion and thiocyanate ion, which produces iron(III) thiocyante ion: Fe3+(aq) + SCN- (aq) FeSCN2+ (aq) The concentration of one of the ions is altered either by directly adding a quantity of one ion to the solution or by selectively removing an ion from the solution through formation of an insoluble salt. Observations of color changes indicate whether the equilibrium has shifted to favor formation of the products or the reactants. In addition, the effect of a temperature change on the solution at equilibrium can be obs


 General Chemistry

Calcification of Vascular Smooth Muscle Cells and Imaging of Aortic Calcification and Inflammation

1Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, 2Cardiovascular Research Center and Cardiology Division of the Department of Medicine, Massachusetts General Hospital, 3Cardiovascular Division, Brigham and Women's Hospital, 4Harvard Medical School, 5Department of Anesthesiology, Uniklinik RWTH Aachen, RWTH Aachen University, 6Center for Immunology and Inflammatory Diseases and the Division of Rheumatology, Allergy, and Immunology of the Department of Medicine, Massachusetts General Hospital

JoVE 54017


 Medicine

Lignin Down-regulation of Zea mays via dsRNAi and Klason Lignin Analysis

1The School of Plant Sciences, University of Arizona, 2Department of Chemical Engineering and Materials Science, DOE Great Lakes Bioenergy Research Center, Michigan State University, 3The Institute for Sustainable and Renewable Resources, The Institute for Advanced Learning and Research, 4Department of Plant, Soil and Microbial Sciences, Michigan State University

JoVE 51340


 Bioengineering

Isolation of Mesenchymal Stem Cells from Human Alveolar Periosteum and Effects of Vitamin D on Osteogenic Activity of Periosteum-derived Cells

1Chang Gung University, 2Department of Periodontics, Chang Gung Memorial Hospital, 3California Northstate University College of Medicine, 4Department of Nephrology, Clinical Poison Center, Chang Gung Memorial Hospital, 5Kidney Research Center, Chang Gung Memorial Hospital, 6Center for Tissue Engineering, Chang Gung Memorial Hospital, 7Department of Periodontics, Chang Gung Memorial Hospital, 8College of Oral Medicine, Taipei Medical University

JoVE 57166


 Bioengineering

Planar and Three-Dimensional Printing of Conductive Inks

1Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, 2Center for Micro- and Nanotechnology, Lawrence Livermore National Laboratory, 3Presently at the Interdisciplinary Center for Wide Band-gap Semiconductors, University Of California Santa Barbara

JoVE 3189


 Bioengineering

A Protocol for Electrochemical Evaluations and State of Charge Diagnostics of a Symmetric Organic Redox Flow Battery

1Joint Center for Energy Storage Research (JCESR), 2Energy & Environment Directorate, Pacific Northwest National Laboratory, 3Earth & Biological Systems Directorate, Pacific Northwest National Laboratory, 4Physical & Computational Sciences Directorate, Pacific Northwest National Laboratory

JoVE 55171


 Chemistry

From a 2DE-Gel Spot to Protein Function: Lesson Learned From HS1 in Chronic Lymphocytic Leukemia

1Division of Molecular Oncology, IRCCS, San Raffaele Scientific Institute, 2Department of Haemato-Oncology, King's College London, 3IFOM, FIRC Institute of Molecular Oncology, 4Università Vita-Salute San Raffaele

JoVE 51942


 Medicine

Manual Isolation of Adipose-derived Stem Cells from Human Lipoaspirates

1Cytori Therapeutics Inc, 2Division of Cardiac Surgery, Department of Surgery, David Geffen School of Medicine at UCLA, 3Division of Plastic and Reconstructive Surgery, Department of Surgery, David Geffen School of Medicine at UCLA, 4Department of Orthopedic Surgery, David Geffen School of Medicine at UCLA, 5Regenerative Bioengineering and Repair Laboratory, David Geffen School of Medicine at UCLA

JoVE 50585


 Biology

Two-dimensional Gel Electrophoresis Coupled with Mass Spectrometry Methods for an Analysis of Human Pituitary Adenoma Tissue Proteome

1Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Xiangya Hospital, Central South University, 2Hunan Engineering Laboratory for Structural Biology and Drug Design, Xiangya Hospital, Central South University, 3State Local Joint Engineering Laboratory for Anticancer Drugs, Xiangya Hospital, Central South University, 4The State Key Laboratory of Medical Genetics, Central South University

JoVE 56739


 Cancer Research

Synthesis of Multi-walled Carbon Nanotubes Modified with Silver Nanoparticles and Evaluation of Their Antibacterial Activities and Cytotoxic Properties

1Center for Biomaterials, Biomedical Research Institute, Korea Institute of Science and Technology, 2School of Integrative Engineering, Chung-Ang University, 3Division of Synthetic Biology and Regenerative Medicine, Institute for Quantitative Health Science and Engineering, Michigan State University

JoVE 57384


 Bioengineering

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

Microfluidic Pneumatic Cages: A Novel Approach for In-chip Crystal Trapping, Manipulation and Controlled Chemical Treatment

1Empa - Swiss Federal Laboratories for Materials Science and Technology, 2Institute of Chemical and Bioengineering, Department of Chemistry and Applied Bioscience, ETH Zurich, 3ICN2-Institut Catala de Nanociencia i Nanotecnologia, 4WITec GmbH, 5Institut de Ciència de Materials de Barcelona, 6School of Chemistry, The University of Nottingham

JoVE 54193


 Chemistry

In vivo Imaging of Optic Nerve Fiber Integrity by Contrast-Enhanced MRI in Mice

1Hans Berger Department of Neurology, Jena University Hospital, 2Immunology, Leibniz Institute for Age Research, Fritz Lipmann Institute, Jena, 3Institute of Diagnostic and Interventional Radiology, Medical Physics Group, Jena University Hospital

JoVE 51274


 Neuroscience

Separation of Mixtures via Precipitation

JoVE 5558

Source: Laboratory of Dr. Ana J. García-Sáez — University of Tübingen

Most samples of interest are mixtures of many different components. Sample preparation, a key step in the analytical process, removes interferences that may affect the analysis. As such, developing separation techniques is an important endeavor not just in academia, but also in industry.  One way to separate mixtures is to use their solubility properties. In this short paper, we will deal with aqueous solutions. The solubility of a compound of interest depends on (1) ionic strength of solution, (2) pH, and (3) temperature. By manipulating with these three factors, a condition in which the compound is insoluble can be used to remove the compound of interest from the rest of the sample.1


 Organic Chemistry

Mesenchymal Stromal Cell Culture and Delivery in Autologous Conditions: A Smart Approach for Orthopedic Applications

1Dept. of Clinical and Experimental Medicine, University of Pisa, 2OtoLab, Azienda Ospedaliero-Universitaria Pisana (AOUP), 3Dept. of Civil and Industrial Engineering, University of Pisa, 4Immunohematology Operative Unit, Azienda Ospedaliero-Universitaria Pisana (AOUP), 5Dept. Of Surgical, Medical, Molecular Pathology and Emergency Medicine, University of Pisa, 6II Orthopedic and Traumatologic Clinic, Azienda Ospedaliero-Universitaria Pisana (AOUP)

JoVE 54845


 Bioengineering

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