Chemical shift

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    Nucleobases Lab Report

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    organic molecules based on the atomic nuclei interactions with their environment. Recent advances have made use of the technology in protein, nucleic acid, and complex natural products structure identification. [1, 2, 3] Its origins lie in the works of Felix Bloch and Edward Purcell, who used the discoveries of Isidor Rabi’s extension on Stern-Gerlach experiment, and were awarded the Nobel Prize in 1952 for their use of NMR on solids and liquids. Packard notably observes this phenomena of nuclear resonance when a magnetic field was applied to an organic molecule by the absorption of RF (radiofrequency) in a magnetic field.[4] This knowledge was expanded to identify structural components of organic molecules based on their reported magnetic shifts caused by the induced change in their spin states. The technique became useful in many areas of chemistry for its versatility and reproducibility. The peaks for the NMR spectra are determined by energetic changes of the spin resonance.[5] Some elements’ spin states exist as fractional spins in the presence of an external magnetic field; particularly for hydrogen, the spin value can be ±1/2. [5] The energy difference between these two states can be calculated knowing the strength of the applied external magnetic field, the magnetic momentum of the element’s nuclei, and the spin.[5] This relationship is represented by this equation: ∆E=uB/I , where I is the spin and u is the magnetic momentum. ∆E equals hν when the frequency of the…

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    found, but only six represented 6-ethoxycarbonyl-3,5-diphenyl-2-cyclohexenone. Impurities found at 2.20 ppm, 1.69 ppm and 1.249 ppm, were caused by acetone and a small amount of residue in the NMR tube. These impurities were only present in 1H NMR, so only the sample contained a small amount of impurities. The peaks found at 7.47 ppm, 6.58 ppm, 4.05 ppm, 3.80 ppm, and 1.04 ppm, are the peaks that represent the 6-ethoxycarbonyl-3,5-diphenyl-2-cyclohexenone. The multiplet at 7.47 ppm represents…

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    new opportunities for the rational design of medicinal agents. Encouragingly, most of the synthesized derivatives possess potent PDE 5 inhibitory activity compared to sildenafil as a reference drug. Experimental section General Melting points were determined on a Boetius melting point apparatus and are uncorrected. Elemental analyses were performed on Carlo Erba CHN-S Elemental analyses 1108. Institute of Chemistry Dresden, Germany. The NMR spectra were obtained using a Brucker AC 300 (300.13…

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    Ethyl Cinnamate Synthesis

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    Experiment 5 Synthesis and NMR Spectroscopy of ethyl cinnamate Introduction: Wittig reactions involve the stereoselective synthesis of olefins from phosphonium ylides and aldehydes or ketones, where the carbonyl bond is converted to an alkene double bond.1 The variety of suitable reagents and the relatively mild experimental conditions facilitate their industrial applications, such as the synthesis of epoxides, esters, carotenoids and vitamin A.2,3 Specifically, the ester ethyl cinnamate is used…

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    optimisation because they "are groups or molecules which have chemical and physical similarities producing broadly similar biological properties" (Brown, 2012) to the original functional group. Bioisosteric substitutions consider important attributes including size (molecular weight), shape (bond angles and hybridization states), electronic distribution (polarizability, inductive effects, charge and dipoles), lipid and water solubility, pKa, chemical reactivity, and hydrogen bonding capacity…

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    Cell Count Procedure

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    areas. This is a lot of tasks to complete in what one considers to be a typical work day, so many employees are easily able to obtain large amounts of overtime if they please. A large part of the job is time management, some tests will be more important than others, meaning they will be need to done before other tests and the results sent out very quickly. While other tests must be done in a specific sequential order while even more requests come in. Keeping up with the tests are very important,…

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    Science and technology is always changing rapidly. Scientists are always going outside of the box to try to create new technologies and better ways of thinking to further how people perceive ideas. Sergio Sismondo states that “Neither science nor technology is a natural kind, having simple properties that define it once and for all. The sources of knowledge and artifacts are complex and various: there is no privileged scientific method that can translate nature into knowledge, and no…

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    12 Hours-Shift Case Study

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    their feelings, concerns, and opinions about the current 12 hours-shift. A 12 hours-shift could be beneficial for many, but in this case, patient satisfaction surveys and the increase in medication errors has demonstrated that quality and patient safety is at risk. It is a fact that after a 12 hours-shift, the productivity and quality of patient care is compromised. A study published on a Health Affairs issue (Witkoski Stimpfel, Sloane, & Aiken, 2012), revealed that nurses shift length and…

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    time period is reworking product that has been either tagged by quality control or product that has been left over from the previous day or if you are on second shift product that has been left over from first shift. “The core idea behind lean manufacturing is maximizing customer value while minimizing waste, thereby achieving manufacturing excellence through the creation of more value with fewer resources” (Faro, 2011). Part of making sure maintenance is able to do their job is having the…

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    Stephen King is the author of novels and short stories with creepy settings admits that he even fears bugs to add to the list of things that freaks him out. One of his earlier short stories happening 1976, several women at New Sharon Teachers' College fall victim to a “Jack the Ripper” style character with a mysterious fog that weighs heavy over the campus. King, the narrator, also a student, leads us on a twisted tale of a foggy New England town to search who committed the horrifying acts.…

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