Les protéines membranaires en hélices alpha forment le tiers des protéines codées par notre génome. D’autres protéines membranaires sont formées typiquement de feuillets bêta. Leur fonction varie de la formation de pores, la transmission de signaux à l’activité antibiotique. Elles sont aussi capables de transporter de larges cargos comme les protéines ou les acides nucléiques au travers de la membrane. Récemment, les peptides ont émergé comme un moyen prometteur pour le transport de médicaments vers leurs cibles.Les protéines membranaires peuvent être synthétisées chimiquement ou exprimées et marquées isotopiquement dans les bactéries, isolées, purifiées et reconstituées dans les bicouches lipidiques hydratées. Elles présentent une variété de configurations en interagissant avec ces bicouches lipidiques. Ceci dépend de la composition et de l’épaisseur de ces bicouches. L’orientation des bicouches lipidiques est maintenue mécaniquement en les disposant entre des plaques de verre. La RMN du solide des échantillons orientés est un des moyens possibles pour accéder à la topologie des peptides associés à des membranes phospholipidiques. Les échantillons sont difficiles à exprimer dans les bactéries en grande quantités et possède une solubilité réduite en dehors des membranes. En outre leur taille est trop importante pour la RMN du liquide et il est difficile de les cristalliser. Un des inconvénients majeur de la spectroscopie RMN est sa faible sensibilité. Cela résulte du faible moment magnétique nucléaire qui résulte en un décalage Zeeman faible et donc une polarisation réduite. Par ailleurs, l’intensité du signal RMN dépend de plusieurs facteurs comme la quantité d’échantillon la polarisation et le champ magnétique B0. Et le temps d’acquisition de certaines expériences peut être très long. Le but de ce projet est d’obtenir plus de signal des protéines membranaires. Dès lors, nous avons développé une cryosonde DNP (dynamic nuclear polarization) / RMN du solide. La DNP est une technique ingénieuse qui est utilisée pour le transfert de polarisation des noyaux hautement polarisés à des noyaux moins polarisés par irradiation microonde. Les microondes vont exister sélectivement les électrons qui transfèreront leur polarisation à l’ensemble des protons voisins, le signal proton peut ainsi être augmenté de 660 fois.Pour cela la cryosonde DNP RMN du solide qui opère à 100 K et 9,4 T a été utilisée. Une sonde est la pièce mécanique qui maintient l’échantillon dans le centre magnétique de l’aimant du spectromètre. C’est une antenne modulable qui irradie et détecte des champs radiofréquence. La pièce centrale de la sonde est une bobine solénoïdale ou une bobine en forme de selle enveloppant l’échantillon. La faisabilité de ces expériences DNP a été validée sur les échantillons orientés en rotation à l’angle magique. Ces expériences ont été menées sur des échantillons enroulés dans un rotor. Même si leur orientation par rapport au champ magnétique B0 est perdue, une valeur d’augmentation de 17 a été obtenue.[...] / Helical membrane proteins comprise one third of the expressed proteins encoded in a typical genome. Other membrane proteins are typically beta sheets. Their function varies from pore formation, signaling to antimicrobial activity. They are also capable of transporting large cargo such as proteins or nucleic acids across the cell membrane. Recently, peptides have emerged as promising tools in drug delivery. Membrane proteins can be synthesized chemically or expressed and isotopically labeled in bacteria, isolated, purified and reconstituted into fully hydrated lipid bilayers. The bilayer orientation is kept mechanically by putting them between glass plates. While interacting with these bilayers they exhibit a variety of configurations depending on the lipids composition and thickness. Solid-state Nuclear Magnetic Resonance (NMR) on oriented bilayers is one way to access the topology of peptides associated with phospholipid membranes. Oriented membrane protein are difficult to study with analytical techniques because of their poor solubility outside the lipid membrane, difficulty of expression in bacteria in big quantities, difficulty to crystallize, and they are too large for solution NMR study. The intensity of an NMR signal depends on several factors such as polarization P and magnetic field magnitude B0. One of the major drawbacks of NMR spectroscopy is low sensitivity. This is caused by the small magnetic moment of the nuclear spins which results in a modest Zeeman splitting of the nuclear spin energy levels and therefore in a limited Boltzmann Polarization. The aim of this project is to obtain a better signal from membrane proteins. Thus a Low temperature (LT) solid state NMR with Dynamic Nuclear Polarization (DNP) probe head was created. DNP is an ingenious technique that is used to transfer polarization from highly polarized targets to less polarized nuclei using microwave irradiation. Microwaves will excite selectively the electron spins which will transfer their polarization to the pool of proton nuclei, the proton NMR signal can be enhanced by 660 times. A probe head for DNP enhanced solid state NMR at 100 K and 9.4 T is described. A probe head includes the mechanical piece that holds the sample in the magnetic center of the NMR magnet. It is a tunable antenna that irradiates and detects the rf fields used in NMR. The centerpiece of the probe is the solenoidal or saddle coil surrounding the sample. The feasibility of such a DNP experiment is proven on magic angle oriented sample spinning. These experiments are conducted on oriented samples wrapped into a rotor. Through their orientation with regards to B0 is lost, enhancement values as high as 17 are obtained. [...]

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Este trabalho apresenta os detalhes da construção de um espectrômetro para a realização de experimentos de transferência de polarização elétron-núcleo (Efeito Overhauser). São também mostrados: as implementações e modificações feitas no espectrômetro de RPE existente no Laboratório de Ressonância Magnética do DFCM, os circuitos para a construção de um equipamento de RMN para operar de forma pulsado na freqüência fixa de 14 MHz, os desenhos da cavidade de RPE construída para a banda-X (~ 9,2 GHz), os \"softwares\" modificados e desenvolvidos para aquisição de dados, tratamento e reconstrução de imagens. São apresentados os resultados do aumento do sinal de RMN e as imagens obtidas através da Tomografia de Ressonância Magnética, usando amostras menores do que 1 mm de diâmetro (volume ~10 ul), a uma concentração de 2,2 mM de TEMPOL dissolvido em água destilada. / This work describes in details the arrangements that must be accomplished for development of a spectrometer for Dynamic Nuclear Polarization - DNP (Overhauser Effect). Also, the construction project of a 14 MHz pulsed NMR spectrometer and drawings of a homemade EPR cavity for X-band (~ 9,2 GHz) are shown. The DNP probe built for the experiments and modifications done on the EPR spectrometer existing at Laboratory of Magnetic Resonance are discussed in detail. Results on the enhancement of the NMR signal due electron-proton dynamic interactions are presented. NMR imaging of very small objects, 1 mm diameter glass tube filled with 5 ~10 ul of 2,2 mM of free radicals (TEMPOL) solution, obtained through back projection reconstruction NMR tomography method, are presented

Este trabalho apresenta os detalhes da construção de um espectrômetro para a realização de experimentos de transferência de polarização elétron-núcleo (Efeito Overhauser). São também mostrados: as implementações e modificações feitas no espectrômetro de RPE existente no Laboratório de Ressonância Magnética do DFCM, os circuitos para a construção de um equipamento de RMN para operar de forma pulsado na freqüência fixa de 14 MHz, os desenhos da cavidade de RPE construída para a banda-X (~ 9,2 GHz), os \"softwares\" modificados e desenvolvidos para aquisição de dados, tratamento e reconstrução de imagens. São apresentados os resultados do aumento do sinal de RMN e as imagens obtidas através da Tomografia de Ressonância Magnética, usando amostras menores do que 1 mm de diâmetro (volume ~10 ul), a uma concentração de 2,2 mM de TEMPOL dissolvido em água destilada. / This work describes in details the arrangements that must be accomplished for development of a spectrometer for Dynamic Nuclear Polarization - DNP (Overhauser Effect). Also, the construction project of a 14 MHz pulsed NMR spectrometer and drawings of a homemade EPR cavity for X-band (~ 9,2 GHz) are shown. The DNP probe built for the experiments and modifications done on the EPR spectrometer existing at Laboratory of Magnetic Resonance are discussed in detail. Results on the enhancement of the NMR signal due electron-proton dynamic interactions are presented. NMR imaging of very small objects, 1 mm diameter glass tube filled with 5 ~10 ul of 2,2 mM of free radicals (TEMPOL) solution, obtained through back projection reconstruction NMR tomography method, are presented

Nurse educators believe that their graduates are well-prepared for entry level positions in nursing. In the acute healthcare setting, new graduates are placed on virtually every type of nursing unit, including critical care. Employers have developed formal orientations to familiarize new graduate nurses new with the institution and its policies and procedures and to teach the things employers believe new RNs need to know but do not, either because they were never taught the material or they have not retained it. The purposes of this project were to (a) examine the evidence relative to a disconnect between nursing education and nursing practice, (b) design a formal residency program for new graduates based on the evidence, and (c) implement and evaluate the residency program. Based on the evidence, a 16-week new nurse residency was developed in which Residents were each assigned both a Preceptor and Mentor to assist their progress. Weekly educational offerings were targeted at specific competency deficits identified by Residents, Preceptors and Mentors at the beginning of the residency program. Seven out of the original 10 Residents completed the Residency. Pre-residency, the Residents were very confident of their clinical skills and abilities and this was unchanged post-residency. The Preceptors and Mentors were much less confident of the clinical skills and abilities of the Residents pre-residency. Post-residency, the confidence level of the Preceptors and Mentors was improved, but significantly so only for the Mentors. It is imperative that nursing administrators be aware of the discrepancy between the confidence new nurses have in their own skills and the perceptions of the nurses who work side by side with them on a daily basis. Residencies for new graduate nurses are costly. Nursing administrators must make the determination if the benefits outweigh the costs. They may find the results of not having a residency are far more costly.

Standards of practice for hospital electrocardiogram monitoring were recommended in 2004 by the American Heart Association; however they are not widely followed. Many nurses monitor in a single lead regardless of diagnosis and are unable to differentiate wide QRS complex tachycardias. The purpose of this project was to evaluate the effectiveness of an interactive web-based education program combined with unit-based collaborative learning activities on both telemetry staff nurses‘ knowledge of dysrhythmias and their monitoring practices for patients at risk for wide QRS complex tachycardias. This interventional, one group before-and-after cohort study design consisted of four components: interactive web-based educational program with a pretest and posttest, unit-based collaborative activities, competency skills validation, and patient audits of electrode placement and lead selection at baseline, six weeks, and 18 weeks. There were 34 nurses who consented to participate, 16 started the program, and nine finished all the components. The pretest scores ranged from 0 – 60% with median of 36.5%. The posttest scores ranged from 47 – 93% with median of 80%. The Wilcoxon Signed Ranks test showed a significant difference between the pretest and posttest scores (p = .008). The patient audit results did not indicate significant differences in proportions of correct electrode placement and correct lead selection between baseline, 6 weeks, and 18 weeks. The program was effective in increasing nurses‘ knowledge about dysrhythmias; however, it was not effective in changing monitoring behavior. More research is needed to see if this type of program is more effective if it involves all the staff on the unit who are responsible for monitoring, and if additional strategies are used, such as unit champions and group rewards.

Recent studies show that more than one-third of U.S. adults (over 72 million people) were obese in 2005–2006. This includes 33.3% of men and 35.3% of women. Obesity is a primary factor in the development of metabolic syndrome, a condition that places individuals at high absolute risk of mortality and morbidity. The use of a nutritionally balanced diet aimed at weight reduction has the potential to decrease the prevalence of obesity, therefore reducing the incidence of metabolic syndrome and its consequences. The purpose of this project was to investigate whether individual nutrition counseling would improve the outcomes of patients with metabolic syndrome. A transdisciplinary team of faculty and graduate students from nutrition and nursing served as consultants and educators at a clinic for the uninsured in a southeastern city in the United States. This study was a one-group before-and-after design, with baseline data obtained on patients prior to the practice change. The study ran for six months. The intervention was an evidence-based practice change incorporating intensive dietary program for 19 patients with metabolic syndrome and an evaluation of the effect of that change on lipoproteins, glucose, blood pressure, weight, and waist circumference. Although there were no positive changes in weight or waist circumference, the participants did enjoy a significant decrease in blood pressure, fasting glucose and plasma lipids. None of these changes were significantly associated with the dietary intervention. Based on the most current evidence, the most effective way to reduce risks associated with metabolic syndrome is weight reduction, adequate nutrition, and exercise.

Proper handwashing is one of the simplest, most affordable and effective means of stopping the spread of infection. Due to the close proximity of children in schools and child care settings, there is a high risk for the spread of infectious disease. The purpose of this project was to improve handwashing behaviors of three to six year old children in a community school setting by implementing an evidence based multi-activity handwashing education program. The objective was to increase understanding of the relationship between germs and handwashing, as well as increase the frequency and correct technique procedure of handwashing behavior in children in the community. The evidence based handwashing education program was implemented over several weeks and included multiple activities that were found in the literature to be effective. These activities included a lecture and presentation, a return demonstration, a Glo Germ™ training device, and a video and story on handwashing. The results of the statistical analysis found that the program was effective in increasing both the frequency and correct technique procedure of the children. Most parents (80%) reported that they noticed an increase in how often their child washes his/her hands. A majority of parents (83%) noticed an increase in the duration of how long their child washes his/her hands; a larger majority (90%) noticed a decrease in how often they needed to prompt their child to wash his/her hands. Nurses working collaboratively with other disciplines in the community can implement evidence based practice handwashing education programs in a variety of public child care settings. The effects of the handwashing programs may significantly decrease child healthcare costs associated with prescriptions, visits to the provider, hospital admissions and emergency room visits and influence positive health promotion behaviors in children. Implementing affordable and effective handwashing education programs can lead to a reduction in infectious diseases, absenteeism, antibiotic resistance and health care costs. By fostering positive health promotion practices, such as proper handwashing behaviors in children, habits may be instilled that carry into adulthood. These habits can increase the health of a child and the community.

Proper collection of blood cultures is needed to identify pathogens causing serious infections and direct appropriate antibiotic therapy. Blood culture contamination can lead to longer hospital stays, incorrect antibiotic treatment, additional testing, and overall increased costs for the patient and hospital. Blood culture collection technique is the most important factor affecting contamination rates. The purpose of this project was to determine the effect of simulation reinforcement of blood culture collection processes on the rate of contamination of blood cultures drawn by nurses in a community medical center emergency department. This one-group before-and-after cohort study utilized a convenience sample of 50 nurses who collect blood cultures on adult clients. Each participant completed a pretest, attended a simulation in-service class, and completed a posttest immediately after the simulation and again one-month later. There was significant knowledge gained from pretest to immediate posttest, with no significant decrease in knowledge at I-month post-intervention. The 3-month blood culture contamination rate was 3.26% prior to the intervention, 4% during the intervention period, 3.7% after the intervention, and 2% in months 4 aI1d 5 postintervention. The use of simulation in the professional development of practicing nurses has the potential to improve clinical practice performance and patient outcomes.

Metabolic syndrome is a serious health problem in the United States. The presence of metabolic syndrome significantly increases the risk of developing type II diabetes and cardiovascular disease by producing a prothrombic state. The prothrombic state that results from the clustering of several independent cardiovascular risk factors within one individual increases the risk of micro and macro vascular changes and eventually to end organ damage. There is considerable evidence to support the serious nature of this medical condition. Medications used to treat the hypertension, diabetic, and dyslipidemia components of metabolic syndrome can be a significant drain on the monthly budget of individuals and families, especially if they do not have health insurance. Diet and exercise programs have been shown to be effective in reducing adiposity and decreasing insulin resistance. These changes in lifestyle may be adjuncts or a low cost alternative to expensive medications for some individuals. The purpose of this project was to identify the effect of an intensive dietary and exercise program on patients with metabolic syndrome. This study even with a small sample size (n = 5) showed that waist size, systolic blood pressure, diastolic blood pressure, and high density lipoprotein levels were trending towards levels that would remove the patient from the diagnosis of metabolic syndrome. The greatest benefit for the general population would result from intervention prior to a diagnosis of hypertension and diabetes and with medication naïve individuals. Early intervention would decrease the cost of medical treatment and hospitalizations.