880 resultados para Ziegler-Nichols


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Despite the overwhelming benefits of antiretroviral therapy (ART) in curtailing viral load in HIV-infected individuals, ART does not fully restore cellular and humoral immunity. HIV-infected individuals under ART show reduced responses to vaccination and infections and are unable to mount an effective antiviral immune response upon ART cessation. Many factors contribute to these defects, including persistent inflammation, especially in lymphoid tissues, where T follicular helper (Tfh) cells instruct and help B cells launch an effective humoral immune response. In this study we investigated the phenotype and function of circulating memory Tfh cells as a surrogate of Tfh cells in lymph nodes and found significant impairment of this cell population in chronically HIV-infected individuals, leading to reduced B cell responses. We further show that these aberrant memory Tfh cells exhibit an IL-2-responsive gene signature and are more polarized toward a Th1 phenotype. Treatment of functional memory Tfh cells with IL-2 was able to recapitulate the detrimental reprogramming. Importantly, this defect was reversible, as interfering with the IL-2 signaling pathway helped reverse the abnormal differentiation and improved Ab responses. Thus, reversible reprogramming of memory Tfh cells in HIV-infected individuals could be used to enhance Ab responses. Altered microenvironmental conditions in lymphoid tissues leading to altered Tfh cell differentiation could provide one explanation for the poor responsiveness of HIV-infected individuals to new Ags. This explanation has important implications for the development of therapeutic interventions to enhance HIV- and vaccine-mediated Ab responses in patients under ART.

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Is "treaty shopping" in international investment law "legitimate nationality planning" or "treaty abuse"? This is the question investment arbitral tribunals have been increasingly faced with over past years. This PhD thesis will examine in a systematic and comprehensive manner investment arbitral decisions that have attempted to draw this line. It will show that while some legal approaches taken by arbitral tribunals have started to consolidate, others remain unsettled, contributing to the picture of an overall inconsistent jurisprudence. The thesis will also make proposals de lege ferenda on how States could reform their international investment agreements in order to make them less susceptible to the practice of treaty shopping.

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Limited evidence exists to suggest that the ability to invade and escape protozoan host cell bactericidal activity extends to members of the Chlamydiaceae, intracellular pathogens of humans and animals and evolutionary descendants of amoeba-resisting Chlamydia-like organisms. PCR and microscopic analyses of Chlamydophila abortus infections of Acanthamoeba castellani revealed uptake of this chlamydial pathogen but, unlike the well-described inhabitant of A. castellani, Parachlamydia acanthamoebae, Cp. abortus did not appear to propagate and is likely digested by its amoebal host. These data raise doubts about the ability of free-living amoebae to serve as hosts and vectors of pathogenic members of the Chlamydiaceae but reveal opportunities, via comparative genomics, to understand virulence mechanisms used by Chlamydia-like organisms to avoid amoebal digestion.

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Tutkielma selvittää dokumenttielokuvaohjaajien käsitystä todellisuuteen perustuvasta elokuvataiteesta. Tutkimusmetodi on teemahaastattelu. Haastateltavina ovat olleet Jouko Aaltonen, Pia Andell, John Webster ja Jaakko Virtanen. Heidän mielipiteensä ovat osin yleistettävissä suomalaisen dokumenttielokuvan kentän yhteiseen käsitykseen, ja osin ne kuvastavat heidän henkilökohtaisia ajatuksiaan. Tutkielman tarkoituksena on antaa määrittelyvalta elokuvan tekijöille. Haastattelu nojaa ensisijaisesti Jouko Aaltosen teokseen Todellisuuden vangit vapauden valtakunnassa. – Dokumenttielokuva ja sen tekoprosessi, joka analysoi haastattelumenetelmää käyttäen suomalaisten dokumentaristien teoksia. Muut keskeiset tutkijat ovat Bill Nichols ja Michael Renov, joiden kirjoittamia tai toimittamia teoksia on lähteinä. Käsitteen ”dokumenttielokuva” määrittelyn tutkielma on ottanut lähtökohtaisesti John Griersonilta. Haastatellut ohjaajat korostavat todellisuuden subjektiivista luonnetta. Dokumenttielokuvassa ilmaisu on yhtä tärkeää kuin sisältö eikä niitä pidä erottaa toisistaan. Ohjaajat vaativat itseltään rehellisyyttä suhteessa aistein havaittavaan todellisuuteen ja eettistä suhtautumista elokuviensa henkilöihin. Dokumenttielokuvan tekoprosessi muuttaa tekijänsä suhdetta käsiteltävänä olevaan todellisuuteen. Tutkielman lopussa pohditaan myös argumentaation ja taideteoksen välistä suhdetta. Dokumenttielokuvan pyrkimys on toimia kokemuksen eikä ainoastaan rationaalisuuden tasolla. Tässä pohdinnassa tutkielma hyödyntää Gilles Deleuzin ja Felix Guattarin ajattelua.

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In the theoretical part, the different polymerisation catalysts are introduced and the phenomena related to mixing in the stirred tank reactor are presented. Also the advantages and challenges related to scale-up are discussed. The aim of the applied part was to design and implement an intermediate-sized reactor useful for scale-up studies. The reactor setting was tested making one batch of Ziegler–Natta polypropylene catalyst. The catalyst preparation with a designed equipment setting succeeded and the catalyst was analysed. The analyses of the catalyst were done, because the properties of the catalyst were compared to the normal properties of Ziegler–Natta polypropylene catalyst. The total titanium content of the catalyst was slightly higher than in normal Ziegler–Natta polypropylene catalyst, but the magnesium and aluminium content of the catalyst were in the normal level. By adjusting the siphonation tube and adding one washing step the titanium content of the catalyst could be decreased. The particle size of the catalyst was small, but the activity was in a normal range. The size of the catalyst particles could be increased by decreasing the stirring speed. During the test run, it was noticed that some improvements for the designed equipment setting could be done. For example more valves for the chemical feed line need to be added to ensure inert conditions during the catalyst preparation. Also nitrogen for the reactor needs to separate from other nitrogen line. With this change the pressure in the reactor can be kept as desired during the catalyst preparation. The proposals for improvements are presented in the applied part. After these improvements are done, the equipment setting is ready for start-up. The computational fluid dynamics model for the designed reactor was provided by cooperation with Lappeenranta University of Technology. The experiments showed that for adequate mixing with one impeller, stirring speed of 600 rpm is needed. The computational fluid dynamics model with two impellers showed that there was no difference in the mixing efficiency if the upper impeller were pumping downwards or upwards.

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In the theory part the membrane emulsification was studied. Emulsions are used in many industrial areas. Traditionally emulsions are prepared by using high shear in rotor-stator systems or in high pressure homogenizer systems. In membrane emulsification two immiscible liquids are mixed by pressuring one liquid through the membrane into the other liquid. With this technique energy could be saved, more homogeneous droplets could be formed and the amount of surfactant could be decreased. Ziegler-Natta and single-site catalysts are used in olefin polymerization processes. Nowadays, these catalysts are prepared according to traditional mixing emulsification. More homogeneous catalyst particles that have narrower particle size distribution might be prepared with membrane emulsification. The aim of the experimental part was to examine the possibility to prepare single site polypropylene catalyst using membrane emulsification technique. Different membrane materials and solidification techniques of the emulsion were examined. Also the toluene-PFC phase diagram was successfully measured during this thesis work. This phase diagram was used for process optimization. The polytetrafluoroethylene membranes had the largest contact angles with toluene and also the biggest difference between the contact angles measured with PFC and toluene. Despite of the contact angle measurement results no significant difference was noticed between particles prepared using PTFE membrane or metal sinter. The particle size distributions of catalyst prepared in these tests were quite wide. This would probably be fixed by using a membrane with a more homogeneous pore size distribution. It is also possible that the solidification rate has an effect on the particle sizes and particle morphology. When polymeric membranes are compared PTFE is probably still the best material for the process as it had the best chemical durability.

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Three recombinant antigens of Treponema pallidum Nichols strain were fused with GST, cloned and expressed in Escherichia coli, resulting in high levels of GST-rTp47 and GST-rTp17 expression, and supplementation with arginine tRNA for the AGR codon was needed to obtain GST-rTp15 overexpression. Purified fusion protein yields were 1.9, 1.7 and 5.3 mg/l of cell culture for GST-rTp47, GST-rTp17 and GST-rTp15, respectively. The identities of the antigens obtained were confirmed by automated DNA sequencing using ABI Prism 310 and peptide mapping by Finningan LC/MS. These recombinant antigens were evaluated by immuno-slot blot techniques applied to 137 serum samples from patients with a clinical and laboratory diagnosis of syphilis (61 samples), from healthy blood donors (50 samples), individuals with sexually transmitted disease other than syphilis (3 samples), and from individuals with other spirochetal diseases such as Lyme disease (20 samples) and leptospirosis (3 samples). The assay had sensitivity of 95.1% (95% CI, 86.1 to 98.7%) and a specificity of 94.7% (95% CI, 87.0 to 98.7%); a stronger reactivity was observed with fraction rTp17. The immunoreactivity results showed that fusion recombinant antigens based-immuno-slot blot techniques are suitable for use in diagnostic assays for syphilis.

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We evaluated dyspnea perception in cystic fibrosis patients compared with normal subjects, during an inspiratory resistive loading test and 6-min walk test. We also evaluated the correlation between dyspnea scores induced by resistive loads and by the 6-min walk test. In this prospective, cross-sectional study, 31 patients with cystic fibrosis (≥15 years of age) and 31 age-, gender-, and ethnicity-matched healthy volunteers (20 females and 11 males per group) underwent inspiratory resistive loading, spirometry, and the 6-min walk test. As the magnitude of the inspiratory loads increased, dyspnea scores increased (P<0.001), but there was no difference between groups in dyspnea score (P=0.654). Twenty-six (84%) normal subjects completed all the resistive loads, compared with only 12 (39%) cystic fibrosis patients (P<0.001). Dyspnea scores were higher after the 6-min walk test than at rest (P<0.001), but did not differ between groups (P=0.080). Post-6-min walk test dyspnea scores correlated significantly with dyspnea scores induced by resistive loads. We conclude that dyspnea perception induced in cystic fibrosis patients by inspiratory resistive loading and by 6-min walk test did not differ from that induced in normal subjects. However, cystic fibrosis patients discontinued inspiratory resistive loading more frequently. There were significant correlations between dyspnea perception scores induced by inspiratory resistance loading and by the 6-min walk test. This study should alert clinicians to the fact that some cystic fibrosis patients fail to discriminate dyspnea perception and could be at risk for delay in seeking medical care.

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Whey protein samples (S-1 to S-5) were tested in vivo and in vitro for nutritional properties and selected bioactivities. Weanling male Wistar rats fed modified AIN-93G (12 g protein.100 g-1) diets for 21 days were used the in vivo studies. The nutritional parameters did not differ among the protein diets tested. Erythrocyte glutathione content was considered high and was higher for S-3, but liver glutathione was the same for all dietary groups. For S-3, cytokine secretion (IL-10 and TNF-α) by human peripheral blood mononuclear cells (in RPMI-1640 medium) was higher in the absence of antigen than in the presence of BCG antigen. Interleukin-4 secretion was repressed in all treatments. The IC50, whey protein concentration required to inhibit 50% of the melanoma cell proliferation, was 2.68 mg.mL-1 of culture medium for the S-3 sample and 3.66 mg.mL-1 for the S-2 sample. Based on these results, it was concluded that S-3 (whey protein concentrate enriched with TGF-β and lactoferrin) produced better nutritional and immunological responses than the other products tested.

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This thesis, entitled, "Where's Albania? Staking Out the Politics of the Real and Reality in Documentary Cinema," charts the documentary tradition's path from its first incarnations, as filmed travelogue or ethnographic study, for example, right through to its development as a form acting as an objective observer, reflexive commentator, and finally, as a postmodern hybrid. This thesis begins by locating the documentary tradition's origins in realism. Foregrounding documentary cinema as a realist style is important in that it is a contention that spans this entire study. After working through the numerous modes of documentary as outlined by Bill Nichols, I suggest the documentary is often best understood as a hybrid form drawing on numerous modes and conventions. This argument permits my study to make a shift into postmodern theory, wherein I examine postmodernism's relationship to the documentary both as being influenced by it, but also as subsequently forcing documentary cinema to look back at itself and reevaluate the claims it has made in the past, and how postmodernism has drawn these claims to the surface of debate. My thesis concludes with a study of the mockumentary. This analysis confirms the link between postmodernism and documentary, but perhaps more importantly, this analysis investigates postmodemism's critique of the image and representation in general, two elements historically linked to documentary cinema's success as "truth teller."

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Specific pages with War of 1812 content in this volume: Page 77: The American senate declares war on Great Britain. Click on the pdf links to the right to view the monthly issue. The Gentleman's Magazine and Historical Chronicle was a monthly periodical published in England during the years of 1736-1833. The volumes of interest from 1812-1815 were written and compiled by Sylvanus Urban, Gentleman. These volumes were printed in London by Nichols, Son and Bentley at Cicero's Head, Red Lion Passage and Fleet Street. The magazine contains accounts of important historical events, abstracts of foreign occurrences, letters from noted figures, articles on geography, biographical entries for prominent people, poems, statistics, obituaries, reviews of books and more.