Silica-Supported Gold Nanoparticles: Synthesis, Characterization and Reactivity

The main aim of this work was the synthesis and applications of functionalized-silica-supported gold nanoparticles. The silica-anchored functionalities employed, e.g. amine, alkynyl carbamate and sulfide moieties, possess a notable affinity with gold, so that they could be able to capture the gold precursor, to spontaneously reduce it (possibly at room temperature), and to stabilize the resulting gold nanoparticles. These new materials, potentially suitable for heterogeneous catalysis applications, could represent a breakthrough among the “green” synthesis of supported gold nanoparticles, since they would circumvent the addition of extra reducing agent and stabilizers, also allowing concomitant absorption of the active catalyst particles on the support immediately after spontaneous formation of gold nanoparticles. In chapter 4 of this thesis is also presented the work developed during a seven-months Marco Polo fellowship stay at the University of Lille (France), regarding nanoparticles nucleation and growth inside a microfluidic system and the study of the corresponding mechanism by in situ XANES spectroscopy. Finally, studies regarding the reparation and reactivity of gold decorated nanodiamonds are also described. Various methods of characterization have been used, such as ultraviolet-visible spectroscopy (UV-Vis), Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), X-ray Fluorescence (XRF), Field Emission Gun Scanning Electron Microscopy (SEM-FEG), X-ray Photoionization (XPS), X ray Absorption Spectroscopy (XAS).

Inhibition allergenspezifischer Immunantworten im Mausmodell der Typ-I Allergie nach biolistischer Vakzinierung mit allergenkodierenden Plasmiden in Kombination mit für immunmodulatorische Moleküle kodierender Plasmid-DNA

Die Induktion von Toleranz spielt bei der Inhibition allergischer Immunreaktionen eine wichtige Rolle. Hierbei ist die Induktion regulatorischer T Zellen (Treg) von großer Bedeutung. Da zu einer erfolgreichen Behandlung von allergischen Erkrankungen bisher nur wenige Therapiemöglichkeiten zur Verfügung stehen wie die spezifische Immuntherapie (SIT), die allerdings nicht immer zum Erfolg führt, ist es wichtig neue Therapieformen zu entwickeln. rnIn dieser Arbeit wurde daher die biolistische DNA-Immunisierung mit Kombinations-Vakzinen bestehend aus einem allergenkodierenden Plasmid (βGalaktosidase (βGal)) in Kombination mit einem Plasmid, welches für ein immunmodulatorisches Molekül kodiert (Indolamin-2,3-Dioxygenase (IDO), Transforming Growth Factor beta (TGF-β) oder Interleukin-10 (IL-10)), durchgeführt und im Mausmodell der allergeninduzierten IgE-vermittelten Atemwegsinflammation auf ihre Wirksamkeit untersucht. Die Expression des Allergens zusammen mit dem immunregulatorischen Molekül in transfizierten Dendritischen Zellen (DCs) sollte zu einer Induktion von Treg führen und somit eine Suppression der Immunantwort bewirken. rnIn den Versuchen wurde zunächst der Effekt einer Transgenexpression unter der Kontrolle des ubiquitären CMV-Promotors mit dem der Transgenexpression unter der Kontrolle des Fascin-Promotors, der eine Genxpression spezifisch in DCs erlaubt, verglichen. Hierbei stellte sich heraus, dass es wichtig ist die Expression des Antigens mit Hilfe des Fascin-Promotors auf DCs zu beschränken. Einzig in diesem Fall konnte nach der Vakzinierung ein inhibitorischer Effekt auf die Entwicklung einer Atemwegshyperreaktivität durch Expression des Immunmodulatoren IDO beobachtet werden. Es zeigte sich auch, dass es von Vorteil ist, wenn das immunregulatorische Molekül unter Verwendung des CMV-Promotors in allen transfizierten Zellen exprimiert wird. Dies bewirkt, dass IDO in ausreichenden Konzentrationen vorhanden ist. rnDie Expression von βGal unter der Kontrolle des Fascin-Promotors (pFascin-βGal) in Kombination mit der Expression der Moleküle IL-10, TGF-β oder IDO unter Kontrolle des CMV-Promotors (pCMV-IL-10, pCMV-TGFβ, pCMV-IDO) bewirkte eine Immunsupprimierung, die sich in einer inhibierten Produktion antigenspezifischer Antikörper, einer verminderten Zytokin-Produktion, einer reduzierten Induktion zytotoxischer T-Zellen und in einer Inhibition der allergeninduzierten Atemwegshyperreaktivität zeigte, im Vergleich zu einer Vakzinierung mit pFascin-βGal in Kombination mit einem Kontroll-Plasmid. Bei nachfolgender Proteinsensibilisierung blieben diese Effekte jedoch nicht bestehen. Einzig durch Vakzinierung mit IL-10-kodierenden Plasmiden konnte eine moderate Verminderung der Atemwegsreaktivität nachgewiesen werden. rnIn einem therapeutischen Modell der Atemwegsinflammation, in dem die Mäuse vor der DNA-Immunisierung mit dem Protein sensibilisiert wurden, wurde demonstriert, dass im Vergleich zu Mäusen, die nur mit dem Protein sensibilisiert wurden, eine DNA-Immunisierung mit pFascin-βGal aber auch mit pCMV-βGal einen inhibierenden Einfluss auf die Entwicklung einer Atemwegsinflammation hat. Eine weitere Reduktion der Atemwegsreaktivität durch eine kombinierte Vakzinierung mit pCMV-IDO wurde nur erreicht, wenn βGal unter der Kontrolle des Fascin-Promotors exprimiert wurde, nicht aber unter Kontrolle des CMV-Promotors.rn

Computational insight into materials properties

The aim of the work was to explore the practical applicability of molecular dynamics at different length and time scales. From nanoparticles system over colloids and polymers to biological systems like membranes and finally living cells, a broad range of materials was considered from a theoretical standpoint. In this dissertation five chemistry-related problem are addressed by means of theoretical and computational methods. The main results can be outlined as follows. (1) A systematic study of the effect of the concentration, chain length, and charge of surfactants on fullerene aggregation is presented. The long-discussed problem of the location of C60 in micelles was addressed and fullerenes were found in the hydrophobic region of the micelles. (2) The interactions between graphene sheet of increasing size and phospholipid membrane are quantitatively investigated. (3) A model was proposed to study structure, stability, and dynamics of MoS2, a material well-known for its tribological properties. The telescopic movement of nested nanotubes and the sliding of MoS2 layers is simulated. (4) A mathematical model to gain understaning of the coupled diffusion-swelling process in poly(lactic-co-glycolic acid), PLGA, was proposed. (5) A soft matter cell model is developed to explore the interaction of living cell with artificial surfaces. The effect of the surface properties on the adhesion dynamics of cells are discussed.

Narratori degli anni zero. Storia, critica, poetiche

Il lavoro si propone come un’indagine sulla letteratura italiana del primo decennio del XXI secolo, in una prospettiva non di semplice ricognizione ma di individuazione di linee interpretative capaci di ripercorrere un archivio di materiali molto vasto e non ancora chiuso. La prima parte affronta questioni relative a condizioni produttive, ricezione e valutazione critica della letteratura contemporanea. Il primo capitolo è dedicato alla discussione di problemi relativi allo studio della narrativa italiana del XXI secolo a partire dalla definizione utilizzata per riferirsi ad essa, quella di “anni zero”. Il secondo capitolo situa la narrativa contemporanea nelle linee di sviluppo della letteratura italiana degli ultimi trent’anni, a partire da un mutamento del rapporto dello scrittore con la tradizione umanistica che risale all’inizio degli anni ottanta. Il terzo capitolo approfondisce uno dei generi maggiormente praticati: il romanzo storico. Considerato negli anni ottanta e novanta un genere d'evasione e intrattenimento, negli anni zero è divenuto veicolo di punti di vista critici nei confronti delle narrazioni dominanti. La seconda parte è dedicata all’approfondimento di romanzi che raccontano, da un’ottica non testimoniale, gli anni settanta italiani, periodo complesso non solo sul piano evenemenziale, ma anche su quello della rielaborazione artistica. I romanzi su cui si concentra l’indagine offrono un racconto degli anni settanta italiani a partire da un’idea di storia plurale, ricostruita attraverso una molteplicità di voci, che muta a seconda della prospettiva da cui viene affrontata. Le storie false dei romanzi sugli anni settanta non chiedono di essere lette come vere, ma dicono comunque qualcosa di vero sulle modalità attraverso le quali si va costruendo il rapporto con il passato recente, nel più ampio contesto dei percorsi della letteratura italiana di inizio millennio, tra spinte che vanno nella direzione del mantenimento dell’autonomia da parte degli autori e pressioni del mercato editoriale.

Antigenspezifische DNA-Immunisierung in Kombination mit IDO-kodierenden Plasmiden zur Therapie der experimentellen Typ I-Allergie

Derzeit stellt die allergenspezifische Immuntherapie die einzige nicht allein antisymptomatische Behandlungsform zur langfristigen Therapie von Typ I-Allergien dar, welche grundlegende Änderungen im immunologischen Geschehen induziert. Sie ist jedoch verbesserungswürdig in Bezug auf Behandlungsdauer, Erfolgschancen und Nebenwirkungen. Daher wurde in dieser Arbeit eine Strategie zur Therapie von Typ I-Allergien entwickelt und evaluiert, welche auf der Inhibition allergenspezifischer T-Zellen durch Dendritische Zellen (DC), die selektiv nach DNA-Immunisierung sowohl das relevante Allergen als auch Indolamin 2,3-dioxygenase (IDO) konstitutiv produzieren, basiert. IDO ist ein Enzym aus dem Tryptophan-Stoffwechsel, dessen Produktion durch DC einen lokalen immunsuppressiven Mechanismus induziert und in verschiedenen Situationen mit der Induktion peripherer Toleranz assoziiert ist. Zunächst wurden Plasmide hergestellt, die entweder IDO alleine oder IDO zusammen mit dem Antigen unter der Kontrolle des ubiquitär aktiven CMV- bzw. des DC-spezifischen Fascin-Promotors kodieren. Die Überprüfung der IDO-Expression durch die monocistronischen Plasmide anhand von Transfektionsexperimenten in vitro ergab, dass die IDO-Expression unter der Kontrolle des CMV-Promotors sehr viel stärker ausfiel als unter der Kontrolle des Fascin-Promotors. Nach Transfektion mit den bicistronischen Vektoren, in denen die Transgene für das Antigen und IDO durch eine IRES-Sequenz verbunden waren, war die IDO-Expression jedoch insgesamt sehr schwach. Im Rahmen der Überprüfung der Funktionalität der IDO-Expressionplasmide in vivo unter Verwendung der Genpistole wurden daher lediglich Plasmide getestet, die alleine IDO unter der Kontrolle des CMV-Promotors bzw. des Fascin-Promotors kodieren. Auch in vivo wurde eine stärkere IDO-Expression nach biolistischer Transfektion mit solchen Vektoren beobachtet, in denen der CMV-Promotor zur Expressionskontrolle verwendet wurde. Die Analyse des Einflusses einer Koexpression von IDO auf die durch biolistische Immunisierung mit einem antigenkodierenden Vektor induzierte systemische Immunantwort offenbarte einen inhibitorischer Effekt für den Fall, dass die Antigenproduktion mittels des Fascin-Promotors auf DC fokussiert war und die Expression des koapplizierten IDO-Transgens unter der Kontrolle des CMV-Promotors stand. In diesem Fall wurde eine Reduktion der antigenspezifischen IgG1- und IgG2a-Produktion, eine verringerte Sekretion von IFN-y durch restimulierte Milz- und Lymphknotenzellen sowie eine Reduktion der Zahl antigenspezifischer CD8+ Effektor-T-Zellen nachgewiesen. Im Mausmodell der IgE-vermittelten Typ I-Allergie wurde weiterhin gezeigt, dass nach prophylaktischer biolistischer Vakzinierung unter Verwendung dieser Vektorkombination eine Inhibition der durch die Vakzinierung bedingten antigenspezifischen Th1-Immunantwort ausgelöst wurde. Die Suppression der Th2-Antwort, welche durch Transfektion mit dem Antigenkodierenden Vektor unter Kontrolle des Fascin-Promotors bewirkt wurde, wurde durch Kotransfektion mit den IDO-kodierenden Vektoren aufrecht erhalten.

Homicide-suicide cases in Switzerland and their impact on the Swiss Weapon Law

Homicide followed by the suicide of the offender is a well-known phenomenon. In most cases, it takes place in the context of the so-called "family tragedies." A recent series of such family tragedies in Switzerland prompted an intensive debate in the media and the Swiss government concerning the Swiss Weapon Law, in particular the requirement to keep personal army weapons at home. The present study of Homicide-Suicide cases in Switzerland, thus focuses on the role played by guns, especially military weapons, in such crimes. We investigated retrospectively 75 cases of Homicide-Suicide, comprising 172 individuals and spanning a period of 23 years in western and central Switzerland. Our results show that if guns were used in 76% of the cases, army weapons were the cause of death in 25% of the total. In 28% of the deaths caused by a gunshot, the exact type of the gun and its origin could not be determined. Thus, the majority of Homicide-Suicide cases in Switzerland involve the use of guns. The exact percentage of cases were military weapons were involved could not be defined. In our opinion, a stricter weapons law, restricting access to firearms, would be a factor of prevention of Homicide- Suicide cases in Switzerland.

Wear of double crown systems: electroplated vs. casted female part

The wear of telescopic crowns is a common problem often reducing the patient's satisfaction with the denture and resulting in a renewal of the denture. The study aims to compare the wear behavior of conical crowns using electroplated copings (group E ) with standard telescopic crowns with cast female parts (group C).

A Systematic Review of the Clinical Performance of Tooth-Retained and Implant-Retained Double Crown Prostheses with a Follow-Up of ≥3 Years

Purpose: The objective of this review was to systematically screen the literature for data related to the survival and complication rates observed with dental or implant double crown abutments and removable prostheses under functional loading for at least 3 years. Materials and Methods: A systematic review of the dental literature from January 1966 to December 2009 was performed in electronic databases (PubMed and Embase) as well as by an extensive hand search to investigate the clinical outcomes of double crown reconstructions. Results: From the total of 2412 titles retrieved from the search, 65 were selected for full-text review. Subsequently, 17 papers were included for data extraction. An estimation of the cumulative survival and complication rates was not feasible due to the lack of detailed information. Tooth survival rates for telescopic abutment teeth ranged from 82.5% to 96.5% after an observation period of 3.4 to 6 years, and for tooth-supported double crown retained dentures from 66.7% to 98.6% after an observation period of 6 to 10 years. The survival rates of implants were between 97.9% and 100% and for telescopic-retained removable dental prostheses with two mandibular implants, 100% after 3.0 and 10.4 years. The major biological complications affecting the tooth abutments were gingival inflammation, periodontal disease, and caries. The most frequent technical complications were loss of cementation and loss of facings. Conclusions: The main findings of this review are: (I) double crown tooth abutments and dentures demonstrated a wide range of survival rates. (II) Implant-supported mandibular overdentures demonstrated a favorable long-term prognosis. (III) A greater need for prosthetic maintenance is required for both tooth-supported and implant-supported reconstructions. (IV) Future areas of research would involve designing appropriate longitudinal studies for comparisons of survival and complication rates of different reconstruction designs.

A new microbiopsy system enables rapid preparation of tissue for high-pressure freezing

A microbiopsy system was developed to overcome long sampling times for tissues before they are cryo-fixed by high-pressure freezing. A commercially available biopsy gun was adapted to the needs of small-organ excisions, and biopsy needles were modified to allow small samples (0.6 mm x 1.2 mm x 0.3 mm) to be taken. Specimen platelets with a central slot of the same dimensions as the biopsy are used. A self-made transfer device (in the meantime optimized by Leica-Microsystems [Vienna, Austria]) coordinates the transfer of the excised sample from the biopsy needle into the platelet slot and the subsequent loading in a specimen holder, which is then introduced into a high-pressure freezer (Leica EM PACT; Leica Microsystems, Vienna, Austria). Thirty seconds preparation time is needed from excision until high-pressure freezing. Brain, liver, kidney and muscle excisions of anesthetised rats are shown to be well frozen.

Clinical evaluation of root filled teeth restored with or without post-and-core systems in a specialist practice setting

AIM: To assess survival rates and complications of root-filled teeth restored with or without post-and-core systems over a mean observation period of >or=4 years. METHODOLOGY: A total of 325 single- and multirooted teeth in 183 subjects treated in a private practice were root filled and restored with either a cast post-and-core or with a prefabricated titanium post and composite core. Root-filled teeth without post-retained restorations served as controls. The restored teeth served as abutments for single unit metal-ceramic or composite crowns or fixed bridges. Teeth supporting cantilever bridges, overdentures or telescopic crowns were excluded. RESULTS: Seventeen teeth in 17 subjects were lost to follow-up (17/325: 5.2%). The mean observation period was 5.2 +/- 1.8 (SD) years for restorations with titanium posts, 6.2 +/- 2.0 (SD) years for cast post-and-cores and 4.4 +/- 1.7 (SD) years for teeth without posts. Overall, 54% of build-ups included the incorporation of a titanium post and 26.5% the cementation of a cast post-and-core. The remaining 19.5% of the teeth were restored without intraradicular retention. The adjusted 5-year tooth survival rate amounted to 92.5% for teeth restored with titanium posts, to 97.1% for teeth restored with cast post-and-cores and to 94.3% for teeth without post restorations, respectively. The most frequent complications included root fracture (6.2%), recurrent caries (1.9%), post-treatment periradicular disease (1.6%) and loss of retention (1.3%). CONCLUSION: Provided that high-quality root canal treatment and restorative protocols are implemented, high survival and low complication rates of single- and multirooted root-filled teeth used as abutments for fixed restorations can be expected after a mean observation period of >or=4 years.

Haptics in forensics: the possibilities and advantages in using the haptic device for reconstruction approaches in forensic science

Non-invasive documentation methods such as surface scanning and radiological imaging are gaining in importance in the forensic field. These three-dimensional technologies provide digital 3D data, which are processed and handled in the computer. However, the sense of touch gets lost using the virtual approach. The haptic device enables the use of the sense of touch to handle and feel digital 3D data. The multifunctional application of a haptic device for forensic approaches is evaluated and illustrated in three different cases: the representation of bone fractures of the lower extremities, by traffic accidents, in a non-invasive manner; the comparison of bone injuries with the presumed injury-inflicting instrument; and in a gunshot case, the identification of the gun by the muzzle imprint, and the reconstruction of the holding position of the gun. The 3D models of the bones are generated from the Computed Tomography (CT) images. The 3D models of the exterior injuries, the injury-inflicting tools and the bone injuries, where a higher resolution is necessary, are created by the optical surface scan. The haptic device is used in combination with the software FreeForm Modelling Plus for touching the surface of the 3D models to feel the minute injuries and the surface of tools, to reposition displaced bone parts and to compare an injury-causing instrument with an injury. The repositioning of 3D models in a reconstruction is easier, faster and more precisely executed by means of using the sense of touch and with the user-friendly movement in the 3D space. For representation purposes, the fracture lines of bones are coloured. This work demonstrates that the haptic device is a suitable and efficient application in forensic science. The haptic device offers a new way in the handling of digital data in the virtual 3D space.

[Zirconia and removable partial dentures]

The present paper deals with the double crown technique in removable prosthodontics. New ceramic materials like zirconia are increasingly used in combination with CAD/CAM technologies for framework fabrication of fixed prosthesis, tooth- or implant-supported. However, zirconia is also a newly accepted material in removable prosthodontics. It replaces gold alloys for the fabrication of primary telescopic crowns. The Galvanoforming technology is preferably used to fabricate the secondary crowns. The combination of both techniques and materials results in a prosthetic reconstruction of high quality, optimum fit and good biocompatibility.

Historic Preservation at Nevada City, Montana

Primary emphasis this summer was placed on restoring the Richards Cabin however, the first week was spent priming and painting the interior of the Iron Rod Post Office. All the buildings within the Nevada City Outdoor Museum complex are historically significant, some more than others. Some have been used as sets on major Hollywood productions such as, "The MissouriBreaks"," Little Big Man", "Return to Lonesome Dove", "Thousand Pieces of Gold" and "The Left Handed Gun". Others have more historical significance. Some are from Yellowstone National Park. One specifically built for a County Sheriff's Department eventually accommodated a legal "triple hanging" of outlaws in 1917. One was used as a location for a Blackfeet treaty signing in 1865.

Geology of a Portion of the Bull Mountain Range Jefferson County, Montana

Work was first done on a known section, the south Boulder Section, in order to familiarize the student with the formations. Most of the area was mapped by plane table and telescopic alidade, general features being surveyed by automobile traverse and a pacing traverse.