Characterization of mode I disbonding behaviour of carbon/epoxy composites bonded with two adhesion qualities

La mancanza di procedure standard per la verifica delle strutture in compositi, al contrario dei materiali metallici, porta all’esigenza di una continua ricerca nel settore, al fine di ottenere risultati significativi che culminino in una standardizzazione delle procedure. In tale contesto si colloca la ricerca svolta per la stesura del presente elaborato, condotta presso il laboratorio DASML del TU Delft, nei Paesi Bassi. Il materiale studiato è un prepreg (preimpregnated) costituito da fibre di carbonio (M30SC) e matrice epossidica (DT120) con la particolare configurazione [0°/90°/±45°/±45°/90°/0°]. L’adesivo utilizzato per l’incollaggio è di tipo epossidico (FM94K). Il materiale è stato assemblato in laboratorio in modo da ottenere i provini da testare, di tipo DCB, ENF e CCP. Due differenti qualità dello stesso materiale sono state ottenute, una buona ottenuta seguendo le istruzione del produttore, ed una povera ottenuta modificando il processo produttivo suggerito, che risulta in un incollaggio di qualità nettamente inferiore rispetto al primo tipo di materiale. Lo scopo era quello di studiare i comportamenti di entrambe le qualità sotto due diversi modi di carico, modo I o opening mode e modo II o shear mode, entrambi attraverso test quasi-statici e a fatica, così da ottenere risultati comparabili tra di essi che permettano in futuro di identificare se si dispone di un materiale di buona qualità prima di procedere con il progetto dell’intera struttura. L’approccio scelto per lo studio dello sviluppo della delaminazione è un adattamento della teoria della Meccanica della Frattura Lineare Elastica (LEFM)

Au(I) Catalyzed Manipulation of Propargylic Alcohols: A New Route Towards the Synthesis of Indole Alkaloids

In this work we presented several aspects regarding the possibility to use readily available propargylic alcohols as acyclic precursors to develop new stereoselective [Au(I)]-catalyzed cascade reactions for the synthesis of highly complex indole architectures. The use of indole-based propargylic alcohols of type 1 in a stereoselective [Au(I)]-catalyzed hydroindolynation/immiun trapping reactive sequence opened access to a new class of tetracyclic indolines, dihydropyranylindolines A and furoindolines B. An enantioselective protocol was futher explored in order to synthesize this molecules with high yields and ee. The suitability of propargylic alcohols in [Au(I)]-catalyzed cascade reactions was deeply investigated by developing cascade reactions in which was possible not only to synthesize the indole core but also to achieve a second functionalization. Aniline based propargylic alcohols 2 were found to be modular acyclic precursors for the synthesis of [1,2-a] azepinoindoles C. In describing this reactivity we additionally reported experimental evidences for an unprecedented NHCAu(I)-vinyl specie which in a chemoselective fashion, led to the annulation step, synthesizing the N1-C2-connected seven membered ring. The chemical flexibility of propargylic alcohols was further explored by changing the nature of the chemical surrounding with different preinstalled N-alkyl moiety in propargylic alcohols of type 3. Particularly, in the case of a primary alcohol, [Au(I)] catalysis was found to be prominent in the synthesis of a new class of [4,3-a]-oxazinoindoles D while the use of an allylic alcohol led to the first example of [Au(I)] catalyzed synthesis and enantioselective functionalization of this class of molecules (D*). With this work we established propargylic alcohols as excellent acyclic precursor to developed new [Au(I)]-catalyzed cascade reaction and providing new catalytic synthetic tools for the stereoselective synthesis of complex indole/indoline architectures.

Phase I/IIa study of cilengitide and temozolomide with concomitant radiotherapy followed by cilengitide and temozolomide maintenance therapy in patients with newly diagnosed glioblastoma

Invasion and migration are key processes of glioblastoma and are tightly linked to tumor recurrence. Integrin inhibition using cilengitide has shown synergy with chemotherapy and radiotherapy in vitro and promising activity in recurrent glioblastoma. This multicenter, phase I/IIa study investigated the efficacy and safety of cilengitide in combination with standard chemoradiotherapy in newly diagnosed glioblastoma.

I think of my family, therefore I am: perceptions of daily occupations of some Albanians in Switzerland

The purpose of this qualitative study was to increase the understanding of the relationship between culture and occupation by exploring the perceptions of current daily occupations of some immigrants living in Switzerland. Semi-structured interviews with eight healthy Muslim Albanian men doing blue-collar work were analysed in a comparative manner followed by an interpretation. Three themes were identified: "Everything I do I do for my family"; "Where do I belong?"; and "Doing something for myself". These themes reflect the occupational perceptions of the participants. The findings are discussed in relation to the ongoing discourses on individualism and collectivism. To offer occupational therapy appropriately to a multicultural clientele the findings indicate the necessity to be conscious of the differences between one's own and the client's attitudes regarding individualism and collectivism.

I know what I like: Stability of aesthetic preference in Alzheimer's disease

Two studies explored the stability of art preference in patients with Alzheimer’s disease and age-matched control participants. Preferences for three different styles of paintings, displayed on art postcards, were examined over two sessions. Preference for specific paintings differed among individuals but AD and non-AD groups maintained about the same stability in terms of preference judgments across two weeks, even though the AD patients did not have explicit memory for the paintings. We conclude that aesthetic responses can be preserved in the face of cognitive decline. This should encourage caregivers and family to engage in arts appreciation activities with patients, and reinforces the validity of a preference response as a dependent measure in testing paradigms.

Glucagon, catecholamine and pancreatic polypeptide secretion in type I diabetic recipients of pancreas allografts

Successful pancreas transplantation in type I diabetic patients restores normal fasting glucose levels and biphasic insulin responses to glucose. However, virtually no data from pancreas recipients are available relative to other islet hormonal responses or hormonal counterregulation of hypoglycemia. Consequently, glucose, glucagon, catecholamine, and pancreatic polypeptide responses to insulin-induced hypoglycemia and to stimulation with arginine and secretin were examined in 38 diabetic pancreas recipients, 54 type I diabetic nonrecipients, and 26 nondiabetic normal control subjects. Glucose recovery after insulin-induced hypoglycemia in pancreas recipients was significantly improved. Basal glucagon levels were significantly higher in recipients compared with nonrecipients and normal subjects. Glucagon responses to insulin-induced hypoglycemia were significantly greater in the pancreas recipients compared with nonrecipients and similar to that observed in control subjects. Glucagon responses to intravenous arginine were significantly greater in pancreas recipients than that observed in both the nonrecipients and normal subjects. No differences were observed in epinephrine responses during insulin-induced hypoglycemia. No differences in pancreatic polypeptide responses to hypoglycemia were observed when comparing the recipient and nonrecipient groups, both of which were less than that observed in the control subjects. Our data demonstrate significant improvement in glucose recovery after hypoglycemia which was associated with improved glucagon secretion in type I diabetic recipients of pancreas transplantation.

Insulin-like growth factor I improves aspects of mycophenolate mofetil-impaired anastomotic healing in an experimental model

BACKGROUND: Patients taking immunosuppressants after transplantation may require intestinal surgery. Mycophenolate mofetil (MMF) has been found to impair the healing of colonic anastomoses in rats. This study examined whether insulin-like growth factor (IGF) I prevents MMF impairment of anastomotic healing. METHODS: Sixty-three rats were divided into three groups (MMF, MMF/IGF and control). Animals underwent a sigmoid colon anastomosis with a 6/0 suture, and were killed on days 2, 4 and 6 after surgery. Investigations included bursting pressure measurement, morphometric analysis, and assessment of mucosal proliferation by 5-bromo-2'-deoxyuridine and Ki67 immunohistochemistry of the anastomoses. RESULTS: The leak rate was three of 21, one of 20 and two of 20 in the MMF, MMF/IGF-I and control groups respectively. Anastomotic bursting pressures were significantly lower in the MMF group than in the control group on days 2 and 4, but there was no significant difference by day 6. Values in the MMF/IGF-I and control groups were similar. Colonic crypt depth was significantly reduced in MMF-treated animals on days 2 and 4, but this impairment was attenuated by IGF-I on day 4. Similarly, IGF-I reduced the negative impact of MMF on mucosal proliferation on days 2 and 6. CONCLUSION: Exogenous IGF-I improves some aspects of MMF-impaired anastomotic healing.

Structural Problems in the Development of Social Work in Central Europe under Transformation. The Case of Poland

Socio-economic transformation the countries of Central Europe are undergoing since 1989 has brought new developments in social welfare systems of this region. Social work, which was in the countries of the region during its communist past either non-existent or superficial activity, has become treated as an instrument of social welfare systems there. The collapse of authoritarian regimes in the region clearly inducted political leaderships there to opt for transition to Western style civil society. Hence an adoption of social work seemed to be natural choice for the countries in the region.

Characterization of the type I secretion system of the RTX toxin ApxII in "Actinobacillus porcitonsillarum"

Strains of Actinobacillus porcitonsillarum are regularly isolated from the tonsils of healthy pigs. A. porcitonsillarum is non pathogenic but phenotypically it strongly resembles the pathogenic species Actinobacillus pleuropneumoniae, thereby interfering with the diagnosis of the latter. A. porcitonsillarum is hemolytic but unlike A. pleuropneumoniae, it contains only apxII genes and not apxI or apxIII genes. In contrast to the truncated apxII operon of A. pleuropneumoniae, which lacks the type I secretion genes BD, characterization of the apxII operon in A. porcitonsillarum revealed that it contains an intact and complete apxII operon. This shows a typical RTX operon structure with the gene arrangement apxIICABD. The region upstream of the apxII operon is also different from that in A. pleuropneumoniae and contains an additional gene, aspC, encoding a putative aspartate aminotransferase. Trans-complementation experiments in Escherichia coli and A. pleuropneumoniae indicated that the entire apxII operon of A. porcitonsillarum is sufficient to express and secrete the ApxIIA toxin and that the ApxIIA toxin of A. pleuropneumoniae can be secreted by the type I secretion system encoded by apxIIBD. These findings suggest that the complete apxII operon found in A. porcitonsillarum might be an ancestor of the truncated homologue found in A. pleuropneumoniae. The genetic context of the apxII locus in A. porcitonsillarum and A. pleuropneumoniae suggests that in the latter, the contemporary truncated operon is the result of a recombination event within the species, rather than a horizontal transfer of an incomplete operon.