971 resultados para RADIATION-INDUCED MENINGIOMA


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Emotional intelligence (EI) is defined as “the ability to recognise, understand and manage emotions in ourselves and others”. Initially identified as a concept applied to leadership and management, EI is now recognised as an important skill in a number of areas, including healthcare [2]. Empathy (the ability to see the world through someone else’s eyes) is known to play an important role in the therapeutic relationship with patients [3]. As EI has been shown to improve empathy [4], it is clear that developing the EI of student health professionals should benefit patients in the long term. It is not surprising, then, that a number of studies have investigated the role of EI in medical, dental and nursing students, however there is little reported evidence relating to EI development in pre-registration radiation therapy (RT) students.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Functional loss of tumor suppressor protein p53 is a common feature in diverse human cancers. The ability of this protein to sense cellular damage and halt the progression of the cell cycle or direct the cells to apoptosis is essential in preventing tumorigenesis. Tumors having wild-type p53 also respond better to current chemotherapies. The loss of p53 function may arise from TP53 mutations or dysregulation of factors controlling its levels and activity. Probably the most significant inhibitor of p53 function is Mdm2, a protein mediating its degradation and inactivation. Clearly, the maintenance of a strictly controlled p53-Mdm2 route is of great importance in preventing neoplastic transformation. Moreover, impairing Mdm2 function could be a nongenotoxic way to increase p53 levels and activity. Understanding the precise molecular mechanisms behind p53-Mdm2 relationship is thus essential from a therapeutic point of view. The aim of this thesis study was to discover factors affecting the negative regulation of p53 by Mdm2, causing activation of p53 in stressed cells. As a model of cellular damage, we used UVC radiation, inducing a complex cellular stress pathway. Exposure to UVC, as well as to several chemotherapeutic drugs, causes robust transcriptional stress in the cells and leads to activation of p53. By using this model of cellular stress, our goal was to understand how and by which proteins p53 is regulated. Furthermore, we wanted to address whether these pathways affecting p53 function could be altered in human cancers. In the study, two different p53 pathway proteins, nucleophosmin (NPM) and promyelocytic leukemia protein (PML), were found to participate in the p53 stress response following UV stress. Subcellular translocations of these proteins were discovered rapidly after exposure to UV. The alterations in the cellular localizations were connected to transient interactions with p53 and Mdm2, implicating their significance in the regulation of p53 stress response. NPM was shown to control Mdm2-p53 interface and mediate p53 stabilization by blocking the ability of Mdm2 to promote p53 degradation. Furthermore, NPM mediated p53 stabilization upon viral insult. We further detected a connection between cellular pathways of NPM and PML, as PML was found to associate with NPM in UV-radiated cells. The observed temporal UV-induced interactions strongly imply existence of a multiprotein complex participating in the p53 response. In addition, PML controlled the UV response of NPM, its localization and complex formation with chromatin associated factors. The relevance of the UV-promoted interactions was demonstrated in studies in a human leukemia cell line, being under abnormal transcriptional repression due to expression of oncogenic PML-RARa fusion protein. Reversing the leukemic phenotype with a therapeutically significant drug was associated with similar complex formation between p53 and its partners as following UV. In conclusion, this thesis study identifies novel p53 pathway interactions associated with the recovery from UV-promoted as well as oncogenic transcriptional repression.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

By using electric-field-induced optical second-harmonic generation (EFISHG) measurement, we analyzed hysteresis behavior of capacitance-voltage (C-V) characteristics of IZO/polyterpenol (PT)/C₆₀/pentacene/Au diodes, where PT layer is actively working as a hole-transport electron-blocking layer. The EFISHG measurement verified the presence of interface accumulated charges in the diodes, and showed that a space charge electric field from accumulated excess electrons (holes) that remain at the PT/C₆₀ (C₆₀/pentacene) interface is responsible for the hysteresis loop observed in the C-V characteristics.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Time-resolved electric field induced second harmonic generation technique was used to probe the carrier transients within double-layer pentacene-based MIM devices. Polyterpenol thin films fabricated from non-synthetic environmentally sustainable source were used as a blocking layer to assist in visualisation of single-species carrier transportation during charging and discharging under different bias conditions. Results demonstrated that carrier transients were comprised of charging on electrodes, followed by carrier injection and charging of the interface. Polyterpenol was demonstrated to be a sound blocking material and can therefore be effectively used for probing of double-layer devices using EFISHG.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The influence of insect attack on bud fall and subsequent poor flowering in cultivated hibiscus (Hibiscus rosa-sinensis) was studied in cages and in the field in southern Queensland. Three species of Hemiptera (most importantly Aulacosternum nigrorubrum but also Nezara viridula and Tectocoris diophthalmus) caused some bud fall in 2 plantations studied. Adults of Macroura concolor suppressed flowering for long periods in spring and summer. Data from white funnel traps and counts in flowers showed that M. concolor was most active in these seasons. Methiocarb (0.75 g a.i./litre) reduced beetle numbers and increased flowering. When 15 or more adults of M. concolor occurred per bud (or flower) most buds fell and few flowers were produced, but when beetles declined to 10 or fewer many buds survived and widespread flowering occurred. Larvae fed in fallen buds and flowers and the mean duration of development of the combined immature stages was 14 days at 26 deg C. The preference of adults of M. concolor for pale coloured flowers was examined. Hibiscus plants produced most buds from December to June with lower numbers in winter and spring (July to November). Bud production in spring and early summer (September-December) varied greatly and probably contributed to poor flowering, however, even when large numbers of buds occurred very few flowers were produced because of the activities of M. concolor.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Atmospheric-pressure plasma (APP) has been successfully used to treat several types of cancers in vivo and in vitro, with the effect being primarily attributed to the generation of reactive oxygen species (ROS). However, the mechanisms by which APP induces apoptosis in cancer cells require further elucidation. In this study, the effects of APP on the expression of 500 genes in melanoma Mel007 cancer cells were examined. Pro-apoptotic phorbol-12-myristate-13-acetate-induced protein (PMAIP1), also known as NOXA, was highly expressed as a result of APP treatment in a dose-dependent manner. Blocking of ROS using scavenger NAC or silencing of NOXA gene by RNA interference inhibited the APP-induced NOXA genes upregulation and impaired caspases 3/7 mediated apoptosis, confirming the important role plasma-generated ROS species and pro-apoptotic NOXA play in APP-induced cancer cell death.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Pectobacterium atrosepticum on Gram-negatiivinen bakteeri, joka aiheuttaa perunan tyvi- ja märkämätää. P. atrosepticum bakteerin optimilämpötila on melko alhainen ja se on yleinen lauhkeilla alueilla. Tyvimätä leviää pääasiassa siemenperunan välityksellä ja siksi se on ongelma erityisesti siemenperunan tuotannossa. P. atrosepticum kannan SCRI1043 genomi on julkaistu ja sitä tutkitaan malliorganismina märkä- ja tyvimädän taudinaiheuttamisen ymmärtämiseksi. Tämä opportunistinen taudinaiheuttaja voi elää isäntäkasvissa kuukausia piilevänä, aiheuttamatta näkyviä oireita. Suotuisissa olosuhteissa bakteerit alkavat jakautua ja tuottaa kasvin kudoksia hajottavia entsyymejä. Mädäntyvä kasvimassa tarjoaa ravinteita bakteerien kasvuun ja mahdollistaa isäntäkasvin asuttamisen. Soluseiniä hajottavien entsyymien merkitys taudinaiheuttamisessa on hyvin tunnettu, mutta oireettomasta jaksosta ja taudin alkuvaiheista tiedätään vain vähän. Bakteerin genomi sisältää monia toksiineja, adhesiineja, hemolysiineja ja muita proteiineja, joilla saattaa olla merkitys taudinaiheuttamisessa. Tässä työssä käytettiin proteomiikkaa ja mikrosiruanalysiä P. atrosepticum bakteerin erittyvien proteiinien ja geeniekspression tutkimiseen. Proteiinit, jotka eritetään ulos bakteerista, toimivat todennäköisesti taudinaiheuttamisessa, koska ne ovat suorassa kontaktissa isäntäkasvin kanssa. Analyysit suoritettiin olosuhteissa, jotka muistuttavat kasvin soluvälitilaa: matala pH, vähän ravinteita ja matala lämpötila. Isäntäkasvin läsnäolon vaikutusta proteiinien tuottoon ja geeniekspressioon tutkittiin lisäämällä perunauutetta kasvatusalustaan. Tutkimuksessa tunnistettiin P. atrosepticum bakteerin monia jo tunnettuja ja mahdollisesti taudinaiheuttamiseen liittyviä proteiineja. Perunauute lisäsi hiljattain tunnistetun, proteiinien eritysreittiä (tyyppi VI sekreetio, T6SS) koodaavien geenien ilmentymistä. Lisäksi bakteerin havaittiin erittävän useita T6SS:n liittyviä proteiineja kasvualustaan, johon oli lisätty perunauutetta. T6SS:n merkitys bakteereille on vielä epäselvä ja sen vaikutuksesta taudinaiheuttamiseen on julkaistu ristiriitaisia tuloksia. Märkä- ja tyvimädän ymmärtäminen molekulaarisella tasolla luo pohjan tautien kontrollointiin tähtäävään soveltavaan tutkimukseen. Tämä tutkimus lisää tietoa kasvi-patogeeni- interaktiosta ja sitä voidaan tulevaisuudessa käyttää hyväksi esimerkiksi diagnostiikassa, resistenttien perunalajikkeiden jalostuksessa tai viljely- ja varastointiolosuhteiden parantamisessa.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The effect of pressure on the electrical resistivity of bulk Si20Te80 glass has been studied up to a pressure of 8 GPa. A discontinuous transition occurs at a pressure of 7 GPa. The X-ray diffraction studies on the pressure quenched sample show that the high pressure phase is crystalline with hexagonal structure (c/a = 1.5). On heating, the high pressure hexagonal phase has on exothermic decomposition atT = 586 K into two crystalline phases, which are the stable phases tellurium and SiTe2 obtained by simple heating of the glass.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The electrical resistivity of layerd crystalline GeSe has been investigated up to a pressure of 100 kbar and down to liquid-nitrogen temperature by use of a Bridgman anvil device. A pressure-induced first-order phase transition has been observed in single-crystal GeSe near 6 GPa. The high-pressure phase is found to be quenchable and an x-ray diffraction study of the quenched material reveals that it has the face-centered-cubic structure. Resistivity measurements as a function of pressure and temperature suggest that the high-pressure phase is metallic.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Inspired by high porosity, absorbency, wettability and hierarchical ordering on the micrometer and nanometer scale of cotton fabrics, a facile strategy is developed to coat visible light active metal nanostructures of copper and silver on cotton fabric substrates. The fabrication of nanostructured Ag and Cu onto interwoven threads of a cotton fabric by electroless deposition creates metal nanostructures that show a localized surface plasmon resonance (LSPR) effect. The micro/nanoscale hierarchical ordering of the cotton fabrics allows access to catalytically active sites to participate in heterogeneous catalysis with high efficiency. The ability of metals to absorb visible light through LSPR further enhances the catalytic reaction rates under photoexcitation conditions. Understanding the mode of electron transfer during visible light illumination in Ag@Cotton and Cu@Cotton through electrochemical measurements provides mechanistic evidence on the influence of light in promoting electron transfer during heterogeneous catalysis for the first time. The outcomes presented in this work will be helpful in designing new multifunctional fabrics with the ability to absorb visible light and thereby enhance light-activated catalytic processes.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background Adolescent Idiopathic Scoliosis is the most common type of spinal deformity, and whilst the risk of progression appears to be biomechanically mediated (larger deformities are more likely to progress), the detailed biomechanical mechanisms driving progression are not well understood. Gravitational forces in the upright position are the primary sustained loads experienced by the spine. In scoliosis they are asymmetrical, generating moments about the spinal joints which may promote asymmetrical growth and deformity progression. Using 3D imaging modalities to estimate segmental torso masses allows the gravitational loading on the scoliotic spine to be determined. The resulting distribution of joint moments aids understanding of the mechanics of scoliosis progression. Methods Existing low-dose CT scans were used to estimate torso segment masses and joint moments for 20 female scoliosis patients. Intervertebral joint moments at each vertebral level were found by summing the moments of each of the torso segment masses above the required joint. Results The patients’ mean age was 15.3 years (SD 2.3; range 11.9 – 22.3 years); mean thoracic major Cobb angle 52° (SD 5.9°; range 42°-63°) and mean weight 57.5 kg (SD 11.5 kg; range 41 – 84.7 kg). Joint moments of up to 7 Nm were estimated at the apical level. No significant correlation was found between the patients’ major Cobb angles and apical joint moments. Conclusions Patients with larger Cobb angles do not necessarily have higher joint moments, and curve shape is an important determinant of joint moment distribution. These findings may help to explain the variations in progression between individual patients. This study suggests that substantial corrective forces are required of either internal instrumentation or orthoses to effectively counter the gravity-induced moments acting to deform the spinal joints of idiopathic scoliosis patients.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This article describes the relationship between avocado fruit firmness, level of impact energy absorbed by the fruit, and post impact fruit holding duration with the incidence of bruising.