3,318 research outputs found
A Biased Resistor Network Model for Electromigration Failure and Related Phenomena in Metallic Lines
Electromigration phenomena in metallic lines are studied by using a biased
resistor network model. The void formation induced by the electron wind is
simulated by a stochastic process of resistor breaking, while the growth of
mechanical stress inside the line is described by an antagonist process of
recovery of the broken resistors. The model accounts for the existence of
temperature gradients due to current crowding and Joule heating. Alloying
effects are also accounted for. Monte Carlo simulations allow the study within
a unified theoretical framework of a variety of relevant features related to
the electromigration. The predictions of the model are in excellent agreement
with the experiments and in particular with the degradation towards electrical
breakdown of stressed Al-Cu thin metallic lines. Detailed investigations refer
to the damage pattern, the distribution of the times to failure (TTFs), the
generalized Black's law, the time evolution of the resistance, including the
early-stage change due to alloying effects and the electromigration saturation
appearing at low current densities or for short line lengths. The dependence of
the TTFs on the length and width of the metallic line is also well reproduced.
Finally, the model successfully describes the resistance noise properties under
steady state conditions.Comment: 39 pages + 17 figure
Enhancing the intercultural effectiveness of exchange programmes: formal and non-formal educational interventions
This paper examines how the addition of intercultural interventions
carried out throughout European credit-bearing exchange
programmes can enhance sojourners’ development of intercultural
competencies, and it explores how both formal and non-formal
pedagogical interventions may be designed and implemented.
Such interventions were conducted at a Portuguese university with
31 sojourners throughout one academic year, and their impact was
assessed using a mixed methods research design. Sojourners included
incoming students of the exchange programmes Campus Europae and
Erasmus, as well as highly skilled immigrants. Findings confirm the
positive impact of interventions on the development of intercultural
competencies and, in turn, their contribution to internationalisation
efforts. Implications for further research suggest a need to increase
interventions and to develop a systematic approach for fostering
intercultural competencies throughout the study abroad cycle
In vitro and in vivo inhibition of breast cancer cell growth by targeting the Hedgehog/GLI pathway with SMO (GDC-0449) or GLI (GANT-61) inhibitors.
Aberrant Hedgehog (Hh)/glioma-associated oncogene (GLI) signaling has
been implicated in cancer progression. Here, we analyzed GLI1, Sonic Hedgehog
(Shh) and NF-κB expression in 51 breast cancer (ductal carcinoma) tissues using
immunohistochemistry. We found a positive correlation between nuclear GLI1
expression and tumor grade in ductal carcinoma cases. Cytoplasmic Shh staining
significantly correlated with a lower tumor grade. Next, the in vitro effects of two
Hh signaling pathway inhibitors on breast cancer cell lines were evaluated using the
Smoothened (SMO) antagonist GDC-0449 and the direct GLI1 inhibitor GANT-61.
GDC-0449 and GANT-61 exhibited the following effects: a) inhibited breast cancer
cell survival; b) induced apoptosis; c) inhibited Hh pathway activity by decreasing
the mRNA expression levels of GLI1 and Ptch and inhibiting the nuclear translocation
of GLI1; d) increased/decreased EGFR and ErbB2 protein expression, reduced p21-
Ras and ERK1/ERK2 MAPK activities and inhibited AKT activation; and e) decreased
the nuclear translocation of NF-κB. However, GANT-61 exerted these effects more
effectively than GDC-0449. The in vivo antitumor activities of GDC-0449 and GANT-
61 were analyzed in BALB/c mice that were subcutaneously inoculated with mouse
breast cancer (TUBO) cells. GDC-0449 and GANT-61 suppressed tumor growth of
TUBO cells in BALB/c mice to different extents. These findings suggest that targeting
the Hh pathway using antagonists that act downstream of SMO is a more efficient
strategy than using antagonists that act upstream of SMO for interrupting Hh signaling
in breast cancer
Couples living with type 1 diabetes : an integrative review of the impacts on health and wellbeing
Impacts of type 1 diabetes and relationship factors on health and wellbeing of both persons with diabetes and partners (T1D partners) have not been investigated. Integrative review methods evaluated the evidence. From 323 titles, we included 24 studies involving 16,083 persons with diabetes and 1020 T1D partners. Studies were quantitative (n = 13), qualitative (n = 9) and mixed methods (n = 2). Maintaining resilient, good quality, intimate relationships optimises physical and psychological outcomes for persons with diabetes. Partners experience disturbed sleep and while general psychological health is maintained, distress surrounding hypoglycaemia is overwhelming for over a third of partners. Nurturing quality relationships could reap significant health benefits
Validation of the Italian version of the Patient Reported Experience Measures for intermediate care services
Background: Intermediate care (IC) services are a key component of integrated care for elderly people, providing a link between hospital and home through provision of rehabilitation and health and social care. The Patient Reported Experience Measures (PREMs) are designed to measure user experience of care in IC settings. Objective: To examine the feasibility and the scaling properties of the Italian version of PREMs questionnaires for use in IC services. Methods: A cross-sectional survey was conducted on consecutive users of 1 home-based and 4 bed-based IC services in Emilia-Romagna (Italy). The main outcome measure was the PREMs questionnaire results. PREMs for each home- and bed-based IC services were translated, back-translated, and adapted through consensus among the members of the advisory board and pilot testing of face validity in 15 patients. A total of 199 questionnaires were returned from users of bed-based services and 185 were returned by mail from users of home-based services. The return rates and responses were examined. Mokken analysis was used to examine the scaling properties of the PREMs. Results: Analysis performed on the bed-based PREMs (N=154) revealed that 13 items measured the same construct and formed a moderate-strength scale (Loevinger H=0.488) with good reliability (Cronbach’s alpha =0.843). Analysis of home-based PREMs (N=134 records) revealed that 15 items constituted a strong scale (Loevinger H=0.543) with good reliability (Cronbach’s alpha =0.875). Conclusion: The Italian versions of the bed- and home-based IC-PREMs questionnaires proved to be valid and reliable tools to assess patients’ experience of care. Future plans include monitoring user experience over time in the same facilities and in other Italian IC settings for between-service benchmarking
Risk adjustment for inter-hospital comparison of caesarean delivery rates in low-risk deliveries
BACKGROUND: Caesarean delivery (CD) rates have been frequently used as quality measures for maternity service comparisons. More recently, primary CD rates (CD in women without previous CD) or CD rates within selected categories such as nulliparous, term, cephalic singleton deliveries (NTCS) have been used. The objective of this study is to determine the extent to which risk adjustment for clinical and socio-demographic variables is needed for inter-hospital comparisons of CD rates in women without previous CD and in NTCS deliveries. METHODS: Hospital discharge records of women who delivered in Emilia-Romagna Region (Italy) from January, 2007 to June 2009 and in Tuscany Region for year 2009 were linked with birth certificates. Adjusted RRs of CD in women without a previous Caesarean and NTCS were estimated using Poisson regression. Percentage differences in RR before and after adjustment were calculated and hospital rankings, based on crude and adjusted RRs, were examined. RESULTS: Adjusted RR differed substantially from crude RR in women without a previous Caesarean and only marginally in NTCS group. Hospital ranking was markedly affected by adjustment in women without a previous CD, but less in NTCS. CONCLUSION: Risk adjustment is warranted for inter-hospital comparisons of primary CD rates but not for NTCS CD rates. Crude NTCS CD rates are a reliable estimate of adjusted NTCS CD
Thermonuclear Reaction Rate of 23Mg(p,gamma)24$Al
Updated stellar rates for the reaction 23Mg(p,gamma)24Al are calculated by
using all available experimental information on 24Al excitation energies.
Proton and gamma-ray partial widths for astrophysically important resonances
are derived from shell model calculations. Correspondences of experimentally
observed 24Al levels with shell model states are based on application of the
isobaric multiplet mass equation. Our new rates suggest that the
23Mg(p,gamma)24Al reaction influences the nucleosynthesis in the mass A>20
region during thermonuclear runaways on massive white dwarfs.Comment: 13 pages (uses Revtex) including 3 postscript figures (uses
epsfig.sty), accepted for publication in Phys. Rev.
Measuring parents’ perspective on continuity of care in children with special health care needs
INTRODUCTION: Children with special health care needs are an exponentially growing population needing integrated health care programmes that involve primary, community, hospital and tertiary care services. The aims of the study are (1) to develop and validate the Special Needs Kids Questionnaire (SpeNK-Q) designed to measure parents' perspective on continuity of care for children with special health care needs and (2) to evaluate the continuity of care based on parental experiences in this population. METHODS: SpeNK-Q was derived from a previous qualitative study and was based on Haggerty's constructs of informational, management and relational continuity. Parents of preterm birth children completed the 20-item SpeNK-Q at the second or subsequent planned follow-up visit after the child's hospital discharge. Principal component analysis was used to examine the structure of the instrument. RESULTS: Principal component analysis of 101 questionnaires administered allowed us to identify five factors explaining 60.2% of item variance: informational continuity; coordination of care; continuity of family-paediatrician relationship; family support; information on care plan. CONCLUSIONS AND DISCUSSION: SpeNK-Q proved to be a psychometrically promising instrument. Its utilisation could improve the identification of areas for service development, the delivery of coordinated care and support policy makers in redesigning integrated services
Eta photoproduction off the neutron at GRAAL: Evidence for a resonant structure at W=1.67 GeV
New (preliminary) data on eta photoproduction off the neutron are presented.
These data reveal a resonant structure at W=1.67 GeV.Comment: 8 pages, 4 figures. Published in Proceedings of Workshop on the
Physics of Excited Nucleons NSTAR2004, Grenoble, France, March 24 - 27,
pg.19
Strategies to prevent the presence of a dominant follicle (DF) between days 15 and 20 of the cow estrous cycle.
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