1,546 research outputs found
Specific neuroprotective effects of manual stimulation of real acupoints versus non-acupoints in rats after middle cerebral artery occlusion
The objective of this study was to investigate the effectiveness and specific effects of acupuncture on ischemic-induced damage in rats after permanent middle cerebral artery occlusion. Cerebral ischemia was induced by middle cerebral artery occlusion in male Wistar rats. The rats were divided into the following 4 groups: normal controls, ischemic, real acupuncture-treated (Shuigou, DU26), and non-acupoint-treated groups. On the third postoperative day, neurological deficit scores, cerebral blood flow, infarction volume, and neuronal cell death counts were measured. In the real acupuncture-treated group, the neurological deficit scores and cerebral blood flow were improved (p < 0.05) and the infarction volume and neuronal cell death counts were reduced (p < 0.01) compared to the ischemic and non-acupoint-treated groups. The present study demonstrated that real acupuncture was effective against focal ischemia-induced damage in rats after middle cerebral artery occlusion, and the effects were specifically related to the right needling location.Key words: specificity, real acupoint, non-acupoint, middle cerebral artery occlusion, animal experimentatio
Real-time counting of single electron tunneling through a T-shaped double quantum dot system
Real-time detection of single electron tunneling through a T-shaped double
quantum dot is simulated, based on a Monte Carlo scheme. The double dot is
embedded in a dissipative environment and the presence of electrons on the
double dot is detected with a nearby quantum point contact. We demonstrate
directly the bunching behavior in electron transport, which leads eventually to
a super-Poissonian noise. Particularly, in the context of full counting
statistics, we investigate the essential difference between the dephasing
mechanisms induced by the quantum point contact detection and the coupling to
the external phonon bath. A number of intriguing noise features associated with
various transport mechanisms are revealed.Comment: 8 pages, 5 figure
ERα inhibits epithelial-mesenchymal transition by suppressing Bmi1 in breast cancer
published_or_final_versio
ERα inhibits epithelial-mesenchymal transition by suppressing Bmi1 in breast cancer
published_or_final_versio
Detecting land subsidence in Shanghai by PS-networking SAR interferometry
2008-2009 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
The t copula with Multiple Parameters of Degrees of Freedom: Bivariate Characteristics and Application to Risk Management
The t copula is often used in risk management as it allows for modelling tail
dependence between risks and it is simple to simulate and calibrate. However,
the use of a standard t copula is often criticized due to its restriction of
having a single parameter for the degrees of freedom (dof) that may limit its
capability to model the tail dependence structure in a multivariate case. To
overcome this problem, grouped t copula was proposed recently, where risks are
grouped a priori in such a way that each group has a standard t copula with its
specific dof parameter. In this paper we propose the use of a grouped t copula,
where each group consists of one risk factor only, so that a priori grouping is
not required. The copula characteristics in the bivariate case are studied. We
explain simulation and calibration procedures, including a simulation study on
finite sample properties of the maximum likelihood estimators and Kendall's tau
approximation. This new copula can be significantly different from the standard
t copula in terms of risk measures such as tail dependence, value at risk and
expected shortfall.
Keywords: grouped t copula, tail dependence, risk management
In-Plane Orbital Texture Switch at the Dirac Point in the Topological Insulator Bi2Se3
Topological insulators are novel macroscopic quantum-mechanical phase of
matter, which hold promise for realizing some of the most exotic particles in
physics as well as application towards spintronics and quantum computation. In
all the known topological insulators, strong spin-orbit coupling is critical
for the generation of the protected massless surface states. Consequently, a
complete description of the Dirac state should include both the spin and
orbital (spatial) parts of the wavefunction. For the family of materials with a
single Dirac cone, theories and experiments agree qualitatively, showing the
topological state has a chiral spin texture that changes handedness across the
Dirac point (DP), but they differ quantitatively on how the spin is polarized.
Limited existing theoretical ideas predict chiral local orbital angular
momentum on the two sides of the DP. However, there have been neither direct
measurements nor calculations identifying the global symmetry of the spatial
wavefunction. Here we present the first results from angle-resolved
photoemission experiment and first-principles calculation that both show,
counter to current predictions, the in-plane orbital wavefunctions for the
surface states of Bi2Se3 are asymmetric relative to the DP, switching from
being tangential to the k-space constant energy surfaces above DP, to being
radial to them below the DP. Because the orbital texture switch occurs exactly
at the DP this effect should be intrinsic to the topological physics,
constituting an essential yet missing aspect in the description of the
topological Dirac state. Our results also indicate that the spin texture may be
more complex than previously reported, helping to reconcile earlier conflicting
spin resolved measurements
Incubateur de Santé Communautaire et de Médecine Sociale : un cadre d’apprentissage par le service pour des projets menés par des étudiants en médecine
Implication Statement
The Community Health and Social Medicine (CHASM) Incubator is a social impact venture that gives medical and other health care students the opportunity to develop initiatives that sustainably promote health equity for, and in partnership with, community partners and historically marginalized communities. Students learn how to develop projects with project management curricula, are paired with community health mentors, and are given seed micro-financing. As the first community health incubator driven by medical students, CHASM provides a framework for students interested in implementing sustainable solutions to local health disparities which extends the service-learning opportunities offered in existing curricula.Énoncé des implications de la recherche
L’incubateur CHASM (Community Health and Social Medicine) est une initiative visant à créer un impact social en donnant aux étudiants en médecine et des autres sciences de la santé la possibilité de développer des initiatives durables en collaboration avec des partenaires communautaires et des communautés historiquement marginalisées. CHASM met en valeur l’équité en matière de santé. Les étudiants apprennent à élaborer des projets via un cursus de gestion de projet, sont jumelés à des mentors en santé communautaire et bénéficient de micro-financement de départ. Ce premier incubateur de santé communautaire mené par des étudiants en médecine fournit un cadre aux étudiants qui souhaitent mettre en œuvre des solutions durables aux inégalités en matière de santé. Il élargit également les possibilités d’apprentissage par le service offertes dans les cursus existants
Higher expression of human kallikrein 10 in breast cancer tissue predicts tamoxifen resistance
The human tissue kallikreins are secreted serine proteases, encoded by a group of homologous genes clustered in tandem on chromosome 19q13.3-4. Human kallikrein 6 and human kallikrein 10 are two new members of this family. Recently, we developed highly sensitive and specific immunofluorometric assays for human kallikrein 6 and human kallikrein 10, which allow for their quantification in tissue extracts and biological fluids. Both human kallikrein 6 and human kallikrein 10 are found to be down-regulated in breast cancer cell lines, suggesting that they may be involved in breast cancer pathogenesis and progression. In this study, we investigated the potential value of human kallikrein 6 and human kallikrein 10 as prognostic and predictive factors in breast cancer. We quantified human kallikrein 6 and human kallikrein 10 protein levels in 749 breast tumour cytosolic extracts and correlated this data with various clinicopathological variables and patient outcomes. Human kallikrein 6 and human kallikrein 10 are positively correlated with each other. Higher human kallikrein 6 and human kallikrein 10 protein levels are associated with younger age, pre-menopausal, status and tumours which are negative for oestrogen and progesterone receptors. No correlation was found between human kallikrein 6 and human kallikrein 10 levels and tumour size, grade, and nodal status. Survival analysis showed that neither human kallikrein 6 nor human kallikrein 10 are related to the rate of relapse-free and overall survival. In the analysis with respect to response to tamoxifen therapy, although human kallikrein 6 levels were not associated with tamoxifen responsiveness, higher levels of human kallikrein 10 were significantly associated with a poor response rate. This association remained significant in the multivariate analysis. Furthermore, higher human kallikrein 10 levels were significantly related with a short progression-free and post-relapse overall survival after start of tamoxifen treatment for advanced disease. Taken together, our results suggest that although human kallikrein 6 and human kallikrein 10 are not prognostic markers for breast cancer, human kallikrein 10 is an independent predictive marker for response of tamoxifen therapy
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