203 research outputs found
Diamagnetism of Confined Dirac Fermions in Disordered Graphene
The diamagnetism of confined Dirac fermions submitted to a uniform magnetic
field in disordered graphene is investigated. The solutions of the energy
spectrum are used to discuss the orbital magnetism from a statistical
mechanical point of view. More precisely, by the technique of Green functions
the self-energy for short and long-ranged disorders is obtained. This allows us
to determine the susceptibility for short and long-ranged disorders together
with confinement. We compare our results with already published work and point
out the relevance of these findings to a systematic formulation of the
diamagnetism in a confining potential.Comment: 21 pages. Version to appear in JP
Fractional Quantum Hall States in Graphene
We quantum mechanically analyze the fractional quantum Hall effect in
graphene. This will be done by building the corresponding states in terms of a
potential governing the interactions and discussing other issues. More
precisely, we consider a system of particles in the presence of an external
magnetic field and take into account of a specific interaction that captures
the basic features of the Laughlin series \nu={1\over 2l+1}. We show that how
its Laughlin potential can be generalized to deal with the composite fermions
in graphene. To give a concrete example, we consider the SU(N) wavefunctions
and give a realization of the composite fermion filling factor. All these
results will be obtained by generalizing the mapping between the
Pauli--Schr\"odinger and Dirac Hamiltonian's to the interacting particle case.
Meantime by making use of a gauge transformation, we establish a relation
between the free and interacting Dirac operators. This shows that the involved
interaction can actually be generated from a singular gauge transformation.Comment: 20 page
Recommended from our members
Rapid progression of prostate cancer in men with a BRCA2 mutation.
Men with BRCA2 mutations have been found to be at increased risk of developing prostate cancer. There is a recent report that BRCA2 carriers with prostate cancer have poorer survival than noncarrier prostate cancer patients. In this study, we compared survival of men with a BRCA2 mutation and prostate cancer with that of men with a BRCA1 mutation and prostate cancer. We obtained the age at diagnosis, age at death or current age from 182 men with prostate cancer from families with a BRCA2 mutation and from 119 men with prostate cancer from families with a BRCA1 mutation. The median survival from diagnosis was 4.0 years for men with a BRCA2 mutation vs 8.0 years for men with a BRCA1 mutation, and the difference was highly significant (P<0.01). It may be important to develop targeted chemotherapies to treat prostate cancer in men with a BRCA2 mutation
Education can improve the negative perception of a threatened long-lived scavenging bird, the Andean condor
Human-wildlife conflicts currently represent one of the main conservation problems for wildlife species around the world. Vultures have serious conservation concerns, many of which are related to people's adverse perception about them due to the belief that they prey on livestock. Our aim was to assess local perception and the factors influencing people's perception of the largest scavenging bird in South America, the Andean condor. For this, we interviewed 112 people from Valle FĂ©rtil, San Juan province, a rural area of central west Argentina. Overall, people in the area mostly have an elementary education, and their most important activity is livestock rearing. The results showed that, in general, most people perceive the Andean condor as an injurious species and, in fact, some people recognize that they still kill condors. We identified two major factors that affect this perception, the education level of villagers and their relationship with livestock ranching. Our study suggests that conservation of condors and other similar scavengers depends on education programs designed to change the negative perception people have about them. Such programs should be particularly focused on ranchers since they are the ones who have the worst perception of these scavengers. We suggest that highlighting the central ecological role of scavengers and recovering their cultural value would be fundamental to reverse their persecution and their negative perception by people.Fil: Cailly Arnulphi, VerĂłnica BeatrĂz. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas FĂsicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Lambertucci, Sergio Agustin. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Borghi, Carlos Eduardo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas FĂsicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentin
Adjuvant vaginal interventional radiotherapy in early-stage non-endometrioid carcinoma of corpus uteri: a systematic review
Purpose: This systematic review focused on rare histological types of corpus uteri malignancy, including uterine carcinosarcoma (UCS), uterine clear cell carcinoma (UCCC), and uterine papillary serous carcinoma (UPSC), and it is proposed to assist with clinical decision-making. Adjuvant treatment decisions must be made based on available evidences. We mainly investigated the role of vaginal interventional radiotherapy (VIRt) in UCS, UCCC, and UPSC managements.
Material and methods: A systematic research using PubMed and Cochrane library was conducted to identify full articles evaluating the efficacy of VIRt in early-stage UPSC, UCCC, and UCS. A search in ClinicalTrials.gov was performed in order to detect ongoing or recently completed trials as well as in PROSPERO for ongoing or recently completed systematic reviews. Survival outcomes and toxicity rates were obtained.
Results: All studies were retrospective. For UCS, the number of evaluated patients was 432. The 2- to 5-year aver- age local control (LC) was 91% (range, 74.2-96%), disease-free survival (DFS) 88% (range, 82-94%), overall survival (OS) 79% (range, 53.8-84.3%), the average 5-year cancer-specific survival (CSS) was 70% (range, 70-94%), and G3-G4 toxicity was 0%. For UCCC, the number of investigated patients was 335 (UCCC â 124, mixed â 211), with an average 5-year LC of 100%, DFS of 83% (range, 82-90%), OS of 93% (range, 83-100%), and G3-G4 toxicity of 0%. For UPSC, the number of examined patients was 1,092 (UPSC â 866, mixed â 226). The average 5-year LC was 97% (range, 87.1-100%), DFS 84% (range, 74.7-95.6%), OS 93% (range, 71.9-100%), CSS 89% (range, 78.9-94%), and G3-G4 toxicity was 0%.
Conclusions: These data suggest that in adequately selected early-stage UPSC and UCCC patients, VIRt alone may be suitable in women who underwent surgical staging and received adjuvant chemotherapy. In early-stage UCS, a multidisciplinary therapeutic approach has to be planned, considering high-rate of pelvic and distant relapses
Combining old and new evidence to increase the known biodiversity value of the Sahamalaza Peninsula, Northwest Madagascar
Phase II study of the combination carboplatin plus celecoxib in heavily pre-treated recurrent ovarian cancer patients
Cyclooxygenase-2 overexpression is associated with poor outcome and resistance to platinum-based chemotherapy in ovarian cancer. We evaluated the antitumor activity and safety of the combination carboplatin plus the COX-2 inhibitor celecoxib in recurrent heavily-treated OC patients
The Pap smear screening as an occasion for smoking cessation and physical activity counselling: baseline characteristics of women involved in the SPRINT randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>Gender-specific smoking cessation strategies have rarely been developed. Evidence of effectiveness of physical activity (PA) promotion and intervention in adjunct to smoking cessation programs is not strong. SPRINT study is a randomized controlled trial (RCT) designed to evaluate a counselling intervention on smoking cessation and PA delivered to women attending the Italian National Health System Cervical Cancer Screening Program. This paper presents study design and baseline characteristics of the study population.</p> <p>Methods/Design</p> <p>Among women undergoing the Pap examination in three study centres (Florence, Turin, Mantua), participants were randomized to the smoking cessation counselling [S], the smoking cessation + PA counselling [S + PA], or the control [C] groups. The program under evaluation is a standard brief counselling on smoking cessation combined with a brief counselling on increasing PA, and was delivered in 2010. A questionnaire, administered before, after 6 months and 1 year from the intervention, was used to track behavioural changes in tobacco use and PA, and to record cessation rates in participants.</p> <p>Discussion</p> <p>Out of the 5,657 women undergoing the Pap examination, 1,100 participants (55% of smokers) were randomized in 1 of the 3 study groups (363 in the S, 366 in the S + PA and 371 in the C groups). The three arms did not differ on any demographic, PA, or tobacco-use characteristics. Recruited smokers were older, less educated than non-participant women, more motivated to quit (33% vs.9% in the Preparation stage, <it>p </it>< 0.001), smoked more cigarettes per day (12 vs.9, <it>p </it>< 0.001), and were more likely to have already done 1 or more quit attempts (64% vs.50%, <it>p </it>< 0.001). The approach of SPRINT study appeared suitable to enrol less educated women who usually smoke more and have more difficulties to quit.</p> <p>Trial registration number</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN52660565">ISRCTN52660565</a></p
An overview of cancer/testis antigens expression in classical Hodgkin's lymphoma (cHL) identifies MAGE-A family and MAGE-C1 as the most frequently expressed antigens in a set of Brazilian cHL patients
<p>Abstract</p> <p>Background</p> <p>Cancer/testis antigens are considered potential targets for immunotherapy due to their tumor-associated expression pattern. Although recent studies have demonstrated high expression of CT45 in classical Hodgkin's lymphomas (cHL), less is known about the expression pattern of other families of CTAs in cHL. We aim to evaluate the expression of MAGE-A family, MAGE-C1/CT7, MAGE-C2/CT10, NY-ESO1 and GAGE family in cHL and to correlate their expression with clinical and prognostic factors in cHL.</p> <p>Methods</p> <p>Tissue microarray was generated from 38 cHL archival cases from Pathology Department of Universidade Federal de Sao Paulo. Immunohistochemistry (IHC) was done using the following panel of antibodies: MAGE-A family (MA454, M3H67, 57B and 6C1), GAGE (#26), NY-ESO-1 (E978), MAGE-C1/CT7 (CT7-33) and MAGE-C2/CT10 (CT10#5).</p> <p>Results</p> <p>We found CTA expression in 21.1% of our cHL series. Among the tested CTAs, only MAGE-A family 7/38 (18.4%) and MAGE-C1/CT7 5/38 (13.2%) were positive in our cHL samples. We found higher CTA positivity in advanced stage (28.6%) compared to early stage (11.8%) disease, but this difference was not statistically significant. Analysis of other clinicopathological subgroups of cHL including histological subtypes, EBV status and response to treatment also did not demonstrate statistical significant differences in CTA expression.</p> <p>Conclusion</p> <p>We found CTA expression in 21.1% of cHL samples using our panel. Our preliminary findings suggest that from all CTAs included in this study, MAGE-A family and MAGE-C1/CT7 are the most interesting ones to be explored in further studies.</p
- âŠ