OALib Journal期刊

ISSN: 2333-9721




2015 ( 12 )

2014 ( 16 )

2013 ( 57 )

2012 ( 281 )


匹配条件: “Beigi AA” ,找到相关结果约1810条。
Primary pancreatic Non-Hodgkin's lymphoma in a young man with abdominal pain and hypersplenism: a case report
Noorian SE,Beigi AA,Safaee M,Heshmat-Ghahdarijani K
Tehran University Medical Journal , 2013,
Abstract: Background: Primary pancreatic lymphoma is really rare and comprising about 0.2-4.9% of all pancreatic malignancies. The diagnosis of this lymphoma is very difficult because the clinical symptoms and signs resemble those of pancreatic adenocarcinoma. Case presentation: A 30-year old man was admitted to the hospital with the complaint of left upper abdominal pain. Because of his splenomegaly and pancytopenia he was candidate for splenectomy but during operation a large mass was found in the pancreas and biopsy was taken from it. Pathology reported lymphoblastic lymphoma of pancreas.Conclusion: It is important to differentiate between primary lymphoma and the adenocarcinoma of the pancreas as prognosis and treatment of them differ significantly. Primary pancreatic lymphoma should be considered in differential diagnosis of pancreatic tumors and an attempt to obtain tissue diagnosis is always necessary before radical surgery, especially in young patients.
Audiometric Changes in Patients Undergoing Coronary Artery Bypass Surgery
Daryoush Beigi
Audiology , 1998,
Abstract: The incidence of severe hearing loss after coronary artery bypass graft surgery has been as rare as 1/1000 surgery (Plasse et al., 1981). To evaluate possible changes in the auditory status, audiograms were taken before and after this operation. Our objectives were to: 1) evaluate hearing losses that were not necessarily severe and; 2) examine the factors associated with any auditory insult. we selected patients among a group without any history of hearing problems and the intake of any ototoxic drugs. All patients underwent careful examination and hearing evaluation the day prior to surgery. 6 days after surgery they were examined again and asked about any hearing problems or experience of tinnitus. Various operative details were taken and the post-operative drug record examined. Patients who were too ill for retesting, or who had been given sedative or ototoxic drugs or opiate analgesia, were dropped from the study. The whole procedure was repeated on a control group of 20 patients who were having thorocotomy but without being placed on a cardiopulmonary bypass. From the bypass sample of 40 ears, five of them (four individuals) had an individually statistically significant high-frequency hearing loss. The results showed a statistically significant difference between the bypass group and the control group, with the bypass patients having worse threshold shifts following the operation. Discriminant analyses have shown that those patients suffering hearing impairment may be discriminated principally with four variables: the patient's age, minimum temperature and minimum blood pressure during the operation, and the time on bypass.
Report of a Case of Primary Abdominal Pregnancy
Sh Beigi
Journal of Shahid Sadoughi University of Medical Sciences , 2006,
Abstract: Ectopic pregnancy (EP) is a potentially life-threatening condition in which the embryo implants outside the uterine endometrial cavity. Abdominal pregnancy is an atypical site wherein the product of conception lies totally outside the reproductive tract. Primary abdominal pregnancy is a very rare condition with a high mortality rate. Diagnosis is often late or misdiagnosed. The aim of introducing this case report is to present a new case of early primary abdominal pregnancy. Despite regular menstrual bleeding and contraception with IUD (intrauterine device), this pregnancy occurred in a 24-year old woman. Emergency laparotomy was performed because of abdominal pain, unstable condition and positive urine pregnancy test. It revealed more than 1500 ml of blood in the abdominal cavity. The uterus, both fallopian tubes and ovaries were completely intact. A 3X4 cm mass lateral to the left utersacral ligament was observed and resected. Since IUD strings could not be identified, endometrial currettage was performed and then the IUD was removed. Histological report of the mass and tissue of uterine cavity was placental villi and secretory endometrium, respectively, which according to Studdifords criteria is a new case of early primary abdominal pregnancy. To reduce maternal mortality and morbidity, early recognition of ectopic pregnancy is critical. According to review of the literature and the case report, a high index of suspicion is vital for the early diagnosis of ectopic pregnancy because the signs and symptoms of EP overlap with many surgical and gynecologic conditions. With early diagnosis of EP, we can suggest many therapeutic options and also retain fertility (if desired by patient), while minimizing disease and treatment-related morbidity.
NP vs QMA_log(2)
Salman Beigi
Physics , 2008,
Abstract: Although it is believed unlikely that $\NP$-hard problems admit efficient quantum algorithms, it has been shown that a quantum verifier can solve $\NP$-complete problems given a "short" quantum proof; more precisely, $\NP\subseteq \QMA_{\log}(2)$ where $\QMA_{\log}(2)$ denotes the class of quantum Merlin-Arthur games in which there are two unentangled provers who send two logarithmic size quantum witnesses to the verifier. The inclusion $\NP\subseteq \QMA_{\log}(2)$ has been proved by Blier and Tapp by stating a quantum Merlin-Arthur protocol for 3-coloring with perfect completeness and gap $\frac{1}{24n^6}$. Moreover, Aaronson {\it et al.} have shown the above inclusion with a constant gap by considering $\widetilde{O}(\sqrt{n})$ witnesses of logarithmic size. However, we still do not know if $\QMA_{\log}(2)$ with a constant gap contains $\NP$. In this paper, we show that 3-SAT admits a $\QMA_{\log}(2)$ protocol with the gap $\frac{1}{n^{3+\epsilon}}$ for every constant $\epsilon>0$.
A Lower Bound on the Value of Entangled Binary Games
Salman Beigi
Physics , 2009,
Abstract: A two-player one-round binary game consists of two cooperative players who each replies by one bit to a message that he receives privately; they win the game if both questions and answers satisfy some predetermined property. A game is called entangled if the players are allowed to share a priori entanglement. It is well-known that the maximum winning probability (value) of entangled XOR-games (binary games in which the predetermined property depends only on the XOR of the two output bits) can be computed by a semidefinite program. In this paper we extend this result in the following sense; if a binary game is uniform, meaning that in an optimal strategy the marginal distributions of the output of each player are uniform, then its entangled value can be efficiently computed by a semidefinite program. We also introduce a lower bound on the entangled value of a general two-player one-round game; this bound depends on the size of the output set of each player and can be computed by a semidefinite program. In particular, we show that if the game is binary, w_q is its entangled value, and w_{sdp} is the optimum value of the corresponding semidefinite program, then 0.68w_{sdp} < w_q <= w_{sdp}.
Engineering an Anthropocene Citizenship Framework
Shima Beigi
Physics , 2015,
Abstract: This article presents an Anthropocene citizen-cantered framework by incorporating the neuroscience of sustainability related stressors, the biology of collaboration in multi-agent ecosystems such as urban systems, and by emphasising on the importance of harnessing the collective intelligence of the crowd in addressing wicked challenges of sustainable development. The Anthropocene citizenship framework aims to transcend the cognitive model of global citizenship and sustainability to a dynamic, resilient and thriving mental model of collective cooperation.
A New Quantum Data Processing Inequality
Salman Beigi
Mathematics , 2012, DOI: 10.1063/1.4818985
Abstract: Quantum data processing inequality bounds the set of bipartite states that can be generated by two far apart parties under local operations; Having access to a bipartite state as a resource, two parties cannot locally transform it to another bipartite state with a mutual information greater than that of the resource state. But due to the additivity of quantum mutual information under tensor product, the data processing inequality gives no bound when the parties are provided with arbitrary number of copies of the resource state. In this paper we introduce a measure of correlation on bipartite quantum states, called maximal correlation, that is not additive and gives the same number when computed for multiple copies. Then by proving a data processing inequality for this measure, we find a bound on the set of states that can be generated under local operations even when an arbitrary number of copies of the resource state is available.
Entanglement-assisted zero-error capacity is upper bounded by the Lovasz theta function
Salman Beigi
Mathematics , 2010, DOI: 10.1103/PhysRevA.82.010303
Abstract: The zero-error capacity of a classical channel is expressed in terms of the independence number of some graph and its tensor powers. This quantity is hard to compute even for small graphs such as the cycle of length seven, so upper bounds such as the Lovasz theta function play an important role in zero-error communication. In this paper, we show that the Lovasz theta function is an upper bound on the zero-error capacity even in the presence of entanglement between the sender and receiver.
Maximal Entanglement - A New Measure of Entanglement
Salman Beigi
Mathematics , 2014,
Abstract: Maximal correlation is a measure of correlation for bipartite distributions. This measure has two intriguing features: (1) it is monotone under local stochastic maps; (2) it gives the same number when computed on i.i.d. copies of a pair of random variables. This measure of correlation has recently been generalized for bipartite quantum states, for which the same properties have been proved. In this paper, based on maximal correlation, we define a new measure of entanglement which we call maximal entanglement. We show that this measure of entanglement is faithful (is zero on separable states and positive on entangled states), is monotone under local quantum operations, and gives the same number when computed on tensor powers of a bipartite state.
Classification of the phases of 1D spin chains with commuting Hamiltonians
Salman Beigi
Mathematics , 2011, DOI: 10.1088/1751-8113/45/2/025306
Abstract: We consider the class of spin Hamiltonians on a 1D chain with periodic boundary conditions that are (i) translational invariant, (ii) commuting and (iii) scale invariant, where by the latter we mean that the ground state degeneracy is independent of the system size. We correspond a directed graph to a Hamiltonian of this form and show that the structure of its ground space can be read from the cycles of the graph. We show that the ground state degeneracy is the only parameter that distinguishes the phases of these Hamiltonians. Our main tool in this paper is the idea of Bravyi and Vyalyi (2005) in using the representation theory of finite dimensional C^*-algebras to study commuting Hamiltonians.

Copyright © 2008-2017 Open Access Library. All rights reserved.