483 research outputs found

    A clinicopathological analysis of ovarian tumours

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    We performed a retrospective analysis of patients with ovarian tumors who were admitted to the Aga Khan University Hospital from January 1985 to December 1989. Sixty one cases were reviewed. Mean age of the whole group was 44 years. Majority of the patients presented with abdominal pain and distention. Most frequent physical finding was a palpable mass on pelvic or abdominal examination. Overall these patients had a higher incidence of breast cancer than expected in the general population. Two-thirds of the tumors were malignant. Comparison of the patients with malignancy against those with benign tumors failed to show any correlation with parity. Majority of the patients with malignant disease were above forty and had ultrasound showing a cystic mass over 10 cms in size. Cancer was mostly epithelial in origin, with widespread disease (stage III or IV) at the time of presentation. Benign tumors, mostly of germ cell type, were predominantly seen in patients under the age of forty with ultrasound showing cystic mass of any size from under 5 cms to over 10 cms

    Dimensional and Temperature Crossover in Trapped Bose Gases

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    We investigate the long-range phase coherence of homogeneous and trapped Bose gases as a function of the geometry of the trap, the temperature, and the mean-field interactions in the weakly interacting limit. We explicitly take into account the (quasi)condensate depletion due to quantum and thermal fluctuations, i.e., we include the effects of both phase and density fluctuations. In particular, we determine the phase diagram of the gas by calculating the off-diagonal one-particle density matrix and discuss the various crossovers that occur in this phase diagram and the feasibility of their experimental observation in trapped Bose gases.Comment: One figure added, typos corrected, refernces adde

    Extension of Bogoliubov theory to quasi-condensates

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    We present an extension of the well-known Bogoliubov theory to treat low dimensional degenerate Bose gases in the limit of weak interactions and low density fluctuations. We use a density-phase representation and show that a precise definition of the phase operator requires a space discretisation in cells of size ll. We perform a systematic expansion of the Hamiltonian in terms of two small parameters, the relative density fluctuations inside a cell and the phase change over a cell. The resulting macroscopic observables can be computed in one, two and three dimensions with no ultraviolet or infrared divergence. Furthermore this approach exactly matches Bogoliubov's approach when there is a true condensate. We give the resulting expressions for the equation of state of the gas, the ground state energy, the first order and second order correlations functions of the field. Explicit calculations are done for homogeneous systems.Comment: 32 pages, 2 figures; typos corrected in revised versio

    Q wave and non-Q wave myocardial infarction: a multivariate analysis of survival experience and clinical outcome after first diagnosis at a tertiary care hospital

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    Introduction: Myocardial infarction (MI) is a well-recognized clinical entity with a worldwide distribution. In the United States alone, 1.5 million cases of MI occur per year. This study compares the in-hospital mortality, 1 year mortality and time to death following a first Q-wave or non Q-wave myocardial infarction (MI).Methods: One thousand five hundred and ninety-six patients were admitted at the Aga Khan University Hospital with a diagnosis of MI over a period of four years of whom 420 patients met our inclusion criteria. Data was collected from the patients\u27 medical records and on telephone using a pretested questionnaire. Logistic regression and Cox proportional hazard models were used to analyze the data.Results: The mean age +/- sd of the patients was 59 +/- 10 years. Of the total patients, 151(36%) and 269(64%) suffered non-Q wave and Q-wave MI respectively. A higher in hospital mortality was observed in patients with Q-wave MI (n = 64, 23.8%) than those with non-Q wave MI [n = 16 (10.6%); adjusted OR = 2.76, 95% CI: 1.5-5.01]. Similarly, patients having Q-wave MI experienced increased 1 year mortality (n = 77, 28.6%) compared to patients suffering non-Q wave MI [n = 26 (17.2%); adjusted OR = 2.04, 95% CI: 1.21-3.43].CONCLUSION: Patients with Q-wave MI had a worse prognosis compared with patients with non-Q-wave MI and therefore warrant a closer follow up. Further prospective studies are needed to evaluate the efficacy of early aggressive interventions in modifying the natural history of this disease

    Cloud-based genomics pipelines for ophthalmology: Reviewed from research to clinical practice

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    Aim: To familiarize clinicians with clinical genomics, and to describe the potential of cloud computing for enabling the future routine use of genomics in eye hospital settings. Design: Review article exploring the potential for cloud-based genomic pipelines in eye hospitals. Methods: Narrative review of the literature relevant to clinical genomics and cloud computing, using PubMed and Google Scholar. A broad overview of these fields is provided, followed by key examples of their integration. Results: Cloud computing could benefit clinical genomics due to scalability of resources, potentially lower costs, and ease of data sharing between multiple institutions. Challenges include complex pricing of services, costs from mistakes or experimentation, data security, and privacy concerns. Conclusions and future perspectives: Clinical genomics is likely to become more routinely used in clinical practice. Currently this is delivered in highly specialist centers. In the future, cloud computing could enable delivery of clinical genomics services in non-specialist hospital settings, in a fast, cost-effective way, whilst enhancing collaboration between clinical and research teams

    Hydrodynamic behavior in expanding thermal clouds of Rb-87

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    We study hydrodynamic behavior in expanding thermal clouds of Rb-87 released from an elongated trap. At our highest densities the mean free path is smaller than the radial size of the cloud. After release the clouds expand anisotropically. The cloud temperature drops by as much as 30%. This is attributed to isentropic cooling during the early stages of the expansion. We present an analytical model to describe the expansion and to estimate the cooling. Important consequences for time-of-flight thermometry are discussed.Comment: 7 pages with 2 figure

    Exact calculation of the skyrmion lifetime in a ferromagnetic Bose condensate

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    The tunneling rate of a skyrmion in ferromagnetic spin-1/2 Bose condensates through an off-centered potential barrier is calculated exactly with the periodic instanton method. The prefactor is shown to depend on the chemical potential of the core atoms, at which level the atom tunnels. Our results can be readily extended to estimate the lifetime of other topological excitations in the condensate, such as vortices and monopoles.Comment: 16 pages, 4 figures, to appear Phys. Rev.

    Tissue expansion reconstruction of head and neck burn injuries in paediatric patients – a systematic review

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    Tissue expansion reconstruction in clinical practice has existed for over half a century. The technique was initially used for breast reconstruction but later found its use in reconstruction of excisional defects resulting from a variety of causes including surgery for post-burn/post-traumatic deformities, congenital giant naevi, skin cancer, etc. It offers an improved matching of skin colour and texture, and avoids the high infrastructure requirements of microsurgery for free flap transfers. We present a systematic literature review of 35 worldwide English language articles with representative cases of paediatric tissue expansion reconstruction of burn injuries of the head and neck. The review identified 68 children of an average age of 11.3 years. The most common burn aetiology was flame burn injury. The average area to be reconstructed was of 206 cm2 and patients went through expansion processes for an average of 99.7 days. Three articles included cases in which patients had more than one expansion session. Supportive techniques provide examples of developments in the area of tissue expansion reconstruction such as self-inflating expanders and endoscopic approaches. Further studies focussing on particular indications, age groups and anatomical locations of tissues to be expanded are required in order to improve the understanding of this technique's limitations and continue its development

    In-situ velocity imaging of ultracold atoms using slow--light

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    The optical response of a moving medium suitably driven into a slow-light propagation regime strongly depends on its velocity. This effect can be used to devise a novel scheme for imaging ultraslow velocity fields. The scheme turns out to be particularly amenable to study in-situ the dynamics of collective and topological excitations of a trapped Bose-Einstein condensate. We illustrate the advantages of using slow-light imaging specifically for sloshing oscillations and bent vortices in a stirred condensate
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