259 research outputs found

    The use of intra aortic baloon pump in patients undergoing coronary artery bypass grafting at the Aga Khan University Hospital, Karachi

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    Objective: To review the experience in the use of Intra Aortic Balloon Pump (IABP) in patietits undergoing Coronary Artery Bypass Grafting (CABG) at a tertiary care hospital with a new Open Heart surgery program. Design: Retrospective study. Setting: The Aga Khan University Hospital, Karachi. Patients: Medical records of all patients undergoing CABG between November 1994 and July 1997 were reviewed and those in whom IABP device was used, were included in this study. Results: A total of 15 patients had IABP suppOrt during the study period. Four surgeries were done urgently while two were emergencies. There were three mortalities. Ejection fractions in all hut one patient were impaired. Among the surviving patients, the average pre-IABP Cardiac Index was 2.6 litres/mm/meter2 which registered an average increase of 21.15% after the initiation of the IABP. The Pulmonary Artery Wedge Pressure also showed an average reduction of 29.11% from the pre IABP levels reflecting an increase in the cardiac output with the use of the IABP. Conclusion: This series represents the early experience of a new cardiac surgery center in Pakistan in the use of IABP. Although the numbers in this study are too small to derive any conclusions, the overall morbidity and mortality in this short series are within acceptable limits in the high risk patients include

    RESPIRATORY SYNDROME: A MAJOR THREAT TO THE LIVESTOCK FARMERS AND ITS ECONOMIC IMPACT

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    Epidemiology of a respiratory syndrome was studied at Landhi Dairy Colony (LDC), Karachi, Pakistan and its economic impact was estimated. Among 5889 buffaloes examined, 2.3% animals were suffering from this syndrome. From some of the sick animals, Pasteurella multocida, the causative agent of haemorrhagic septicaemia, was isolated. In the present study, an average loss of Rs. 0.2 million per farm was calculated and the extrapolated values for 0.2 and 0.8 million animals present in LDC and other dairy colonies in Karachi were Rs. 225.6 and Rs. 1128.1 million, respectively

    Analysis of solar direct irradiance models under clear-skies: Evaluation of the improvements for locally adapted models

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    Direct solar irradiance has to be determined for the design of many energy applications such as photovoltaic systems and concentration systems, and the generation of solar potential maps for energy use. Knowledge of the accurate values of radiation components in a local area will allow optimal sizing of solar energy conversion systems. The estimated values of direct solar irradiance from models are still necessary at those sites where no measurements are available. In this work, different models used for the estimation of the direct component of solar irradiance are analyzed. First, an evaluation of the performance of eight existing original models was performed from which three were selected. Second, the selected models were calibrated to adapt them to our studied geographical area, which is the important aspect of this work, and an assessment of performance improvements for locally adapted models is reported. Experimental data consisted of hourly horizontal global, direct, and diffuse solar irradiance values, provided by the National Meteorological Agency in Spain (AEMET) for Madrid. Long-term data series, corresponding to a total period of time of 32 years (1980–2011), have been used in this study. Only clear sky models were treated at present. The three selected models were adapted to the specific location of Madrid, and root mean square error (RMSE) and mean-biased error were determined. By comparing the performance in the direct horizontal irradiance estimation from existing original and the corresponding locally adapted models, it is found that the values of RMSE decreased from 9.9% to 5.7% for the Louche model, from 7.8% to 7.4% for the Robledo-Soler model, and finally from 8.8% to 6.7% for the European Solar Radiation Atlas model. Thus, significant improvements can be reached when parametric models are locally adapted. In our case, it is up to approximately 4% for the Louche model. It is expected that calibrated algorithms presented in this work will be applicable to regions of similar climatic characteristics.Spanish Government (grant ENE2011-27511) and the Department of Culture and Education of the Regional Government of Castilla y León, Spain (grant BU358A12-2

    Constraints on coupling constant between dark energy and dark matter

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    We have investigated constraints on the coupling between dark matter and the interacting Chaplygin gas. Our results indicate that the coupling constant cc between these two entities can take arbitrary values, which can be either positive or negative, thus giving arbitrary freedom to the inter-conversion between Chaplygin gas and dark matter. Thus our results indicate that the restriction 0<c<10<c<1 on the coupling constant occurs as a very special case. Our analysis also supports the existence of phantom energy under certain conditions on the coupling constant.Comment: 16 Pages, 3 figure

    Clinicopathologic predictors of finding additional inguinal lymph node metastases in penile cancer patients following positive dynamic sentinel node biopsy:a European multicentre evaluation

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    OBJECTIVES: Following tumour positive sentinel lymph node biopsy (+DSNB), completion inguinal lymph node dissection (ILND) is negative in 84-89% of basins. Thus, ILND after +DSNB may be considered overtreatment resulting in substantial morbidity. This study aimed to develop a predictive model for additional inguinal lymph node metastases (LNM) at ILND following +DSNB using DSNB characteristics to identify a patient group in which ILND might be omitted. PATIENTS AND METHODS: A retrospective study of 407 inguinal basins with a +DSNB of penile cancer patients who underwent subsequent ILND from seven European centres. From the histopathology reports, the number of positive and negative lymph nodes, extranodal extension and size of the metastasis were recorded. Using bootstrapped logistic regression, variables were selected for the clinical prediction model based on the optimisation of Akaike's information criterion. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was calculated for the resulting model. Decision curve analysis (DCA) was used to evaluate the clinical utility of the model. RESULTS: 64 (16%) of +DSNB harboured additional LNM at ILND. The number of positive nodes at +DSNB (odds ratio (OR) 2.19; 95% confidence interval (CI) 1.17-4.00; p=0.01) and the largest metastasis size in mm (OR 1.06; 95%CI 1.03-1.10; p=0.001) were selected for the clinical prediction model. The AUC was 0.67 (95%CI 0.60-0.74). The DCA showed no clinical benefit of using the clinical prediction model. CONCLUSION: A small but clinically important group of basins harbour additional LNM at completion ILND following +DSNB. While DSNB characteristics were associated with additional LNM, they did not improve the selection of basins in which ILND could be omitted. Thus, completion ILND remains necessary in all basins with a +DSNB

    Tongue metastasis as an initial presentation of renal cell carcinoma: a case report and literature review

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    <p>Abstract</p> <p>Introduction</p> <p>Primary tumour of the kidney metastasizing to the tongue is very unusual and only anecdotal cases have been reported. An exhaustive literature review covering the period from 1911 onwards disclosed 28 cases. Out of those, only 3 cases presented initially with tongue metastases before the diagnosis of primary renal cell carcinoma.</p> <p>The prognosis for patients with lingual metastasis of renal cell carcinoma is poor. Treatment of tongue metastasis is usually palliative and aims to provide patient comfort by means of pain relief and prevention of bleeding and infection. Surgical excision is recommended as the primary treatment with emphasis on preservation of tongue structure and function.</p> <p>Case presentation</p> <p>We report a case of tongue metastasis as an initial presentation of renal cell carcinoma in a 78-year-old man. Initially thought to be primary tongue cancer but on review of his histopathology again, it was diagnosed to be a rare metastasis from kidney cancer.</p> <p>Conclusion</p> <p>Tongue metastasis from renal cell carcinoma is rare and its diagnosis is a challenge. The prognosis of patients with tongue metastasis is poor. Similar to the primary tumours of the tongue, metastatic lesions may be ulcerated or polypoid. Since the tongue is a rare metastatic site, when a lesion is detected, a thorough evaluation to distinguish between metastasis and primary cancer should be made as the management and prognosis vary.</p

    Notes on dark energy interacting with dark matter and unparticle in loop quantum cosmology

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    We investigate the behavior of dark energy interacting with dark matter and unparticle in the framework of loop quantum cosmology. In four toy models, we study the interaction between the cosmic components by choosing different coupling functions representing the interaction. We found that there are only two attractor solutions namely dark energy dominated and dark matter dominated Universe. The other two models are unstable, as they predict either a dark energy filled Universe or one completely devoid of it.Comment: 9 pages, 10 figures. v2: Minor revisions, matches published versio

    A Reconfigurable Quantum Local Area Network Over Deployed Fiber

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    Practical quantum networking architectures are crucial for scaling the connection of quantum resources. Yet quantum network testbeds have thus far underutilized the full capabilities of modern lightwave communications, such as flexible-grid bandwidth allocation. In this work, we implement flex-grid entanglement distribution in a deployed network for the first time, connecting nodes in three distinct campus buildings time-synchronized via the Global Positioning System (GPS). We quantify the quality of the distributed polarization entanglement via log-negativity, which offers a generic metric of link performance in entangled bits per second. After demonstrating successful entanglement distribution for two allocations of our eight dynamically reconfigurable channels, we demonstrate remote state preparation -- the first realization on deployed fiber -- showcasing one possible quantum protocol enabled by the distributed entanglement network. Our results realize an advanced paradigm for managing entanglement resources in quantum networks of ever-increasing complexity and service demands
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