47 research outputs found

    AP-PA field orientation followed by IMRT reduces lung exposure in comparison to conventional 3D conformal and sole IMRT in centrally located lung tumors

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    Little attention has been paid to the fact that intensity modulated radiation therapy (IMRT) techniques do not easily enable treatment with opposed beams. Three treatment plans (3 D conformal, IMRT, and combined (anterior-posterior-posterio-anterior (AP-PA) + IMRT) of 7 patients with centrally-located lung cancer were compared for exposure of lung, spinal cord and esophagus. Combined IMRT and AP-PA techniques offer better lung tissue sparing compared to plans predicated solely on IMRT for centrally-located lung tumors

    Problem drug use the public health imperative: what some of the literature says

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    <p>Abstract</p> <p>Background</p> <p>With more than 200,000 problem drug users is contact with structured treatment services in England the public health imperative behind drug treatment is great. Problem drug use for many is a chronic and relapsing condition, where "cure" is often neither a reasonable or appropriate expectation and it can further be argued that in these circumstances problem drug use is no different from any number of chronic and enduring health conditions that are managed in the health care system and therefore should be conceptualised as such.</p> <p>Discussion</p> <p>A public health approach to drug treatment emphasises the need for drug users in or accessing treatment, to reduce their harmful drug use, reduce drug use related risks such as sepsis and overdose and stay alive for longer. However a public health perspective in relation to problem drug use isn't always either apparent or readily understood and to that end there is still a significant need to continue the arguments and debate that treatment and interventions for problem and dependent drug users need to extend beyond an individualistic approach. For the purposes of discussion in this article public and population health will be used interchangeably.</p> <p>Summary</p> <p>A recognition and acceptance that a public and population health approach to the management of problem drug users is sound public health policy also then requires a long term commitment in terms of staffing and resources where service delivery mirrors that of chronic condition management.</p

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Subgradient Descent Learning Over Fading Multiple Access Channels With Over-the-Air Computation

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    We focus on a distributed learning problem in a communication network, consisting of NN distributed nodes and a central parameter server (PS). The PS is responsible for performing the computation based on data received from the nodes, which are transmitted over a multiple access channel (MAC). The objective function for this problem is the sum of the local loss functions of the nodes. This problem has gained attention in the field of distributed sensing systems, as well as in the area of federated learning (FL) recently. However, current approaches to solving this problem rely on the assumption that the loss functions are continuously differentiable. In this paper, we first address the case where this assumption does not hold. We develop a novel algorithm called Sub-Gradient descent Multiple Access (SGMA) to solve the learning problem over MAC. SGMA involves each node transmitting an analog shaped waveform of its local subgradient over MAC, and the PS receiving a superposition of the noisy analog signals, resulting in a bandwidth-efficient over-the-air (OTA) computation used to update the learned model. We analyze the performance of SGMA and prove that it has a convergence rate that approaches that of the centralized subgradient algorithm in large networks. Simulation results using real datasets show the effectiveness of SGMA

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    Topical superoxide dismutase reduces post-irradiation breast cancer fibrosis

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    Fibrosis following breast radiotherapy for mammary cancer is a frequent undesired effect with objective (esthetic) and subjective (pain) consequences. Forty-four patients with clinical radiofibrosis following conservative treatment of breast cancer were evaluated for the local antifibrosis effect of copper zinc superoxide dismutase [SOD(Cu/Zn)]. Extracted SOD(Cu/Zn) in a concentration of 3,600 units/mg was applied as ointment to the fibrotic affected area, b.i.d. for 90 days, in a total dose of 40 mg. The radiofibrosis intensity was scored on the basis of clinical criteria (pain and the fibrosis area) before and after SOD(Cu/Zn) treatment. SOD(Cu/Zn) was found to be effective in reducing radiation induced fibrosis by a lowering pain score in 36/39 patients and a decrease of the fibrotic area size in half cases, after 6 months. The intensity and changes of breast fibrosis were assessed also by mammography and, for the topographical distribution of subcutaneous temperature, by infrared thermography. Mammography density suggested decreased fibrosis in one third of patients. Thermography showed that fibrosis was accompanied by two zones clinically indistinctive: a central area with maximum thermal activity, called &quot;Maximal Thermic zone&quot; (MTZ) and a peripheral area with less thermal activity but higher than in the surrounding normal tissue, &quot;Transitional Thermic Zone&quot; (TTZ). Both MTZ and TTZ were significantly decreased in 36/44 patients after SOD(Cu/Zn) treatment. Clinical changes persisted all along the study. Treatment was well tolerated except for one case of local allergic reaction, and no important side effects. Molecular mechanisms involved are discussed. Further studies are running to confirm and explain these results
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