882 research outputs found

    Хирургические методы лечения эхинококкоза печени

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    Curs Chirurgie, Facultatea stomatologie, USMF ”Nicolae Testemiţanu“The literature review presents an analysis of traditional methods of surgical treatment for liver hydatid cyst (ideal cystectomy, partial and full perichistectomy, typical and atypical liver resection) and laparoscopic methods (PAIR, resection of liver, partial and full perichistectomy, ideal cystectomy). For each of these methods the advantages and disadvantages are described as well as where their use is welcome and would decrease the rate of the postoperative complications. Laparoscopic surgical techniques used in the treatment of liver hydatid cyst has a high efficacy, but are relatively new, and needs a thorough study of theoretical and practical skills to use them.В обзоре литературы представлен анализ традиционных методов хирургического лечения эхинококкоза печени (идеальная кистэктомия, частичная и полная перикистэктомия, типичная и атипичная резекция печени) и лапароскопических методов (PAIR, резекция печени, идеальная кистэктомия, частичная и полная перикистэктомия). В работе отражены преимущества и недостатки различных методов хирургического лечения эхинококкоза печени, а также послеоперационные осложнения. Лапароскопические хирургические методы, используемые при лечении эхинококкоза печени, имеют высокую эффективность, но, являясь относительно новыми методами, требуют тщательного изучения теоретических и практических навыков их использования

    Active-distributed temperature sensing to continuously quantify vertical flow in boreholes

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    We show how a distributed borehole flowmeter can be created from armored Fiber Optic cables with the Active-Distributed Temperature Sensing (A-DTS) method. The principle is that in a flowing fluid, the difference in temperature between a heated and unheated cable is a function of the fluid velocity. We outline the physical basis of the methodology and report on the deployment of a prototype A-DTS flowmeter in a fractured rock aquifer. With this design, an increase in flow velocity from 0.01 to 0.3 m s−1 elicited a 2.5°C cooling effect. It is envisaged that with further development this method will have applications where point measurements of borehole vertical flow do not fully capture combined spatiotemporal dynamics

    Common Complications of Sickle Cell Disease: A Simulation-Based Curriculum

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    Introduction: Sickle cell disease (SCD), the most common autosomal recessive genetic disorder worldwide, affects nearly every organ of the body and results in accelerated mortality. Nationally, internal medicine physicians lack a complete understanding of morbidity and mortality in this population leading to health care disparities. Methods: We created a 2-hour curriculum consisting of three SCD case vignettes representing common disease complications (acute stroke, acute chest syndrome, and septic shock) with the goal to increase medicine house staff knowledge and confidence in patient management. Residents completed a pretest to assess baseline knowledge and were divided into groups of four to five. Three simulation cases were completed by each group; learners needed to work through a differential diagnosis and describe key management steps. Each group was graded on achieving the 10 critical actions for each case. Following each case, there was a faculty-led debriefing session. Residents repeated the pretest 30 days after completion of the curriculum (posttest). RESULTS: Thirty-six second year internal medicine residents participated in this curriculum. After completing this curriculum, residents improved their test score from 33% (SD = 12%) to 57% (SD = 18%) (p \u3c .0001). Additionally, self-reported confidence in management scores increased from 2.6 (SD = 0.8) in the pretest to 3.5 (SD = 0.4) in the posttest (p = .02) on a 5-point Likert scale (1 = not very confident, 5 = very confident). Discussion: Use of a simulation curriculum increased knowledge and confidence of internal medicine residents in the management of critical illness in patients with SCD

    Synthetic Microfiber and Microbead Exposure and Retention Time in Model Aquatic Species Under Different Exposure Scenarios

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    Synthetic microfibers have been reported in most aquatic environments and represent a large proportion of environmental microplastics. However, they remain largely under-represented in microplastic ecotoxicity studies. The present study aims to investigate particle interaction with, and retention time in, aquatic organisms comparing microfibers, and microbeads. We used brine shrimp (Artemia sp.) and fish (Gasterosteus aculeatus) as invertebrate and vertebrate models, respectively. Organisms were exposed to a mixture of microbeads (polyethylene, 27–32 μm) and microfibers (dope dyed polyester; 500 μm-long) for 2 h, at high concentrations (100,000 part./L) in order to maximize organism-particles interaction. Artemia were exposed in the presence or absence of food. Fish were exposed either via the trophic route or directly via water, and water exposures were performed either in freshwater or seawater. In the absence of food, Artemia ingested high numbers of microbeads, retained in their digestive tract for up to 96 h. Microfiber ingestion was very limited, and its egestion was fast. In the presence of food, no microfiber was ingested, microbead ingestion was limited, and egestion was fast (48 h). Limited particle ingestion was observed in fish exposed via water, and particle retention time in gut did not exceed 48 h, both for direct and trophic exposure. However, water exposures resulted in a higher number of particles present in gills, and average retention time was higher in gills, compared to gut. This suggests that gills are organs susceptible to microplastic exposure and should be taken into account in fish exposure and effect studies. Our results show that particle ingestion and retention by organisms differ between microbeads and microfibers, suggesting particle selection based on size, shape, and/or color and species-specific selective feeding. We also showed that the presence of food results in limited particle ingestion and retention in Artemia and that microbeads are more likely to be transferred to organisms from upper trophic levels than microfibers. Finally, fish exposure to particles was not significantly different between freshwater and seawater conditions

    Exact Solutions to the Sine-Gordon Equation

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    A systematic method is presented to provide various equivalent solution formulas for exact solutions to the sine-Gordon equation. Such solutions are analytic in the spatial variable xx and the temporal variable t,t, and they are exponentially asymptotic to integer multiples of 2π2\pi as x±.x\to\pm\infty. The solution formulas are expressed explicitly in terms of a real triplet of constant matrices. The method presented is generalizable to other integrable evolution equations where the inverse scattering transform is applied via the use of a Marchenko integral equation. By expressing the kernel of that Marchenko equation as a matrix exponential in terms of the matrix triplet and by exploiting the separability of that kernel, an exact solution formula to the Marchenko equation is derived, yielding various equivalent exact solution formulas for the sine-Gordon equation.Comment: 43 page

    Coherent instabilities in a semiconductor laser with fast gain recovery

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    We report the observation of a coherent multimode instability in quantum cascade lasers (QCLs), which is driven by the same fundamental mechanism of Rabi oscillations as the elusive Risken-Nummedal-Graham-Haken (RNGH) instability predicted 40 years ago for ring lasers. The threshold of the observed instability is significantly lower than in the original RNGH instability, which we attribute to saturable-absorption nonlinearity in the laser. Coherent effects, which cannot be reproduced by standard laser rate equations, can play therefore a key role in the multimode dynamics of QCLs, and in lasers with fast gain recovery in general.Comment: 5 pages, 4 figure

    Improving the sensitivity of future GW observatories in the 1-10 Hz band: Newtonian and seismic noise

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    The next generation gravitational wave interferometric detectors will likely be underground detectors to extend the GW detection frequency band to frequencies below the Newtonian noise limit. Newtonian noise originates from the continuous motion of the Earth’s crust driven by human activity, tidal stresses and seismic motion, and from mass density fluctuations in the atmosphere. It is calculated that on Earth’s surface, on a typical day, it will exceed the expected GW signals at frequencies below 10 Hz. The noise will decrease underground by an unknown amount. It is important to investigate and to quantify this expected reduction and its effect on the sensitivity of future detectors, to plan for further improvement strategies. We report about some of these aspects. Analytical models can be used in the simplest scenarios to get a better qualitative and semi-quantitative understanding. As more complete modeling can be done numerically, we will discuss also some results obtained with a finite-element-based modeling tool. The method is verified by comparing its results with the results of analytic calculations for surface detectors. A key point about noise models is their initial parameters and conditions, which require detailed information about seismic motion in a real scenario. We will describe an effort to characterize the seismic activity at the Homestake mine which is currently in progress. This activity is specifically aimed to provide informations and to explore the site as a possible candidate for an underground observatory. Although the only compelling reason to put the interferometer underground is to reduce the Newtonian noise, we expect that the more stable underground environment will have a more general positive impact on the sensitivity.We will end this report with some considerations about seismic and suspension noise

    A novel myelin P0–specific T cell receptor transgenic mouse develops a fulminant autoimmune peripheral neuropathy

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    Autoimmune-prone nonobese diabetic mice deficient for B7-2 spontaneously develop an autoimmune peripheral neuropathy mediated by inflammatory CD4+ T cells that is reminiscent of Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy. To determine the etiology of this disease, CD4+ T cell hybridomas were generated from inflamed tissue–derived CD4+ T cells. A majority of T cell hybridomas were specific for myelin protein 0 (P0), which was the principal target of autoantibody responses targeting nerve proteins. To determine whether P0-specific T cell responses were sufficient to mediate disease, we generated a novel myelin P0–specific T cell receptor transgenic (POT) mouse. POT T cells were not tolerized or deleted during thymic development and proliferated in response to P0 in vitro. Importantly, when bred onto a recombination activating gene knockout background, POT mice developed a fulminant form of peripheral neuropathy that affected all mice by weaning age and led to their premature death by 3–5 wk of age. This abrupt disease was associated with the production of interferon γ by P0-specific T cells and a lack of CD4+ Foxp3+ regulatory T cells. Collectively, our data suggest that myelin P0 is a major autoantigen in autoimmune peripheral neuropathy
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