36 research outputs found

    Observations of Far-Infrared Molecular Emission Lines from the Orion Molecular Cloud

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    The Orion Nebula was the subject of intensive study for over one hundred years. Recently, several far infrared transitions among the low-lying levels of OH were observed toward IRc2. The OH is thought to be abundant, and plays an important role in the chemical evolution of shock and post-shock regions. The OH emission serves as a sensitive probe of the temperature and density for the shock-processed gas. A rigorous treatment of the radiative transfer of these measured transitions was performed using the escape probability formalism. From this analysis, the temperature of the OH-emitting region was determined to be on the order of 40K. This suggests that the gas is part of the post-shock gas that has cooled sufficiently, most likely by way of radiative cooling by CO. Such cooling from shock temperatures of several degrees can be accomplished in 100 years. A molecular hydrogen density of 3 million/cubic cm and an OH column density of 1.0 x 10 to the 17th /sq cm is found. The beam filling factor is determined to be 36%

    Submillimeter observations of OH and CH in M42

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    The (sup 2) pi sub 1/2 (J = 3/2 to 1/2) transitions of OH at 163.12 and 163.40 micro m have been detected and upper limits have been obtained for the (sup 2) pi sub 3/2 (J = 3/2 to 1/2) transitions of CH at 149.09 and 149.39 micro m, in observations of the Kleinmann-Low Nebula of Orion. All four flux levels lie between 1 and 1.2 x 10 to the 17th power/sq.cm. The OH lines are bright when compared to the lower, (sup 2) pi sub 3/2 (J = 5/2 to 3/2) fluxes reported and imply that the 119 micro m emission observed is partially self-absorbed. The combined results provide strong constraints. Taken together with existing data on molecular hydrogen and CO and recent data on other OH transition, they suggest OH emission from post-shock regions at temperatures T approx 1000 k, densities approx. 7 x 10 to the 6th powr/cu cm N sub OH approx 80/cu cm optically thick for the (sup 2) pi sub 3/2 (J = 5/2 to 3/2), 119 micro m but only partially self-absorbing in the (J = 7/2 to 3/2), 84 micro m transitions over a Doppler velocity bandwidth of 30 km/sec. The OH column density is N sub OH approx 4 x 10 to the 16th powr/sq cm. in the emitting regions which occupy a fraction of approx 0.1 of a 1' x 1' field of view centered on the Becklin-Neugebauer source. The CO (J = 31 to 30), 84 micro m transition appears to lie sufficiently close to one of the 84 micro m OH line components to be partially absorbed as well, through a Bowen-type mechanism

    Observations of far-infrared transitions between excited states of OH

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    In observations of the Kleinmann-Low Nebula were detected of Orion 84.42 and 84.60 micron transitions between the P-2 sub 3/2 and Pi-2 sub 3/2 (J = 5/2) levels of OH with respective fluxes of 1.0 + or - 0.3 to the minus 17th power and 1.4 + or - 0.4 x 10 to the minus 17th power W cm/sq. When compared to 119 micron flux levels of OH and 153 micron flux levels of these radicals by Viscuso, these results suggest appreciable self-absorption of OH line radiation within the Nebula. It is probable that the CO emission due to the J = 31 yields 30 rotational transition at 84.411 micron makes a substantial contribution to the observed 84.42 micron flux, and that it also is at least partially absorbed at the 84.42 micron OH transition frequency. The 88.55 and 88.78 micron (J = 9/2 to 7/2) transitions of CH also were sought, but yielded only to upper limits of 3 x 10 to the minus 18th power W /sq cm each. A search of W3-IRS5 yields upper limits to the 84.42 micron OH and 87.19 micron CO (J = 30 to 29) transitions of 2 x 10 minus 18th power W cm/2

    Aplicaciones médico-quirúrgicas de la anatomía ósea del seno frontal en relación al trauma cráneo facial

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    Los senos frontales son dos cavidades en forma de pirámide triangular, de vértice superior y base inferior, a cada lado de la línea media y excavados en el espesor de este hueso. La anatomía y morfología de los senos frontales se utiliza desde hace años en la medicina forense para la identificación de cadáveres dada su gran versatilidad. En lo que respecta a la cirugía maxilofacial es de suma importancia la presencia de megasenos frontales en el diagnóstico y tratamiento de fracturas hundimiento por ruptura de la tabla externa ante trauma de dicha región, observándose la presencia de las mismas ante patrones de senos anormalmente desarrollados.Facultad de Ciencias Médica

    Aplicaciones médico-quirúrgicas de la anatomía ósea del seno frontal en relación al trauma cráneo facial

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    Los senos frontales son dos cavidades en forma de pirámide triangular, de vértice superior y base inferior, a cada lado de la línea media y excavados en el espesor de este hueso. La anatomía y morfología de los senos frontales se utiliza desde hace años en la medicina forense para la identificación de cadáveres dada su gran versatilidad. En lo que respecta a la cirugía maxilofacial es de suma importancia la presencia de megasenos frontales en el diagnóstico y tratamiento de fracturas hundimiento por ruptura de la tabla externa ante trauma de dicha región, observándose la presencia de las mismas ante patrones de senos anormalmente desarrollados.Facultad de Ciencias Médica

    Aplicaciones médico-quirúrgicas de la anatomía ósea del seno frontal en relación al trauma cráneo facial

    Get PDF
    Los senos frontales son dos cavidades en forma de pirámide triangular, de vértice superior y base inferior, a cada lado de la línea media y excavados en el espesor de este hueso. La anatomía y morfología de los senos frontales se utiliza desde hace años en la medicina forense para la identificación de cadáveres dada su gran versatilidad. En lo que respecta a la cirugía maxilofacial es de suma importancia la presencia de megasenos frontales en el diagnóstico y tratamiento de fracturas hundimiento por ruptura de la tabla externa ante trauma de dicha región, observándose la presencia de las mismas ante patrones de senos anormalmente desarrollados.Facultad de Ciencias Médica

    SOFIA observations of far-infrared hydroxyl emission toward classical ultracompact HII/OH maser regions

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    The hydroxyl radical (OH) is found in various environments within the interstellar medium (ISM) of the Milky Way and external galaxies, mostly either in diffuse interstellar clouds or in the warm, dense environments of newly formed low-mass and high-mass stars, i.e, in the dense shells of compact and ultracompact HII regions (UCHIIRs). Until today, most studies of interstellar OH involved the molecule's radio wavelength hyperfine structure (hfs) transitions. These lines are generally not in LTE and either masing or over-cooling complicates their interpretation. In the past, observations of transitions between different rotational levels of OH, which are at far-infrared wavelengths, have suffered from limited spectral and angular resolution. Since these lines have critical densities many orders of magnitude higher than the radio wavelength ground state hfs lines and are emitted from levels with more than 100 K above the ground state, when observed in emission, they probe very dense and warm material. We probe the warm and dense molecular material surrounding the UCHIIR/OH maser sources W3(OH), G10.62-0.39 and NGC 7538 IRS1 by studying the 2Π1/2,J=3/21/2^2\Pi_{{1/2}}, J = {3/2} - {1/2} rotational transition of OH in emission and, toward the last source also the molecule's 2Π3/2,J=5/23/2^2\Pi_{3/2}, J = 5/2 - 3/2 ground-state transition in absorption. We used the Stratospheric Observatory for Infrared Astronomy (SOFIA) to observe these OH lines, which are near 1.84 THz (163μ163 \mum) and 2.51 THz (119.3μ119.3 \mum). We clearly detect the OH lines, some of which are blended with each other. Employing non-LTE radiative transfer calculations we predict line intensities using models of a low OH abundance envelope versus a compact, high-abundance source corresponding to the origin of the radio OH lines.Comment: Accepted for publication in A&A (SOFIA/GREAT special issue

    Contemporary Trends of Systemic Neoadjuvant and Adjuvant Intravesical Chemotherapy in Patients With Upper Tract Urothelial Carcinomas Undergoing Minimally Invasive or Open Radical Nephroureterectomy: Analysis of US Claims on Perioperative Outcomes and Health Care Costs

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    Introduction: New evidence indicates that minimally invasive surgery (MIS) (laparoscopic or robotic-assisted [LNU, RANU]) reaches oncologic equivalence compared with Open Radical Nephroureterectomy (ORNU) for high-risk upper-tract urothelial carcinoma (UTUC). Recently, European Association of Urology (EAU) Guidelines suggested implementing neoadjuvant chemotherapy (NAC) to standard treatment to improve oncologic outcomes of high-risk UTUC. We aimed (1) To explore contemporary trends of MIS for RNU in the United States and to compare perioperative outcomes and costs with that of ORNU. (2) To determine the trends of NAC and postoperative intravesical chemotherapy (PIC) administration for high-risk UTUC and to assess their contribution to perioperative outcomes and costs. Patients and methods: The Optum Clinformatics Data Mart de-identified database was queried from 2003 to 2018 to retrospectively examine patients who had undergone LNU/RANU or ORNU with or without NAC and PIC. We evaluated temporal adoption trends, complications, and health care cost analyses. We obtained descriptive statistics and utilized multivariable regression modeling to assess outcomes. Results: A total of n = 492 ORNU and n = 1618 LNU/RANU procedures were reviewed. The MIS approach was associated with a statistically significant lower risk of intraoperative complications (adjusted Odds Ratio [aOR], 0.48, 95% CI:0.24-0.96), risk of hospitalization costs (aOR: 0.62, 95% CI:0.49-0.78), and shorter hospital stay (aOR: 0.20, 95% CI:0.15-0.26) when compared to ORNU. Overall, adoption of NAC and PIC accounted for only n = 81 and n < 37 cases respectively. The implementation of NAC and higher number of cycles were associated with an increased probability of any complication rate (aOR: 2.06, 95% CI:1.26-3.36) and hospital costs (aOR: 2.12, 95% CI:1.33-3.38). Conclusion: MIS has become the approach of choice for RNU in the US. Although recommended by guidelines, neither NAC nor postoperative bladder instillation of chemotherapy has been routinely incorporated into the clinical practice of patients with UTUC

    Influence of operative time and blood loss on surgical margins and functional outcomes for laparoscopic versus robotic-assisted radical prostatectomy: a prospective analysis

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    Introduction: The aim of this article was to analyze whether operative time and blood loss during radical prostatectomy (RP) can significantly influence surgical margins (SM) status and post-operative functional outcomes. Material and methods: We prospectively analyzed prostate cancer (PC) patients undergoing RP, using robot-assisted (RARP) or laparoscopic (LRP) procedures. Blood loss was defined using the variation in hemoglobin (Hb, g/dl) values from the day before surgery and no later than 4 hours after surgery. Results: From a whole population of 413 cases considered for RP, 67% underwent LRP and 33.0% RARP. Positive SM (SM+) were found in 33.9% of cases. Mean surgical operative time was 172.3 ±76 min (range 49-485), whereas blood loss was 2.3 ±1.2 g/dl (range 0.3-7.6). Operative time and blood loss at RP were not significantly correlated (r = -0.028275; p = 0.684). SM+ rates significantly (p = 0.002) varied by operative time; a higher SM+ rate was found in cases with an operative time <120 min (41.2%) and >240 min (53.4%). The risk of SM+ significantly increased 1.70 and 1.94 times in cases with an operative time <120 min and >240 min, respectively, independently to the surgical approach. The rate of erectile disfunction (ED) varied from 22.4% to 60.3% between <120 min and >240 min procedures (p = 0.001). According to blood loss, SM+ rates slightly but significantly (p = 0.032) varied; a higher rate of SM+ was found in cases with a Hb variation between 2-4 g/dl (35.9%). Conclusions: Independently to the surgical approach, operative time, more than blood loss at RP, represents a significant variable able to influence SM status and post-operative ED

    Large capacity, multi-fuel, and high temperature working fluid heaters to optimize CSP plant cost, complexity and annual generation

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    © 2016 Author(s). This paper analyses the potential to optimize high temperature fluid back-up systems for concentrating solar power (CSP) plants by investigating the cost impact of component capacity and the impact of using multiple fuels on annual generation. Until now back-up heaters have been limited to 20MWth capacity but larger units have been realised in other industries. Installing larger units yields economy-of-scale benefits through improved manufacturing, optimised transport, and minimized on-site installation work. Halving the number of back-up boilers can yield cost reduction of 23% while minimizing plant complexity and on-site construction risk. However, to achieve these benefits it is important to adapt the back-up heaters to the plant's requirements (load change, capacity, minimum load, etc.) and design for manufacture, transport and assembly. Despite the fact that biomass availability is decreasing with increasing direct normal irradiance (DNI), some biomass is available in areas suitable for CSP plants. The use of these biomass resources is beneficial to maximise annual renewable energy generation, substitute natural gas, and use locally/seasonally available biomass resources that may not be used otherwise. Even small biomass quantities of only 50,000 t/a can increase the capacity factor of a 50MWe parabolic trough plant with 7h thermal energy storage from 40 to 49%. This is a valuable increase and such a concept is suitable for new plants and retrofit applications. However, similar to the capacity optimisation of back-up heaters, various design criteria have to be considered to ensure a successful project
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