16,878 research outputs found
NAVA-TEKNIIKKA VASTASYNTYNEIDEN HENGITYSKONEHOIDOSSA
No full textVuonna 2009 Turun Yliopistollisen Keskussairaalan (TYKS) vastasyntyneiden teho- osastolla otettiin käyttöön uusi hengityskonetekniikka, NAVA (neurally adjusted ventilatory assist). NAVA hyödyntää pallean sähköistä aktivaatiota ja mukailee vastasyntyneen omaa hengitystä. NAVA-tekniikka tuli vaihtoehdoksi kahden toisen tekniikan rinnalle; SIMV (synchronized intermittent mechanical ventilation) sekä HFOV (high frequency oscillatory ventilation). Tässä retrospektiivisessä tutkimuksessa tarkastellaan vastasyntyneen hengityskonehoidon toteutusta ennen ja jälkeen NAVA- tekniikan käyttöönottoa. Lisäksi vertaillaan hengityskonehoidon aikaista kipulääkityksen tarvetta. Kipulääkityksenä tässä potilasryhmässä käytetään pääosin opioideja. Opioidihoidon vaikutuksista vastasyntyneisiin tiedetään vielä suhteellisen vähän, mutta on tutkimuksia, jotka osoittavat opioidihoidon epäsuotuisia pitkäaikaisvaikutuksia lapsen aivojen ja kognition kehitykseen.
Aineistoa on kerätty TYKS:n vastasyntyneiden teho-osaston potilaista vuosilta 2007 – 2008 sekä 2010 – 2011, ja se käsittää 408 hengityskonehoidossa ollutta potilasta. Heistä 72 sai NAVA-hengityskonehoitoa vuosina 2010 – 2011. Potilaina oli sekä täysiaikaisina että keskosina syntyneitä lapsia. Syitä hengityskonehoitoon oli monia; mm. keskosen hengitysvaikeusoireyhtymä, keskosen krooninen keuhkosairaus ja vastasyntyneen keuhkokuume.
Tutkimuksen hypoteesina oli, että opioidihoidon tarve vähenee NAVA-tekniikan käyttöönoton myötä. Huomasimme, että NAVA-tekniikan kaudella opioidihoidon kesto väheni (P = 0.005), samoin kokonaisannosmäärät vähenivät (P = 0.001). Tämä viittaisi siihen, että NAVA on vastasyntyneelle mieluisampi ja kivuttomampi hengityksen tukimuoto, jolloin vastasyntynyt pärjää vähemmällä kipulääkityksellä. Tulevaisuuden tavoitteena on optimoida hengityskonehoitoa siten, että se on potilasystävällisempää ja pitkäaikaishaitat vähenevät. NAVA-hengityskonehoidon saamiseksi laajempaan käyttöön tarvitaan jatkossa satunnaistettuja vertailututkimuksia
Recent Results From the EU POF-PLUS Project: Multi-Gigabit Transmission Over 1 mm Core Diameter Plastic Optical Fibers
No full textRecent activity to achieve multi-gigabit transmission over 1 mm core diameter graded-index and step-index plastic optical fibers for distances up to 50 meters is reported in this paper. By employing a simple intensity-modulated direct-detection system with pulse amplitude or digital multi-tone modulation techniques, low-cost transceivers and easy to install large-core POFs, it is demonstrated that multi-gigabit transmission up to 10 Gbit/s over 1-mm core diameter POF infrastructure is feasible. The results presented in this paper were obtained in the EU FP7 POF-PLUS project, which focused on applications in different scenarios, such as in next-generation in-building residential networks and in datacom applications
Scaling-Up Techniques for the Nanofabrication of Cell Culture Substrates via Two-Photo Polymerization for Industrial-Scale Expansion of Stem Cells
No full textAnálisis semiótico comparativo en el trato de una misma problemática : el snuff, en la representación de los textos cinematográficos : Tesis y 8 mm / N.I. Nava Ramírez
No full textTesis de Lic. en Comunicación, Universidad Autónoma del Estado de MéxicoAnálisis de las películas Tesis y 8 MM, bajo una perspectiva semiótica de la argumentación, que permite comparar el trato a una misma problemática y la construcción de una representación simbólica semejante para “leerlos”, pese a que los contextos de su realización son diferentes
An Experimental-Numerical Investigation on the Effects of the Macroporous Scaffold Geometry on Cell Culture Parameters
No full textEmploying M1 direct calibration/de-embedding approaches for large signal model validation at mm-wave frequencies
No full textIn this contribution, we employ direct calibration/de-embedding approaches to validate the large signal device model of state-of-the-art HBTs and CMOS technologies operating in the mm-wave frequency band WR6. The capability of placing the first tier calibration reference plane in close proximity to the DUT allows the large signal metric to be directly compared with foundry models.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic
Epitaxial Silicon Carbide for X-ray Detection
No full textWe present the first experimental results of X-ray detection and spectroscopy by means of Schottky junctions on epitaxial silicon carbide (SLC). The devices have a junction area of 3 mm(2) on an n-type 4H-SiC layer 30 mum thick with a dopant concentration of 1.8 X 10(15)cm(-3) At 300K, the reverse current density of the best device varies between 2 pA/cm(2) and 18 pA/cm(2) as the mean electric field is increased from 40 kY/cm up to 170 kV/cm. The devices have been tested with X and gamma raysfrom Am-241; the best measured energy resolution is 2.7 keV FWHM at room temperature
Dynamic Estimation of Vital Signs with mm-wave FMCW Radar
No full textIn this paper, we propose a method for continuous monitoring of vital signs-in particular, respiration frequency-with a commercial mm-wave radar. The nearly constant frequency (NCF) model is adopted to represent chest displacement due to respiration and simulate radar response. Based on this model, an extended Kalman filter (EKF) based estimator is developed to track the breathing frequency of a person. The impact of dynamic model parameters is investigated in numerical simulation. The possibility to track breathing frequency with the proposed method is demonstrated by experimental data processing. Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Microwave Sensing, Signals & System
A 23-to-29GHz Receiver with mm-Wave N-Input-N-Output Spatial Notch Filtering and Autonomous Notch-Steering Achieving 20-to-40dB mm-Wave Spatial Rejection and -14dBm In-Notch IP1 dB
No full textDigital beamforming receivers (RXs) support MIMO operation and offer great flexibility and accuracy in multi-beam formation and calibration. However, compared with analog phased-array and hybrid systems, due to the absence of any rejection for spatial in-band blockers, the RX/ADC dynamic range and linearity should be high enough to prevent array saturation. Therefore, the use of self-steering spatial notch filters (SNFs) is necessary to aid the digital beamformers and reduce RX/ADC power consumption while strong blockers exist. To address that, the sub-6GHz RXs in [1], [2] synthesize a baseband spatial notch impedance and translate it to RF by passive mixers. However, this technique cannot be directly applied at mm-wave frequencies as the impedance translational performance of the passive mixers degrades significantly. Hence, the mm-wave beamformer in [3] realizes a cascadable SNF at an intermediate frequency (IF). However, the front-end mm-wave components like mixers and phase shifters have to tolerate strong blockers, thus degrading RX linearity. Besides, it uses multiple IF buffers and VGAs for signal scaling and combining, which could be power-hungry if a similar method is adopted to realize a mm-wave SNF. To improve on those limitations, we propose a scalable SNF structure, which (1) suppresses the strongest in-band blocker at mm-wave frequencies, (2) supports N-input-N-output MIMOs, and (3) requires no active blocks except the phase shifters. A two-step autonomous notch-steering technique is also developed to adjust the SNF notch direction power-efficiently and accurately.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic
Mineralogical composition and geological features of c-type asteroids inferred from meteorites and space missions data
No full textWe investigate the composition of C-type asteroids and comets providing insights with the combined petrographic and spectroscopic study of micrometeorites (MMs) (TAM5.29, TAM5.30, TAM18c.11 and TAM18c.13) and laboratory experiments on carbonaceous chondrites (CCs): FRO95002, FRO99040 and FRO90006 (CO3 CCs), MCY14001 (CM2) and DaG521 (CV3). The composition of C-type asteroids is similar to that of CCs. The IR reflectance spectra of C-type asteroids show some unresolved features, in particular the 3 μm band is difficult to attribute to a specific compound and the origin of the organic matter indicated by the 3.4-3.5 μm bands is still debated. The main processes suggested to create these features are low-T aqueous alteration, hydrothermalism and cryovolcanism. TAM5.29 is dominated by a matrix of Fe-olivines and clasts of andradite surrounded by diopside-jarosite derived from hydrothermal alteration at T~250°C. A second episode of alteration at T<100°C resulted in the formation of iddingsite. TAM5.29 mineralogy is unique among the MMs and is also different from the known CV CCs representing a newly described alteration environment on the CV parent body. TAM18c.11 and TAM18c.13 have a high Antarctic alteration with widespread replacement with jarosite. Phyllosilicates are recognisable along with small metal alloys and CH, SH and NH functional groups are ubiquitous. TAM5.30 is a CO-like MM and records a processing history characterised by an initial episode of low-temperature CM-like aqueous alteration, which later transitioned into higher temperature (~300°C) CV-like metasomatic alteration. The 3.15 μm band of TAM5.29 is found scattered around the matrix, thus related to Fe-rich hydrous phases. An isolated spot gave spectra characterised by a 3.04 μm band that always appears together with the 3.4 μm and 3.5 μm bands of the aliphatic organics, indicating a relation between the 3.04 μm band and the organic matter. In TAM18c.11 the 3 μm is found at 3.05-3.06 μm in close relationship with ammonium-jarosite. Spectra of MCY14001 after the experiment exhibit two bands at 2.9 and 3.05 μm, not present in the original spectra. The 3.05 μm band is due to ammoniation of serpentine. Original powders of MCY14001 also had Na-carbonates, which after the experiment were replaced by ammoniated analcime-natrolite. In addition Fe-enstatite, diopside, magnetite and sulfides are also formed during the hydrothermal alteration. Cryovolcanism experiments gave insights on the hydrocarbon formation. The ejected outgassed powders FRO99040, FRO90006, FRO95002 and DaG521 show absorption bands at 3.4 μm and 3.5 μm while in the original unprocessed powders this feature is not found. Gas-chromatography analyses show that these features are given by aliphatic hydrocarbons. The 3.15 μm band in TAM 5.29 is given by Fe-OH bonds, proving that the Europa-like asteroids are Fe-rich hydrous worlds involved by hydrothermal alteration. The 3.07 μm band in TAM18c.11 is related to organic matter, in particular CH and NH in aromatic or aliphatic hydrocarbons, in phyllosilicates structure, sulphates and salts. Hydrothermal experiments on MCY14001 confirm that the 3.05 μm band is related to NH and indicates that Ceres-like asteroids with the 3.05 ± 0.01 μm band are enriched in organic matter. Aliphatic hydrocarbons are created through sublimation-outbursting at T≤-40°C. This is also evidence that organics can be created by Cometary activity itself. TAM5.29 and TAM5.30 give new perspectives in the hydrothermal alteration of CCs parent bodies. They are products of unique accretion windows, occurring on a more heterogeneous CVs parent body in the case of TAM5.29 and in a mixed environment in-between the CO and CM chondrites parent bodies in case of TAM5.30
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