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1.
Nature ; 555(7695): 216-219, 2018 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-29516997

RESUMO

The familiar axisymmetric zones and belts that characterize Jupiter's weather system at lower latitudes give way to pervasive cyclonic activity at higher latitudes. Two-dimensional turbulence in combination with the Coriolis ß-effect (that is, the large meridionally varying Coriolis force on the giant planets of the Solar System) produces alternating zonal flows. The zonal flows weaken with rising latitude so that a transition between equatorial jets and polar turbulence on Jupiter can occur. Simulations with shallow-water models of giant planets support this transition by producing both alternating flows near the equator and circumpolar cyclones near the poles. Jovian polar regions are not visible from Earth owing to Jupiter's low axial tilt, and were poorly characterized by previous missions because the trajectories of these missions did not venture far from Jupiter's equatorial plane. Here we report that visible and infrared images obtained from above each pole by the Juno spacecraft during its first five orbits reveal persistent polygonal patterns of large cyclones. In the north, eight circumpolar cyclones are observed about a single polar cyclone; in the south, one polar cyclone is encircled by five circumpolar cyclones. Cyclonic circulation is established via time-lapse imagery obtained over intervals ranging from 20 minutes to 4 hours. Although migration of cyclones towards the pole might be expected as a consequence of the Coriolis ß-effect, by which cyclonic vortices naturally drift towards the rotational pole, the configuration of the cyclones is without precedent on other planets (including Saturn's polar hexagonal features). The manner in which the cyclones persist without merging and the process by which they evolve to their current configuration are unknown.

2.
Philos Trans A Math Phys Eng Sci ; 377(2154): 20180406, 2019 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-31378178

RESUMO

The instrument JIRAM (Jovian Infrared Auroral Mapper), on board the NASA spacecraft Juno, is both an imager and a spectrometer. Two distinct detectors are used for imaging and spectroscopy. The imager acquires Jupiter images in two bands, one of which (L band, 3.3-3.6 µm) is devoted to monitor the H3+ emission. The spectrometer covers the spectral region from 2 to 5 µm (average spectral resolution 9 nm) with a 256 pixels slit that can observe the same scene of the L band imager with some delay. JIRAM scientific goals are the exploration of the Jovian aurorae and the planet's atmospheric structure, dynamics and composition. Starting early July 2016 Juno is orbiting around Jupiter. Since then, JIRAM has provided an unprecedented amount of measurements, monitoring both Jupiter's atmosphere and aurorae. In particular, the camera has monitored Jupiter's poles with very high spatial resolution, providing new insights in both its aurorae and the polar dynamic. The main findings obtained by the L imager are detailed pictures of Jupiter's aurorae showing an extremely complex morphology of the H3+ distribution in the main oval and in the moon's footprints. The spectrometer has enabled the measure the distribution of both H3+ concentration and temperature. The analysis of the north auroral region limb observations shows that the peak density of H3+ is above 750 km and that often it is anticorrelated to the temperature, confirming the infrared cooling effect of H3+. This article is part of a discussion meeting issue 'Advances in hydrogen molecular ions: H3+, H5+ and beyond'.

3.
Astrobiology ; 23(6): 691-704, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37126783

RESUMO

The Mars Multispectral Imager for Subsurface Studies (Ma_MISS) instrument is a miniaturized visible and near-infrared spectrometer that is integrated into the drilling system of the ESA Rosalind Franklin rover, which is devoted to subsurface exploration on Mars. Ma_MISS will acquire spectral data on the Martian subsurface from excavated borehole walls. The spectral data collected by Ma_MISS on unexposed rocks will be crucial for determination of the composition of subsurface rocks and optical and physical properties of materials (i.e., grain size). Ma_MISS will further contribute to a reconstruction of the stratigraphic column and acquire data on subsurface geological processes. Ma_MISS data may also inform with regard to the presence of potential biomarkers in the subsurface, given the presence of organic matter that may affect some spectral parameters. In this framework, we performed a wide range of measurements using the laboratory model of the Ma_MISS to investigate mineral/organic mixtures in different proportions. We prepared mixtures by combining kaolinite and nontronite with glycine, asphaltite, polyoxymethylene, and benzoic acid. These organic compounds show different spectral characteristics in the visible and near-infrared; therefore their presence can be detected by the Ma_MISS instrument. Our results indicate that the Ma_MISS instrument can detect organic material down to abundances of around 1 wt %. In particular, the data collected on low-concentration mixtures show that, by analyzing sediments with a grain size smaller than the Ma_MISS spatial resolution, the instrument can still discern those points where organic matter is present from points with exclusive mineral composition. The results also show that a collection of multiple contiguous measurements on a hypothetical borehole wall could help indicate the presence of organic matter in clay-rich soils if present.


Assuntos
Meio Ambiente Extraterreno , Marte , Exobiologia/métodos , Minerais , Fenômenos Geológicos
4.
Rev Sci Instrum ; 94(9)2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37655988

RESUMO

The Ma_MISS miniaturized spectrometer is integrated within the Drilling System of the ExoMars Rosalind Franklin Rover for Mars exploration. Here we focus on the on ground calibration campaign to obtain radiometric and linearity calibrations of the Ma_MISS instrument, while the first paper dealt with the spectral calibration [De Angelis et al., Rev. Sci. Instrum. 93, 123704 (2022)]. The experimental setup used to carry out radiometric calibration is described, as are the methods used for data processing and key parameter retrieval. In particular, the Spectrometer Transfer Function (Responsivity), Signal-to-Noise Ratio, and detector linearity are determined. In a third paper [De Sanctis et al., Planet. Sci. J. 3, 142 (2022)], validation of the Ma_MISS calibration results through spectral measurements performed on rock and synthetic targets during the radiometric calibration campaign is described.

5.
J Geophys Res Planets ; 127(5): e2021JE007083, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35865508

RESUMO

The Nadir and Occultation for MArs Discovery (NOMAD) instrument suite aboard ExoMars/Trace Gas Orbiter spacecraft is mainly conceived for the study of minor atmospheric species, but it also offers the opportunity to investigate surface composition and aerosols properties. We investigate the information content of the Limb, Nadir, and Occultation (LNO) infrared channel of NOMAD and demonstrate how spectral orders 169, 189, and 190 can be exploited to detect surface CO2 ice. We study the strong CO2 ice absorption band at 2.7 µm and the shallower band at 2.35 µm taking advantage of observations across Martian Years 34 and 35 (March 2018 to February 2020), straddling a global dust storm. We obtain latitudinal-seasonal maps for CO2 ice in both polar regions, in overall agreement with predictions by a general climate model and with the Mars Express/OMEGA spectrometer Martian Years 27 and 28 observations. We find that the narrow 2.35 µm absorption band, spectrally well covered by LNO order 189, offers the most promising potential for the retrieval of CO2 ice microphysical properties. Occurrences of CO2 ice spectra are also detected at low latitudes and we discuss about their interpretation as daytime high altitude CO2 ice clouds as opposed to surface frost. We find that the clouds hypothesis is preferable on the basis of surface temperature, local time and grain size considerations, resulting in the first detection of CO2 ice clouds through the study of this spectral range. Through radiative transfer considerations on these detections we find that the 2.35 µm absorption feature of CO2 ice clouds is possibly sensitive to nm-sized ice grains.

6.
Rev Sci Instrum ; 93(12): 123704, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36586927

RESUMO

The Ma_MISS spectrometer is integrated within the drilling system of the Rosalind Franklin ExoMars rover. This paper reports the on-ground calibration campaign performed on the spectrometer. Here, we focus on the spectral calibration of the instrument. The experimental setup used to carry out calibration is described, and the methods used for data processing and key parameters retrieval are explained. In particular, the spectral parameters such as (i) pixel central wavelengths, (ii) spectral response function, (iii) spectral resolution, (iv) sampling, and (v) range are determined. In a follow-up paper, the linearity and radiometric calibrations are described, while in De Sanctis et al. [Planet. Sci. J. 3, 142 (2022)], the validation of spectral measurements performed on synthetic and natural rock targets is presented.

7.
Nature ; 438(7068): 623-7, 2005 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-16319882

RESUMO

The recent identification of large deposits of sulphates by remote sensing and in situ observations has been considered evidence of the past presence of liquid water on Mars. Here we report the unambiguous detection of diverse phyllosilicates, a family of aqueous alteration products, on the basis of observations by the OMEGA imaging spectrometer on board the Mars Express spacecraft. These minerals are mainly associated with Noachian outcrops, which is consistent with an early active hydrological system, sustaining the long-term contact of igneous minerals with liquid water. We infer that the two main families of hydrated alteration products detected-phyllosilicates and sulphates--result from different formation processes. These occurred during two distinct climatic episodes: an early Noachian Mars, resulting in the formation of hydrated silicates, followed by a more acidic environment, in which sulphates formed.


Assuntos
Silicatos de Alumínio/análise , Silicatos de Alumínio/química , Clima , Meio Ambiente Extraterreno/química , Marte , Argila , Concentração de Íons de Hidrogênio , Ferro/análise , Magnésio/análise , Voo Espacial , Astronave , Sulfatos/análise , Sulfatos/química , Água/análise , Água/química
8.
Int J Oral Maxillofac Surg ; 49(5): 649-654, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31735528

RESUMO

The aim of this study was to evaluate the effectiveness of loading at 2 months after the surgical placement of implants. A tapered implant was used. Implant stability was determined using resonance frequency analysis at implant insertion (T0; primary stability), after 2 months (T1), and at the 6-month follow-up (T2). Descriptive statistics and the t-test were used. Significance was at P ≤ 0.05. A total of 268 implants were inserted in 142 patients. No patient dropped out and no implant had failed at the 6-month follow-up. The mean implant stability quotient value (ISQ) increased over time, with a statistically non-significant difference for T0 vs. T1 (P = 0.08) and a statistically significant difference for T1 vs. T2 (P = 0.0018) and T0 vs. T2 (P = 0.000). Only 99 implants, characterized by an extremely high mean primary stability value (80.34), did not have a recorded increase in ISQ at T1. A 2-month healing period allowed the implant to achieve secondary stability, confirming the effectiveness of the loading protocol at 2 months.


Assuntos
Implantes Dentários , Osseointegração , Estudos de Coortes , Implantação Dentária Endóssea , Planejamento de Prótese Dentária , Humanos , Estudos Prospectivos
9.
Int J Oral Maxillofac Surg ; 49(10): 1335-1342, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32217033

RESUMO

Static computer-assisted surgery (s-CAS) has been introduced to improve the results of implantology. A prospective cohort study was conducted following the STROBE guidelines to determine the presence of a learning curve in s-CAS. Six partially and six totally edentulous patients were treated by two surgeons experienced in implantology but completely inexperienced in s-CAS. Preoperative and postoperative computed tomography scans were matched to assess coronal, apical, and angular deviation and the positioning error. The accuracy data were used to evaluate the learning curve. Fifty-six implants were inserted. In partially and totally edentulous patients, the mean (range; standard deviation) coronal deviation was 0.87 (0.34-1.27; 0.35) and 1.24 (0.72-2.67; 0.79); the mean apical deviation was 1.13 (0.48-1.63; 0.39) and 1.52 (0.88-3.84; 1.15); the mean angular deviation was 2.63 (1.89-4.50; 0.98) and 3.59 (1.69-6.30; 1.65); and the mean positioning error was 0.80 (0.32-1.25; 0.35) and 1.14 (0.35-2.56; 0.77), respectively. A typical 'learning curve' effect was not identified for s-CAS.


Assuntos
Implantes Dentários , Cirurgia Assistida por Computador , Desenho Assistido por Computador , Implantação Dentária Endóssea , Humanos , Curva de Aprendizado , Planejamento de Assistência ao Paciente , Estudos Prospectivos
10.
Int J Oral Maxillofac Surg ; 47(9): 1195-1198, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29653870

RESUMO

The aim of this report was to describe a new computer-guided technique for a controlled site preparation and palatal orthodontic miniscrew insertion using a dedicated software. A surgical guide was designed after planning the appropriate insertion sites on three-dimensional images created by the fusion of cone-beam computed tomography (CBCT) and digital dental model images. Pre- and postoperative CBCT images were compared and the angular, coronal, and apical deviations between the planned and the placed miniscrews were calculated. The mean coronal and apical deviations were 1.38mm (range: 3.48-0.15mm; standard deviation (SD): 0.65) and 1.73mm (range: 5.41-0.10mm; SD: 1.03), respectively, while the mean angular deviation was 4.60° (range: 15.23-0.54°; SD: 2.54). The present surgical guide allows a controlled and accurate palatal miniscrew placement in three dimensions.


Assuntos
Parafusos Ósseos , Desenho Assistido por Computador , Procedimentos de Ancoragem Ortodôntica/métodos , Palato Duro/diagnóstico por imagem , Palato Duro/cirurgia , Cirurgia Assistida por Computador/métodos , Tomografia Computadorizada de Feixe Cônico , Humanos , Imageamento Tridimensional , Itália , Procedimentos Cirúrgicos Minimamente Invasivos , Modelos Dentários , Radiografia Dentária Digital , Software
11.
Astron J ; 156(2)2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30510303

RESUMO

We characterize the origin and evolution of a mesoscale wave pattern in Jupiter's North Equatorial Belt (NEB), detected for the first time at 5 µm using a 2016-17 campaign of "lucky imaging" from the VISIR instrument on the Very Large Telescope and the NIRI instrument on the Gemini observatory, coupled with M-band imaging from Juno's JIRAM instrument during the first seven Juno orbits. The wave is compact, with a 1°.1-1°.4 longitude wavelength (wavelength 1300-1600 km, wavenumber 260-330) that is stable over time, with wave crests aligned largely north-south between 14°N and 17°N (planetographic). The waves were initially identified in small (10° longitude) packets immediately west of cyclones in the NEB at 16°N but extended to span wider longitude ranges over time. The waves exhibit a 7-10 K brightness temperature amplitude on top of an ∼210 K background at 5 µm. The thermal structure of the NEB allows for both inertio-gravity waves and gravity waves. Despite detection at 5 µm, this does not necessarily imply a deep location for the waves, and an upper tropospheric aerosol layer near 400-800 mbar could feature a gravity wave pattern modulating the visible-light reflectivity and attenuating the 5-µm radiance originating from deeper levels. Strong rifting activity appears to obliterate the pattern, which can change on timescales of weeks. The NEB underwent a new expansion and contraction episode in 2016-17 with associated cyclone-anticyclone formation, which could explain why the mesoscale wave pattern was more vivid in 2017 than ever before.

12.
Science ; 361(6404): 774-777, 2018 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-29976795

RESUMO

Jupiter's aurorae are produced in its upper atmosphere when incoming high-energy electrons precipitate along the planet's magnetic field lines. A northern and a southern main auroral oval are visible, surrounded by small emission features associated with the Galilean moons. We present infrared observations, obtained with the Juno spacecraft, showing that in the case of Io, this emission exhibits a swirling pattern that is similar in appearance to a von Kármán vortex street. Well downstream of the main auroral spots, the extended tail is split in two. Both of Ganymede's footprints also appear as a pair of emission features, which may provide a remote measure of Ganymede's magnetosphere. These features suggest that the magnetohydrodynamic interaction between Jupiter and its moon is more complex than previously anticipated.

13.
Gene ; 398(1-2): 103-13, 2007 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-17555889

RESUMO

The possible enzymatic activities of neuro- and cytoglobin as well as their potential function as substrates in enzymatic reactions were studied. Neuro- and cytoglobin are found to show no appreciable superoxide dismutase, catalase, and peroxidase activities. However, the internal disulfide bond (CD7-D5) of human neuroglobin can be reduced by thioredoxin reductase. Furthermore, our in vivo and in vitro studies show that Escherichia coli cells contain an enzymatic reducing system that keeps the heme iron atom of neuroglobin in the Fe(2+) form in the presence of dioxygen despite the high autoxidation rate of the molecule. This reducing system needs a low-molecular-weight compound as co-factor. In vitro tests show that both NADH and NADPH can play this role. Furthermore, the reducing system is not specific for neuroglobin but allows the reduction of the ferric forms of other globins such as cytoglobin and myoglobin. A similar reducing system is present in eukaryotic tissue protein extracts.


Assuntos
Enzimas/metabolismo , Globinas/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Animais , Catalase/metabolismo , Dissulfetos/química , Dissulfetos/metabolismo , Globinas/química , Globinas/genética , Heme/química , Heme/metabolismo , Humanos , Ferro/química , Ferro/metabolismo , NAD/metabolismo , NADP/metabolismo , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Neuroglobina , Oxirredução , Peroxidase/metabolismo , Espectrofotometria , Análise Espectral Raman , Especificidade por Substrato , Superóxido Dismutase/metabolismo , Tiorredoxina Dissulfeto Redutase/metabolismo
14.
Int J Oral Maxillofac Surg ; 46(7): 905-911, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28408148

RESUMO

The brass wire ligature is an efficient method to correct a moderately mesially impacted mandibular second molar (MM2). The aim of this prospective clinical pilot study was to evaluate the influence of mandibular third molar (MM3) germectomy on the treatment time for this procedure and to determine its impact on oral health-related quality of life (OHRQoL) using the short-form Oral Health Impact Profile (OHIP-14). The STROBE guidelines were followed. Impacted MM2 were assigned randomly to receive brass wire ligature treatment either with germectomy (group A) or without germectomy (group B). Descriptive statistics and the Student t-test were used in the statistical analysis; significance was set at P≤0.05. One thousand and thirty patients were assessed. Fourteen subjects with 20 mesially angulated (range 25-40°) impacted MM2 were identified. Paired comparisons of groups A and B showed no statistically significant difference in treatment time (171days for group A and 174days for group B; P=0.440), but a statistically significant difference in OHIP-14 values at the 3- (P=0.017) and 7-day (P=0.002) follow-up. The brass wire technique can be used effectively in moderately impacted MM2, but the combined use of MM3 germectomy does not influence the treatment time and shows a negative impact on OHRQoL.


Assuntos
Ligadura/instrumentação , Mandíbula/cirurgia , Dente Molar/cirurgia , Qualidade de Vida , Extração Dentária/métodos , Dente Impactado/cirurgia , Adolescente , Cobre , Feminino , Humanos , Masculino , Dente Molar/diagnóstico por imagem , Dente Serotino/diagnóstico por imagem , Dente Serotino/cirurgia , Projetos Piloto , Estudos Prospectivos , Radiografia Panorâmica , Retalhos Cirúrgicos , Dente Impactado/diagnóstico por imagem , Resultado do Tratamento , Zinco
15.
Rev Sci Instrum ; 88(9): 094503, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28964217

RESUMO

The Visible and near Infrared Hyperspectral Imager (VIHI) is the VIS-IR spectrometer with imaging capabilities aboard the ESA BepiColombo mission to Mercury. In this second paper, we report the instrument spectral characterization derived by the calibration campaign carried out before spacecraft integration. Complementary measurements concerning radiometric and linearity responses, as well as geometric performances, are described in Paper I [G. Filacchione et al., Rev. Sci. Instrum. 88, 094502 (2017)]. We have verified the VIHI spectral range, spectral dispersion, spectral response function, and spectral uniformity along the whole slit. Instrumental defects and optical aberrations due to smiling and keystone effects have been evaluated, and they are lower than the design requirement (<1/3 pixel). The instrumental response is uniform along the whole slit, while spectral dispersion is well represented by a second order curve, rather than to be constant along the spectral dimension.

16.
FEBS Lett ; 307(3): 383-5, 1992 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-1644195

RESUMO

In order to detect the nuclear matrix proteins involved in DNA binding, avoiding possible artifacts derived from the disruption of nuclei, proteins were crosslinked to DNA by the action of cis-diamminedichloroplatinum on intact chicken liver cells and analyzed by two-dimensional gel electrophoresis. At least eleven species of crosslinked proteins were found to derive from the nuclear matrix prepared from the same cell type, and five of these were found also among the proteins crosslinked to DNA in intact liver cells from ox and pig. This subset of common proteins, conserved in different animal species, is likely to have a fundamental role for the anchorage of DNA to the nuclear matrix.


Assuntos
Cisplatino/farmacologia , Reagentes de Ligações Cruzadas/farmacologia , Proteínas de Ligação a DNA/análise , DNA/química , Proteínas Nucleares/análise , Animais , Antígenos Nucleares , Bovinos , Células Cultivadas , Galinhas , DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/efeitos dos fármacos , Eletroforese em Gel Bidimensional , Fígado/citologia , Fígado/metabolismo , Proteínas Nucleares/efeitos dos fármacos , Especificidade da Espécie , Suínos
17.
Ann Thorac Surg ; 66(5): 1852-9, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9875819

RESUMO

Jointly developed by members of the American Society for Artificial Internal Organs and the Society of Thoracic Surgeons along with staff from the Food and Drug Administration, the National Heart, Lung and Blood Institute and other experts, this recommendation describes the reliability considerations and goals for Investigational Device Exemption and Premarket Approval submissions for long-term, mechanical circulatory support systems. The recommendation includes a definition of system failure, a discussion of an appropriate reliability model, a suggested in vitro reliability test plan, reliability considerations for animal implantation tests, in vitro and animal in vivo performance goals, the qualification of design changes during the Investigational Device Exemption clinical trial, the development of a Failure Modes Effects and Criticality Analysis, and the reliability information for surgeons and patient candidates. The document will be periodically reviewed to assess its timeliness and appropriateness within five years.


Assuntos
Coração Auxiliar/normas , Animais , Órgãos Artificiais , Desenho de Equipamento , Falha de Equipamento , Humanos , Seleção de Pacientes , Sociedades Médicas , Cirurgia Torácica , Estados Unidos
18.
Acta Biochim Pol ; 42(2): 145-51, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8588456

RESUMO

To detect the interactions of DNA with the nuclear matrix proteins, DNA-protein cross-linkages were induced in intact nuclei from chicken liver by the use of cis-diammine dichloroplatinum. Methods have been devised for fast purification both of the proteins and of the DNA fragments involved in the cross-linked complexes. By Southern-Western blotting a number of matrix proteins isolated from the complexes have been shown to recognize specifically DNA sequences present in the cross-linked DNA fragments. This experimental approach not only allows to identify the nuclear matrix-DNA interactions existing in the nucleus before its disruption, but also provides a preparation of matrix proteins enriched in those species which are involved in such interactions and which can therefore be detected with high sensitivity.


Assuntos
Núcleo Celular/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Fígado/efeitos dos fármacos , Proteínas Nucleares/metabolismo , Animais , Antígenos Nucleares , Núcleo Celular/metabolismo , Galinhas , Cisplatino , Reagentes de Ligações Cruzadas , Fígado/metabolismo
19.
Biosci Rep ; 6(3): 257-63, 1986 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3730532

RESUMO

Total half-cystine residues in proteins of pig liver chromatin have been measured. About half of them are present in the reduced state. Thiol groups of non-histone chromatin proteins, which amount to about 40 nmol/mg of protein, are preferentially located in chromatin fragments which are more easily solubilised either by DNAse I or by DNAse II. The data obtained are compatible with an involvement of SH and SS groups in chromatin structure and function.


Assuntos
Cromatina/análise , Nucleoproteínas/análise , Aminoácidos/análise , Animais , Proteínas Cromossômicas não Histona/análise , Cistina/análise , Desoxirribonuclease I , Endodesoxirribonucleases , Fígado/análise , Compostos de Sulfidrila/análise , Suínos
20.
ASAIO J ; 44(1): 108-14, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9466510

RESUMO

Jointly developed by members of the American Society for Artificial Internal Organs and the Society of Thoracic Surgeons along with staff from the Food and Drug Administration, the National Heart, Lung and Blood Institute and other experts, this recommendation describes the reliability considerations and goals for Investigational Device Exemption and Premarket Approval submissions for long-term, mechanical circulatory support systems. The recommendation includes a definition of system failure, a discussion of an appropriate reliability model, a suggested in vitro reliability test plan, reliability considerations for animal implantation tests, in vitro and animal in vivo performance goals, the qualification of design changes during the Investigational Device Exemption clinical trial, the development of a Failure Modes Effects and Criticality Analysis, and the reliability information for surgeons and patient candidates. The document will be periodically reviewed to assess its timeliness and appropriateness within five years.


Assuntos
Coração Auxiliar , Cirurgia Torácica , Ensaios Clínicos como Assunto , Aprovação de Equipamentos , Falha de Equipamento , Humanos , National Institutes of Health (U.S.) , Estados Unidos , United States Food and Drug Administration
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