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1.
Sci Rep ; 11(1): 7438, 2021 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-33811229

RESUMO

Impact ejecta formation and emplacement is of great importance when it comes to understanding the process of impact cratering and consequences of impact events in general. Here we present a multidisciplinary investigation of a distal impact ejecta layer, the Blockhorizont, that occurs near Bernhardzell in eastern Switzerland. We provide unambiguous evidence that this layer is impact-related by confirming the presence of shocked quartz grains exhibiting multiple sets of planar deformation features. Average shock pressures recorded by the quartz grains are ~ 19 GPa for the investigated sample. U-Pb dating of zircon grains from bentonites in close stratigraphic context allows us to constrain the depositional age of the Blockhorizont to ~ 14.8 Ma. This age, in combination with geochemical and paleontological analysis of ejecta particles, is consistent with deposition of this material as distal impact ejecta from the Ries impact structure, located ~ 180 km away, in Germany. Our observations are important for constraining models of impact ejecta emplacement as ballistically and non-ballistically transported fragments, derived from vastly different depths in the pre-impact target, occur together within the ejecta layer. These observations make the Ries ejecta one of the most completely preserved ejecta deposit on Earth for an impact structure of that size.

2.
Br J Anaesth ; 119(6): 1194-1205, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29045567

RESUMO

Background: General anaesthesia leads to atelectasis, reduced end-expiratory lung volume (EELV), and diminished arterial oxygenation in obese patients. We hypothesized that a combination of a recruitment manoeuvre (RM) and individualized positive end-expiratory pressure (PEEP) can avoid these effects. Methods: Patients with a BMI ≥35 kg m -2 undergoing elective laparoscopic surgery were randomly allocated to mechanical ventilation with a tidal volume of 8 ml kg -1 predicted body weight and (i) an RM followed by individualized PEEP titrated using electrical impedance tomography (PEEP IND ) or (ii) no RM and PEEP of 5 cm H 2 O (PEEP 5 ). Gas exchange, regional ventilation distribution, and EELV (multiple breath nitrogen washout method) were determined before, during, and after anaesthesia. The primary end point was the ratio of arterial partial pressure of oxygen to inspiratory oxygen fraction ( P aO 2 / F iO 2 ). Results: For PEEP IND ( n =25) and PEEP 5 ( n =25) arms together, P aO 2 / F iO 2 and EELV decreased by 15 kPa [95% confidence interval (CI) 11-20 kPa, P <0.001] and 1.2 litres (95% CI 0.9-1.6 litres, P <0.001), respectively, after intubation. Mean ( sd ) PEEP IND was 18.5 (5.6) cm H 2 O. In the PEEP IND arm, P aO 2 / F iO 2 before extubation was 23 kPa higher (95% CI 16-29 kPa; P <0.001), EELV was 1.8 litres larger (95% CI 1.5-2.2 litres; P <0.001), driving pressure was 6.7 cm H 2 O lower (95% CI 5.4-7.9 cm H 2 O; P <0.001), and regional ventilation was more equally distributed than for PEEP 5 . After extubation, however, these differences between the arms vanished. Conclusions: In obese patients, an RM and higher PEEP IND restored EELV, regional ventilation distribution, and oxygenation during anaesthesia, but these differences did not persist after extubation. Therefore, lung protection strategies should include the postoperative period. Clinical trial registration: German clinical trials register DRKS00004199, www.who.int/ictrp/network/drks2/en/ .


Assuntos
Anestesia Geral , Impedância Elétrica/uso terapêutico , Obesidade/complicações , Obesidade/cirurgia , Respiração com Pressão Positiva/métodos , Atelectasia Pulmonar/prevenção & controle , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medicina de Precisão/métodos , Tomografia , Resultado do Tratamento , Adulto Jovem
3.
Astrobiology ; 17(6-7): 595-611, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28731819

RESUMO

The Close-Up Imager (CLUPI) onboard the ESA ExoMars Rover is a powerful high-resolution color camera specifically designed for close-up observations. Its accommodation on the movable drill allows multiple positioning. The science objectives of the instrument are geological characterization of rocks in terms of texture, structure, and color and the search for potential morphological biosignatures. We present the CLUPI science objectives, performance, and technical description, followed by a description of the instrument's planned operations strategy during the mission on Mars. CLUPI will contribute to the rover mission by surveying the geological environment, acquiring close-up images of outcrops, observing the drilling area, inspecting the top portion of the drill borehole (and deposited fines), monitoring drilling operations, and imaging samples collected by the drill. A status of the current development and planned science validation activities is also given. Key Words: Mars-Biosignatures-Planetary Instrumentation. Astrobiology 17, 595-611.

4.
Actas Fund. Puigvert ; 34(3/4): 114-120, oct.-dic. 2015. ilus
Artigo em Espanhol | IBECS | ID: ibc-154653

RESUMO

El tratamiento de elección para el carcinoma urotelial del tramo urinario superior (CU-TUS) de alto grado, musculoinvasivo o de amplia extensión es la nefroureterectomía (NFU). La exé- resis del tramo distal del uréter ha pasado por diversas opciones siendo finalmente la desinserción ureteral y rodete vesical la que ofrece mejores resultados. En caso de no realizarse dicha desinserción, el remanente ureteral presenta un riesgo de recurrencia (o recidiva) tumoral de hasta del 45%, siendo el seguimiento oncológico más dificultoso. Se presenta el caso clínico de un paciente con antecedente de NFU por CU-TUS en el que se quedó un remanente ureteral que presentó recurrencia tumoral (AU)


The gold standard treatment for upper urinary tract urothelial carcinoma is nephroureterectomy (NFU) plus uretherectomy with bladder cuff. If such detachment is not made, risk of recurrence up to 45% in the uretheral remaining is feasible, being oncological follow-up more difficult. We present a case report of a patient with history of NFU by CU- TUS with tumor recurrence in the residual urether (AU)


Assuntos
Humanos , Masculino , Adulto , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/metabolismo , Sistema Urinário/anormalidades , Sistema Urinário/metabolismo , Carcinoma de Células de Transição/complicações , Carcinoma de Células de Transição/patologia , Isquemia Miocárdica/patologia , Recidiva Local de Neoplasia/complicações , Recidiva Local de Neoplasia/patologia , Sistema Urinário/lesões , Sistema Urinário/patologia , Carcinoma de Células de Transição/metabolismo , Carcinoma de Células de Transição/fisiopatologia , Isquemia Miocárdica/metabolismo
5.
Astrobiology ; 15(8): 637-68, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26247371

RESUMO

A variety of actively precipitating mineral environments preserve morphological evidence of microbial biosignatures. One such environment with preserved microbial biosignatures is the oxidized portion of a massive sulfide deposit, or gossan, such as that at Iron Mountain, California. This gossan may serve as a mineralogical analogue to some ancient martian environments due to the presence of oxidized iron and sulfate species, and minerals that only form in acidic aqueous conditions, in both environments. Evaluating the potential biogenicity of cryptic textures in such martian gossans requires an understanding of how microbial textures form biosignatures on Earth. The iron-oxide-dominated composition and morphology of terrestrial, nonbranching filamentous microbial biosignatures may be distinctive of the underlying formation and preservation processes. The Iron Mountain gossan consists primarily of ferric oxide (hematite), hydrous ferric oxide (HFO, predominantly goethite), and jarosite group minerals, categorized into in situ gossan, and remobilized iron deposits. We interpret HFO filaments, found in both gossan types, as HFO-mineralized microbial filaments based in part on (1) the presence of preserved central filament lumina in smooth HFO mineral filaments that are likely molds of microbial filaments, (2) mineral filament formation in actively precipitating iron-oxide environments, (3) high degrees of mineral filament bending consistent with a flexible microbial filament template, and (4) the presence of bare microbial filaments on gossan rocks. Individual HFO filaments are below the resolution of the Mars Curiosity and Mars 2020 rover cameras, but sinuous filaments forming macroscopic matlike textures are resolvable. If present on Mars, available cameras may resolve these features identified as similar to terrestrial HFO filaments and allow subsequent evaluation for their biogenicity by synthesizing geochemical, mineralogical, and morphological analyses. Sinuous biogenic filaments could be preserved on Mars in an iron-rich environment analogous to Iron Mountain, with the Pahrump Hills region and Hematite Ridge in Gale Crater as tentative possibilities.


Assuntos
Compostos Férricos/análise , Fósseis , Sedimentos Geológicos/química , California , Exobiologia , Meio Ambiente Extraterreno/química , Ferro/análise , Compostos de Ferro/análise , Marte , Fenômenos Microbiológicos , Microscopia Eletrônica de Varredura , Fibras Minerais/análise , Minerais/análise , Quartzo/análise , Sulfetos/análise
6.
Physiol Meas ; 32(9): 1389-401, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21775796

RESUMO

The capability of respiratory sinus arrhythmia (RSA) to generate privileged locations for the occurrence of R-peaks within the respiratory cycle has been questioned in recent works, challenging the hypothesis that RSA might play a role in improving pulmonary gas exchange. We assessed such a capability submitting healthy humans to spontaneous and paced breathing (SB and PB) protocols, estimating the fraction of beats occurring during inspiration, at low, medium, and high respiratory volumes, and during the first and second half of inspiration and expiration. Then, the same fractions were computed assuming a random uniform distribution of heartbeats, and the differences were compared. The results found are as follows: (1) during PB at 6 rpm, heartbeats redistribute toward inspiration; (2) during SB and PB at 12 rpm, heartbeats tend to cluster when respiratory volume is high; (3) since such redistributions are limited in magnitude, it is possible that its physiological relevance is marginal, for instance, in terms of within-cycle variations in lung perfusion; (4) two groups of subjects with considerably different levels of RSA showed similar redistribution of heartbeats, suggesting that this phenomenon might be an underlying effect of the overall cardio-respiratory interactions, and not directly of RSA.


Assuntos
Frequência Cardíaca/fisiologia , Coração/fisiologia , Mecânica Respiratória/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
7.
Chimia (Aarau) ; 64(10): 736-40, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21138163

RESUMO

Meteorites are fragments from solar system bodies, dominantly asteroids. A small fraction is derived from the Moon and from Mars. These rocks tell a rich history of the early solar system and range from solids little changed since the earliest phases of solid matter condensation in the solar nebula (chondrites) to material representing asteroidal metamorphism and melting, impact processes on the Moon and even aqueous alteration near the surface of Mars. Meteorites are very rare. Currently many meteorites result from searches in Antarctica and the hot deserts of North Africa and Arabia. The present high find rate likely represents a unique short-term event, asking for a careful management of this scarce scientific resource.

8.
Intensive Care Med ; 36(11): 1836-44, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20689909

RESUMO

PURPOSE: Clinical applications of quantitative computed tomography (qCT) in patients with pulmonary opacifications are hindered by the radiation exposure and by the arduous manual image processing. We hypothesized that extrapolation from only ten thoracic CT sections will provide reliable information on the aeration of the entire lung. METHODS: CTs of 72 patients with normal and 85 patients with opacified lungs were studied retrospectively. Volumes and masses of the lung and its differently aerated compartments were obtained from all CT sections. Then only the most cranial and caudal sections and a further eight evenly spaced sections between them were selected. The results from these ten sections were extrapolated to the entire lung. The agreement between both methods was assessed with Bland-Altman plots. RESULTS: Median (range) total lung volume and mass were 3,738 (1,311-6,768) ml and 957 (545-3,019) g, the corresponding bias (limits of agreement) were 26 (-42 to 95) ml and 8 (-21 to 38) g, respectively. The median volumes (range) of differently aerated compartments (percentage of total lung volume) were 1 (0-54)% for the nonaerated, 5 (1-44)% for the poorly aerated, 85 (28-98)% for the normally aerated, and 4 (0-48)% for the hyperaerated subvolume. The agreement between the extrapolated results and those from all CT sections was excellent. All bias values were below 1% of the total lung volume or mass, the limits of agreement never exceeded ± 2%. CONCLUSION: The extrapolation method can reduce radiation exposure and shorten the time required for qCT analysis of lung aeration.


Assuntos
Processamento de Imagem Assistida por Computador , Pneumopatias/diagnóstico por imagem , Medidas de Volume Pulmonar/métodos , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Pneumopatias/fisiopatologia , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Adulto Jovem
9.
Physiol Meas ; 30(11): 1151-62, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19779224

RESUMO

Respiratory sinus arrhythmia (RSA) is a fluctuation of heart period that occurs during a respiratory cycle. It has been suggested that inspiratory heart period acceleration and expiratory deceleration during spontaneous ventilation (henceforth named positive RSA) improve the efficiency of gas exchange compared to the absence or the inversion of such a pattern (negative RSA). During mechanical ventilation (MV), for which maximizing the efficiency of gas exchange is of critical importance, the pattern of RSA is still the object of debate. In order to gain a better insight into this matter, we compared five different methods of RSA classification using the data of five mechanically ventilated piglets. The comparison was repeated using the data of 15 volunteers undergoing a protocol of paced spontaneous breathing, which is expected to result in a positive RSA pattern. The results showed that the agreement between the employed methods is limited, suggesting that the lack of a consensus about the RSA pattern during MV is, at least in part, of methodological origin. However, independently of the method used, the pattern of RSA within the respiratory cycle was not consistent among the subjects and conditions of MV considered. Also, the outcomes showed that even during paced spontaneous breathing a negative RSA pattern might be present, when a low respiratory frequency is imposed.


Assuntos
Arritmia Sinusal/classificação , Arritmia Sinusal/terapia , Respiração Artificial/métodos , Respiração , Mecânica Respiratória/fisiologia , Adulto , Animais , Animais Recém-Nascidos , Arritmia Sinusal/fisiopatologia , Feminino , Humanos , Masculino , Testes de Função Respiratória/métodos , Testes de Função Respiratória/normas , Suínos , Adulto Jovem
10.
Astrobiology ; 8(3): 583-95, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18680409

RESUMO

The Urey organic and oxidant detector consists of a suite of instruments designed to search for several classes of organic molecules in the martian regolith and ascertain whether these compounds were produced by biotic or abiotic processes using chirality measurements. These experiments will also determine the chemical stability of organic molecules within the host regolith based on the presence and chemical reactivity of surface and atmospheric oxidants. Urey has been selected for the Pasteur payload on the European Space Agency's (ESA's) upcoming 2013 ExoMars rover mission. The diverse and effective capabilities of Urey make it an integral part of the payload and will help to achieve a large portion of the mission's primary scientific objective: "to search for signs of past and present life on Mars." This instrument is named in honor of Harold Urey for his seminal contributions to the fields of cosmochemistry and the origin of life.


Assuntos
Meio Ambiente Extraterreno/química , Marte , Compostos Orgânicos/análise , Oxidantes/análise , Voo Espacial/instrumentação , Aminoácidos/química , Eletroforese Capilar , Fluorescamina/química , Procedimentos Analíticos em Microchip , Estereoisomerismo
11.
Astrobiology ; 8(1): 87-117, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18241094

RESUMO

The fossil record of the subsurface biosphere is sparse. Results obtained on subsurface filamentous fabrics (SFF) from >225 paleosubsurface sites in volcanics, oxidized ores, and paleokarst of subrecent to Proterozoic age are presented. SFF are mineral encrustations on filamentous or fibrous substrates that formed in subsurface environments. SFF occur in association with low-temperature aqueous mineral assemblages and consist of tubular, micron-thick (median 1.6 micron) filaments in high spatial density, which occur as irregular masses, matted fabrics, and vertically draped features that resemble stalactites. Micron-sized filamentous centers rule out a stalactitic origin. Morphometric analysis of SFF filamentous forms demonstrates that their shape more closely resembles microbial filaments than fibrous minerals. Abiogenic filament-like forms are considered unlikely precursors of most SFF, because abiogenic forms differ in the distribution of widths and have a lower degree of curvature and a lower number of direction changes. Elemental analyses of SFF show depletion in immobile elements (e.g., Al, Th) and a systematic enrichment in As and Sb, which demonstrates a relation to environments with high flows of water. Sulfur isotopic analyses are consistent with a biological origin of a SFF sample from a Mississippi Valley-Type deposit, which is consistent with data in the literature. Fe isotopes in SFF and active analogue systems, however, allow no discrimination between biogenic and abiogenic origins. The origin of most SFF is explained as permineralized remains of microbial filaments that possibly record rapid growth during phases of high water flow that released chemical energy. It is possible that some SFF formed due to encrustation of mineral fibers. SFF share similarities with Microcodium from soil environments. SFF are a logical target in the search for past life on Mars. The macroscopic nature of many SFF allows for their relatively easy in situ recognition and targeting for more detailed microstructural and geochemical analysis.


Assuntos
Fósseis , Sedimentos Geológicos/microbiologia , Marte , Exobiologia , Gallionellaceae/isolamento & purificação , Sedimentos Geológicos/química , Isótopos de Ferro/análise , Microscopia Eletrônica de Varredura , Minerais/análise , Isótopos de Enxofre/análise
12.
Astrobiology ; 8(1): 119-56, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18211229

RESUMO

We have investigated how morphological biosignatures (i.e., features related to life) might be identified with an array of viable instruments within the framework of robotic planetary surface operations at Mars. This is the first time such an integrated lab-based study has been conducted that incorporates space-qualified instrumentation designed for combined in situ imaging, analysis, and geotechnics (sampling). Specimens were selected on the basis of feature morphology, scale, and analogy to Mars rocks. Two types of morphological criteria were considered: potential signatures of extinct life (fossilized microbial filaments) and of extant life (crypto-chasmoendolithic microorganisms). The materials originated from a variety of topical martian analogue localities on Earth, including impact craters, high-latitude deserts, and hydrothermal deposits. Our in situ payload included a stereo camera, microscope, Mössbauer spectrometer, and sampling device (all space-qualified units from Beagle 2), and an array of commercial instruments, including a multi-spectral imager, an X-ray spectrometer (calibrated to the Beagle 2 instrument), a micro-Raman spectrometer, and a bespoke (custom-designed) X-ray diffractometer. All experiments were conducted within the engineering constraints of in situ operations to generate realistic data and address the practical challenges of measurement. Our results demonstrate the importance of an integrated approach for this type of work. Each technique made a proportionate contribution to the overall effectiveness of our "pseudopayload" for biogenic assessment of samples yet highlighted a number of limitations of current space instrument technology for in situ astrobiology.


Assuntos
Exobiologia/instrumentação , Sedimentos Geológicos/microbiologia , Marte , América , Regiões Antárticas , Carbonato de Cálcio/química , Sulfato de Cálcio/química , Sedimentos Geológicos/química , Alemanha , Compostos de Ferro/química , Minerais , Origem da Vida
13.
J. venom. anim. toxins incl. trop. dis ; 14(1): 161-165, 2008. ilus
Artigo em Inglês | LILACS | ID: lil-479347

RESUMO

Phalotris matogrossensis (Serpentes, Colubridae) was reported as a new host for Haplometroides intercaecalis (Digenea, Plagiorchiidae). The host snake was obtained from the municipality of Anastácio, state of Mato Grosso do Sul, Brazil. One specimen of H. intercaecalis was recovered from the esophagus of the host and identified by the intercecal position of the vitellaria in the pre-acetabular region. This paper describes the second report of the occurrence of this trematode in fossorial snakes of the genus Phalotris in the state of Mato Grosso do Sul, Brazil.


Assuntos
Animais , Colubridae/parasitologia , Serpentes/parasitologia , Trematódeos
14.
Science ; 305(5684): 657-9, 2004 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-15286369

RESUMO

The lunar meteorite Sayh al Uhaymir 169 consists of an impact melt breccia extremely enriched with potassium, rare earth elements, and phosphorus [thorium, 32.7 parts per million (ppm); uranium, 8.6 ppm; potassium oxide, 0.54 weight percent], and adherent regolith. The isotope systematics of the meteorite record four lunar impact events at 3909 +/- 13 million years ago (Ma), approximately 2800 Ma, approximately 200 Ma, and <0.34 Ma, and collision with Earth sometime after 9.7 +/- 1.3 thousand years ago. With these data, we can link the impact-melt breccia to Imbrium and pinpoint the source region of the meteorite to the Lalande impact crater.


Assuntos
Evolução Planetária , Meteoroides , Lua , Cristalização , Elementos Químicos , Isótopos , Chumbo , Metais Terras Raras/análise , Fósforo/análise , Potássio/análise , Tório/análise , Urânio/análise
15.
Klin Lab Diagn ; (2): 29-30, 1996.
Artigo em Russo | MEDLINE | ID: mdl-8680765

RESUMO

Immunochemical testing of salivary samples of 73 patients revealed a positive correlation between increased level of lactoferrin and the presence of chronic pancreatoduodenal diseases (gastroduodenitis, gastroduodenal ulcers, polyps of the antral portion of the stomach, cholecystitis, cholangitis, cholelithiasis, hepatitis, and pancreatitis, correlation coefficient 0.9). The test is proposed as a cheap and informative method for screening of the above diseases.


Assuntos
Doenças Biliares/diagnóstico , Gastroenteropatias/diagnóstico , Lactoferrina/análise , Pancreatopatias/diagnóstico , Saliva/química , Adulto , Feminino , Humanos , Imunodifusão , Masculino , Pessoa de Meia-Idade
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