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1.
World J Emerg Surg ; 19(1): 21, 2024 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-38840189

RESUMO

BACKGROUND: The high rate of stoma placement during emergency laparotomy for secondary peritonitis is a paradigm in need of change in the current fast-track surgical setting. Despite growing evidence for the feasibility of primary bowel reconstruction in a peritonitic environment, little data substantiate a surgeons' choice between a stoma and an anastomosis. The aim of this retrospective analysis is to identify pre- and intraoperative parameters that predict the leakage risk for enteric sutures placed during source control surgery (SCS) for secondary peritonitis. METHODS: Between January 2014 and December 2020, 497 patients underwent SCS for secondary peritonitis, of whom 187 received a primary reconstruction of the lower gastro-intestinal tract without a diverting stoma. In 47 (25.1%) patients postoperative leakage of the enteric sutures was directly confirmed during revision surgery or by computed tomography. Quantifiable predictors of intestinal suture outcome were detected by multivariate analysis. RESULTS: Length of intensive care, in-hospital mortality and failure of release to the initial home environment were significantly higher in patients with enteric suture leakage following SCS compared to patients with intact anastomoses (p < 0.0001, p = 0.0026 and p =0.0009, respectively). Reduced serum choline esterase (sCHE) levels and a high extent of peritonitis were identified as independent risk factors for insufficiency of enteric sutures placed during emergency laparotomy. CONCLUSIONS: A preoperative sCHE < 4.5 kU/L and generalized fecal peritonitis associate with a significantly higher incidence of enteric suture insufficiency after primary reconstruction of the lower gastro-intestinal tract in a peritonitic abdomen. These parameters may guide surgeons when choosing the optimal surgical procedure in the emergency setting.


Assuntos
Fezes , Peritonite , Humanos , Feminino , Masculino , Estudos Retrospectivos , Peritonite/cirurgia , Pessoa de Meia-Idade , Idoso , Suturas , Fístula Anastomótica , Complicações Pós-Operatórias , Fatores de Risco , Biomarcadores/sangue , Laparotomia/métodos , Laparotomia/efeitos adversos
2.
Nat Astron ; 8(5): 567-576, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38798715

RESUMO

Jupiter's moon Europa has a predominantly water-ice surface that is modified by exposure to its space environment. Charged particles break molecular bonds in surface ice, thus dissociating the water to ultimately produce H2 and O2, which provides a potential oxygenation mechanism for Europa's subsurface ocean. These species are understood to form Europa's primary atmospheric constituents. Although remote observations provide important global constraints on Europa's atmosphere, the molecular O2 abundance has been inferred from atomic O emissions. Europa's atmospheric composition had never been directly sampled and model-derived oxygen production estimates ranged over several orders of magnitude. Here, we report direct observations of H2+ and O2+ pickup ions from the dissociation of Europa's water-ice surface and confirm these species are primary atmospheric constituents. In contrast to expectations, we find the H2 neutral atmosphere is dominated by a non-thermal, escaping population. We find 12 ± 6 kg s-1 (2.2 ± 1.2 × 1026 s-1) O2 are produced within Europa's surface, less than previously thought, with a narrower range to support habitability in Europa's ocean. This process is found to be Europa's dominant exogenic surface erosion mechanism over meteoroid bombardment.

3.
J Geophys Res Space Phys ; 127(8): e2022JA030334, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36247326

RESUMO

The Juno spacecraft's polar orbits have enabled direct sampling of Jupiter's low-altitude auroral field lines. While various data sets have identified unique features over Jupiter's main aurora, they are yet to be analyzed altogether to determine how they can be reconciled and fit into the bigger picture of Jupiter's auroral generation mechanisms. Jupiter's main aurora has been classified into distinct "zones", based on repeatable signatures found in energetic electron and proton spectra. We combine fields, particles, and plasma wave data sets to analyze Zone-I and Zone-II, which are suggested to carry upward and downward field-aligned currents, respectively. We find Zone-I to have well-defined boundaries across all data sets. H+ and/or H3 + cyclotron waves are commonly observed in Zone-I in the presence of energetic upward H+ beams and downward energetic electron beams. Zone-II, on the other hand, does not have a clear poleward boundary with the polar cap, and its signatures are more sporadic. Large-amplitude solitary waves, which are reminiscent of those ubiquitous in Earth's downward current region, are a key feature of Zone-II. Alfvénic fluctuations are most prominent in the diffuse aurora and are repeatedly found to diminish in Zone-I and Zone-II, likely due to dissipation, at higher altitudes, to energize auroral electrons. Finally, we identify significant electron density depletions, by up to 2 orders of magnitude, in Zone-I, and discuss their important implications for the development of parallel potentials, Alfvénic dissipation, and radio wave generation.

4.
Geophys Res Lett ; 49(9): e2022GL098111, 2022 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-35864892

RESUMO

Water-group gas continuously escapes from Jupiter's icy moons to form co-orbiting populations of particles or neutral toroidal clouds. These clouds provide insights into their source moons as they reveal loss processes and compositions of their parent bodies, alter local plasma composition, and act as sources and sinks for magnetospheric particles. We report the first observations of H2 + pickup ions in Jupiter's magnetosphere from 13 to 18 Jovian radii and find a density ratio of H2 +/H+ = 8 ± 4%, confirming the presence of a neutral H2 toroidal cloud. Pickup ion densities monotonically decrease radially beyond 13 R J consistent with an advecting Europa-genic toroidal cloud source. From these observations, we derive a total H2 neutral loss rate from Europa of 1.2 ± 0.7 kg s-1. This provides the most direct estimate of Europa's H2 neutral loss rate to date and underscores the importance of both ion composition and neutral toroidal clouds in understanding satellite-magnetosphere interactions.

5.
Geophys Res Lett ; 49(9): e2022GL098741, 2022 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-35859815

RESUMO

Two distinct proton populations are observed over Jupiter's southern polar cap: a ∼1 keV core population and ∼1-300 keV dispersive conic population at 6-7 RJ planetocentric distance. We find the 1 keV core protons are likely the seed population for the higher-energy dispersive conics, which are accelerated from a distance of ∼3-5 RJ. Transient wave-particle heating in a "pressure-cooker" process is likely responsible for this proton acceleration. The plasma characteristics and composition during this period show Jupiter's polar-most field lines can be topologically closed, with conjugate magnetic footpoints connected to both hemispheres. Finally, these observations demonstrate energetic protons can be accelerated into Jupiter's magnetotail via wave-particle coupling.

6.
Geophys Res Lett ; 46(1): 19-27, 2019 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-30828110

RESUMO

We compare electron and UV observations mapping to the same location in Jupiter's northern polar region, poleward of the main aurora, during Juno perijove 5. Simultaneous peaks in UV brightness and electron energy flux are identified when observations map to the same location at the same time. The downward energy flux during these simultaneous observations was not sufficient to generate the observed UV brightness; the upward energy flux was. We propose that the primary acceleration region is below Juno's altitude, from which the more intense upward electrons originate. For the complete interval, the UV brightness peaked at ~240 kilorayleigh (kR); the downward and upward energy fluxes peaked at 60 and 700 mW/m2, respectively. Increased downward energy fluxes are associated with increased contributions from tens of keV electrons. These observations provide evidence that bidirectional electron beams with broad energy distributions can produce tens to hundreds of kilorayleigh polar UV emissions.

7.
J Orthop Surg (Hong Kong) ; 27(1): 2309499018820349, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30739571

RESUMO

INTRODUCTION: The long head of the biceps (LHB) is often resected in shoulder surgery. However, its contribution to inflammatory processes in the shoulder remains unclear. In the present study, inflamed and noninflamed human LHBs were comparatively characterized for features of inflammation. MATERIALS AND METHODS: Twenty-two resected LHB tendons were classified into inflamed ( n = 11) and noninflamed ( n = 11) samples. For histological examination, samples were stained with hematoxylin eosin, Azan, van Gieson, and Masson Goldner trichrome. Neuronal tissue was immunohistochemically visualized. In addition, specific inflammatory marker gene expression of primary LHB-derived cell cultures were analyzed. RESULTS: Features of tendinopathy, such as collagen disorganization, infiltration by inflammatory cells, neovascularization, and extensive neuronal innervation were found in the tendinitis group. Compared to noninflamed samples, inflamed LHBs showed a significantly increased inflammatory marker gene expression. CONCLUSION: Structural and biomolecular differences of both groups suggest that the LHB tendon acts as an important pain generator in the shoulder joint. These findings can, on the one hand, contribute to the understanding of the biomolecular genesis of LHB tendinitis and, on the other hand, provide possibilities for new therapeutic approaches.


Assuntos
Articulação do Ombro , Dor de Ombro/etiologia , Dor de Ombro/patologia , Tendinopatia/complicações , Tendinopatia/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Artroscopia , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/patologia , Dor de Ombro/cirurgia , Tendinopatia/cirurgia
8.
Leukemia ; 32(3): 736-743, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29064484

RESUMO

Cell adhesion in the multiple myeloma (MM) microenvironment has been recognized as a major mechanism of MM cell survival and the development of drug resistance. Here we addressed the hypothesis that the protein junctional adhesion molecule-A (JAM-A) may represent a novel target and a clinical biomarker in MM. We evaluated JAM-A expression in MM cell lines and in 147 MM patient bone marrow aspirates and biopsies at different disease stages. Elevated JAM-A levels in patient-derived plasma cells were correlated with poor prognosis. Moreover, circulating soluble JAM-A (sJAM-A) levels were significantly increased in MM patients as compared with controls. Notably, in vitro JAM-A inhibition impaired MM migration, colony formation, chemotaxis, proliferation and viability. In vivo treatment with an anti-JAM-A monoclonal antibody (αJAM-A moAb) impaired tumor progression in a murine xenograft MM model. These results demonstrate that therapeutic targeting of JAM-A has the potential to prevent MM progression, and lead us to propose JAM-A as a biomarker in MM, and sJAM-A as a serum-based marker for clinical stratification.


Assuntos
Biomarcadores Tumorais , Molécula A de Adesão Juncional/sangue , Mieloma Múltiplo/sangue , Mieloma Múltiplo/mortalidade , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Medula Óssea/patologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Feminino , Expressão Gênica , Humanos , Molécula A de Adesão Juncional/genética , Masculino , Camundongos , Terapia de Alvo Molecular , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/patologia , Prognóstico
9.
Science ; 356(6340): 821-825, 2017 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-28546206

RESUMO

On 27 August 2016, the Juno spacecraft acquired science observations of Jupiter, passing less than 5000 kilometers above the equatorial cloud tops. Images of Jupiter's poles show a chaotic scene, unlike Saturn's poles. Microwave sounding reveals weather features at pressures deeper than 100 bars, dominated by an ammonia-rich, narrow low-latitude plume resembling a deeper, wider version of Earth's Hadley cell. Near-infrared mapping reveals the relative humidity within prominent downwelling regions. Juno's measured gravity field differs substantially from the last available estimate and is one order of magnitude more precise. This has implications for the distribution of heavy elements in the interior, including the existence and mass of Jupiter's core. The observed magnetic field exhibits smaller spatial variations than expected, indicative of a rich harmonic content.

10.
Regul Toxicol Pharmacol ; 78: 8-23, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27041393

RESUMO

The present publication describes an integrative grouping concept to derive threshold values for inhalation exposure. The classification scheme starts with differences in toxicological potency and develops criteria to group compounds into two potency classes, namely toxic (T-group) or low toxic (L-group). The TTC concept for inhalation exposure is based on the TTC RepDose data set, consisting of 296 organic compounds with 608 repeated-dose inhalation studies. Initially, 21 structural features (SFs) were identified as being characteristic for compounds of either high or low NOEC values (Schüürmann et al., 2016). In subsequent analyses these SF groups were further refined by taking into account structural homogeneity, type of toxicological effect observed, differences in absorption, metabolism and mechanism of action (MoA), to better define their structural and toxicological boundaries. Differentiation of a local or systemic mode of action did not improve the classification scheme. Finally, 28 groups were discriminated: 19 T-groups and 9 L-groups. Clearly distinct thresholds were derived for the T- and L-toxicity groups, being 2 × 10(-5) ppm (2 µg/person/day) and 0.05 ppm (4260 µg/person/day), respectively. The derived thresholds and the classification are compared to the initial mainly structure driven grouping (Schüürmann et al., 2016) and to the Cramer classification.


Assuntos
Mineração de Dados/métodos , Substâncias Perigosas/toxicidade , Exposição por Inalação/efeitos adversos , Modelos Moleculares , Compostos Orgânicos/toxicidade , Testes de Toxicidade/métodos , Absorção Fisiológica , Animais , Bases de Dados Factuais , Relação Dose-Resposta a Droga , Substâncias Perigosas/química , Substâncias Perigosas/classificação , Substâncias Perigosas/farmacocinética , Humanos , Estrutura Molecular , Nível de Efeito Adverso não Observado , Compostos Orgânicos/química , Compostos Orgânicos/classificação , Compostos Orgânicos/farmacocinética , Reconhecimento Automatizado de Padrão , Medição de Risco , Relação Estrutura-Atividade
11.
Rev Sci Instrum ; 86(5): 054501, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26026539

RESUMO

We have developed a novel concept for a Compact Dual Ion Composition Experiment (CoDICE) that simultaneously provides high quality plasma and energetic ion composition measurements over 6 decades in ion energy in a wide variety of space plasma environments. CoDICE measures the two critical ion populations in space plasmas: (1) mass and ionic charge state composition and 3D velocity and angular distributions of ∼10 eV/q-40 keV/q plasma ions­CoDICE-Lo and (2) mass composition, energy spectra, and angular distributions of ∼30 keV-10 MeV energetic ions­CoDICE-Hi. CoDICE uses a common, integrated Time-of-Flight (TOF) versus residual energy (E) subsystem for measuring the two distinct ion populations. This paper describes the CoDICE design concept, and presents results of the laboratory tests of the TOF portion of the TOF vs. E subsystem, focusing specifically on (1) investigation of spill-over and contamination rates on the start and stop microchannel plate (MCP) anodes vs. secondary electron steering and focusing voltages, scanned around their corresponding model-optimized values, (2) TOF measurements and resolution and angular resolution, and (3) cross-contamination of the start and stop MCPs' singles rates from CoDICE-Lo and -Hi, and (4) energy resolution of avalanche photodiodes near the lower end of the CoDICE-Lo energy range. We also discuss physical effects that could impact the performance of the TOF vs. E subsystem in a flight instrument. Finally, we discuss advantages of the CoDICE design concept by comparing with capabilities and resources of existing flight instruments.

12.
Chemosphere ; 119: 184-189, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24992220

RESUMO

Oxidative coupling reactions take place during the passage of xylenols through a laboratory-scale helophyte-based constructed wetland system. Typical coupling product groups including tetramethyl-[1,1'-biphenyl] diols and tetramethyl diphenylether monools as stable organic intermediates could be identified by a combination of pre-chromatographic derivatization and GC/MS analysis. Structural assignment of individual analytes was performed by an increment system developed by Zenkevich to pre-calculate retention sequences. The most abundant analyte turned out to be 3,3',5,5'-tetramethyl-[1,1'-biphenyl]-4,4'-diol, which can be formed by a combination of radicals based on 2,6-xylenol or by an attack of a 2,6-xylenol-based radical on 2,6-xylenol. Organic intermediates originating from oxidative coupling could also be identified in anaerobic constructed wetland systems. This finding suggested the presence of (at least partly) oxic conditions in the rhizosphere.


Assuntos
Magnoliopsida/metabolismo , Acoplamento Oxidativo , Rizosfera , Áreas Alagadas , Xilenos/química , Xilenos/metabolismo , Biodegradação Ambiental , Cromatografia Gasosa-Espectrometria de Massas
13.
Rev Sci Instrum ; 81(11): 114501, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21133487

RESUMO

Electrostatic analyzers (ESAs), in various forms, are used to measure plasma in a range of applications. In this article, we describe how ions reflect from the interior surfaces of an ESA, the detection of which constitutes a fundamentally nonideal response of ESAs. We demonstrate this effect by comparing laboratory data from a real ESA-based space instrument, the Solar Wind Around Pluto (SWAP) instrument, aboard the NASA New Horizons spacecraft, to results from a model based on quantum mechanical simulations of particles reflected from the instrument's surfaces combined with simulations of particle trajectories through the instrument's applied electrostatic fields. Thus, we show, for the first time, how reflected ions in ESAs lead to nonideal effects that have important implications for understanding the data returned by these instruments, as well as for designing new low-background ESA-based instruments. Specifically, we show that the response of SWAP widens considerably below a level of 10(-3) of the peak response. Thus, a direct measurement of a plasma distribution with SWAP will have an energy-dependent background on the order of ≤10(-3) of the peak of the signal due to that distribution. We predict that this order of magnitude estimate for the background applies to a large number of ESA-based instruments because ESAs operate using a common principle. However, the exact shape of the energy-dependent response will be different for different instruments. The principle of operation is that ions outside the ideal range of energy-per-charge are deflected into the walls of the ESA. Therefore, we propose that a new design paradigm is necessary to mitigate the effect of ion reflections and thus accurately and directly measure the energy spectrum of a plasma using ESAs. In this article, we build a framework for minimizing the effect of ion reflections in the design of new ESAs. Through the use of existing computer simulation software, a design team can use our method to quantify the amount of reflections in their instrument and iteratively change design parameters before fabrication, conserving resources. A possible direction for the new design paradigm is having nonsolid walls of the ESA, already used in some applications.

14.
Rev Sci Instrum ; 79(9): 096107, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19044461

RESUMO

NASA's Interstellar Boundary Explorer (IBEX) mission, scheduled to launch in October 2008, will make the first observations of charge exchange energetic neutral atoms (ENAs) produced near the edge of the heliosphere. IBEX will measure these ENAs with two ultra-high sensitivity, single-pixel ENA sensors in the energy range of approximately 0.01- approximately 2 keV (IBEX-Lo) and approximately 0.3- approximately 6 keV (IBEX-Hi), respectively. The primary purpose of IBEX is to measure hydrogen ENAs from the outer heliosphere, but it will also be sensitive to heavier species of ENAs produced anywhere throughout the solar system. For this study, we measured the coincidence response of the IBEX-Hi detector section to H, He, N, and O ions. Based on these results, we have developed an innovative technique in estimating the hydrogen to heavy ion ratio in the signal. This new technique can be applied more widely than the IBEX-Hi detector section, and the basic principle may be useful for other, future space and ground-based measurements.

15.
Internist (Berl) ; 49(10): 1159-60, 1162, 1164 passim, 2008 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-18810375

RESUMO

Osteoporosis is a multifactorial disease entailing a high risk to sustain fragility fractures. Its susceptibility is determined by genetic and environmental factors and underlying diseases. Bone is rebuilt and regenerated by osteoclasts, osteoblasts and osteocytes. Local and systemic growth and differentiation factors such as Insulin-like growth factors, bone morphogenetic proteins and wnt-proteins confer anabolic signals, while the RANK/RANK-Ligand and Osteoprotegerin (OPG) system regulates bone resorption. The ratio of osteoclast stimulating RANKL and its soluble decoy receptor OPG is modulated by sex hormones, vitamin D, parathyroid hormone, local growth factors and mechanical loading. Osteocytes regulate bone mass via the bone formation inhibitor sclerostin. Bone is tightly interconnected with and regulated by the calcium/phosphate/vitamin D system via the parathyroid gland, the gut, liver and kidneys. Sex hormones are important for bone formation during adolescence and their loss in menopause/andropause exaggerates bone resorption. Basically over-activity of osteoclasts and/or functional deficits of osteoblasts can cause negative bone balance and favor osteoporosis.


Assuntos
Osso e Ossos/metabolismo , Osteomalacia/fisiopatologia , Osteoporose/fisiopatologia , Densidade Óssea/fisiologia , Regeneração Óssea/fisiologia , Cálcio/metabolismo , Comorbidade , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Osteoblastos/fisiologia , Osteoclastos/fisiologia , Osteócitos/fisiologia , Osteomalacia/etiologia , Osteoporose/etiologia , Fatores de Risco , Vitamina D/metabolismo
17.
Science ; 318(5848): 217-20, 2007 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-17932282

RESUMO

Jupiter's magnetotail is the largest cohesive structure in the solar system and marks the loss of vast numbers of heavy ions from the Jupiter system. The New Horizons spacecraft traversed the magnetotail to distances exceeding 2500 jovian radii (R(J)) and revealed a remarkable diversity of plasma populations and structures throughout its length. Ions evolve from a hot plasma disk distribution at approximately 100 R(J) to slower, persistent flows down the tail that become increasingly variable in flux and mean energy. The plasma is highly structured-exhibiting sharp breaks, smooth variations, and apparent plasmoids-and contains ions from both Io and Jupiter's ionosphere with intense bursts of H(+) and H(+)(3). Quasi-periodic changes were seen in flux at approximately 450 and approximately 1500 R(J) with a 10-hour period. Other variations in flow speed at approximately 600 to 1000 R(J) with a 3- to 4-day period may be attributable to plasmoids moving down the tail.


Assuntos
Júpiter , Meio Ambiente Extraterreno , Hidrogênio , Íons , Magnetismo , Prótons , Astronave
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