Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
1.
Pediatr Cardiol ; 45(3): 483-490, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38214737

RESUMO

Congenital heart disease (CHD) is one of the most common congenital birth defects. As surgical and interventional techniques have improved, the mortality has been greatly reduced and the focus has shifted to quality of life and long-term outcomes. The impact of CHD on development and cognition is becoming increasingly recognized. However, more research is needed to understand how children with CHD perform across various cognitive and intellectual domains. This study explored the performance of children with CHD on the newest version of the Wechsler Intelligence Scale for Children compared to normative controls. Children with CHD performed more poorly than normal controls across all indices and most subtests with large effect sizes. Additionally, we explored the patterns of impairment across indices and subtests, as well as the relationships between heard disease variables and WISC-V performance. Block design, Digit Span, and Similarities were the most commonly impaired scores in children with CHD, while Symbol Search, Picture Span, Figure Weights, and Vocabulary were least likely to be impaired.


Assuntos
Cardiopatias Congênitas , Qualidade de Vida , Criança , Humanos , Escalas de Wechsler , Cardiopatias Congênitas/cirurgia
3.
Ann Intern Med ; 175(4): 616, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35436435
4.
5.
JAMA ; 327(7): 688, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-35166798
6.
7.
J Environ Qual ; 44(6): 1923-9, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26641344

RESUMO

The use of ionophores as antiparasitic drugs plays an important role in US poultry production, especially in the broiler () industry. However, administered ionophores can pass through the bird's digestive system and appear in broiler litter, which, when applied to agricultural fields, can present an environmental hazard. Stacking (storing or stockpiling) broiler litter for some time might decrease the litter ionophore concentrations before land application. Because ionophores undergo abiotic hydrolysis at low pH, decreasing litter pH with acidic aluminum sulfate (alum) might also decrease ionophore concentrations. We assessed the change in ionophore concentrations in broiler litter in response to the length of time broiler litter was stored (stacking time) and alum addition. We spiked broiler litter with monensin and salinomycin, placed alum-amended litter (∼pH 4-5) and unamended litter (∼pH 8-9) into 1.8-m bins, and repeatedly sampled each bin for 112 d. Our findings showed that stacking broiler litter alone did not have an impact on monensin concentration, but it did slowly reduce salinomycin concentration by 55%. Adding alum to broiler litter reduced monensin concentration by approximately 20% relative to unamended litter, but it did not change salinomycin concentration. These results call for continued search for alternative strategies that could potentially reduce the concentration of ionophores in broiler litter before their application to agricultural soils.

8.
J Environ Qual ; 44(5): 1657-66, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26436282

RESUMO

Polyether ionophores, monensin, and salinomycin are commonly used as antiparasitic drugs in broiler production and may be present in broiler litter (bird excreta plus bedding material). Long-term application of broiler litter to pastures may lead to ionophore contamination of surface waters. Because polyether ionophores break down at low pH, we hypothesized that decreasing litter pH with an acidic material such as aluminum sulfate (alum) would reduce ionophore losses to runoff (i.e., monensin and salinomycin concentrations, loads, or amounts lost). We quantified ionophore loss to runoff in response to (i) addition of alum to broiler litter and (ii) length of time between litter application and the first simulated rainfall event. The factorial experiment consisted of unamended (∼pH 9) vs. alum-amended litters (∼pH 6), each combined with simulated rainfall at 0, 2, or 4 wk after litter application. Runoff from alum-amended broiler litter had 33% lower monensin concentration ( < 0.01), 57% lower monensin load ( < 0.01), 48% lower salinomycin concentration ( < 0.01), and 66% lower salinomycin load ( < 0.01) than runoff from unamended broiler litter when averaged across all events of rainfall. Ionophore losses to runoff were also less when rainfall was delayed for 2 or 4 wk after litter application relative to applying rainfall immediately after litter application. While the weather is difficult to predict, our data suggest that ionophore losses in runoff can be reduced if broiler litter applications are made to maximize dry time after application.

10.
13.
Geobiology ; 20(2): 310-330, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34676677

RESUMO

Microbial mats floating within multiple hydrothermally sourced streams in El Tatio, Chile, frequently exhibit brittle siliceous crusts (~1 mm thick) above the air-water interface. The partially silicified mats contain a diverse assemblage of microbial clades and metabolisms, including cyanobacteria performing oxygenic photosynthesis. Surficial crusts are composed of several amorphous silica layers containing well-preserved filaments (most likely cyanobacteria) and other cellular textures overlying EPS-rich unsilicified mats. Environmental logs, silica crust distribution, and microbial preservation patterns provide evidence for crust formation via repeated cycles of evaporation and silica precipitation. Within the mats, in situ microelectrode profiling reveals that daytime oxygen concentrations and pH values are diminished beneath silica crusts compared with adjacent unencrusted communities, indicating localized inhibition of oxygenic photosynthesis due to light attenuation. As a result, aqueous conditions under encrusted mats have a higher saturation state with regard to amorphous silica compared with adjacent, more active mats where high pH increases silica solubility, likely forming a modest feedback loop between diminished photosynthesis and crust precipitation. However, no fully lithified sinters are associated with floating encrusted mats in El Tatio streams, as both subaqueous and subaerial silica precipitation are limited by undersaturated, low-SiO2 (<150 ppm) stream waters. By contrast, well-cemented sinters can form by evaporation in silica-undersaturated solutions above 200 ppm SiO2 . Floating mats in El Tatio therefore represent a specific sinter preservation window, where evaporation in silica-undersaturated microbial mats produces crusts, which preserve cells and affect mat chemistry, but low-silica concentrations prevent the formation of lasting sinter deposits. Patterns of silica precipitation in El Tatio microbial communities show that the preservation potential of silicifying mats in the rock record is strongly dependent on aqueous silica concentrations.


Assuntos
Cianobactérias , Dióxido de Silício , Chile , Oxigênio , Rios
14.
Geobiology ; 20(1): 137-155, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34590770

RESUMO

In silica-rich hot spring environments, internally laminated, digitate sinter deposits are often interpreted as bio-mediated structures. The organic components of microbial communities (cell surfaces, sheaths and extracellular polymeric substances) can act as templates for silica precipitation, therefore influencing digitate sinter morphogenesis. In addition to biologic surface-templating effects, various microenvironmental factors (hydrodynamics, local pH and fluctuating wind patterns) can also influence silica precipitation, and therefore the morphology of resulting digitate sinters. Digitate sinter morphology thus depends on the dynamic interplay between microenvironmentally driven silica precipitation and microbial growth, but the relative contributions of both factors are a topic of continuing research. Here we present a detailed study of digitate silica sinters in distal, low-temperature regimes of the El Tatio geothermal field, Chile. This high-altitude geothermal field is extremely arid and windy, and has one of the highest silica precipitation rates found in the world. We find that digitate silica sinters at El Tatio always accrete into the prevailing eastward wind direction and exhibit laminar growth patterns coinciding with day-night cycles of wind- and thermally driven evaporation and rewetting. Subaerial parts of digitate sinters lack preserved organics and sinter textures that would indicate past microbial colonization, while filamentous cyanobacteria with resistant, silicified sheaths only inhabit subaqueous cavities that crosscut the primary laminations. We conclude that, although fragile biofilms of extremophile micro-organisms may have initially been present and templated silica precipitation at the tips of these digitate sinters, the saltation of sand grains and precipitation of silica by recurrent wind- and thermally driven environmental forcing at El Tatio are important, if not dominant factors shaping the morphology of these digitate structures. Our study sheds light on the relative contributions of biogenic and abiogenic factors in sinter formation in geothermal systems, with geobiological implications for the cautious interpretation of stromatolite-like features in ancient silica deposits on Earth and Mars.


Assuntos
Cianobactérias , Fontes Termais , Chile , Fontes Termais/microbiologia , Morfogênese , Dióxido de Silício/química
15.
Proc Natl Acad Sci U S A ; 105(30): 10571-6, 2008 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-18653761

RESUMO

Membrane penetration by reovirus is associated with conversion of a metastable intermediate, the ISVP, to a further-disassembled particle, the ISVP*. Factors that promote this conversion in cells are poorly understood. Here, we report the in vitro characterization of a positive-feedback mechanism for promoting ISVP* conversion. At high particle concentration, conversion approximated second-order kinetics, and products of the reaction operated in trans to promote the conversion of target ISVPs. Pore-forming peptide mu1N, which is released from particles during conversion, was sufficient for promoting activity. A mutant that does not undergo mu1N release failed to exhibit second-order conversion kinetics and also failed to promote conversion of wild-type target ISVPs. Susceptibility of target ISVPs to promotion in trans was temperature dependent and correlated with target stability, suggesting that capsid dynamics are required to expose the interacting epitope. A positive-feedback mechanism of promoting escape from the metastable intermediate has not been reported for other viruses but represents a generalizable device for sensing a confined volume, such as that encountered during cell entry.


Assuntos
Membrana Celular/metabolismo , Retroalimentação Fisiológica , Reoviridae/genética , Animais , Capsídeo/química , Bovinos , Linhagem Celular , Epitopos , Eritrócitos/metabolismo , Hemólise , Insetos , Cinética , Camundongos , Modelos Biológicos , Temperatura
16.
Astrobiology ; 20(4): 500-524, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31663774

RESUMO

Palisade fabric is a ubiquitous texture of silica sinter found in low temperature (<40°C) regimes of hot spring environments, and it is formed when populations of filamentous microorganisms act as templates for silica polymerization. Although it is known that postdepositional processes such as biological degradation and dewatering can strongly affect preservation of these fabrics, the impact of extreme aridity has so far not been studied in detail. Here, we report a detailed analysis of recently silicified palisade fabrics from a geyser in El Tatio, Chile, tracing the progressive degradation of microorganisms within the silica matrix. This is complemented by heating experiments of natural sinter samples to assess the role of diagenesis. Sheathed cyanobacteria, identified as Leptolyngbya sp., were found to be incorporated into silica sinter by irregular cycles of wetting, evaporation, and mineral precipitation. Transmission electron microscopy analyses revealed that nanometer-sized silica particles are filling the pore space within individual cyanobacterial sheaths, giving rise to their structural rigidity to sustain a palisade fabric framework. Diagenesis experiments further show that the sheaths of the filaments are preferentially preserved relative to the trichomes, and that the amount of water present within the sinter is an important factor for overall preservation during burial. This study confirms that palisade fabrics are efficiently generated in a highly evaporative geothermal field, and that these biosignatures can be most effectively preserved under dry diagenetic conditions.


Assuntos
Cianobactérias/ultraestrutura , Sedimentos Geológicos/química , Fontes Termais , Dióxido de Silício/análise , Carbono/análise , Chile , Sedimentos Geológicos/microbiologia , Microscopia Confocal , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Nitrogênio/análise , RNA Ribossômico 16S/análise , Análise de Sequência de DNA , Água
17.
Biol Reprod ; 81(2): 343-52, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19420386

RESUMO

Two isoforms of phosphoprotein phosphatase 1, PPP1CC1 and PPP1CC2, are translated from alternatively spliced transcripts of a single gene, Ppp1cc, and differ only at their extreme C-termini. While PPP1CC1 expression is almost ubiquitous, PPP1CC2 is largely restricted to testicular germ cells and mature spermatozoa. Targeted deletion of Ppp1cc leads to sterility of -/- males due to a combination of gross structural defects in developing spermatids resulting in apoptosis and faulty spermiation. Because PPP1CC2 is the only PP1 isoform that demonstrates high-level expression in wild-type meiotic and postmeiotic male germ cells, we have tested whether its loss in Ppp1cc-/- males is largely responsible for manifestation of this phenotype by expressing PPP1CC2 transgenically in the testis of Ppp1cc-/- mice (rescue mice). Herein, we demonstrate that PPP1CC2 expression in the Ppp1cc-/- testis is antiapoptotic, thus reestablishing spermatid development and spermiation. However, because aberrant flagellar morphogenesis is incompletely ameliorated, rescue males remain infertile. Because these results suggest that expression of PPP1CC2 in developing germ cells is essential but insufficient for normal spermatogenesis to occur, appropriate spatial and temporal expression of both PPP1CC isoforms in the testis during spermatogenesis appears to be necessary to produce structurally normal fertility-competent spermatozoa.


Assuntos
Fertilidade/genética , Proteína Fosfatase 1/genética , Espermatogênese/genética , Espermatozoides/fisiologia , Testículo/metabolismo , Animais , Apoptose/genética , Sobrevivência Celular , Implantação do Embrião , Epididimo/ultraestrutura , Feminino , Expressão Gênica , Masculino , Camundongos , Camundongos Transgênicos , Especificidade de Órgãos , Regiões Promotoras Genéticas/genética , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteína Fosfatase 1/metabolismo , RNA Mensageiro/metabolismo , Ratos , Cabeça do Espermatozoide/ultraestrutura , Motilidade dos Espermatozoides/genética , Cauda do Espermatozoide/metabolismo , Cauda do Espermatozoide/ultraestrutura , Espermátides/fisiologia , Testículo/ultraestrutura , Transgenes
19.
MedEdPublish (2016) ; 8: 199, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-38089354

RESUMO

This article was migrated. The article was marked as recommended. In 2018, anonymous online provocative comments were submitted to student leaders of a Syrian Refugee Initiative (SRI) at the Penn State College of Medicine. This triggered a series of actions with students and medical school leaders aimed at identifying the person who submitted the comments, trying to understand mutual perspectives, and managing the impact of the event on the student body. We describe the history of our college's commitment to humanism and how the SRI was a direct outgrowth of that culture. Voices of the student leaders who were directly impacted by the provocative comments and educational leaders who worked to resolve the crisis are presented. We also describe a collaborative process that involved engaging cybersecurity experts to identify the perpetrator, and share how the students and educational leaders were able to develop trust despite initial skepticism by students over the leadership's avowed commitment to taking the hate speech seriously. While the perpetrator was never identified and opportunities for improvement were identified along the way, by including student leaders in the process, students and administrators were able to develop trust and reach reasonable closure on this disturbing event. Take home messages are presented to guide other institutions in navigating instances of provocative comments or speech.

20.
Perm J ; 242019.
Artigo em Inglês | MEDLINE | ID: mdl-31710837

RESUMO

CONTEXT: Parkinson disease (PD) can be physically, emotionally, and financially burdensome. Understanding its impact from the patient's perspective is an important way to sensitize clinicians to the challenges of living with PD. OBJECTIVE: To evaluate whether a book-length graphic memoir (an illness story in comic form) can help clinicians appreciate PD from the patient's perspective. DESIGN: A convergent mixed-methods study of clinicians working in a multidisciplinary movement disorders clinic. Participants read My Degeneration and completed preintervention and post-intervention questionnaires. They also attended a book group discussion. Quantitative findings were compared before and after the intervention, and qualitative data were analyzed for themes. MAIN OUTCOME MEASURES: Clinicians': 1) confidence in understanding patients' experiences with PD, 2) knowledge about PD, and 3) empathy toward patients and families. RESULTS: After reading the book, participants' confidence in understanding patients' experiences with PD increased significantly in the areas of stigma and disease impact on patients and families. Clinical knowledge was unchanged. Qualitative analysis revealed 3 main themes: 1) the book provides a meaningful way for clinicians to learn about the experience of living with PD; 2) the medium of comics engages clinicians in ways different from other mediums; and 3) benefits of the book may extend beyond the clinical team. CONCLUSION: Clinicians who read My Degeneration gained insight into the psychosocial effects of PD on patients and their loved ones. The book helped facilitate deeper understanding of patients' experiences living with PD and fostered greater empathy and self-reflection.


Assuntos
Livros , Empatia , Conhecimentos, Atitudes e Prática em Saúde , Doença de Parkinson/psicologia , Adulto , Atitude do Pessoal de Saúde , Competência Clínica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Autoeficácia , Centros de Atenção Terciária
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa