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1.
J Dairy Sci ; 106(2): 1002-1012, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36543642

RESUMO

The objective of this study was to determine the effects of including exogenous amylolytic or fibrolytic enzymes in a diet for high-producing dairy cows on in vitro ruminal fermentation. Eight dual-flow continuous-culture fermentors were used in a replicated 4 × 4 Latin square. The treatments were control (CON), a xylanase and glucanase mixture (T1), an α-amylase mixture (T2), or a xylanase, glucanase, and α-amylase mixture (T3). Treatments were included at a rate of 0.008% of diet dry matter (DM) for T1 and T2 and at 0.02% for T3. All treatments replaced the equivalent amount of soybean meal in the diet compared with CON. All diets were balanced to have the same nutrient composition [30.2% neutral detergent fiber (NDF), 16.1% crude protein (CP), and 30% starch; DM basis], and fermentors were fed 106 g/d divided into 2 feedings. At each feeding, T2 was pipetted into the respective fermentor and an equivalent amount of deionized water was added to each fermentor to eliminate potential variation. Experimental periods were 10 d (7 d for adaptation and 3 d for sample collection). Composite samples of daily effluent were collected and analyzed for volatile fatty acids (VFA), NH3-N, and lactate concentrations, degradability of DM, organic matter, NDF, CP, and starch, and flow and metabolism of N. Samples of fermentor contents were collected from each fermentor at 0, 1, 2, 4, 6, and 8 h after feeding to determine kinetics of pH, NH3-N, lactate, and VFA concentrations over time. All data were analyzed using PROC GLIMMIX of SAS (SAS Institute Inc.), and the repeated variable of time was included for kinetics measurements. Treatment did not affect mean pH, degradability, N flow and metabolism, or the concentrations of VFA, NH3-N, or lactate in the effluent samples. Treatment did not affect pH, acetate:propionate ratio, or the concentrations of lactate, NH3-N, total VFA, acetate, propionate, butyrate, isobutyrate, valerate, or caproate. However, the concentration of total VFA tended to change at each time point depending upon the treatment, and T2 tended to have a greater proportion of 2-methylbutyrate and isovalerate than CON, T1, or T3. As 2-methylbutyrate and isovalerate are branched-chain VFA that are synthesized from branched-chain amino acids, T2 may have an increased fermentation of branched-chain amino acids or decreased uptake by fibrolytic microorganisms. Although we did not observe changes in N metabolism due to the enzymes, there could be changes in microbial populations that utilize branched-chain VFA. Overall, the tested enzymes did not improve in vitro ruminal fermentation in the diet of high-producing dairy cows.


Assuntos
Lactação , Propionatos , Animais , Bovinos , Feminino , alfa-Amilases/metabolismo , Ração Animal/análise , Dieta/veterinária , Digestão , Ácidos Graxos Voláteis/metabolismo , Fermentação , Lactatos/metabolismo , Propionatos/metabolismo , Rúmen/metabolismo , Amido/metabolismo
2.
Neuroimage ; 225: 117438, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33039623

RESUMO

Brain development has largely been studied through unimodal analysis of neuroimaging data, providing independent results for structural and functional data. However, structure clearly impacts function and vice versa, pointing to the need for performing multimodal data collection and analysis to improve our understanding of brain development, and to further inform models of typical and atypical brain development across the lifespan. Ultimately, such models should also incorporate genetic and epigenetic mechanisms underlying brain structure and function, although currently this area is poorly specified. To this end, we are reporting here a multi-site, multi-modal dataset that captures cognitive function, brain structure and function, and genetic and epigenetic measures to better quantify the factors that influence brain development in children originally aged 9-14 years. Data collection for the Developmental Chronnecto-Genomics (Dev-CoG) study (http://devcog.mrn.org/) includes cognitive, emotional, and social performance scales, structural and functional MRI, diffusion MRI, magnetoencephalography (MEG), and saliva collection for DNA analysis of single nucleotide polymorphisms (SNPs) and DNA methylation patterns. Across two sites (The Mind Research Network and the University of Nebraska Medical Center), data from over 200 participants were collected and these children were re-tested annually for at least 3 years. The data collection protocol, sample demographics, and data quality measures for the dataset are presented here. The sample will be made freely available through the collaborative informatics and neuroimaging suite (COINS) database at the conclusion of the study.


Assuntos
Encéfalo/diagnóstico por imagem , Desenvolvimento Infantil , Cognição , Adolescente , Encéfalo/crescimento & desenvolvimento , Encéfalo/fisiologia , Criança , Conectoma , Metilação de DNA , Imagem de Difusão por Ressonância Magnética , Feminino , Neuroimagem Funcional , Genômica , Humanos , Imageamento por Ressonância Magnética , Magnetoencefalografia , Masculino , Neuroimagem , Polimorfismo de Nucleotídeo Único , Fatores de Tempo
3.
Nat Commun ; 11(1): 6255, 2020 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-33288746

RESUMO

Oceans provide critical ecosystem services, but are subject to a growing number of external pressures, including overfishing, pollution, habitat destruction, and climate change. Current models typically treat stressors on species and ecosystems independently, though in reality, stressors often interact in ways that are not well understood. Here, we use a network interaction model (OSIRIS) to explicitly study stressor interactions in the Chukchi Sea (Arctic Ocean) due to its extensive climate-driven loss of sea ice and accelerated growth of other stressors, including shipping and oil exploration. The model includes numerous trophic levels ranging from phytoplankton to polar bears. We find that climate-related stressors have a larger impact on animal populations than do acute stressors like increased shipping and subsistence harvesting. In particular, organisms with a strong temperature-growth rate relationship show the greatest changes in biomass as interaction strength increased, but also exhibit the greatest variability. Neglecting interactions between stressors vastly underestimates the risk of population crashes. Our results indicate that models must account for stressor interactions to enable responsible management and decision-making.


Assuntos
Mudança Climática , Conservação dos Recursos Naturais/métodos , Ecossistema , Pesqueiros/estatística & dados numéricos , Peixes/fisiologia , Algoritmos , Animais , Regiões Árticas , Biomassa , Peixes/classificação , Camada de Gelo , Modelos Teóricos , Oceanos e Mares , Fitoplâncton/fisiologia , Temperatura , Ursidae/fisiologia
4.
Opt Express ; 28(18): 25915-25934, 2020 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-32906872

RESUMO

The modern-day resurgence of machine learning has encouraged researchers to revisit older problem spaces from a new perspective. One promising avenue has been implementing deep neural networks to aid in the simulation of physical systems. In the field of optics, densely connected neural networks able to mimic wave propagation have recently been constructed. These diffractive deep neural networks (D2NN) not only offer new insights into wave propagation, but provide a novel tool for investigating and discovering multi-functional diffractive elements. In this paper, we derive an efficient GPU-friendly D2NN methodology based on Rayleigh-Sommerfeld diffraction. We then use the implementation to virtually forge cascades of optical phase masks subject to different beam steering conditions. The input and output conditions we use to train each D2NN instance is based on commercial electro-optic modulated waveguide systems to encourage experimental follow-on. In total, we analyze the beam steering efficacy of 27 individual D2NN instances which explore different permutations of input sources, mask cascades, and output steering targets.

5.
Opt Express ; 28(17): 24629-24656, 2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32907001

RESUMO

Optical materials engineered to dynamically and selectively manipulate electromagnetic waves are essential to the future of modern optical systems. In this paper, we simulate various metasurface configurations consisting of periodic 1D bars or 2D pillars made of the ternary phase change material Ge2Sb2Te5 (GST). Dynamic switching behavior in reflectance is exploited due to a drastic refractive index change between the crystalline and amorphous states of GST. Selectivity in the reflection and transmission spectra is manipulated by tailoring the geometrical parameters of the metasurface. Due to the immense number of possible metasurface configurations, we train deep neural networks capable of exploring all possible designs within the working parameter space. The data requirements, predictive accuracy, and robustness of these neural networks are benchmarked against a ground truth by varying quality and quantity of training data. After ensuring trustworthy neural network advisory, we identify and validate optimal GST metasurface configurations best suited as dynamic switchable mirrors depending on selected light and manufacturing constraints.

6.
J Chem Phys ; 151(3): 034702, 2019 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-31325927

RESUMO

In this work, we examine metal electrode-ionomer electrolyte systems at high voltage (negative surface charge) and at high pH to assess factors that influence hydrogen production efficiency. We simulate the hydrogen evolution electrode interface investigated experimentally in the work of Bates et al. [J. Phys. Chem. C 119, 5467 (2015)] using a combination of first principles calculations and classical molecular dynamics. With this detailed molecular information, we explore the hypotheses posed in the work of Bates et al. In particular, we examine the response of the system to increased bias voltage and oxide coverage in terms of the potential profile, changes in solvation and species concentrations away from the electrode, surface concentrations, and orientation of water at reactive surface sites. We discuss this response in the context of hydrogen production.

7.
J Phys Condens Matter ; 31(39): 394002, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31239417

RESUMO

We present the results of muon-spin relaxation ([Formula: see text]SR) measurements on antiferromagnetic and ferromagnetic spin chains. In antiferromagnetic CuF2(pyz) we identify a transition to long range magnetic order taking place at [Formula: see text] K, allowing us to estimate a ratio with the intrachain exchange of [Formula: see text] and the ratio of interchain to intrachain exchange coupling as [Formula: see text]. The ferromagnetic chain [Sm(hfac)3(boaDTDA)] n undergoes an ordering transition at [Formula: see text] K, seen via a broad freezing of dynamic fluctuations on the muon (microsecond) timescale and implying [Formula: see text]. The ordered radical moment continues to fluctuate on this timescale down to 0.3 K, while the Sm moments remain disordered. In contrast, the radical spins in [La(hfac)3(boaDTDA)] n remain magnetically disordered down to T = 0.1 K suggesting [Formula: see text].

8.
Opt Express ; 27(12): 16571-16577, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-31252881

RESUMO

We demonstrate the generation of spectrally tunable phase-dependent wavefronts, using the 2D Airy as the primary test case, via a polymer-stabilized cholesteric liquid crystal (PSCLC) element. Specifically, we use a novel spatial light modulator (SLM) based projection system to photo-align the initial helix angle landscape of the PSCLC so that it imparts the appropriate cubic phase profile to the reflected beam. This element is spectrally selective, with a reflection bandwidth of ≈ 100 nm, and electrically tunable from λ = 530 nm to 760 nm. Under both green and red laser illumination, the element is shown to conditionally form an Airy beam depending on the position of the electrically tailored reflection band. We briefly demonstrate the generality of this approach by producing PSCLC elements which form a computer-generated hologram and a higher-order Mathieu beam.

9.
Pediatr Blood Cancer ; 65(12): e27298, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30094928

RESUMO

BACKGROUND: English-speaking Caribbean (ESC) childhood cancer outcomes are unknown. PROCEDURE: Through the SickKids-Caribbean Initiative (SCI), we established a multicenter childhood cancer database across seven centers in six ESC countries. Data managers entered patient demographics, disease, treatment, and outcome data. Data collection commenced in 2013, with retrospective collection to 2011 and subsequent prospective collection. RESULTS: A total of 367 children were diagnosed between 2011 and 2015 with a median age of 5.7 years (interquartile range 2.9-10.6 years). One hundred thirty (35.4%) patients were diagnosed with leukemia, 30 (8.2%) with lymphoma, and 149 (40.6%) with solid tumors. A relative paucity of children with brain tumors was seen (N = 58, 15.8%). Two-year event-free survival (EFS) for the cohort was 48.5% ± 3.2%; 2-year overall survival (OS) was 55.1% ± 3.1%. Children with acute lymphoblastic leukemia (ALL) and Wilms tumor (WT) experienced better 2-year EFS (62.1% ± 6.4% and 66.7% ± 10.1%), while dismal outcomes were seen in children with acute myeloid leukemia (AML; 22.7 ± 9.6%), rhabdomyosarcoma (21.0% ± 17.0%), and medulloblastoma (21.4% ± 17.8%). Of 108 deaths with known cause, 58 (53.7%) were attributed to disease and 50 (46.3%) to treatment complications. Death within 60 days of diagnosis was relatively common in acute leukemia [13/98 (13.3%) ALL, 8/26 (30.8%) AML]. Despite this, traditional prognosticators adversely impacted outcome in ALL, including higher age, higher white blood cell count, and T-cell lineage. CONCLUSIONS: ESC childhood cancer outcomes are significantly inferior to high-income country outcomes. Based on these data, interventions for improving supportive care and modifying treatment protocols are under way. Continued data collection will allow evaluation of interventions and ensure maximal outcome improvements.


Assuntos
Neoplasias/mortalidade , Neoplasias/terapia , Fatores Etários , Região do Caribe/epidemiologia , Criança , Pré-Escolar , Intervalo Livre de Doença , Feminino , Humanos , Contagem de Leucócitos , Masculino , Neoplasias/sangue , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de Tempo
10.
J Microsc ; 270(1): 27-40, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28960300

RESUMO

This research introduces and evaluates a novel method that offers the potential of providing objective criteria to forensic microscopical hair comparisons. The method combines hair diameter with numeric characterisations of red, green, and blue colour content as determined with the use of digital imaging at defined locations of the hair. Thirty hairs were collected from each of twenty participants, all with naturally coloured brown hair. The hairs were examined with an Olympus BX53® polarising light microscope and digital images were viewed with an Olympus DP72® camera under 400× magnification. Using Olympus cellSens™ Entry software, hair diameter was measured at 1000, 1500 and 2000 µm from the base of the root. The Olympus cellSens™ Entry software uses a red, green and blue (RGB) colour model to quantitatively define the colour of each pixel on an image based on its composition of these three principal colour components. This software was used to collect numerical characterisations of hair colour at each distance interval. The diameter and colour values for each hair were compared using discriminant analysis (DA) and principal component analysis. Although a large amount of intrapersonal variation was observed, the degree of interpersonal variation was greater and enabled the statistical model to differentiate between the hair samples from each participant. The DA model achieved sample reclassification with an error rate of 7.33%. A validation study was conducted on a subset of hair samples from which 18 of the 20 were correctly assigned to the participant from whom they originated. These results support the potential of this method to provide an objective addition to current microscopical hair comparison practices.


Assuntos
Antropometria/métodos , Bioestatística/métodos , Medicina Legal/métodos , Cabelo/anatomia & histologia , Processamento de Imagem Assistida por Computador/métodos , Microscopia/métodos , Pigmentos Biológicos/análise , Cabelo/química , Humanos , Software
11.
Ultramicroscopy ; 185: 32-41, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29175745

RESUMO

We introduce an extension of the Darwin-Howie-Whelan (DHW) equations for the case of coherent L12 precipitates in an FCC matrix. The equations are similar in form to the conventional DHW equations and are sufficiently general to account for the different translational variants of the precipitate phase as well as for the displacement fields of arbitrary lattice defects. An approximate scheme to perform fast and accurate image simulations using a pre-computed list of scattering matrices is also introduced. Finally, the results of diffraction pattern and image simulations are shown for two synthetic microstructures for a Ni-Al alloy generated using phase field simulations. The dynamical scattering equations reveal that the precipitate phase superlattice beams can propagate through the disordered matrix, but they are fully decoupled from the fundamental waves.

12.
Geophys Res Lett ; 44(9): 4280-4286, 2017 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-29225384

RESUMO

Stratospheric aerosols (SAs) are a variable component of the Earth's albedo that may be intentionally enhanced in the future to offset greenhouse gases (geoengineering). The role of tropospheric-sourced sulfur dioxide (SO2) in maintaining background SAs has been debated for decades without in-situ measurements of SO2 at the tropical tropopause to inform this issue. Here we clarify the role of SO2 in maintaining SAs by using new in-situ SO2 measurements to evaluate climate models and satellite retrievals. We then use the observed tropical tropopause SO2 mixing ratios to estimate the global flux of SO2 across the tropical tropopause. These analyses show that the tropopause background SO2 is about 5 times smaller than reported by the average satellite observations that have been used recently to test atmospheric models. This shifts the view of SO2 as a dominant source of SAs to a near-negligible one, possibly revealing a significant gap in the SA budget.

13.
AJNR Am J Neuroradiol ; 38(10): 2008-2014, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28775057

RESUMO

BACKGROUND AND PURPOSE: Multiple methods have been used to determine the lumbar vertebral level on MR imaging, particularly when full spine imaging is unavailable. Because postmortem studies show 95% accuracy of numbering the lumbar vertebral bodies by counting the lumbar nerve roots, attention to lumbar nerve morphology on axial MR imaging can provide numbering clues. We sought to determine whether the L5 vertebra could be accurately localized by using nerve morphology on MR imaging. MATERIALS AND METHODS: One hundred eight cases with full spine MR imaging were numbered from the C2 vertebral body to the sacrum with note of thoracolumbar and lumbosacral transitional states. The origin level of the L5 nerve and iliolumbar ligament were documented in all cases. The reference standard of numbering by full spine imaging was compared with the nerve morphology numbering method. Five blinded raters evaluated all lumbar MRIs with nerve morphology technique twice. Prevalence and bias-adjusted κ were used to measure interrater and intrarater reliability. RESULTS: The L5 nerve arose from the 24th presacral vertebra (L5) in 106/108 cases. The percentage of perfect agreement with the reference standard was 98.1% (95% CI, 93.5%-99.8%), which was preserved in transitional and numeric variation states. The iliolumbar ligament localization method showed 83.3% (95% CI, 74.9%-89.8%) perfect agreement with the reference standard. Inter- and intrarater reliability when using the nerve morphology method was strong. CONCLUSIONS: The exiting L5 nerve can allow accurate localization of the corresponding vertebrae, which is essential for preprocedure planning in cases where full spine imaging is not available. This neuroanatomic method displays higher agreement with the reference standard compared with previously described methods, with strong inter- and intrarater reliability.


Assuntos
Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Vértebras Lombares/diagnóstico por imagem , Região Lombossacral/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sacro/diagnóstico por imagem , Raízes Nervosas Espinhais/diagnóstico por imagem , Vértebras Torácicas/diagnóstico por imagem , Adulto Jovem
14.
Clin Radiol ; 72(12): 1038-1046, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28851490

RESUMO

AIM: To investigate the technical success rate and procedure-related complications of computed tomography (CT)-guided needle biopsy of lung lesions and to identify the factors that are correlated with the occurrence of procedure-related complications. MATERIALS AND METHODS: This was a single- institution retrospective study of 867 consecutive CT-guided needle biopsies of lung lesions performed on 772 patients in a tertiary cancer centre. The technical success rate and complications were correlated with patient, lung lesion, and procedure-related variables. RESULTS: The technical success rate was 87.2% and the mortality rate was 0.12%. Of the 867 total biopsies 25.7% were associated with pneumothorax, and 6.5% required chest tube drainage. The haemothorax rate was 1.8%. There was positive correlation between the development of pneumothorax and smaller lesion diameter (p<0.001), longer transparenchymal distance (p<0.001), and prone position (p=0.027). There was positive correlation between the need for chest tube placement and longer transparenchymal distance (p=0.007) and smaller lesion diameter (p=0.018). Lesions in the left lower lobe had the lowest rates of pneumothorax (p=0.008) and chest tube drainage (p=0.018). Patients whose pneumothoraces were diagnosed on the follow-up chest X-ray, but not on the immediate post-procedural CT scan had significantly higher requirement for chest tube drainage (p=0.039). CONCLUSION: CT-guided lung biopsy has a high rate of technical success and a low rate of major complications. The present study has revealed several variables that can be used to identify high-risk procedures. A post-procedural chest X-ray within hours after the procedure is highly recommended to identify high-risk patients who require chest tube placement.


Assuntos
Biópsia por Agulha , Pulmão/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia por Agulha/efeitos adversos , Biópsia por Agulha/métodos , Tubos Torácicos/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pneumotórax/etiologia , Radiologia Intervencionista/métodos , Estudos Retrospectivos , Adulto Jovem
15.
Opt Express ; 25(8): 9078-9087, 2017 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-28437982

RESUMO

We demonstrate that the pump's spatial input profile can provide additional degrees of freedom in tailoring at will the nonlinear dynamics and the ensuing spectral content of supercontinuum generation in highly multimoded optical fibers. Experiments and simulations carried out at 1550 nm indicate that the modal composition of the input beam can substantially alter the soliton fission process as well as the resulting Raman and dispersive wave generation that eventually lead to supercontinuum in such a multimode environment. Given the multitude of conceivable initial conditions, our results suggest that it is possible to pre-engineer the supercontinuum spectral content in a versatile manner.

16.
Ecotoxicol Environ Saf ; 143: 336-343, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28434758

RESUMO

Rather than migrating, mallard ducks may choose to overwinter in northern cities on open-water thermal refuges, such as municipal wastewater treatment ponds, which in Edmonton, Canada, stay ≥10°C during frigid winter months. Refuging mallards spend appreciable time daily on these ponds and hydrate using secondary clarified municipal wastewater (SCEW). We aimed to determine if SCEW ingestion affected mallard health. To this end, we gavaged newly hatched mallards (domesticated Pekin strain) over their first month with SCEW, as well as water representing negative and positive controls (municipal tap water, and the primary active ingredient from birth control pills, 17α-ethinyl estradiol (EE2), respectively). The gavage of SCEW did not affect mass of the body, liver, spleen or heart, but was associated with small increases in beak and wing chord length. In the positive control, EE2 gavage caused similar responses, but also increased tarsus and phallus length. The increases likely owed to the stimulatory effects of estrogenic substances on bone and phallus development. For the biotransformation enzyme CYP2H1, gene expression was numerically increased by both SCEW and EE2. In terms of behavior, SCEW and EE2 gavage reduced two infrequently detected behaviours, pecking and resting alone. Our results suggest that SCEW ingestion would be unlikely to cause any overt health effects in adults, but may evoke subtle, covert effects nevertheless.


Assuntos
Comportamento Animal/fisiologia , Patos/fisiologia , Comportamento de Retorno ao Território Vital/fisiologia , Lagoas/química , Águas Residuárias/química , Poluentes Químicos da Água , Alberta , Animais , Cidades , Patos/crescimento & desenvolvimento , Patos/metabolismo , Ingestão de Alimentos , Etinilestradiol/análise , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismo
17.
J Med Entomol ; 54(3): 559-567, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28399198

RESUMO

Culicoides biting midges transmit multiple ruminant viruses, including bluetongue virus and epizootic hemorrhagic disease virus, causing significant economic burden worldwide. To further enhance current control techniques, understanding vector-virus interactions within the midge is critical. We developed previously a double-stranded RNA (dsRNA) delivery method to induce RNA interference (RNAi) for targeted gene knockdown in adult Culicoides sonorensis Wirth & Jones. Here, we confirm the C. sonorensis inhibitor of apoptosis 1 (CsIAP1) as an anti-apoptotic functional ortholog of IAP1 in Drosophila, identify the ortholog of the Drosophila initiator caspase DRONC (CsDRONC), and demonstrate that injection of dsRNA into the hemocoel can be used for targeted knockdown in the midgut in C. sonorensis. We observed CsIAP1 transcript reduction in whole midges, with highest transcript reduction in midgut tissues. IAP1knockdown (kd) resulted in pro-apoptotic caspase activation in midgut tissues. In IAP1kd midges, midgut tissue integrity and size were severely compromised. This phenotype, as well as reduced longevity, was partially reverted by co-RNAi suppression of CsDRONC and CsIAP1. Therefore, RNAi can be directed to the midgut of C. sonorensis, the initial site of virus infection, using dsRNA injection into the hemocoel. In addition, we provide evidence that the core apoptosis pathway is conserved in C. sonorensis and can be experimentally activated in the midgut to reduce longevity in C. sonorensis. This study thus paves the way for future reverse genetic analyses of midgut-virus interactions in C. sonorensis, including the putative antiviral properties of RNAi and apoptosis pathways.


Assuntos
Apoptose , Ceratopogonidae/genética , Proteínas Inibidoras de Apoptose/genética , Proteínas de Insetos/genética , RNA de Cadeia Dupla/metabolismo , Animais , Ceratopogonidae/metabolismo , Feminino , Técnicas de Silenciamento de Genes , Proteínas Inibidoras de Apoptose/metabolismo , Proteínas de Insetos/metabolismo , Interferência de RNA , Distribuição Tecidual
18.
Gene Ther ; 24(1): 60-66, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27858942

RESUMO

The worldwide prevalence of obesity is increasing, raising health concerns regarding obesity-related complications. Chronic inflammation has been characterized as a major contributor to the development of obesity and obesity-associated metabolic disorders. The purpose of the current study is to assess whether the overexpression of interferon beta (IFNß1), an immune-modulating cytokine, will attenuate high-fat diet-induced adipose inflammation and protect animals against obesity development. Using hydrodynamic gene transfer to elevate and sustain blood concentration of IFNß1 in mice fed a high-fat diet, we showed that the overexpression of Ifnß1 gene markedly suppressed immune cell infiltration into adipose tissue, and attenuated production of pro-inflammatory cytokines. Systemically, IFNß1 blocked adipose tissue expansion and body weight gain, independent of food intake. Possible browning of white adipose tissue might also contribute to blockade of weight gain. More importantly, IFNß1 improved insulin sensitivity and glucose homeostasis. These results suggest that targeting inflammation represents a practical strategy to block the development of obesity and its related pathologies. In addition, IFNß1-based therapies have promising potential for clinical applications for the prevention and treatment of various inflammation-driven pathologies.


Assuntos
Tecido Adiposo/metabolismo , Terapia Genética , Glucose/metabolismo , Homeostase , Interferon beta/genética , Obesidade/terapia , Tecido Adiposo/imunologia , Tecido Adiposo/patologia , Animais , Dieta Hiperlipídica/efeitos adversos , Inflamação/metabolismo , Inflamação/terapia , Resistência à Insulina , Interferon beta/sangue , Interferon beta/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Infiltração de Neutrófilos , Obesidade/etiologia , Obesidade/metabolismo
19.
J Mater Res ; 32(23): 4342-4353, 2017 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-32499666

RESUMO

The origin of the extraordinary strengthening of the highly-alloyed austenitic stainless steel Sanicro 25 during cyclic loading at 700°C was investigated by use of advanced scanning transmission electron microscopy (STEM). Along with substantial change of dislocation structure, nucleation of two distinct populations of nanoparticles was revealed. Fully coherent Cu-rich nanoparticles were observed homogeneously dispersed with high density along with nanometer-sized incoherent NbC carbides precipitating on dislocations during cyclic loading. Probe-corrected HAADF STEM imaging was used to characterize the atomic structure of nanoparticles. Compositional analysis was conducted using both EELS and high spatial resolution EDS. High temperature exposure induced precipitation of a high density of coherent Cu-rich nanoparticles while strain-induced nucleation of incoherent NbC nanoparticles leads to retardation of dislocation movement. The pinning effects and associated obstacles to dislocation motion prevent recovery and formation of the localized low-energy cellular structures. As a consequence, the alloy exhibits remarkable cyclic hardening at elevated temperature.

20.
Nat Commun ; 7: 13434, 2016 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-27874007

RESUMO

Decades of research has been focused on improving the high-temperature properties of nickel-based superalloys, an essential class of materials used in the hot section of jet turbine engines, allowing increased engine efficiency and reduced CO2 emissions. Here we introduce a new 'phase-transformation strengthening' mechanism that resists high-temperature creep deformation in nickel-based superalloys, where specific alloying elements inhibit the deleterious deformation mode of nanotwinning at temperatures above 700 °C. Ultra-high-resolution structure and composition analysis via scanning transmission electron microscopy, combined with density functional theory calculations, reveals that a superalloy with higher concentrations of the elements titanium, tantalum and niobium encourage a shear-induced solid-state transformation from the γ' to η phase along stacking faults in γ' precipitates, which would normally be the precursors of deformation twins. This nanoscale η phase creates a low-energy structure that inhibits thickening of stacking faults into twins, leading to significant improvement in creep properties.

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