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1.
eNeuro ; 8(2)2021.
Artigo em Inglês | MEDLINE | ID: mdl-33593732

RESUMO

The lateral orbitofrontal cortex (LOFC) is thought to encode information associated with consumption of rewarding substances and is essential for flexible decision-making. Indeed, firing patterns of LOFC neurons are modulated following changes in reward value associated with an action outcome relationship. Damage to the LOFC impairs behavioral flexibility in humans and is associated with suboptimal performance in reward devaluation protocols in rodents. As chronic intermittent ethanol (CIE) exposure also impairs OFC-dependent behaviors, we hypothesized that CIE exposure would alter LOFC neuronal activity during alcohol drinking, especially under conditions when the reward value of ethanol was modulated by aversive or appetitive tastants. To test this hypothesis, we monitored LOFC activity using GCaMP6f fiber photometry in mice receiving acute injections of ethanol and in those trained in operant ethanol self-administration. In naive mice, an acute injection of ethanol caused a dose-dependent decrease in the frequency but not amplitude of GCaMP6f transients. In operant studies, mice were trained on a fixed ratio one schedule of reinforcement and were then separated into CIE or Air groups. Following four cycles of CIE exposure, GCaMP6f activity was recorded during self-administration of alcohol, alcohol+quinine (aversive), or alcohol+sucrose (appetitive) solutions. LOFC neurons showed discrete patterns of activity surrounding lever presses and surrounding drinking bouts. Responding for and consumption of ethanol was greatly enhanced by CIE exposure, was aversion resistant, and was associated with signs of LOFC hyperexcitability. CIE-exposed mice also showed altered patterns of LOFC activity that varied with the ethanol solution consumed.


Assuntos
Etanol , Córtex Pré-Frontal , Consumo de Bebidas Alcoólicas , Animais , Camundongos , Camundongos Endogâmicos C57BL , Neurônios
2.
Rev Sci Instrum ; 91(9): 094505, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33003803

RESUMO

We have designed a non-imaging telescope for measurement of the spectral irradiance of the moon. The telescope was designed to be integrated into a wing pod of a National Aeronautics and Space Administration ER-2 research aircraft to measure lunar spectral irradiance during flight. The telescope and support system were successfully flown in August 2018 at altitudes near 21 km and at speeds of ∼760 km/h. The wing pod in which the telescope is mounted has an opening through which the moon can be observed. The mount exposes the telescope to high winds, low pressures, temperatures near -60 °C, and vibrations both due to flight and due to the motion of the aircraft on the ground. This required a telescope design with high thermal stability and high resistance to shock. The optical design of the telescope is optimized to have high throughput and spatially uniform transmission from 380 nm to 1000 nm over a field of view about three times the angular size of the moon as viewed from the Earth. The final design resulted in a telescope with singlet design incorporating a 139.7 mm lens with an effective focal length of 377 mm and a field of view of 1.6°. The light from the telescope is introduced into an integrating sphere, which destroys the image and the polarization for measurement by a fiber-coupled spectroradiometer. Herein, we present an overview of the instrument and support system with emphasis on the telescope design.

3.
Nanoscale ; 12(17): 9744-9755, 2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-32324185

RESUMO

Targeted alpha therapy (TAT) offers great promise for treating recalcitrant tumors and micrometastatic cancers. One drawback of TAT is the potential damage to normal tissues and organs due to the relocation of decay daughters from the treatment site. The present study evaluates La(227Th)PO4 core (C) and core +2 shells (C2S) nanoparticles (NPs) as a delivery platform of 227Th to minimize systemic distribution of decay daughters, 223Ra and 211Pb. In vitro retention of decay daughters within La(227Th)PO4 C NPs was influenced by the concentration of reagents used during synthesis, in which the leakage of 223Ra was between 0.4 ± 0.2% and 20.3 ± 1.1% in deionized water. Deposition of two nonradioactive LaPO4 shells onto La(227Th)PO4 C NPs increased the retention of decay daughters to >99.75%. The toxicity of the nonradioactive LaPO4 C and C2S NP delivery platforms was examined in a mammalian breast cancer cell line, BT-474. No significant decrease in cell viability was observed for a monolayer of BT-474 cells for NP concentrations below 233.9 µg mL-1, however cell viability decreased below 60% when BT-474 spheroids were incubated with either LaPO4 C or C2S NPs at concentrations exceeding 29.2 µg mL-1. La(227Th)PO4 C2S NPs exhibit a high encapsulation and in vitro retention of radionuclides with limited contribution to cellular cytotoxicity for TAT applications.


Assuntos
Nanopartículas/química , Fosfatos/química , Tório/química , Animais , Linhagem Celular Tumoral , Sobrevivência Celular , Composição de Medicamentos , Sistemas de Liberação de Medicamentos , Humanos , Camundongos , Nanopartículas/toxicidade , Fosfatos/toxicidade , Células RAW 264.7 , Radioisótopos/química , Radioisótopos/toxicidade , Tório/toxicidade
4.
J R Soc Interface ; 16(157): 20190247, 2019 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-31387480

RESUMO

Oceanic flows do not necessarily mix planktonic species. Differences in individual organisms' physical and hydrodynamic properties can cause changes in drift normal to the mean flow, leading to segregation between species. This physically driven heterogeneity may have important consequences at the scale of population dynamics. Here, we describe how one form of physical forcing, circulating flows with different inertia effects between phytoplankton and zooplankton, can dramatically alter excitable plankton bloom dynamics. This may impact our understanding of the initiation and development of harmful algal blooms (HABs), which have significant negative ecological and socio-economic consequences. We study this system in detail, providing spatio-temporal dynamics for particular scenarios and summarizing large-scale behaviour via spatially averaged bifurcation diagrams. The key message is that, across a large range of parameter values, fluid flow can induce plankton blooms and mean-field population dynamics that are distinct from those predicted for well-mixed systems. The implications for oceanic population dynamic studies are manifest: we argue that the formation of HABs will depend strongly on the physical and biological state of the ecosystem, and that local increases in zooplankton heterogeneity are likely to precede phytoplankton blooms.


Assuntos
Simulação por Computador , Modelos Biológicos , Fitoplâncton/fisiologia , Zooplâncton/fisiologia , Animais , Dinâmica Populacional
5.
Clin Nutr ESPEN ; 30: 204-207, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30904223

RESUMO

There is little data on the safety or efficacy of insulin added to parenteral nutrition in the homecare setting. We report the use of this route of insulin administration in a series of 4 patients spanning 39 patient years in which it appeared effective, safe and well tolerated.


Assuntos
Hiperglicemia/dietoterapia , Insulina/administração & dosagem , Enteropatias , Nutrição Parenteral no Domicílio , Adulto , Diabetes Mellitus Tipo 1/prevenção & controle , Diabetes Mellitus Tipo 2/prevenção & controle , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
7.
Neurobiol Learn Mem ; 144: 136-146, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28720405

RESUMO

While thepsychoactive inhalant toluene causes behavioral effects similarto those produced by other drugs of abuse, the persistent behavioral and anatomical abnormalities induced by toluene exposure are not well known. To mimic human "binge-like" inhalant intoxication, adolescent, male Sprague-Dawley rats were exposed to toluene vapor (5700ppm) twice daily for five consecutive days. These rats remained in their home cages until adulthood (P60), when they were trained in operant boxes to respond to a palatable food reward and then challenged with several different cognitive tasks. Rats that experienced chronic exposure to toluene plus abstinence ("CTA") showed enhanced performance in a strategy set-shifting task using a between-session, but not a within-session test design. CTA also blunted operant and classical conditioning without affecting responding during a progressive ratio task. While CTA rats displayed normal latent inhibition, previous exposure to a non-reinforced cue enhanced extinction of classically conditioned approach behavior of these animals compared to air controls. To determine whether CTA alters the structural plasticity of brain areas involved in set-shifting and appetitive behaviors, we quantified basal dendritic spine morphology in DiI-labeled pyramidal neurons in layer 5 of the medial prefrontal cortex (mPFC) and medium spiny neurons in the nucleus accumbens (NAc). There were no changes in dendritic spine density or subtype in the mPFC of CTA rats while NAc spine density was significantly increased due to an enhanced prevalence of long-thin spines. Together, these findings suggest that the persistent effects of CTA on cognition are related to learning and memory consolidation/recall, but not mPFC-dependent behavioral flexibility.


Assuntos
Cognição/efeitos dos fármacos , Aprendizagem/efeitos dos fármacos , Núcleo Accumbens/efeitos dos fármacos , Córtex Pré-Frontal/efeitos dos fármacos , Tolueno/administração & dosagem , Animais , Condicionamento Clássico/efeitos dos fármacos , Condicionamento Operante/efeitos dos fármacos , Espinhas Dendríticas/efeitos dos fármacos , Espinhas Dendríticas/patologia , Extinção Psicológica/efeitos dos fármacos , Masculino , Núcleo Accumbens/patologia , Córtex Pré-Frontal/patologia , Ratos Sprague-Dawley
8.
Sci Rep ; 7: 39979, 2017 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-28054598

RESUMO

Reconstructing the dynamic response of the Antarctic ice sheets to warming during the Last Glacial Termination (LGT; 18,000-11,650 yrs ago) allows us to disentangle ice-climate feedbacks that are key to improving future projections. Whilst the sequence of events during this period is reasonably well-known, relatively poor chronological control has precluded precise alignment of ice, atmospheric and marine records, making it difficult to assess relationships between Antarctic ice-sheet (AIS) dynamics, climate change and sea level. Here we present results from a highly-resolved 'horizontal ice core' from the Weddell Sea Embayment, which records millennial-scale AIS dynamics across this extensive region. Counterintuitively, we find AIS mass-loss across the full duration of the Antarctic Cold Reversal (ACR; 14,600-12,700 yrs ago), with stabilisation during the subsequent millennia of atmospheric warming. Earth-system and ice-sheet modelling suggests these contrasting trends were likely Antarctic-wide, sustained by feedbacks amplified by the delivery of Circumpolar Deep Water onto the continental shelf. Given the anti-phase relationship between inter-hemispheric climate trends across the LGT our findings demonstrate that Southern Ocean-AIS feedbacks were controlled by global atmospheric teleconnections. With increasing stratification of the Southern Ocean and intensification of mid-latitude westerly winds today, such teleconnections could amplify AIS mass loss and accelerate global sea-level rise.

9.
Clin Exp Immunol ; 188(3): 363-370, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-27753065

RESUMO

Chronic infection with norovirus is emerging as a significant risk for patients with immunodeficiency - either primary or secondary to therapeutic immunosuppression. Patients with primary immunodeficiency present a range of pathological responses to norovirus infection. Asymptomatic infections occur and differentiating viral carriage or prolonged viral shedding after self-limiting infection from infection causing protracted diarrhoea can be challenging, due to relatively mild pathological changes that may mimic other causes of diarrhoea in such patients (for instance pathogenic bacteria or parasites or graft-versus-host disease). However, a subset of patients with common variable immunodeficiency (CVID) experience a severe norovirus-associated enteropathy leading to intestinal villous atrophy and malabsorption. Symptomatic infection of up to 8 years has been demonstrated with clinical and histological recovery on viral clearance. Although oral immunoglobulins and nitazoxanide have been used to treat noroviral infections associated with immunosuppression, ribavirin is the only agent to date that has been linked to viral clearance in the Noroviral enteropathy associated with CVID.


Assuntos
Infecções por Caliciviridae/patologia , Imunodeficiência de Variável Comum/complicações , Imunodeficiência de Variável Comum/terapia , Imunoglobulinas/administração & dosagem , Antivirais/uso terapêutico , Infecções por Caliciviridae/tratamento farmacológico , Doença Crônica , Diarreia/etiologia , Duodeno/patologia , Humanos , Norovirus , Ribavirina/uso terapêutico , Tomografia Computadorizada por Raios X
10.
Transplant Proc ; 48(2): 492-6, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27109985

RESUMO

BACKGROUND: Cytomegalovirus (CMV) disease is a common and clinically significant complication following intestinal or multivisceral transplantation. CMV disease is more common in cases of serologic mismatch between donor and recipient. Though in some cases it may be asymptomatic, in the immunosuppressed population it often manifests with evidence of systemic infection or end-organ disease. METHODS: We conducted a retrospective review of all patients undergoing intestinal or multivisceral transplantation over 8 years at our institution. RESULTS: Forty-eight transplantations were performed, with 40% of the patients (19/48) having ≥1 episode of CMV viremia, which rose to 90% in the "donor-positive, recipient-negative" (DPRN) serologic mismatch group. The median time to 1st episode following transplantation was 22.3 weeks (range, 1-78) and median duration of each episode was 4.9 weeks (range, 1.6-37.4). Six of the 19 viremic patients (31.6%) developed virologic resistance with 4 of these occurring in the DPRN group. Four of the 6 patients with drug-resistant CMV died with CMV viremia. All patients with drug resistance acquired ganciclovir resistance; these patients were more challenging to manage with second-line toxicity-limited treatments, including foscarnet, cidofovir, and leflunomide. CMV immunoglobulin has been used and we briefly discuss the use of CMV-specific adoptive T-lymphocyte transfer in the management of 1 case. CONCLUSIONS: Post-transplantation CMV disease continues to be challenging to manage, and there is little consensus on optimal management strategies in this patient group, with a significant requirement for novel therapies; these may be pharmacologic or cell based. Extensive multidisciplinary discussion is important for most cases, but particularly for those patients who acquire virologic resistance.


Assuntos
Infecções por Citomegalovirus/epidemiologia , Farmacorresistência Viral , Intestinos/transplante , Viremia/epidemiologia , Adulto , Idoso , Antivirais/uso terapêutico , Infecções por Citomegalovirus/tratamento farmacológico , Feminino , Foscarnet/uso terapêutico , Ganciclovir/uso terapêutico , Humanos , Imunoglobulinas/uso terapêutico , Imunoglobulinas Intravenosas , Imunossupressores/uso terapêutico , Isoxazóis/uso terapêutico , Leflunomida , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Viremia/tratamento farmacológico
11.
Philos Trans A Math Phys Eng Sci ; 374(2064): 20150045, 2016 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-26903100

RESUMO

We describe the design, construction, calibration and use of a near-infrared thermodynamic radiation thermometer to measure blackbodies from 400 K to 1300 K. The motivation for this work is the pending redefinition of the kelvin and the need for direct, thermodynamic temperature measurements of the fixed-point blackbodies presently used in the realization of the temperature scale. The challenges of accurately measuring Planck radiances which vary greatly in radiance level and spectral shape are discussed. Methods to characterize the components used in the radiation thermometer design are described. The use of this radiation thermometer as a relative primary thermometer and the resulting residuals are shown. We describe radiometric calibration procedures for using the radiation thermometer as an absolute primary thermometer. Preliminary data showing the initial radiometric calibration steps are discussed.

12.
Philos Trans A Math Phys Eng Sci ; 374(2064): 20150044, 2016 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-26903099

RESUMO

The thermodynamic temperature of the point of inflection of the melting transition of Re-C, Pt-C and Co-C eutectics has been determined to be 2747.84 ± 0.35 K, 2011.43 ± 0.18 K and 1597.39 ± 0.13 K, respectively, and the thermodynamic temperature of the freezing transition of Cu has been determined to be 1357.80 ± 0.08 K, where the ± symbol represents 95% coverage. These results are the best consensus estimates obtained from measurements made using various spectroradiometric primary thermometry techniques by nine different national metrology institutes. The good agreement between the institutes suggests that spectroradiometric thermometry techniques are sufficiently mature (at least in those institutes) to allow the direct realization of thermodynamic temperature above 1234 K (rather than the use of a temperature scale) and that metal-carbon eutectics can be used as high-temperature fixed points for thermodynamic temperature dissemination. The results directly support the developing mise en pratique for the definition of the kelvin to include direct measurement of thermodynamic temperature.

13.
Philos Trans A Math Phys Eng Sci ; 374(2059)2016 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-26667906

RESUMO

During the attempt to directly access, measure and sample Subglacial Lake Ellsworth in 2012-2013, we conducted microbiological analyses of the drilling equipment, scientific instrumentation, field camp and natural surroundings. From these studies, a number of lessons can be learned about the cleanliness of deep Antarctic subglacial lake access leading to, in particular, knowledge of the limitations of some of the most basic relevant microbiological principles. Here, we focus on five of the core challenges faced and describe how cleanliness and sterilization were implemented in the field. In the light of our field experiences, we consider how effective these actions were, and what can be learnt for future subglacial exploration missions. The five areas covered are: (i) field camp environment and activities, (ii) the engineering processes surrounding the hot water drilling, (iii) sample handling, including recovery, stability and preservation, (iv) clean access methodologies and removal of sample material, and (v) the biodiversity and distribution of bacteria around the Antarctic. Comparisons are made between the microbiology of the Lake Ellsworth field site and other Antarctic systems, including the lakes on Signy Island, and on the Antarctic Peninsula at Lake Hodgson. Ongoing research to better define and characterize the behaviour of natural and introduced microbial populations in response to deep-ice drilling is also discussed. We recommend that future access programmes: (i) assess each specific local environment in enhanced detail due to the potential for local contamination, (ii) consider the sterility of the access in more detail, specifically focusing on single cell colonization and the introduction of new species through contamination of pre-existing microbial communities, (iii) consider experimental bias in methodological approaches, (iv) undertake in situ biodiversity detection to mitigate risk of non-sample return and post-sample contamination, and (v) address the critical question of how important these microbes are in the functioning of Antarctic ecosystems.


Assuntos
Organismos Aquáticos/microbiologia , Sedimentos Geológicos/microbiologia , Camada de Gelo/microbiologia , Lagos/microbiologia , Regiões Antárticas , Ecossistema , Sedimentos Geológicos/química , Camada de Gelo/química , Lagos/química
14.
Nucl Med Biol ; 42(7): 614-20, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25900730

RESUMO

INTRODUCTION: Targeted alpha therapy (TAT) has the potential for killing micro-metastases with minimum collateral damage to surrounding healthy tissue. In-vivo generator radionuclides, such as(223)Ra, (225)Ra, and (225)Ac, are of special interest for radiotherapeutic applications as they emit multiple α-particles during their decay. Utilizing appropriate carriers capable of retaining both the parent radioisotope as well as daughter products is important for the effective delivery of the radioisotope to the tumor site while mitigating global in vivo radiotoxicity. In this work, LaPO4 core and core+2 shells nanoparticles (NPs) (NPs with 2 layers of cold LaPO4 deposited on the core surfaces) were synthesized containing either (223)Ra or(225)Ra/(225)Ac, and the retention of the parents and daughters within the NPs in vitro was investigated. METHODS: Core LaPO4 NPs were synthesized in aqueous solution by reacting 1 equivalent of La(NO3)3, along with few microcuries of either (223)Ra or (225)Ra/(225)Ac, with 1 equivalent of sodium tripolyphosphate (TPP) under moderate heating and purified by membrane dialysis. Core-shell NPs were also synthesized with one (core+1 shell) and two (core+2 shells) cold LaPO4 layers deposited onto the radioactive cores. The NPs were then characterized by transmission electron microscopy (TEM) and powder x-ray diffraction (XRD). Identification and quantification of radioactive parents and daughters released from the NPs in vitro were investigated using gamma-ray spectroscopy. RESULTS: XRD and TEM analysis revealed that the NPs crystallized in the rhabdophane phase with mean diameters of 3.4 and 6.3nm for core and core+2 shells, respectively. The core LaPO4 NPs retained up to 88% of (223)Ra over 35days. However, in the core+2 shells NPs, the retention of (223)Ra and its daughter, (211)Pb, was improved to >99.9% over 27days. Additionally, the retention of (225)Ra/(225)Ac parents was >99.98% and ~80% for the (221)Fr and (213)Bi daughters over 35days for the core+2 shells NPs. CONCLUSIONS: The in vitro retention of both parents and daughters results suggests that LaPO4 NPs are potentially effective carriers of radium isotopes.


Assuntos
Partículas alfa/uso terapêutico , Lantânio/química , Nanocápsulas/química , Nanocápsulas/ultraestrutura , Fosfatos/química , Rádio (Elemento)/administração & dosagem , Difusão , Tamanho da Partícula , Compostos Radiofarmacêuticos/uso terapêutico , Rádio (Elemento)/química
17.
Transplant Proc ; 46(6): 2114-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25131119

RESUMO

The first intestinal transplantation in the United Kingdom was performed in Cambridge in 1991. Thirty-eight intestinal transplantations have since been performed in 35 patients. All deaths in the first postoperative month related to hemorrhage, in 2 cases to severe portal hypertension (SPH) and poor venous access in 2. We have modified our practice to reduce the bleeding risk with SPH. Loss of venous access can be avoided by timely referral. Rejection was implicated in 3/14 deaths all dying of sepsis. Cytomegalovirus disease resulted in 2 deaths; we try to avoid CMV-positive donors giving to CMV-negative recipients. Three deaths were related to psychiatric illness, which led to loss of graft in 2 others. Three patients were retransplanted (2 rejections and 1 infarction) and all remain alive. Most patients (10/13) experienced a fall in body weight in the first postoperative year after SB/MV transplantation. Body weight fell by as much as 25%. As transplantation resulted in a net gain in small bowel in most cases, the postoperative loss of native body weight may be underestimated. Interestingly this was not associated with a significant fall in midarm circumference or handgrip strength. Long-term nutrition can be maintained with oral intake in the majority of patients post-SBT. There is improvement in handgrip strength post-transplant. Transplantation does not significantly alter weight, albumin, or other common anthropometric markers. Despite these problems, our 5-year survival results remain relatively good at 73% in the cohort from 1991, 79% from 2003, and 80% from 2008. We consider that deployment of strategies learned from our experiences has improved outcomes.


Assuntos
Enteropatias/cirurgia , Intestino Delgado/transplante , Transplante de Órgãos , Adulto , Feminino , Força da Mão , Humanos , Enteropatias/mortalidade , Enteropatias/patologia , Masculino , Pessoa de Meia-Idade , Estado Nutricional , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento , Reino Unido , Redução de Peso
18.
J Nematol ; 46(2): 101-7, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24987161

RESUMO

Management of Meloidogyne incognita (root-knot nematode) in cotton in the United States was substantially affected by the decision to stop production of aldicarb by its principle manufacturer in 2011. The remaining commercially available tools to manage M. incognita included soil fumigation, nematicide seed treatments, postemergence nematicide application, and cultivars partially resistant to M. incognita. Small plot field studies were conducted on a total of nine sites from 2011-2013 to examine the effects of each of these tools alone or in combinations, on early season galling, late-season nematode density in soil, yield, and value ($/ha = lint value minus chemical costs/ha). The use of a partially resistant cultivar resulted in fewer galls/root system at 35 d after planting in eight of nine tests, lower root-knot nematode density late in the growing season for all test sites, higher lint yield in eight of nine sites, and higher value/ha in six of nine sites. Galls per root were reduced by aldicarb in three of nine sites and by 1,3-dichloropropene (1,3-D) in two of eight sites, relative to the nontreated control (no insecticide or nematicide treatment). Soil fumigation reduced M. incognita density late in the season in three of nine sites. Value/ha was not affected by chemical treatment in four of nine sites, but there was a cultivar × chemical interaction in four of nine sites. When value/ha was affected by chemical treatment, the nontreated control had a similar value to the treatment with the highest value/ha in seven of eight cultivar-site combinations. The next "best" value/ha were associated with seed treatment insecticide (STI) + oxamyl and aldicarb (similar value to the highest value/ha in six of eight cultivar-site combinations). The lowest valued treatment was STI + 1,3-D. In a semi-arid region, where rainfall was low during the spring for all three years, cultivars with partial resistance to M. incognita was the most profitable method of managing root-knot nematode in cotton.

19.
Ultramicroscopy ; 144: 43-9, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24830764

RESUMO

Three-dimensional scanning electron microscopy generates quantitative volumetric structural data from SEM images of macromolecules. This technique provides a quick and easy way to define the quaternary structure and handedness of protein complexes. Here, we apply a variety of preparation and imaging methods to filamentous actin in order to explore the relationship between resolution, signal-to-noise ratio, structural preservation and dataset size. This information can be used to define successful imaging strategies for different applications.


Assuntos
Imageamento Tridimensional/métodos , Substâncias Macromoleculares/química , Substâncias Macromoleculares/ultraestrutura , Microscopia Eletrônica de Varredura/métodos , Actinas/química , Actinas/ultraestrutura , Algoritmos , Animais , Imageamento Tridimensional/estatística & dados numéricos , Microscopia Eletrônica de Varredura/estatística & dados numéricos , Microscopia Eletrônica de Transmissão/métodos , Microscopia Eletrônica de Transmissão/estatística & dados numéricos , Coelhos , Razão Sinal-Ruído , Manejo de Espécimes
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