Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Dairy Sci ; 107(7): 4524-4536, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38395396

RESUMO

The objective of the experiment was to determine the effects of supplemental SFA sources, lysophospholipids (LPL), and their interaction on production and nutrient digestibility in lactating dairy cows. The experiment was conducted with 48 cows in a randomized complete block design. Cows were blocked (12 blocks total) by parity and days in milk and randomly assigned to 4 dietary treatments in each block (2 × 2 factorial arrangement), i.e., 2 sources of fat supplements, C16:0 (PA)- or C18:0 (SA)-enriched fat, and with or without LPL. The experiment was conducted for 6 wk to measure daily dry matter intake, milk yield, and weekly milk composition. During the last week of the experiment, spot fecal and urine samples were collected to determine total-tract nutrient digestibility. Milk samples in the last week were also collected to analyze the milk fatty acid (FA) profile. All data were analyzed using the MIXED procedure of SAS, where block was used as a random effect and FA, LPL, and the interaction of FA by LPL were used as fixed effects. Week and interactions of week by FA or LPL were included for production measures. Different sources of SFA did not affect dry matter intake and milk yield. However, the PA treatment increased (39.7 vs. 36.8 kg) energy-corrected milk compared with SA due to increased milk fat yield. No effect of LPL on production measures was observed. Total-tract digestibilities of dry matter, organic matter, crude protein, and total FA were not different between the PA and SA groups, but PA increased (41.4% vs. 38.8%) neutral detergent fiber digestibility compared with SA. Supplementation of LPL increased (64.7% vs. 60.5%) total FA digestibility, especially 18-carbon FA (74.1% vs. 68.2%). An interaction of SFA by LPL was found for 16-carbon FA digestibility. The PA diet increased the concentration of 16-carbon FA in milk fat and SA increased the concentration of preformed FA (≥18 carbons). Supplementation of LPL decreased the concentration of trans-10 C18:1. No difference in N utilization and excretion among treatments was observed. In conclusion, the PA diet was more effective in improving milk fat yield of lactating cows compared with SA. Supplementation of LPL increased digestibility of total FA, especially 18-carbon FA but did not affect production.


Assuntos
Dieta , Digestão , Ácidos Graxos , Lactação , Lisofosfolipídeos , Leite , Animais , Bovinos , Feminino , Leite/química , Leite/metabolismo , Dieta/veterinária , Lisofosfolipídeos/metabolismo , Digestão/efeitos dos fármacos , Ração Animal , Suplementos Nutricionais , Nutrientes/metabolismo
2.
J Dairy Sci ; 106(6): 3932-3946, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37225579

RESUMO

Increasing ruminal starch digestibility has the potential to improve microbial protein synthesis (MPS), milk production, and feed efficiency. Enogen corn (Syngenta Seeds LLC) expresses high α-amylase activity, and we evaluated effects of Enogen corn silage (CS) and grain (CG) on ruminal starch digestibility, MPS, and milk production in lactating dairy cows. Fifteen Holstein cows (6 ruminally cannulated and 9 noncannulated; average ± standard deviation at the beginning of the trial: 170 ± 40 d in milk; milk yield, 37.2 ± 7.73 kg/d; body weight, 714 ± 37 kg) were used in a replicated 3 × 3 Latin square design (28 d per period) with 3 treatments: a diet containing isoline CS and CG (control, CON); a diet with Enogen CS and isoline CG (ECS); and a diet with Enogen CS and CG (ECSCG). Dry matter (DM; 30%), starch (35% of DM), and particle size distribution of the isoline and Enogen CS were similar. However, the mean particle size of Enogen CG was larger (1.05 vs. 0.65 mm) than that of the isoline CG. Cannulated cows were used for digestibility and nutrient flow measurements, noncannulated cows were used for enteric CH4 measurements, and all cows were used for production evaluation. Dry matter intake (DMI) and milk yield were greater for ECS and ECSCG compared with CON (26.7 and 26.6 vs. 25.1 kg/d and 36.5 and 34.1 vs. 33.1 kg/d, respectively) without a difference between ECS and ECSCG. Milk protein yield was greater (1.27 vs. 1.14 and 1.17 kg/d) for ECS compared with CON and ECSCG. Milk fat content was greater (3.79 vs. 3.32%) for ECSCG compared with ECS. Milk fat yield and energy-corrected milk did not differ among treatments. Ruminal digestibilities of DM, organic matter, starch, and neutral detergent fiber were not different among treatments. However, ruminal digestibility of nonammonia, nonmicrobial N was greater (85 vs. 75%) for ECS compared with ECSCG. Total-tract apparent starch digestibility was lower (97.6 and 97.1 vs. 98.3%) for ECS and ECSCG compared with CON, respectively, and tended to be lower (97.1 vs. 98.3%) for ECSCG compared with ECS. Ruminal outflows of bacterial OM and nonammonia N tended to be greater for ECS than for ECSCG. Efficiency of MPS tended to be greater (34.1 vs. 30.6 g of N/kg of organic matter truly digested) for ECS versus ECSCG. Ruminal pH and total and individual short-chain fatty acid concentrations did not differ among treatments. Concentration of ruminal NH3 for ECS and ECSCG was lower (10.4 and 12.4 vs. 13.4 mmol/L, respectively) compared with CON. Methane per unit of DMI decreased for ECS and ECSCG compared with CON (11.4 and 12.2 vs. 13.5 g/kg of DMI, respectively) without a difference between ECS and ECSCG. In conclusion, ECS and ECSCG did not increase ruminal or total-tract starch digestibility. However, the positive effects of ECS and ECSCG on milk protein yield, milk yield, and CH4 per unit of DMI may show potential benefits of feeding Enogen corn. Effects of ECSCG were not apparent when compared with ECS, partly due to larger particle size of Enogen CG compared with its isoline counterpart.


Assuntos
Lactação , Silagem , Feminino , Bovinos , Animais , Silagem/análise , Zea mays/metabolismo , alfa-Amilases/metabolismo , Metano/metabolismo , Proteínas do Leite/análise , Dieta/veterinária , Nutrientes , Amido/metabolismo , Digestão , Rúmen/metabolismo , Fermentação
3.
J Dairy Sci ; 105(10): 8054-8068, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36028344

RESUMO

In a randomized complete block design, 40 lactating Holstein cows (average 98 d in milk and 41 kg/d of milk yield) were randomly assigned to 1 of 4 diets: (1) containing soybean meal as the major protein supplement (CON diet); (2) CON diet with high-protein dried corn distillers grains at 20% on a dry matter (DM) basis by replacing mainly soybean meal (DG diet); (3) DG diet except that high-protein dried corn distillers grains with yeast bodies (extracted after corn ethanol production) was used (DGY diet); or (4) DG diet supplemented with sodium bicarbonate and potassium carbonate to elevate the dietary cation and anion difference (DCAD; DG-DCAD diet). The DCAD of CON, DG, DGY, and DG-DCAD were 185, 62, 67, and 187 mEq/kg of DM, respectively. The experiment began with a 10-d covariate period and then cows were fed the experimental diets for 5 wk (2-wk diet adaptation and 3-wk data collection periods). Dry matter intake and milk yield were measured daily, and spot urine and fecal samples were collected in the last week of the experiment to measure nutrient digestibility; N, S, and P utilization and excretion; and in vitro NH3 and H2S emissions from manure. All data were analyzed using the MIXED procedure of SAS (random effect: block; fixed effects: diets, repeated week, and interactions). During data collection, DM intake was not different among treatment groups, but milk yield tended to be lower (42.4 vs. 39.9 kg/d) for DG, DGY, and DG-DCAD versus CON, which could have been caused by decreases in organic matter and neutral detergent fiber digestibility. Milk protein yield tended to be lower (1.33 vs. 1.24 kg/d) for DG, DGY, and DG-DCAD versus CON. Milk fat yield was lower (1.26 vs. 1.55 kg/d) for DG and DGY versus CON, but that for DG-DCAD (1.43 kg/d) did not differ from CON. Similarly, energy-corrected milk was lower (38.0 vs. 43.3 kg/d) for cows on DG and DGY versus those on CON, but it did not differ between DG-DCAD (40.7 kg/d) and CON. Urinary and fecal N excretion were greater for DG, DGY, and DG-DCAD compared with CON due to greater dietary crude protein content and N intake. However, NH3 emissions did not differ across treatments. Intakes of dietary P and S were greater for DG, DGY, and DG-DCAD, resulting in greater excretion of those in manure and greater H2S emissions from manure compared with CON. These data suggest that the negative effects of feeding distillers grains on production of lactating cows can be partly explained by a decrease in nutrient digestibility (milk yield) and excessive anion load (milk fat). The milk fat response to DG-DCAD suggests that milk fat depression observed with a diet with high content of distillers grains can be partially alleviated by supplementation of cations. In the current study, we observed no beneficial effects of DG containing yeast bodies.


Assuntos
Lactação , Esterco , Ração Animal/análise , Animais , Ânions , Cátions , Bovinos , Detergentes , Dieta/veterinária , Proteínas Alimentares/farmacologia , Etanol/farmacologia , Feminino , Lactação/fisiologia , Proteínas do Leite/farmacologia , Nutrientes , Saccharomyces cerevisiae , Bicarbonato de Sódio/farmacologia , Zea mays
4.
Phys Chem Chem Phys ; 20(29): 19307-19313, 2018 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-29900442

RESUMO

In this work, we have found complete water miscibility for a priori, water immiscible (highly hydrophobic) ionic liquids by chemical manipulation of the quaternary ammonium cation grafted with hydroxyethyl moieties. Specifically, we were able to obtain bistriflimide-based ionic liquids completely miscible with water, even below room temperature. The underlying reason is the full integration of the OH groups of the cation in the continuous H-bonded network of water.

5.
J Dairy Sci ; 101(9): 7980-7989, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30007807

RESUMO

Indirect methods of spot sampling with intrinsic markers to estimate fecal output and nutrient digestibility often have been used in dairy nutrition research as alternatives to total collection of feces (TC) because of labor and expense. However, fecal output and nutrient digestibility estimated from the indirect method must be accurate regardless of altering dietary conditions. This experiment was designed to validate the accuracy of using indigestible neutral detergent fiber (iNDF) or acid-insoluble ash (AIA) as intrinsic markers to estimate fecal outputs and nutrient digestibility compared with TC and to determine the optimal number of spot sampling events to accurately determine fecal output and then nutrient excretion. The experiment used 12 multiparous lactating Holstein cows in a randomized complete block design. Cows were blocked by days in milk and milk yield and randomly assigned to 1 of 2 diets: a diet containing about 49% corn silage on a dry matter basis and a diet containing about 48% alfalfa silage with high by-product (soyhulls) and supplemental K. During the final 3 d of 21-d periods, TC was performed, and 12 spot samples were collected for the same 3 d to represent every 2 h in a 24-h cycle. Fecal outputs and nutrient digestibility of dry matter, organic matter, or nitrogen estimated with iNDF or AIA as an intrinsic marker were compared with TC. Overall, fecal outputs and digestibility estimated with iNDF were similar to that estimated with TC, whereas AIA overestimated fecal output by 44 to 61% and underestimated nutrient digestibilities by 16 to 32%. However, potential differences in statistical inference of dietary effects between iNDF and TC were found. Data from individual spot samples were aggregated to represent spot sampling frequencies of 12 (SP12), 6 (SP6), 4 (SP4), or 2 (SP2) evenly spaced events starting at feeding time. Compared with TC, SP12 produced similar fecal content of iNDF, organic matter, and nitrogen, but fecal AIA content was greater. Furthermore, compared with SP12, SP6 produced similar fecal content of all nutrients, whereas marker and nutrient concentrations in SP4 and SP2 were different. In this experiment, iNDF was a better fecal marker than AIA, and a spot sampling frequency of at least 6 events was necessary. However, interpretation of dietary effects could be confounded when iNDF was used to estimate fecal outputs.


Assuntos
Biomarcadores/análise , Bovinos/metabolismo , Digestão , Fezes , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta , Fibras na Dieta , Feminino , Lactação , Leite , Distribuição Aleatória , Rúmen , Silagem , Zea mays
6.
Phys Chem Chem Phys ; 17(20): 13480-94, 2015 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-25933136

RESUMO

The viscosity (η) of four binary mixtures (ionic liquids plus molecular solvents, ILs+MSs) was measured in the 283.15 < T/K < 363.15 temperature range. Different IL/MS combinations were selected in such a way that the corresponding η(T) functions exhibit crossover temperatures at which both pure components present identical viscosity values. Consequently, most of the obtained mixture isotherms, η(x), exhibit clear viscosity minima in the studied T-x range. The results are interpreted using auxiliary molecular dynamics (MD) simulation data in order to correlate the observed η(T,x) trends with the interactions in each mixture, including the balance between electrostatic forces and hydrogen bonding.

7.
Soft Matter ; 10(13): 2141-9, 2014 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-24651941

RESUMO

We propose a magnetic force modulation method to measure the stiffness and viscosity of living cells using a modified AFM apparatus. An oscillating magnetic field makes a magnetic cantilever oscillate in contact with the sample, producing a small AC indentation. By comparing the amplitude of the free cantilever motion (A0) with the motion of the cantilever in contact with the sample (A1), we determine the sample stiffness and viscosity. To test the method, the frequency-dependent stiffness of 3T3 fibroblasts was determined as a power law k(s)(f) = α + ß(f/f¯)(γ) (α = 7.6 × 10(-4) N m(-1), ß = 1.0 × 10(-4) N m(-1), f¯ = 1 Hz, γ = 0.6), where the coefficient γ = 0.6 is in good agreement with rheological data of actin solutions with concentrations similar to those in cells. The method also allows estimation of the internal friction of the cells. In particular we found an average damping coefficient of 75.1 µN s m(-1) for indentation depths ranging between 1.0 µm and 2.0 µm.

8.
Animal ; 18(4): 101127, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38574452

RESUMO

Supplementing a diet with rumen-protected amino acids (AAs) is a common feeding strategy for efficient production. For a cost-effective use of rumen-protected AA, the accurate bioavailability of rumen-protected amino acids should be known and their metabolism after absorption needs to be well understood. The current study determined the bioavailability, absorption, utilization, and excretion of rumen-protected Lys (RP-Lys). Four ruminally cannulated cows in a 4 × 4 Latin square design (12 d for diet adaptation; 5 or 6 d for total collections) received the following treatments: L0, a basal diet; L25, the basal diet and L-Lys infused into the abomasum to provide 25.9 g/d L-Lys; L50, the basal diet and L-Lys infused into the abomasum to provide 51.8 g/d L-Lys; and RPL, the basal diet supplemented with 105 g/d (as-is) of RP-Lys to provide 26.7 g of digestible Lys. During the last 5 or 6 d in each period, 15N-Lys (0.38 g/d) was infused into the abomasum for all cows to label the pool of AA, and the total collection of milk, urine, and feces were conducted. 15N enrichment of samples on d 4 and 5 were used to calculate the bioavailability and Lys metabolism. We used a model containing a fast AA turnover (≤ 5 d) and slow AA turnover pool (> 5 d) to calculate fluxes of Lys. The Lys flux to the fast AA turnover pool (absorbed Lys + Lys from the slow AA turnover pool to fast AA turnover pool) was calculated using 15N enrichment of milk Lys. The flux of Lys from the fast AA turnover pool to milk and urine was calculated using 15N transfer into milk and urine. Then, absorbed Lys was estimated by the sum of Lys flux to milk and urine assuming no net utilization of Lys by body tissues. Duodenal Lys flow was estimated by 15N enrichment of fecal Lys. The bioavailability of RP-Lys was calculated from duodenal Lys flows and Lys absorption for RPL. Increasing Lys supply from L25 to L50 increased Lys utilization for milk by 9 g/d but also increased urinary excretion by 10 g/d. For RPL, absorbed Lys was estimated to be 136 g/d where 28 g of absorbed Lys originated from RP-Lys. In conclusion, 68% of bioavailability was obtained for RP-Lys. The Lys provided from RP-Lys was not only utilized for milk protein (48%) but also excreted in urine (20%) after oxidation.


Assuntos
Lactação , Lisina , Feminino , Bovinos , Animais , Lisina/metabolismo , Rúmen/metabolismo , Disponibilidade Biológica , Dieta/veterinária , Aminoácidos/metabolismo , Proteínas do Leite/metabolismo , Aminas/metabolismo , Metionina/metabolismo
9.
Nanotechnology ; 24(5): 055102, 2013 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-23324556

RESUMO

The viscoelastic properties of human kidney cell lines from different tumor types (carcinoma (A-498) and adenocarcinoma (ACHN)) are compared to a non-tumorigenic cell line (RC-124). Our methodology is based on the mapping of viscoelastic properties (elasticity modulus E and apparent viscosity η) over the surface of tens of individual cells with atomic force microscopy (AFM). The viscoelastic properties are averaged over datasets as large as 15000 data points per cell line. We also propose a model to estimate the apparent viscosity of soft materials using the hysteresis observed in conventional AFM deflection-displacement curves, without any modification to the standard AFM apparatus. The comparison of the three cell lines show that the non-tumorigenic cells are less deformable and more viscous than cancerous cells, and that cancer cell lines have distinctive viscoelastic properties. In particular, we obtained that E(RC-124) > E(A-498) > E(ACHN) and η(RC-124) > Î·(A-498) > Î·(ACHN).


Assuntos
Elasticidade , Neoplasias Renais/patologia , Neoplasias Renais/fisiopatologia , Microscopia de Força Atômica/métodos , Fenômenos Biomecânicos , Linhagem Celular Tumoral , Forma Celular , Módulo de Elasticidade , Humanos , Imagem Óptica , Fenótipo , Viscosidade
10.
Phys Chem Chem Phys ; 15(26): 10960-70, 2013 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-23710486

RESUMO

This work investigates for the first time shifts in the temperature of maximum density (TMD) of water caused by ionic liquid solutes. A vast amount of high-precision volumetric data--more than 6000 equilibrated (static) high-precision density determination corresponding to ∼90 distinct ionic liquid aqueous solutions of 28 different types of ionic liquid--allowed us to analyze the TMD shifts for different homologous series or similar sets of ionic solutes and explain the overall effects in terms of hydrophobic, electrostatic and hydrogen-bonding contributions. The differences between the observed TMD shifts in the -2 < t/°C < 4 range and salting-in or salting-out effects produced by the same type of ions in aqueous solutions at higher temperatures are discussed taking into account the different types of possible solute-water interactions that can modify the structure of the aqueous phase. The results also reveal different insights concerning the nature of the ions that constitute typical ionic liquids and are consistent with previous results that established hydrophobic and hydrophilic scales for ionic liquid ions based on their specific interactions with water and other probe molecules.

11.
JDS Commun ; 3(4): 250-254, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36338021

RESUMO

A previously developed abomasal infusion device was modified for easy and successful placement of infusion lines into the abomasum of dairy cows. Similar to the original device, the modified device consists of 2 pieces: an insertion tool and a delivery tool. Updates include streamlining both the insertion and delivery tools by slightly altering dimensions and design, then smoothing all rough edges. The primary changes include a parallel cut along the entire length of the insertion and delivery tools and encasement of the infusion line inside both tools, allowing for smoother insertion through the reticulum-omasum orifice and into the omasum and abomasum. Additionally, increasing the outside diameter of the delivery tool to reduce the gap between the delivery tool and insertion tool, increasing the length of the tools, and making a loop of cord attached to the insertion tool facilitate insertion and easy ejection of the flange into the abomasum. By using this modified device, placement of abomasal infusion lines (including flange) was more successful.

12.
J Environ Manage ; 90(7): 2144-53, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-18367311

RESUMO

A multiple purpose wetland inventory is being developed and promoted through partnerships and specific analyses at different scales in response to past uncertainties and gaps in inventory coverage. A partnership approach is being promoted through the Ramsar Convention on Wetlands to enable a global inventory database to be compiled from individual projects and analyses using remote sensing and GIS. Individual projects that are currently part of this global effort are described. They include an analysis of the Ramsar sites' database to map the distribution of Ramsar sites across global ecoregions and to identify regions and wetland types that are under-represented in the database. Given the extent of wetland degradation globally, largely due to agricultural activities, specific attention is directed towards the usefulness of Earth Observation in providing information that can be used to more effectively manage wetlands. As an example, a further project using satellite data and GIS to quantify the condition of wetlands along the western coastline of Sri Lanka is described and trends in land use due to changes in agriculture, sedimentation and settlement patterns are outlined. At a regional scale, a project to map and assess, using remote sensing, individual wetlands used for agriculture in eight countries in southern Africa is also described. Land cover and the extent of inundation at each site is being determined from a multi-temporal data set of images as a base for further assessment of land use change. Integrated fully within these analyses is the development of local capacity to plan and undertake such analyses and in particular to relate the outcomes to wetland management and to compile data on the distribution, extent and condition of wetlands globally.


Assuntos
Monitoramento Ambiental/métodos , Sistemas de Informação Geográfica , Comunicações Via Satélite , Áreas Alagadas
13.
J Environ Manage ; 90(7): 2234-42, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-18462862

RESUMO

Over one hundred wetland specialists and Earth Observation experts from around the world gathered at the European Space Agency's 'GlobWetland Symposium: Looking at wetlands from space' in Frascati, Italy, from 19 to 20 October, 2006. The aim of the Symposium was to stimulate discussion between the two communities by reviewing the latest developments in Earth Observation (EO) for the inventory, assessment and monitoring of wetlands and identify key scientific, technical and policy-relevant challenges for the future. The results provide an overview of the key areas of current research in the use of EO for mapping and managing wetlands, while also pointing out gaps that could hinder global inventory, assessment and monitoring of wetlands. This paper provides a summary of the main outputs with a focus on the role of EO technologies in supporting the implementation of the Ramsar Convention on Wetlands. The summary contains a qualitative analysis of the state of the art and considers possible directions and priorities for future research, development and application of EO-based technologies in wetland management. In this context we: 1) highlight those applications where EO technologies are ready for wider uptake by wetland managers, and provide suggestions for supporting such uptake; 2) indicate where EO technologies and applications currently in the research and development stages could potentially be useful in wetland management; and 3) provide recommendations for new research and development of EO technologies, that can be utilized to address aspects of wetland management not covered by the range of current EO applications.


Assuntos
Conservação dos Recursos Naturais/métodos , Monitoramento Ambiental/métodos , Áreas Alagadas
14.
J Phys Chem B ; 112(39): 12394-400, 2008 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-18781808

RESUMO

The interactions between ionic liquids and totally fluorinated alkanes are investigated by associating gas solubility measurements with molecular simulation calculations. Experimental values for the solubility of perfluoromethane, perfluoroethane, and perfluoropropane in one ionic liquidtrihexyltetradecylphophonium bis(trifluoromethylsulfonyl)amide [P 6,6,6,14][Ntf 2]are reported between 303 and 343 K and close to atmospheric pressure. All mole fraction solubilities decrease with increasing temperature. From the variation of Henry's law constants with temperature, the thermodynamic functions of solvation were calculated. The precision of the experimental data, considered as the average absolute deviation of the Henry's law constants from appropriate smoothing equations, is always better than +/-3%. By the analysis of the differences between the solute-solvent radial distribution functions of perfluoromethane and perfluoropropane obtained by molecular simulation, it was possible to explain why solubility increases with the size of the perfluoroalkane. The trend of solubility is explained on the basis of the location of the solute with respect to the solvent ions as well as on the differences in the solute-solvent energies of interaction.

15.
Mol Biol Cell ; 7(7): 1137-51, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8862526

RESUMO

The coiled body is a specific intranuclear structure of unknown function that is enriched in splicing small nuclear ribonucleoproteins (snRNPs). Because adenoviruses make use of the host cell-splicing machinery and subvert the normal subnuclear organization, we initially decided to investigate the effect of adenovirus infection on the coiled body. The results indicate that adenovirus infection induces the disassembly of coiled bodies and that this effect is probably secondary to the block of host protein synthesis induced by the virus. Furthermore, coiled bodies are shown to be very labile structures, with a half-life of approximately 2 h after treatment of HeLa cells with protein synthesis inhibitors. After blocking of protein synthesis, p80 coilin was detected in numerous microfoci that do not concentrate snRNP. These structures may represent precursor forms of the coiled body, which goes through a rapid cycle of assembly/disassembly in the nucleus and requires ongoing protein synthesis to reassemble.


Assuntos
Infecções por Adenovirus Humanos/patologia , Adenovírus Humanos/patogenicidade , Núcleo Celular/ultraestrutura , Infecções por Adenovirus Humanos/metabolismo , Adenovírus Humanos/metabolismo , Sequência de Bases , Núcleo Celular/metabolismo , Núcleo Celular/virologia , Meia-Vida , Células HeLa , Humanos , Hibridização In Situ , Microscopia Imunoeletrônica , Sondas Moleculares/genética , Proteínas Nucleares/metabolismo , Inibidores da Síntese de Proteínas/farmacologia , RNA Viral/metabolismo , Ribonucleoproteínas Nucleares Pequenas/metabolismo
16.
J Chem Thermodyn ; 97: 354-361, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27642190

RESUMO

This paper reports the thermal, thermodynamic, thermophysical and surface properties of eight ionic liquids with fluorinated alkyl side chain lengths equal or greater than four carbon atoms. Melting and decomposition temperatures were determined together with experimental densities, surface tensions, refractive indices, dynamic viscosities and ionic conductivities in a temperature interval ranging from 293.15 to 353.15 K. The surface properties of these fluorinated ionic liquids were discussed and several thermodynamic functions, as well as critical temperatures, were estimated. Coefficients of isobaric thermal expansion, molecular volumes and free volume effects were calculated from experimental values of density and refractive index and compared with previous data. Finally, Walden plots were used to evaluate the ionicity of the investigated ionic liquids.

17.
Ann Thorac Surg ; 51(6): 999-1001, 1991 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2039335

RESUMO

Two patients with primary cardiac leiomyosarcoma, one of the rarest malignant tumors of the heart, are described. The first patient had a tumor of the pulmonary trunk and was admitted with symptoms suggestive of pulmonary thromboembolism. The second had a tumor of the left atrium and had signs and symptoms of mitral valve obstruction and regurgitation. The 2 patients were operated on and later underwent adjuvant chemotherapy. Both died more than 22 months after operation, having required multiple hospital admissions for treatment of complications related to the pathology or the treatment of the primary cardiac leiomyosarcoma. Nonetheless, aggressive surgical excision followed by chemotherapy appears to have improved survival in these patients with primary cardiac leiomyosarcoma, as they are among the longest survivors reported.


Assuntos
Neoplasias Cardíacas , Leiomiossarcoma , Adulto , Diagnóstico Diferencial , Feminino , Neoplasias Cardíacas/diagnóstico , Neoplasias Cardíacas/terapia , Humanos , Leiomiossarcoma/diagnóstico , Leiomiossarcoma/terapia , Pessoa de Meia-Idade , Embolia Pulmonar/diagnóstico
18.
Clin Nurs Res ; 12(2): 159-73, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12741668

RESUMO

This study described and compared the sleep experience of medical and surgical patients during a hospital stay. During 3 consecutive nights, patients (n = 110) self-reported sleep quality using the Verran and Snyder Sleep Scale (VSH) and potentially disruptive factors using items from the Factors Influencing Sleep Questionnaire (FISQ). Surgical patients, on the first night, received more procedural care (p = .001), less sedative medication (p < .001), reported more sleep disturbance (p = .02), less sleep effectiveness (p = .03), and more need for sleep supplementation (p = .03). Variance in sleep effectiveness was explained by the FISQ score, age, and length of time in hospital (F = 6.86, p < .001). The sleep experience of patients varies between diagnostic groupings and across the hospital stay. Unit environmental and personal factors, factors that are amenable to therapeutic interventions, strongly influence the sleep experience.


Assuntos
Atitude Frente a Saúde , Pacientes Internados/psicologia , Assistência Noturna/psicologia , Cuidados Pós-Operatórios/psicologia , Privação do Sono/psicologia , Idoso , Feminino , Ambiente de Instituições de Saúde/normas , Hospitais Universitários , Humanos , Masculino , Pessoa de Meia-Idade , Assistência Noturna/normas , Ruído/efeitos adversos , Pesquisa em Avaliação de Enfermagem , Ontário , Cuidados Pós-Operatórios/normas , Estudos Prospectivos , Análise de Regressão , Inquéritos e Questionários
19.
Rev Port Cardiol ; 10(3): 259-62, 1991 Mar.
Artigo em Português | MEDLINE | ID: mdl-1854518

RESUMO

The authors describe the case of a 52-year-old patient with several hospitalizations due to acute pulmonary edema, clarified only during the performance of cardiac surgery for the correction of presumable mitral valvular pathology. A leiomiossarcome of the left auricle was concerned, which involved the posterior ring of the mitral valve, the interauricular septum and the orifices of the pulmonary veins. Due to the impossibility of proceeding with the complete resection of the tumor, the tumoral mass was wasted away in order to liberate the involved structures, this followed by chemotherapy. Two years since, the patient shows a generally deteriorated state, submitted to various hospitalizations due to cardiac insufficiency, having been objectivated hepatic metastization and recurrence of the primary neoplasm.


Assuntos
Neoplasias Cardíacas , Leiomiossarcoma , Feminino , Átrios do Coração , Neoplasias Cardíacas/complicações , Neoplasias Cardíacas/diagnóstico , Septos Cardíacos , Humanos , Leiomiossarcoma/complicações , Leiomiossarcoma/diagnóstico , Pessoa de Meia-Idade , Valva Mitral
20.
Rev Port Cardiol ; 13(4): 323-6, 292, 1994 Apr.
Artigo em Português | MEDLINE | ID: mdl-7917381

RESUMO

The authors describe a case of a floating thrombus in the left atrium, detected by a 2D echocardiography in a female patient suffering from dilated cardiomyopathy. At the follow-up, it was found that the mass was no longer detected inside the left atrium. This occurrence was not associated to any major embolic phenomena. A transesophageal echocardiographic study revealed the presence of a thrombus in the left atrial appendage.


Assuntos
Cardiopatias , Trombose , Ecocardiografia Transesofagiana , Feminino , Átrios do Coração , Cardiopatias/diagnóstico por imagem , Humanos , Pessoa de Meia-Idade , Trombose/diagnóstico por imagem
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa