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1.
Emerg Microbes Infect ; 12(1): 2186608, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36880345

RESUMO

The GsGd lineage (A/goose/Guangdong/1/1996) H5N1 virus was introduced to Canada in 2021/2022 through the Atlantic and East Asia-Australasia/Pacific flyways by migratory birds. This was followed by unprecedented outbreaks affecting domestic and wild birds, with spillover into other animals. Here, we report sporadic cases of H5N1 in 40 free-living mesocarnivore species such as red foxes, striped skunks, and mink in Canada. The clinical presentations of the disease in mesocarnivores were consistent with central nervous system infection. This was supported by the presence of microscopic lesions and the presence of abundant IAV antigen by immunohistochemistry. Some red foxes that survived clinical infection developed anti-H5N1 antibodies. Phylogenetically, the H5N1 viruses from the mesocarnivore species belonged to clade 2.3.4.4b and had four different genome constellation patterns. The first group of viruses had wholly Eurasian (EA) genome segments. The other three groups were reassortant viruses containing genome segments derived from both North American (NAm) and EA influenza A viruses. Almost 17 percent of the H5N1 viruses had mammalian adaptive mutations (E627 K, E627V and D701N) in the polymerase basic protein 2 (PB2) subunit of the RNA polymerase complex. Other mutations that may favour adaptation to mammalian hosts were also present in other internal gene segments. The detection of these critical mutations in a large number of mammals within short duration after virus introduction inevitably highlights the need for continually monitoring and assessing mammalian-origin H5N1 clade 2.3.4.4b viruses for adaptive mutations, which potentially can facilitate virus replication, horizontal transmission and posing pandemic risks for humans.


Assuntos
Virus da Influenza A Subtipo H5N1 , Influenza Aviária , Animais , Humanos , Virus da Influenza A Subtipo H5N1/genética , Raposas , Aves , Canadá/epidemiologia , Mutação , Filogenia
2.
Res Pract Thromb Haemost ; 7(1): 100044, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36817938

RESUMO

Background: Oral anticoagulants for venous thromboembolism are not thoroughly managed in ambulatory settings in low-/middle-income countries, primarily because of patients' neglect of medication knowledge and adherence. Objectives: This study was conducted to investigate patient knowledge, adherence, and the associated factors at a Vietnamese tertiary hospital, serving as a reference for educational programs in other local and regional health care facilities. Methods: A randomly recruited cross-sectional study was conducted on patients using vitamin K antagonists (VKA) or direct oral anticoagulants (DOAC). The primary and secondary outcomes were the knowledge score (in percent) and adherence to oral anticoagulants. Student's t-tests or chi-squared tests were used to compare the crude differences in mean or proportion between patients taking VKA and DOAC. Regression models were conducted to adjust the potential confounders and determine factors associated with patient knowledge and adherence. Results: A total of 199 patients were included. After adjusting for potential confounders, patients receiving a DOAC had similar knowledge scores and levels of adherence compared with those taking VKA, with both groups being suboptimal. Previous counseling was associated with higher knowledge. Better medication knowledge, female sex, and no history of venous thromboembolism were associated with better adherence. Conclusion: Good knowledge and adherence of oral anticoagulant-taking patients remain limited in Southeast Asian clinical practice. Further studies in similar settings should examine the associations between these factors and the effectiveness of the regimens. More effective measures targeting patient knowledge and adherence should be implemented to optimize anticoagulation therapy, improve the patients' outcomes, and mitigate the associated adverse effects.

3.
Food Chem ; 141(2): 695-701, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-23790836

RESUMO

In polymeric nanoparticle preparation, despite similar conditions, large fluctuations in particle size distributions are usually observed. Herein, we demonstrate that the intermittent addition of a desolvating agent can improve reproducibility in the preparation of polymeric bovine serum albumin (BSA) nanoparticles. Using this modification, BSA nanoparticles of controlled size can be manufactured with narrow particle size distributions. In our study, ethanol as a desolvating agent was added intermittently to 1% BSA solutions at different pHs with stirring at 700rpm. The effect of the preparation parameters on size and optical density of the fabricated nanoparticles were studied. The average particles sizes of BSA nanoparticles prepared at pH values of 6, 7 and 9 were approximately 100, 200 and 300nm, respectively. As ethanol addition increased, desolvation of BSA molecules resulted in formation of loose-structured particles with pH-dependent size. Beyond that, only particle density increased, but size remained unchanged with further addition of ethanol. Consistently uniform particle size distribution was achieved by adding ethanol intermittently.


Assuntos
Etanol/química , Nanopartículas/química , Soroalbumina Bovina/química , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Polimerização , Soroalbumina Bovina/ultraestrutura
4.
J Hazard Mater ; 192(3): 1321-9, 2011 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-21764213

RESUMO

Silver nanoparticles colloid has been prepared by a modified sonoelectrodeposition technique in which a silver plate was used as the source of silver ions. This technique allows producing Ag nanoparticles with the size of 4-30 nm dispersed in a non-toxic solution. The Ag nanoparticles were loaded in a high surface activated carbon produced from coconut husk, a popular agricultural waste in Vietnam by thermal activation. The surface area of the best activated carbon is 890 m(2)/g. The presence of Ag nanoparticles does not change significantly properties of the activated carbon in terms of morphology and methylene blue adsorption ability. The Ag nanoparticle-loaded activated carbon shows a good antibacterial activity against Escherichia coli with very low minimal inhibitory concentration of 16 µg/ml and strong As(V) adsorption. The materials are potential for prevention and treatment of microbial infection and contamination for environmental applications.


Assuntos
Nanopartículas Metálicas/química , Nanotecnologia/métodos , Prata/química , Adsorção , Antibacterianos/farmacologia , Carbono/química , Eletroquímica/métodos , Monitoramento Ambiental/métodos , Escherichia coli/metabolismo , Azul de Metileno/farmacologia , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura/métodos , Microscopia Eletrônica de Transmissão/métodos , Difração de Raios X
5.
Nanotechnology ; 22(28): 285603, 2011 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-21642760

RESUMO

Co-Pt nanoparticles encapsulated in carbon cages have been prepared by sonoelectrodeposition followed by annealing in a CO atmosphere. Sonoelectrodeposition is a useful technique to make metallic nanoparticles, using ultrasound during electrodeposition to remove nanoparticles as they grow on the cathode surface. We used an electrolyte containing chloroplatinic acid and cobalt chloride and found that the atomic ratio of Co:Pt in the as-formed materials varied from 0.2 to 0.8 as the deposition current density was changed from 15 to 35 mA cm(-2). However, the as-deposited materials were inhomogeneous, comprising a mixture of Pt-rich and Co-rich nanoparticles. X-ray diffraction indicated that subsequent heat treatment (700 °C for 1 h) under CO gas created an ordered CoPt alloy phase that exhibited hard magnetic properties. Transmission electron microscopy showed many of the resulting nanoparticles to be encapsulated in carbon cages, which we ascribe to Co-catalyzed decomposition of CO during annealing. The thickness of the carbon cages was about ten layers, which may have helped reduce sintering during annealing. The size of the resultant nanoparticles was about 100 nm diameter, larger than the typical 5-10 nm diameter of as-deposited nanoparticles.

6.
Nanotechnology ; 20(16): 165707, 2009 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-19420580

RESUMO

In this paper, a systematic investigation of the microstructure, high performance magnetic hardness as well as novel magnetic memory effect of the Pr(4)Fe(76)Co(10)B(6)Nb(3)Cu(1) nanocomposite magnet fabricated by conventional melt-spinning followed by annealing at temperatures ranging from 600 to 700 degrees C in Ar gas for nanocrystallization are presented and discussed. Transmission electron microscopy (TEM) observation confirms an ultrafine structure of bcc-Fe(Co) as a magnetically soft phase and Pr(2)Fe(14)B as a hard magnetic phase with a spring-exchange coupling in order to form the nanocomposite state. Electron diffraction analysis also indicates that the Co atoms together with Fe atoms form the Fe(70)Co(30) phase with a very high magnetic moment (2.5 mu(B)), leading to a high saturation magnetization of the system. High magnetic hardness is obtained in the optimally heat-treated specimen with coercivity H(c) = 3.8 kOe, remanence B(r) = 12.0 kG, M(r)/M(s) = 0.81 and maximum energy product (BH)(max) = 17.8 MG Oe, which is about a 25% improvement in comparison with recent results for similar compositions. High remanence and reduced remanence are the key factors in obtaining the high performance with low rare-earth concentration (only 4 at.%). High-resolution TEM analysis shows that there is a small amount of residual amorphous phase in the grain boundary, which plays a role of interphase to improve the exchange coupling. Otherwise, in terms of magnetic after-effect measurement, a magnetic memory effect was observed for the first time in an exchange-coupled hard magnet.

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