Recent studies on surface reflection illustrate how light beams can be laterally shifted from the position predicted by geometrical optics, the so called Goos-Hänchen effect. In antiferromagnets this ...shifts can be controlled with an external magnetic field. We show that a configuration in which spins cant in response to applied magnetic fields enhance possibilities of field controlled shifts. Moreover, we show that nonreciprocal displacements are possible, for both oblique and normal incidence, due to inherent nonreciprocity of the polariton phase with respect to the propagation direction. In the absence of an external field, reciprocal displacements occur.
Magnetite nanoparticles coated with (3-aminopropyl)triethoxysilane, NH
2(CH
2)
3Si(OC
2H
5)
3, were prepared by silanization reaction and characterized by X-ray diffractometry, transmission electron ...microscopy, atomic force microscopy, Fourier transform infrared spectroscopy and magnetization measurements. Both uncoated and organosilane-coated magnetite exhibited superparamagnetic behavior and strong magnetization at room temperature. Basic groups anchored on the external surface of the coated magnetite were observed. The superparamagnetic particles of coated magnetite are able to bind to biological molecules, drugs and metals and in this way remove them from medium by magnetic separation procedures.
We tested the hypothesis that administration of omega (o)-9, rn-3, and rn-6 to mice can prevent oxidative alterations responsible for behavioral and cognitive alterations related with aging. ...Twenty-eight-day- old mice received skim milk (SM group), SM enriched with omega oil mixture (EM group), or water (control group) for 10 and 14 months, equivalent to middle age. Mice were evaluated for behavioral alterations related to depression and memory and oxidative status brain levels of thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), and myeloperoxidase (MPO). The 10-month EM group increased immobility time during the forced swimming test compared with control, indicating increased stress response. The 14-month SM- and EM-treated groups increased sucrose consumption compared with control, showing an expanded motivational state. The 14-month SM group decreased the number of rearings compared with the 14- month control and EM groups. The number of entries and time spent in the central square of the open field was higher in the 10-month EM group than in the control, revealing an anxiolytic-like behavior. TBARS decreased in the hippocampus and striatum of the 10-month EM group compared with the control. A similar decrease was observed in the striatum of the 10-month SM group. GSH levels were higher in all 14-month treated groups compared with 10-month groups. MPO activity was higher in the 14- month EM group compared with the 14-month control and SM groups, revealing a possible pro-inflammatory status. In conclusion, omega oils induced conflicting alterations in middle-aged mice, contributing to enhanced behavior and anxiolytic and expanded motivational state, but also to increased stress response and pro-inflammatory alterations. Key words: Aging; Nutraceuticals; Omega 3 fatty acids; Omega 6 fatty acids; Omega 9 fatty acids; Oxidative stress markers
Human alphaherpesvirus 1 (HuAHV1) causes fatal neurologic infections in captive New World primates. To determine risks for interspecies transmission, we examined data for 13 free-ranging, ...black-tufted marmosets (Callithrix penicillata) that died of HuAHV1 infection and had been in close contact with humans in anthropized areas in Brazil during 2012-2019. We evaluated pathologic changes in the marmosets, localized virus and antigen, and assessed epidemiologic features. The main clinical findings were neurologic signs, necrotizing meningoencephalitis, and ulcerative glossitis; 1 animal had necrotizing hepatitis. Transmission electron microscopy revealed intranuclear herpetic inclusions, and immunostaining revealed HuAHV1 and herpesvirus particles in neurons, glial cells, tongue mucosal epithelium, and hepatocytes. PCR confirmed HuAHV1 infection. These findings illustrate how disruption of the One Health equilibrium in anthropized environments poses risks for interspecies virus transmission with potential spillover not only from animals to humans but also from humans to free-ranging nonhuman primates or other animals.
Sporotrichosis is a neglected zoonosis caused by pathogenic fungi belonging to the Sporothrix schenckii complex. In Rio de Janeiro state, this disease reached an epidemic status with over 4700 ...domestic felines and around 4000 humans affected since the mid-90s. The present study evaluated clinical and epidemiological aspects and also the frequency of colonization and infection by these fungi in healthy cats and among those with suspicious cutaneous lesions, inhabiting four Rio de Janeiro state distinct areas.
Three hundred and seventy-one cats were included in two groups: 175 healthy cats CRG and 196 cats showing lesions suggesting sporotrichosis SSG. Mycological diagnosis allowed SSG animals to be divided in positive 104 cats; +SG and negative 92 cats; -SG groups. Nails, oral mucosa and lesions swabs were submitted to culture and potential colonies were subculture for micromorphologycal analysis, dimorphism and molecular tests. In the CRG, only one cat was colonized in the oral cavity 0.57%; in the -SG group, four animals showed colonization of the nail and/or oral cavity 4.3%; while the highest frequency of colonization 39.4% was observed in the +SG. All molecularly typed isolates were identified as S. brasiliensis.
The results obtained here indicate that healthy cats have a minor role in sporotrichosis transmission within the state of Rio de Janeiro. Conversely, a higher participation of diseased feline in sporotrichosis transmission was evidenced, especially by the colonization of their oral cavity. Sporothrix brasiliensis equally affects and colonizes animals from distinct Rio de Janeiro state areas. Thus, we hypothesize that sporotrichosis is a uniform endemic throughout the state, whose transmission depends mainly on the contact with cats with sporotrichosis. Since Rio de Janeiro displays a world unique epidemic model of the disease, not fully understood, data on the infected and non-infected animals can be of major importance for future strategies of sporotrichosis prevention and control. Finally, considering the importance of the current concept of "one health", the experience here observed can be helpful for distinct epizootias and/or zoonosis.
Selaginella convoluta (Arn.) Spring is a species popularly known as "jericó", and used in folk medicine as analgesic and anti-inflammatory. This study aimed to investigate in mice the antinociceptive ...and anti-inflammatory activities of the hexane (Sc-Hex) and chloroform (Sc-CHCl3) fractions (100, 200 and 400 mg/kg) obtained by partition of crude ethanol extract from S. convoluta. The preliminary phytochemical analysis of the fractions was performed. Antinociceptive activity was evaluated by writhing, formalin and hot-plate tests. Anti-inflammatory activity was evaluated using carrageenan-induced pleurisy. The rota-rod test was used to evaluate motor coordination. Preliminary phytochemical screening showed that the Sc-Hex and the Sc-CHCl3 were positive for the presence of flavonoids, anthracene derivatives, quinones, triterpenes and steroids. Inhibition of writhing was observed for fractions tested. The Sc-Hex at all doses tested was effective in reducing the nociceptive behavior produced by formalin only in the second phase. However, the Sc-CHCl3 decreased the paw licking time in the first and second phases. In the hot plate no significant effect was observed for any fraction. In the rota-rod test, treated mice did not demonstrate any significant motor performance changes. In the carrageenan-induced pleurisy, Sc-CHCl3 (200 mg/kg) reduced cell migration to the pleural cavity. These results reveal the antinociceptive properties of S. convoluta , which support, in part, its traditional use, since the fractions did not presented significant activity in the inflammatory response profile. We further verify that this antinociceptive effect could be by activation of nociceptive peripheral pathway.
The intricate, tightly controlled mechanism of wound healing that is a vital physiological mechanism is essential to maintaining the skin's natural barrier function. Numerous studies have focused on ...wound healing as it is a massive burden on the healthcare system. Wound repair is a complicated process with various cell types and microenvironment conditions. In wound healing studies, novel therapeutic approaches have been proposed to deliver an effective treatment. Nanoparticle-based materials are preferred due to their antibacterial activity, biocompatibility, and increased mechanical strength in wound healing. They can be divided into six main groups: metal NPs, ceramic NPs, polymer NPs, self-assembled NPs, composite NPs, and nanoparticle-loaded hydrogels. Each group shows several advantages and disadvantages, and which material will be used depends on the type, depth, and area of the wound. Better wound care/healing techniques are now possible, thanks to the development of wound healing strategies based on these materials, which mimic the extracellular matrix (ECM) microenvironment of the wound. Bearing this in mind, here we reviewed current studies on which NPs have been used in wound healing and how this strategy has become a key biotechnological procedure to treat skin infections and wounds.
Nanoparticle-modified hydrogels exhibit substantial promise in the realm of wound healing, with their ability to expedite tissue regeneration, mitigate infection risks, and facilitate enhanced therapeutic outcomes.
Magnetic artificial spin ice provides examples of how competing interactions between magnetic nanoelements can lead to a range of fascinating and unusual phenomena. We examine theoretically a class ...of spin ice tilings, called the pinwheel, for which near degeneracy of the spin configuration energies can be achieved. Pinwheel tiling is a simple but crucial variant on the square ice geometry, in which each nanoelement of square ice is rotated some angle about its midpoint. Surprisingly, this rotation leads to an intriguing phase transition; and even though the spins are not parallel to one another, a ferromagnetic phase is found for rotation angles near 45∘. Here, magnetic domains and domain walls are found when viewed in terms of net magnetization. Moreover, the ferromagnetic behavior of the system depends on its anisotropy which we can control by array shape and size.
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