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Made available in DSpace on 2021-06-25T19:36:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-01 This study aimed to evaluate a correlation between environmental temperature-humidity index (THI), rectal temperature (RT) and plasmatic concentration of cortisol in pregnancy rates of recipient cows in the Amazon biome. Recipient cows (n = 235) were submitted to an estrus synchronization simplified P36 protocol for a Fixed-Time Embryo Transference (FTEF). Rectal temperature of recipient cows and ambient temperature, relative humidity (RH) and dry-bulb temperature ( degrees C) were recorded on day zero (DO), eight (D8) and 16 (D16) of the protocol. On D16, each recipient received an embryo after the confirmation of a corpus luteum. At this moment, a blood sample was collected and cortisol concentration was evaluated in the sample with radioimmunoassay. On D41 (D33 embryo), pregnancy diagnosis was assessed (PD). The yield rates of recipient cows and pregnancy after the protocol were 66.81% (151/226) and 35.76% (54/151), respectively. Cows that became pregnant presented lower means in RT, plasmatic cortisol and THI parameters (P < 0.05) in comparison to nonpregnant group. The percentage of pregnant cows at Day 41 was higher (P < 0.0001) for cows that had RT

Made available in DSpace on 2018-11-26T17:40:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-09-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) FAP/DF INCT in Nanobiotechnology In this study we report on successful production of two samples (BR15 and BR16) comprising magnetite (Fe3O4) nanoparticles (similar to 10 nm) surface-functionalized via hydrolysis and condensation of alkoxysilane agents, namely 3-aminopropyl-trimethoxisilane (APTS) and N-propyl-trimethoxisilane (NPTS). The as-produced samples were characterized using transmission electron microscopy (TEM), x-ray diffraction (XRD), magnetization measurements (5 K and 300 K hysteresis cycles and zero field-cooled/field-cooled measurements), and Mossbauer spectroscopy (77 and 297 K). The Mossbauer data supported the model picture of a core-shell magnetite-based system. This material system shows shell properties influenced by the surface-coating design, either APTS-coated (BR15) or APTS+NPTS-coated (sample BR16). Analyses of the Mossbauer spectra indicates that the APTS-coated sample presents Fe(III)-rich core and Fe(II)-rich shell with strong hyperfine field; whereas, the APTS+NPTS-coated sample leads to a mixture of two main nanostructures, one essentially surface-terminated with APTS whereas the other surface-terminated with NPTS, both presenting weak hyperfine fields compared with the single surface-coated sample. Magnetization measurements support the core-shell picture built from the analyses of the Mossbauer data. Our findings emphasize the capability of the Mossbauer spectroscopy in assessing subtle differences in surface-functionalized iron-based core-shell nanostructures. Univ Fed Acre, Postgrad Studies Biotechnol & Biodivers, Rio Branco, Acre, Brazil Univ Estadual Paulista, Inst Chem, Dept Phys Chem, Sao Paulo, Brazil Univ Brasilia, Inst Ciencias Biol, BR-70910900 Brasilia, DF, Brazil Univ Brasilia, Inst Fis, BR-70910900 Brasilia, DF, Brazil Anhui Univ, Sch Chem & Chem Engn, Hefei 230601, Anhui, Peoples R China Univ Estadual Paulista, Inst Chem, Dept Phys Chem, Sao Paulo, Brazil