Effect of Restricted Suckling or Temporal Weaning on Some Physiological and Behavioural Stress Parameters in Zebu Cattle (Bos indicus)

Acevedo, N.,Hernandez, C.,Orihuela, A.,Lidfors, L.M.,Berg, C. Asian Australasian Association of Animal Productio 2005 Animal Bioscience Vol.18 No.8

This study investigated the effects of restricted suckling (RS) on some physiological and behavioural stress parameters compared to temporal weaning (TW). Twenty Brahman (Bos indicus) cow-calf pairs were assigned to one of two groups: Calves in the RS group were limited to suckle their dams once daily for 30 min during days 30 to 33, while calves in the TW group were removed from their dams during days 59 to 62 postpartum. Heart and respiratory rates, serum cortisol concentration and body temperature were registered in cows and calves. In addition, the number of steps was also registered in calves. All parameters were recorded 24, 48 and 72 h after the beginning of the two treatments, respectively. In TW calves, higher (p<0.05) cortisol concentration and number of steps were recorded in the 1st samples and 1$^{st}$ and 2$^{nd}$ observations, respectively. No difference was found in body temperature between treatments. However, respiration and heart rates differed in the 1$^{st}$ and 2$^{nd}$ observations, respectively. In general, a significant decrease (p<0.05) in these three parameters was observed over time. In cows, no differences were found in cortisol concentration or body temperature between treatments or with time. Heart and respiratory rates were lower (p<0.05) in the TW treatment only 24 h after beginning of treatment. It was concluded that (a) RS resulted in less behavioural and physiological indices of distress compared to TW in calves, although in general, differences were found only in some variables, mainly during the 1$^{st}$ day following start of the treatment, and there in a chance of age effects. (b) Cows were less affected than their young, regardless of the treatment applied.

Optimization of silver nanoparticle synthesis by chemical reduction and evaluation of its antimicrobial and toxic activity

Catalina Quintero-Quiroz,Natalia Acevedo,Jenniffer Zapata-Giraldo,Luz E. Botero,Julián Quintero,Diana Zárate-Triviño,Jorge Saldarriaga,Vera Z. Pérez 한국생체재료학회 2020 생체재료학회지 Vol.24 No.1

Background: Chemical reduction has become an accessible and useful alternative to obtain silver nanoparticles (AgNPs). However, its toxicity capacity depends on multiple variables that generate differences in the ability to inhibit the growth of microorganisms. Thus, optimazing parameters for the synthesis of AgNPs can increase its antimicrobial capacity by improving its physical-chemical properties. Methods: In this study a Face Centered Central Composite Design (FCCCD) was carried out with four parameters: AgNO3 concentration, sodium citrate (TSC) concentration, NaBH4 concentration and the pH of the reaction with the objective of inhibit the growth of microorganisms. The response variables were the average size of AgNPs, the peak with the greatest intensity in the size distribution, the polydispersity of the nanoparticle size and the yield of the process. AgNPs obtained from the optimization were characterized physically and chemically. The antimicrobial activity of optimized AgNPs was evaluated against Staphylococcus aureus, Escherichia coli, Escherichia coli AmpC resistant, and Candida albicans and compared with AgNPs before optimization. In addition, the cytotoxicity of the optimized AgNPs was evaluated by the colorimetric assay MTT (3- (4,5- Dimethylthiazol- 2- yl)- 2, 5 - Diphenyltetrazolium Bromide). Results: It was found that the four factors studied were significant for the response variables, and a significant model (p <0.05) was obtained for each variable. The optimal conditions were 8 for pH and 0.01 M, 0.0 6M, 0.01 M for the concentration of TSC, AgNO3, and NaBH4, respectively. Optimized AgNPs spherical and hemispherical were obtained, and 67.66% of it had a diameter less than 10.30 nm. A minimum bactericidal concentration (MBC) and minimum fungicidal Concentration (MFC) of optimized AgNPs was found against Staphylococcus aureus, Escherichia coli, Escherichia coli AmpC resistant, and Candida albicans at 19.89, 9.94, 9.94, 2.08 μg/mL, respectively. Furthermore, the lethal concentration 50 (LC50) of optimized AgNPs was found on 19.11 μg/mL and 19.60 μg/mL to Vero and NiH3T3 cells, respectively. Conclusions: It was found that the factors studied were significant for the variable responses and the optimization process used was effective to improve the antimicrobial activity of the AgNPs.

The Amazon Tall Tower Observatory (ATTO): overview of pilot measurements on ecosystem ecology, meteorology, trace gases, and aerosols

Andreae, M. O.,Acevedo, O. C.,Araù,jo, A.,Artaxo, P.,Barbosa, C. G. G.,Barbosa, H. M. J.,Brito, J.,Carbone, S.,Chi, X.,Cintra, B. B. L.,da Silva, N. F.,Dias, N. L.,Dias-Jú,nior, C. Q.,Dita Copernicus GmbH 2015 Atmospheric Chemistry and Physics Vol.15 No.18

<P>Abstract. The Amazon Basin plays key roles in the carbon and water cycles, climate change, atmospheric chemistry, and biodiversity. It has already been changed significantly by human activities, and more pervasive change is expected to occur in the coming decades. It is therefore essential to establish long-term measurement sites that provide a baseline record of present-day climatic, biogeochemical, and atmospheric conditions and that will be operated over coming decades to monitor change in the Amazon region, as human perturbations increase in the future. The Amazon Tall Tower Observatory (ATTO) has been set up in a pristine rain forest region in the central Amazon Basin, about 150 km northeast of the city of Manaus. Two 80 m towers have been operated at the site since 2012, and a 325 m tower is nearing completion in mid-2015. An ecological survey including a biodiversity assessment has been conducted in the forest region surrounding the site. Measurements of micrometeorological and atmospheric chemical variables were initiated in 2012, and their range has continued to broaden over the last few years. The meteorological and micrometeorological measurements include temperature and wind profiles, precipitation, water and energy fluxes, turbulence components, soil temperature profiles and soil heat fluxes, radiation fluxes, and visibility. A tree has been instrumented to measure stem profiles of temperature, light intensity, and water content in cryptogamic covers. The trace gas measurements comprise continuous monitoring of carbon dioxide, carbon monoxide, methane, and ozone at five to eight different heights, complemented by a variety of additional species measured during intensive campaigns (e.g., VOC, NO, NO2, and OH reactivity). Aerosol optical, microphysical, and chemical measurements are being made above the canopy as well as in the canopy space. They include aerosol light scattering and absorption, fluorescence, number and volume size distributions, chemical composition, cloud condensation nuclei (CCN) concentrations, and hygroscopicity. In this paper, we discuss the scientific context of the ATTO observatory and present an overview of results from ecological, meteorological, and chemical pilot studies at the ATTO site. </P>

Direct Chemical Vapor Deposition Synthesis of Phase-Pure Iron Pyrite (FeS₂) Thin Films

Samad, Leith,Cabá,n-Acevedo, Miguel,Shearer, Melinda J.,Park, Kwangsuk,Hamers, Robert J.,Jin, Song American Chemical Society 2015 Chemistry of materials Vol.27 No.8

<P>Resurgent interest in iron pyrite (FeS<SUB>2</SUB>) as an earth-abundant, nontoxic semiconductor for solar applications has resulted in many attempts to grow phase-pure thin films via chemical vapor deposition (CVD). However, all thin films grown via CVD or sulfidation to date have contained marcasite phase or other iron sulfide impurities. Here, we report the use of metallic cobalt pyrite (cattierite, CoS<SUB>2</SUB>) thin films as an ideal substrate leading to the first direct growth of phase-pure iron pyrite thin films via atmospheric pressure CVD. This synthesis was achieved by reacting FeCl<SUB>3</SUB> and ditert butyl disulfide (TBDS) at 400–450 °C. The products were confirmed as phase-pure iron pyrite using X-ray diffraction (XRD), Raman spectroscopy, and energy dispersive X-ray spectroscopy (EDS). In addition to phase-purity, the synthesis produced crystal domains >1 μm and a conformal coating 3–5 μm thick, which are attributed to the <2% lattice mismatch of the isostructural cattierite substrate. The surface was characterized by ultraviolet and X-ray photoelectron spectroscopy (UPS & XPS) and the electrical properties by electrochemical impedance spectroscopy (EIS) and Mott–Schottky analysis. The direct growth of a phase-pure iron pyrite film on a conductive substrate provides the most convenient configuration so far for potential solar cells.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2015/cmatex.2015.27.issue-8/acs.chemmater.5b00664/production/images/medium/cm-2015-00664c_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cm5b00664'>ACS Electronic Supporting Info</A></P>

Acute and Repeated 28-Day Oral Dose Toxicity Studies of Thymus vulgaris L. Essential Oil in Rats

Juan Rojas Armas,Jorge Arroyo-Acevedo,Manuel Ortiz-Sánchez,Miriam Palomino-Pacheco,Américo Castro-Luna,Norma Ramos-Cevallos,Hugo Justil-Guerrero,Julio Hilario-Vargas,Oscar Herrera-Calderón 한국독성학회 2019 Toxicological Research Vol.35 No.3

Thymus vulgaris L. is widely used as an ingredient in cooking and in herbal medicine. However, there is little information about its toxicity. The present study was performed to evaluate the acute and repeated 28-day oral dose toxicity of thyme essential oil in rats. For the acute toxicity test, two groups of three rats were used. The rats received a single dose of essential oil: 300 or 2,000 mg/kg of body weight (bw). The rats were observed individually during the first four hours, and then daily until day 14. For the toxicity test with repeated doses, four groups of 10 rats were used. Doses of 100, 250, and 500 mg/kg/day were tested for 28 days. At the end of the experiment, blood was collected and the animals were sacrificed. Histopathological examination showed that in the lungs of rats given the 2,000 mg/kg bw dose, polymorph nuclear infiltrates, hemosiderin macrophages, and interstitial space thickening were present. In the repeated dose study, all rats survived the 28-day treatment period and apparently showed no signs of toxicity. The hematological and biochemical parameters were not altered. The histopathological study of the organs showed severe changes in the lung, with the dose of 500 mg/kg/day; in the other organs, no alterations were observed or the changes were slight. The body weight was only altered in male rats given the 500 mg/kg dose. The relative weight of the organs did not show any significant changes. Our studies revealed that the essential oil of Thymus vulgaris has moderate oral toxicity according to the results of the acute test, whereas the results of the 28-day oral toxicity test suggest that the no-observed-adverse effect level (NOAEL) is greater than 250 mg/kg/day.

Use of inductors in the control of Colletotrichum gloeosporioides and Rhizopus stolonifer isolated from soursop fruits: in vitro tests

Anelsy Ramos-Guerrero,Ramse´s Ramo´n Gonza´lez-Estrada,Greta Hanako-Rosas,Silvia Bautista-Ban˜os,Gustavo Acevedo-Herna´ndez,Martin Ernesto Tiznado-Herna´ndez,Porfirio Gutie´rrez-Martı´nez 한국식품과학회 2018 Food Science and Biotechnology Vol.27 No.3

Soursop (Annona muricata) is a tropical fruit that can be infected by Colletotrichum gloeosporioides and Rhizopus stolonifer. Traditional methods used for postharvest disease control include the application of fungicides, however due to their excessive use, as well as their persistence in the environment, the development of new strategies that control pathogens are required. The application of chitosan (Chi), salicylic acid (SA) and methyl jasmonate (MJ) is an environmentally-friendly alternative with antimicrobial properties and also induces defense mechanisms in plant tissues. In this study, Colletotrichum was reactivated and Rhizopus was identified using morphological features and molecular tools. In vitro, the application of 0.5 and 1.0% of Chi alone or in combination with SA and MJ decreased mycelial growth and sporulation, a complete inhibition of spore germination was obtained. Thus, the application of Chi in combination with SA and MJ could be a smart strategy to inhibit the development of pathogens that attack soursop fruit.

Diagnostic challenge and management of intraosseous mandibular hemangiomas: a case report and literature review

Maria Isabel Sá,nchez Jorge,Jorge Corté,s-Bretó,n Brinkmann,Aranzazu Gonzá,lez Corchó,n,Rosa Acevedo Ocañ,a 대한구강악안면외과학회 2021 대한구강악안면외과학회지 Vol.47 No.4

Hemangioma is a benign tumor characterized by the proliferation of blood vessels. Although it often appears in soft tissues, its occurrence in bone tissue, particularly the mandible, is extremely rare. A 32-year-old female sought attention at the dental clinic complaining of a painless swelling in the posterior region of the left side of the mandible. A panoramic radiograph and computed axial tomography scan were taken, showing honeycomb and sunburst images, respectively, in the affected area. The patient underwent a biopsy, which led to the diagnosis of intraosseous hemangioma. Having assessed the characteristics of the lesion, it was decided to perform complete excision including safety margins, followed by an iliac crest bone graft to reconstruct the mandible. Awareness of the possible clinical and radiographic presentations of intraosseous hemangioma is considered important, as non-diagnosis could have severe consequences given its possible relation to dental structures.

Effect of acid treatment on extraction yield and gel strength of gelatin from whiptail stingray (Dasyatis brevis) skin

Marco Antonio Sa´ntiz-Go´mez,Miguel Angel Mazorra-Manzano,Hugo Enrique Ramı´rez-Guerra,Susana Marı´a Scheuren-Acevedo,Gerardo Navarro-Garcı´a,Ramo´n Pacheco-Aguilar,Juan Carlos Ramı´rez-Sua´rez 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.3

Chemical properties of fish gelatins differ fromthose of conventional mammalian sources, representing anattractive technological alternative for the food industry. Ray filleting generates a considerable amount of skin wastethat can be used as a collagen source for gelatin extraction. Thus, this research evaluated the HCl and CH3COOHeffect, at 0.01, 0.025, 0.05, 0.075, 0.1, 0.15, and 0.2 M, onextraction yield, molecular weight distribution, and gelstrength (GS) of whiptail stingray (Dasyatis brevis) skingelatins. Results showed differences (P\0.05) betweenacid type and concentration used. CH3COOH (0.15 M)gave the highest extraction yield (7.0% vs. 5.5% at 0.15 MHCl) and GS (653 ± 71 g vs. 619.5 ± 82 g at 0.2 M HCl). Gelatin electrophoretic profile from CH3COOH revealeda-/b-components and high molecular weight ([200 kDa)polymers. Ray gelatin GS was higher than commercialbovine gelatin, suggesting its possible use for technologicalfood applications.