453 resultados para Quantum effects


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The objective was to determine the cardiopulmonary effects and eyeball centralization time obtained with 15 or 30µg kg-1 of atracurium in anesthetized dogs under spontaneous breathing. Eighteen healthy adult mixed-breed dogs were used, which received 0.1mg kg-1 acepromazine and 0.5mg kg-1 morphine IM, followed by 4mg kg-1 propofol IV and maintained on isoflurane anesthesia with spontaneous breathing. Animals received 1mL 0.9% NaCl IV (CG), 15µg kg-1 (G15) or 30µg kg-1 (G30) of atracurium IV. Eyeball centralization time was measured; heart rate (HR), systolic (SAP), mean (MAP) and diastolic (DAP) arterial pressures, respiratory rate (RR), tidal volume (Vt) and minute volume (Vm) were determined every 5min, and pH, arterial CO2 pressure (PaCO2 ), arterial O2 pressure (PaO2 ), hemoglobin oxygen saturation (SaO2 ), bicarbonate (HCO3-) and base excess (BE) every 15min until 60min. Both doses of atracurium produced a similar period of eyeball centralization. Vt in groups treated with atracurium was lower than in CG up to 15min. Vm in G15 differed from CG up to 10min and in G30 up to 25min. No differences were observed for cardiovascular parameters, RR, SaO2, PaO2, HCO3- and BE. pH decreased in CG between 30 and 60min and in G15 and G30 at 15min. G30 differed from CG between 15 and 30min. PaCO2 in GC differed from baseline between 30 and 60min and in G15 differed at 15min. Atracurium at the dose of 15µg kg-1 is adequate for short corneal procedures in inhalant-anesthetized dogs under spontaneous breathing.

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Increased tourist activity in coastal regions demands management strategies to reduce impacts on rocky shores. The highly populated coastal areas in southeastern Brazil are an example of degradation caused by development of industry and tourism. Among different shore impacts, trampling has been intensively studied, and may represent a significant source of stress for intertidal fauna. A randomised blocks design was applied to experimentally study the effects of two different trampling intensities on richness, diversity, density and biomass of the rocky shore fauna of Obuseiro beach, Guarujá, southeastern Brazil. Blocks were distributed in two portions of the intertidal zone, dominated respectively by Chthamalus bisinuatus (Cirripedia) and Isognomon bicolor (Bivalvia). Blocks were trampled over three months, simulating the vacation period in Brazil and were monitored for the following nine months. Results indicate that Chthamalus bisinuatus is vulnerable to trampling impacts. Richness, diversity and turn-over index tended to be higher in trampled plots four months after trampling ceased. In general, results agree with previous trampling studies, suggesting that even low intensities of trampling may cause some impact on intertidal communities. Management strategies should include isolation of sensitive areas, construction of boardwalks, visitor education and monitoring programmes. In Brazil, additional data obtained from experimental studies are necessary in order to achieve a better understanding of trampling impacts on rocky shore communities.

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The tolerance to the combined effects of temperature and salinity was investigated in the interstitial isopod Coxicerberus ramosae (Albuquerque, 1978), a species of intertidal zone of sandy beaches in Rio de Janeiro, Brazil. The animals were collected on Praia Vermelha Beach. The experiments lasted 24 h and nine salinities and seven temperatures were used for a total of 63 combinations. Thirty animals were tested in each combination. The species showed high survival in most of the combinations. The temperature of 35 ºC was lethal and at 5 ºC, the animals tolerated only a narrow range of salinities. The statistical analyses showed that the effects of temperature and salinity were significant on the survival, which confirmed the euryhalinity and eurythermy of this species.

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PURPOSE: To verify if uterine cerclage can induce craniosynostosis or any cranial deformity in new born Wistar rats. METHODS: One pregnant female Wistar rat underwent laparotomy on day 18 of gestation and the uterus cervix was closed with a 3-0 nylon suture to avoid delivery, that occurs normally on the 21 day. The suture was released after 48 hours beyond the normal gestation period. The female rat delivered 11 pups. Six surviving rats from the delivery (group A - constrained group). Two rats were born from another mother and in the same age were used as control group (group B - 2 nonconstrained controls) were allowed to grow. They were sacrificed 1.2 years after their birth all the eight animals. Linear measurement, routine histology and computed tomography of the skull were performed at the time of their death to evaluate the cranial asymmetries by mesurements of the anatomical landmarks of the craniofacial skeleton of the rats on the two groups and compared then. RESULTS: We did not observe statistically significant differences in any of the compared measurements (p>0.05) obtained through the morphologic and radiologic methods. Histologic examinations did not reveal any sign of premature fusion or suture imbrications. Critical decrease in longitudinal body size was noticed as the limbs too in all the animals of group A. CONCLUSION: Constriction of uterine cervix leads to fetus suffering, even death for a few animals, associated to small body size, but not to craniosynostosis.

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We present new data on litter size and date of birth (month) for 21 South American scorpions species. We provide data for one katoikogenic species, the liochelid Opisthacanthus cayaporum Vellard, 1932 (offspring = 3; birth month: Jan); and for several apoikogenic species, such as the bothriurids Bothriurus araguayae Vellard, 1934 (53; Sep), B. rochensis San Martín, 1965 (22-28; Jan, Aug); the buthids Ananteris balzanii Thorell, 1891 (10-34; Jan-Mar), Physoctonus debilis (Koch, 1840) (2; Sep), Rhopalurus amazonicus Lourenço, 1986 (19; Nov), R. lacrau Lourenço & Pinto-da-Rocha, 1997 (30; Dec), R. laticauda Thorell, 1876 (41; Nov), R. rochai Borelli, 1910 (11-47; Dec-Jan, Mar-Apr), Tityus bahiensis (Perty, 1833) (4-23; Oct-Mar), T. clathratus Koch, 1844 (8-18; Nov-Jan), T. costatus (Karsch, 1879) (21-25; Jan, Apr), T. kuryi Lourenço, 1997 (4-16; Mar), T. mattogrossensis Borelli, 1901(8-9; May), T. obscurus (Gervais, 1843) (16-31; Jan-Feb, May, Jul), T. serrulatus Lutz & Mello, 1922 (8-36; Dec, Feb-Apr), T. silvestris Pocock, 1897 (5-14; Dec-Jan, Apr), T. stigmurus (Thorell, 1876) (10-18; Nov, Jan, Mar), Tityus sp. 1 (T. clathratus group - 7-12; Feb-Apr), Tityus sp. 2 (T. bahiensis group - 2; Mar); and the chactid Brotheas sp. (8-21; Jan, Apr). We observed multiple broods: R. lacrau (offspring in the 2nd brood = 27), T. kuryi (6-16), T. obscurus (2-32), T. silvestris (8), T. stigmurus (4-9), T. bahiensis (offspring in the 2nd brood = 2-18; 3rd = 1), and T. costatus (2nd brood = 18; 3rd = 4). We found statistically significant positive correlation between female size and litter size for T. bahiensis and T. silvestris, and nonsignificant correlation for T. serrulatus.

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INTRODUCTION: The antibacterial effect of ozone (O3) has been described in the extant literature, but the role of O3 therapy in the treatment of certain types of infection remains controversial. OBJECTIVES: To evaluate the effect of intraperitoneal (i.p.) O3 application in a cecal ligation/puncture rat model on interleukins (IL-6, IL-10) and cytokine-induced neutrophil chemoattractant (CINC)-1 serum levels, acute lung injury and survival rates. METHODS: Four animal groups were used for the study: a) the SHAM group underwent laparotomy; b) the cecal ligation/puncture group underwent cecal ligation/puncture procedures; and c) the CLP+O2 and CLP+O3 groups underwent CLP+ corresponding gas mixture infusions (i.p.) throughout the observation period. IL-6, CINC-1 and IL-10 concentrations were determined by enzyme-linked immunosorbent assay (ELISA). Acute lung injury was evaluated with the Evans blue dye lung leakage method and by lung histology. P<0.05 was considered significant. RESULTS: CINC-1 was at the lowest level in the SHAM group and was lower for the CLP+O3 group vs. the CLP+O2 group and the cecal ligation/puncture group. IL-10 was lower for the SHAM group vs. the other three groups, which were similar compared to each other. IL-6 was lower for the SHAM group vs. all other groups, was lower for the CLP+O3 or CLP+O2 group vs. the cecal ligation/puncture group, and was similar for the CLP+O3 group vs. the CLP+O2 group. The lung histology score was lower for the SHAM group vs. the other groups. The Evans blue dye result was lower for the CLP+O3 group vs. the CLP+O2 group and the cecal ligation/puncture group but similar to that of the SHAM group. The survival rate for the CLP+O3 group was lower than for the SHAM group and similar to that for the other 2 groups (CLP and CLP+O2). CONCLUSION: Ozone therapy modulated the inflammatory response and acute lung injury in the cecal ligation/puncture infection model in rats, although there was no improvement on survival rates.

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PURPOSE: To compare the effectiveness of mechanical ventilation of supine versus prone position in hydrochloric acid (HCl)-induced lung dysfunction. METHODS: Twenty, adult, male, Wistar-EPM-1 rats were anesthetized and randomly grouped (n=5 animals per group) as follows: CS-MV (mechanical ventilation in supine position); CP-MV (mechanical ventilation in prone position); bilateral instillation of HCl and mechanical ventilation in supine position (HCl+S); and bilateral instillation of HCl and mechanical ventilation in prone position (HCl+P). All groups were ventilated for 180 minutes. The blood partial pressures of oxygen and carbon dioxide were measured in the time points 0 (zero; 10 minutes before lung injury for stabilization), and at the end of times acid injury, 60, 120 and 180 minutes of mechanical ventilation. At the end of experiment the animals were euthanized, and bronchoalveolar lavages (BALs) were taken to determine the contents of total proteins, inflammatory mediators, and lungs wet-to-dry ratios. RESULTS: In the HCl+P group the partial pressure of oxygen increased when compared with HCl+S (128.0±2.9 mmHg and 111.0±6.7 mmHg, respectively) within 60 minutes. TNF-α levels in BAL do not differ significantly in the HCl+P group (516.0±5.9 pg/mL), and the HCl+S (513.0±10.6 pg/mL). CONCLUSION: The use of prone position improved oxygenation, but did not reduce TNF-α in BAL upon lung dysfunction induced by HCl.

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High molecular weight components from Ascaris suum extract suppress ovalbumin-specific immunity in mice. In IFN-γ-deficient mice, ovalbumin-specific delayed-type hypersensitivity reactions are more strongly downregulated by these suppressive components. Here, the cellularity of the delayed-type hypersensitivity reaction in IFN-γ-deficient mice and the increased downregulation induced by Ascaris suum components were analyzed. IL-12p40-dependent neutrophilic influx was predominant. Suboptimal doses of the suppressive fraction from this nematode completely inhibited the hypersensitivity reaction, thus indicating intensification of the immunosuppression under conditions of intense recruitment of IFN-γ-independent neutrophils.

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Development of the positive temperature coefficient of resistivity (PTCR) in Er3+ and Ca2+ co-doped ferroelectric BaTiO3 was studied in this work, with Er3+ being used to act as a donor doping. Irrespective of all the materials showing high densities after sintering at 1200 to 1300 ºC, these revealed insulator at the lowest sintering temperature, changing to semiconducting and PTCR-type materials only when the sintering temperature was further increased. Observations from X-ray diffraction help correlating this effect with phase development in this formulated (Ba,Ca,Er)TiO3 system, considering the formation of initially two separated major (Ba,Ca)TiO3- and minor (Ca,Er)TiO3-based compounds, as a consequence of cation size-induced stress energy effects. Thus, appearance and enhancement here of the semiconducting and PTCR responses towards higher sintering temperatures particularly involve the incorporation of Er3+ into the major phase, rendering finally possible the generation and "percolative-like" migration of electrons throughout the whole material.

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Nitric oxide (NO) is a free radical synthesized from L-arginine by different isoforms NO-synthases. NO possesses multiple and complex biological functions. NO is an important mediator of homeostasis, and changes in its generation or actions can contribute or not to pathological states. The knowledge of effects of NO has been not only important to our understanding of immune response, but also to new tools for research and treatment of various diseases. Knowing the importance of NO as inflammatory mediator in diverse infectious diseases, we decided to develop a revision that shows the participation/effect of this mediator in immune response induced against Giardia spp. Several studies already demonstrated the participation of NO with microbicidal and microbiostatic activity in giardiasis. On the other hand, some works report that Giardia spp. inhibit NO production by consuming the intermediate metabolite arginine. In fact, studies in vitro showed that G. lamblia infection of human intestinal epithelial cells had reduced NO production. This occurs due to limited offer of the crucial substrate arginine (essential aminoacid for NO production), consequently reducing NO production. Therefore, the balance between giardial arginine consumption and epithelial NO production could contribute to the variability of the duration and severity of infections by this ubiquitous parasite.

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In this work we describe a subtle effect in nuclear physics, associated with three-nucleon forces, which is nevertheless fundamental in the interpretation of experimental results. It is important to notice that three-body effects are of non-pertubative origins, which makes this problem more involving theoretically. The use of Quantum Chromodynamics is fundamental in the understanding of the physics process.

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The n→π* absorption transition of formaldehyde in water is analyzed using combined and sequential classical Monte Carlo (MC) simulations and quantum mechanics (QM) calculations. MC simulations generate the liquid solute-solvent structures for subsequent QM calculations. Using time-dependent density functional theory in a localized set of gaussian basis functions (TD-DFT/6-311++G(d,p)) calculations are made on statistically relevant configurations to obtain the average solvatochromic shift. All results presented here use the electrostatic embedding of the solvent. The statistically converged average result obtained of 2300 cm-1 is compared to previous theoretical results available. Analysis is made of the effective dipole moment of the hydrogen-bonded shell and how it could be held responsible for the polarization of the solvent molecules in the outer solvation shells.

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The aim of the present study was to evaluate the effect of soil characteristics (pH, macro- and micro-nutrients), environmental factors (temperature, humidity, period of the year and time of day of collection) and meteorological conditions (rain, sun, cloud and cloud/rain) on the flavonoid content of leaves of Passiflora incarnata L., Passifloraceae. The total flavonoid contents of leaf samples harvested from plants cultivated or collected under different conditions were quantified by high-performance liquid chromatography with ultraviolet detection (HPLC-UV/PAD). Chemometric treatment of the data by principal component (PCA) and hierarchic cluster analyses (HCA) showed that the samples did not present a specific classification in relation to the environmental and soil variables studied, and that the environmental variables were not significant in describing the data set. However, the levels of the elements Fe, B and Cu present in the soil showed an inverse correlation with the total flavonoid contents of the leaves of P. incarnata.

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This work reports the photophysical properties (excitation and fluorescence spectra, fluorescence quantum yield, fluorescence lifetimes) of the poly(2,7-9,9'-dihexylfluorene-dyil) in dilute solutions of four solvents (toluene, tetrahydrofuran, chloroform and ethyl acetate) as well as the properties in solid state. Photoluminescence showed spectra characteristic of disordered α-backbone chain conformation. Simulation of the electronic absorption spectra of oligomers containing 1 to 11 mers showed that the critical conjugation length is between 6 and 7 mers. We also estimated the theoretical dipole moments which indicated that a coil conformation is formed with 8 repeating units per turn. We also showed that some energy transfer process appears in solid state which decreases the emission lifetime. Furthermore, based on luminescent response of the systems herein studied and electroluminescent behavior reported on literature, both photo and electroluminescence emissions arise from the same emissive units.