990 resultados para Hysterisis of Suction
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The present work aimed to investigate the diversity of bacteria and filamentous fungi of southern Atlantic Ocean marine sponge Dragmacidon reticulatum using cultivation-independent approaches. Fungal ITS rDNA and 18S gene analyses (DGGE and direct sequencing approaches) showed the presence of representatives of three order (Polyporales, Malasseziales, and Agaricales) from the phylum Basidiomycota and seven orders belonging to the phylum Ascomycota (Arthoniales, Capnodiales, Dothideales, Eurotiales, Hypocreales, Pleosporales, and Saccharomycetales). On the other hand, bacterial 16S rDNA gene analyses by direct sequencing approach revealed the presence of representatives of seven bacterial phyla (Cyanobacteria, Proteobacteria, Actinobacteria, Bacteroidetes, Lentisphaerae, Chloroflexi, and Planctomycetes). Results from statistical analyses (rarefaction curves) suggested that the sampled clones covered the fungal diversity in the sponge samples studied, while for the bacterial community additional sampling would be necessary for saturation. This is the first report related to the molecular analyses of fungal and bacterial communities by cultivation-independent approaches in the marine sponges D. reticulatum. Additionally, the present work broadening the knowledge of microbial diversity associated to marine sponges and reports innovative data on the presence of some fungal genera in marine samples.
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Cyclosporin A (CsA) is a widely employed immunosuppressive drug that is associated with several side effects, among then hepatotoxicity. Heteropterys tomentosa is a Brazilian plant efficient in reducing damage caused by CsA on the rat testis and prostate. The aim of this study was to evaluate the effect of CsA and H. tomentosa (administered isolated or simultaneously) on the liver of Wistar rats. The animals were treated daily with water (control), CsA (15mg/kg/day), H. tomentosa infusion or CsA+H. tomentosa, for 21 or 56 days. The treatments did not alter liver morphology or cause fibrosis. H. tomentosa administered for 21 days increased the number of hepatocyte nuclei and Kupffer cell volumetric proportion. After 56 days of treatment, H. tomentosa administration did not alter the parameters analyzed. Biochemical plasma dosages and liver stereology showed impairment caused by CsA-treatment after 21 days; these results were not observed after 56 days of treatment. The simultaneous treatment with CsA and H. tomentosa for 21 or 56 days did not alleviate nor accentuate CsA hepatic effects. The present study showed that the 21 days treatment with CsA caused more alteration to the liver than the 56 days treatment; this could be related to hepatic recovery after the long term treatment.
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Objective To assess depression and anxiety symptoms of adolescents with epilepsy compared with adolescents without epilepsy. Method The study sample consisted of: case participants (50 subjects) attending the pediatric epilepsy clinic of a tertiary hospital and control participants (51 subjects) from public schools. The instruments utilized were: identification card with demographic and epilepsy data, Beck Depression Inventory and State-Trait Anxiety Inventory. Results No significant differences were founded between the groups regarding scores for depression and anxiety symptoms but both groups presented moderate scores of anxiety. A correlation was found between low scores anxiety and not frequent seizures, low scores anxiety and perception of seizure control, high scores of anxiety and depression and occurrence of seizures in public places. Conclusion Low scores of anxiety are associated with not frequent seizures; high scores of anxiety and depression are associated with occurrence of seizures in public places.
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Mechanically evoked reflexes have been postulated to be less sensitive to presynaptic inhibition (PSI) than the H-reflex. This has implications on investigations of spinal cord neurophysiology that are based on the T-reflex. Preceding studies have shown an enhanced effect of PSI on the H-reflex when a train of ~10 conditioning stimuli at 1 Hz was applied to the nerve of the antagonist muscle. The main questions to be addressed in the present study are if indeed T-reflexes are less sensitive to PSI and whether (and to what extent and by what possible mechanisms) the effect of low frequency conditioning, found previously for the H-reflex, can be reproduced on T-reflexes from the soleus muscle. We explored two different conditioning-to-test (C-T) intervals: 15 and 100 ms (corresponding to D1 and D2 inhibitions, respectively). Test stimuli consisted of either electrical pulses applied to the posterior tibial nerve to elicit H-reflexes or mechanical percussion to the Achilles tendon to elicit T-reflexes. The 1 Hz train of conditioning electrical stimuli delivered to the common peroneal nerve induced a stronger effect of PSI as compared to a single conditioning pulse, for both reflexes (T and H), regardless of C-T-intervals. Moreover, the conditioning train of pulses (with respect to a single conditioning pulse) was proportionally more effective for T-reflexes as compared to H-reflexes (irrespective of the C-T interval), which might be associated with the differential contingent of Ia afferents activated by mechanical and electrical test stimuli. A conceivable explanation for the enhanced PSI effect in response to a train of stimuli is the occurrence of homosynaptic depression at synapses on inhibitory interneurons interposed within the PSI pathway. The present results add to the discussion of the sensitivity of the stretch reflex pathway to PSI and its functional role.
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In this work, we discuss the use of multi-way principal component analysis combined with comprehensive two-dimensional gas chromatography to study the volatile metabolites of the saprophytic fungus Memnoniella sp. isolated in vivo by headspace solid-phase microextraction. This fungus has been identified as having the ability to induce plant resistance against pathogens, possibly through its volatile metabolites. Adequate culture media was inoculated, and its headspace was then sampled with a solid-phase microextraction fiber and chromatographed every 24 h over seven days. The raw chromatogram processing using multi-way principal component analysis allowed the determination of the inoculation period, during which the concentration of volatile metabolites was maximized, as well as the discrimination of the appropriate peaks from the complex culture media background. Several volatile metabolites not previously described in the literature on biocontrol fungi were observed, as well as sesquiterpenes and aliphatic alcohols. These results stress that, due to the complexity of multidimensional chromatographic data, multivariate tools might be mandatory even for apparently trivial tasks, such as the determination of the temporal profile of metabolite production and extinction. However, when compared with conventional gas chromatography, the complex data processing yields a considerable improvement in the information obtained from the samples. This article is protected by copyright. All rights reserved.
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Ropivacaine (RVC) is an aminoamide local anesthetic widely used in surgical procedures. Studies with RVC encapsulated in liposomes and complexed in cyclodextrins have shown good results, but in order to use RVC for lengthy procedures and during the postoperative period, a still more prolonged anesthetic effect is required. This study therefore aimed to provide extended RVC release and increased upload using modified liposomes. Three types of vesicles were studied: (i) large multilamellar vesicle (LMV), (ii) large multivesicular vesicle (LMVV) and (iii) large unilamellar vesicle (LUV), prepared with egg phosphatidylcholine/cholesterol/α-tocopherol (4:3:0.07 mol%) at pH 7.4. Ionic gradient liposomes (inside: pH 5.5, pH 5.5 + (NH4)2SO4 and pH 7.4 + (NH4)2SO4) were prepared and showed improved RVC loading, compared to conventional liposomes (inside: pH 7.4). An high-performance liquid chromatography analytical method was validated for RVC quantification. The liposomes were characterized in terms of their size, zeta potential, polydispersion, morphology, RVC encapsulation efficiency (EE(%)) and in vitro RVC release. LMVV liposomes provided better performance than LMV or LUV. The best formulations were prepared using pH 5.5 (LMVV 5.5in) or pH 7.4 with 250 mM (NH4)2SO4 in the inner aqueous core (LMVV 7.4in + ammonium sulfate), enabling encapsulation of as much as 2% RVC, with high uptake (EE(%) ∼70%) and sustained release (∼25 h). The encapsulation of RVC in ionic gradient liposomes significantly extended the duration of release of the anesthetic, showing that this strategy could be a viable means of promoting longer-term anesthesia during surgical procedures and during the postoperative period.
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The establishment of the most stable structures of eight membered rings is a challenging task to the field of conformational analysis. In this work, a series of 2-halocyclooctanones were synthesized (including fluorine, chlorine, bromine and iodine derivatives) and submitted to conformational studies using a combination of theoretical calculation and infrared spectroscopy. For each compound, four conformations were identified as the most important ones. These conformations are derived from the chair-boat conformation of cyclooctanone. The pseudo-equatorial (with respect to the halogen) conformer is preferred in vacuum and in low polarity solvents for chlorine, bromine and iodine derivatives. For 2-fluorocyclooctanone, the preferred conformation in vacuum is pseudo-axial. In acetonitrile, the pseudo-axial conformer becomes the most stable for the chlorine derivative. According to NBO calculations, the conformational preference is not dictated by electron delocalization, but by classical electrostatic repulsions.
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Species identification is an essential step in the progress and completion of work in several areas of biological knowledge, but it is not a simple process. Due to the close phylogenetic relationship of certain species, morphological characters are not always sufficiently distinguishable. As a result, it is necessary to combine several methods of analysis that contribute to a distinct categorization of taxa. This study aimed to raise diagnostic characters, both morphological and molecular, for the correct identification of species of the genus Chrysomya (Diptera: Calliphoridae) recorded in the New World, which has continuously generated discussion about its taxonomic position over the last century. A clear example of this situation was the first record of Chrysomya rufifacies in Brazilian territory in 2012. However, the morphological polymorphism and genetic variability of Chrysomya albiceps studied here show that both species (C. rufifacies and C. albiceps) share very similar character states, leading to misidentification and subsequent registration error of species present in our territory. This conclusion is demonstrated by the authors, based on a review of the material deposited in major scientific collections in Brazil and subsequent molecular and phylogenetic analysis of these samples. Additionally, we have proposed a new taxonomic key to separate the species of Chrysomya found on the American continent, taking into account a larger number of characters beyond those available in current literature.
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In recent years, the scientific community has undertaken research on plant extracts, searching for compounds with pharmacological activities that can be used in diverse fields of medicine. Calendula officinalis L. is known to have antioxidant, anti-inflammatory, antibacterial, and wound healing properties when used to treat skin burns. Therefore, the purpose of this study was to analyze the effects of C. officinalis on the initial phase of Achilles tendon healing. Wistar rats were separated in three groups: Calendula (Cal)-rats with a transected tendon were treated with topical applications of C. officinalis cream and then euthanized 7 days after injury; Control (C)-rats were treated with only vehicle after transection; and Normal (N)-rats without tenotomy. Higher concentrations of hydroxyproline (an indicator of total collagen) and non-collagenous proteins were observed in the Cal group in relation to the C group. Zymography showed no difference in the amount of the isoforms of metalloproteinase-2 and of metalloproteinase-9, between C and Cal groups. Polarization microscopy images analysis showed that the Cal group presented a slightly higher birefringence compared with the C group. In sections of tendons stained with toluidine blue, the transected groups presented higher metachromasy as compared with the N group. Immunocytochemistry analysis for chondroitin-6-sulfate showed no difference between the C and Cal groups. In conclusion, the topical application of C. officinalis after tendon transection increases the concentrations of collagen and non-collagenous proteins, as well as the collagen organization in the initial phase of healing.
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Riboflavin (vitamin B2) is a precursor for coenzymes involved in energy production, biosynthesis, detoxification, and electron scavenging. Previously, we demonstrated that irradiated riboflavin (IR) has potential antitumoral effects against human leukemia cells (HL60), human prostate cancer cells (PC3), and mouse melanoma cells (B16F10) through a common mechanism that leads to apoptosis. Hence, we here investigated the effect of IR on 786-O cells, a known model cell line for clear cell renal cell carcinoma (CCRCC), which is characterized by high-risk metastasis and chemotherapy resistance. IR also induced cell death in 786-O cells by apoptosis, which was not prevented by antioxidant agents. IR treatment was characterized by downregulation of Fas ligand (TNF superfamily, member 6)/Fas (TNF receptor superfamily member 6) (FasL/Fas) and tumor necrosis factor receptor superfamily, member 1a (TNFR1)/TNFRSF1A-associated via death domain (TRADD)/TNF receptor-associated factor 2 (TRAF) signaling pathways (the extrinsic apoptosis pathway), while the intrinsic apoptotic pathway was upregulated, as observed by an elevated Bcl-2 associated x protein/B-cell CLL/lymphoma 2 (Bax/Bcl-2) ratio, reduced cellular inhibitor of apoptosis 1 (c-IAP1) expression, and increased expression of apoptosis-inducing factor (AIF). The observed cell death was caspase-dependent as proven by caspase 3 activation and poly(ADP-ribose) polymerase-1 (PARP) cleavage. IR-induced cell death was also associated with downregulation of v-src sarcoma (Schmidt-Ruppin A-2) viral oncogene homologue (avian)/protein serine/threonine kinase B/extracellular signal-regulated protein kinase 1/2 (Src/AKT/ERK1/2) pathway and activation of p38 MAP kinase (p38) and Jun-amino-terminal kinase (JNK). Interestingly, IR treatment leads to inhibition of matrix metalloproteinase-2 (MMP-2) activity and reduced expression of renal cancer aggressiveness markers caveolin-1, low molecular weight phosphotyrosine protein phosphatase (LMWPTP), and kinase insert domain receptor (a type III receptor tyrosine kinase) (VEGFR-2). Together, these results show the potential of IR for treating cancer.
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Different storage conditions can induce changes in the colour and carotenoid profiles and levels in some fruits. The goal of this work was to evaluate the influence of low temperature storage on the colour and carotenoid synthesis in two banana cultivars: Prata and Nanicão. For this purpose, the carotenoids from the banana pulp were determined by HPLC-DAD-MS/MS, and the colour of the banana skin was determined by a colorimeter method. Ten carotenoids were identified, of which the major carotenoids were all-trans-lutein, all-trans-α-carotene and all-trans-β-carotene in both cultivars. The effect of the low temperatures was subjected to linear regression analysis. In cv. Prata, all-trans-α-carotene and all-trans-β-carotene were significantly affected by low temperature (p<0.01), with negative estimated values (β coefficients) indicating that during cold storage conditions, the concentrations of these carotenoids tended to decrease. In cv. Nanicão, no carotenoid was significantly affected by cold storage (p>0.05). The accumulation of carotenoids in this group may be because the metabolic pathways using these carotenoids were affected by storage at low temperatures. The colour of the fruits was not negatively affected by the low temperatures (p>0.05).
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In recent years, agronomical researchers began to cultivate several olive varieties in different regions of Brazil to produce virgin olive oil (VOO). Because there has been no reported data regarding the phenolic profile of the first Brazilian VOO, the aim of this work was to determine phenolic contents of these samples using rapid-resolution liquid chromatography coupled to electrospray ionisation time-of-flight mass spectrometry. 25 VOO samples from Arbequina, Koroneiki, Arbosana, Grappolo, Manzanilla, Coratina, Frantoio and MGS Mariense varieties from three different Brazilian states and two crops were analysed. It was possible to quantify 19 phenolic compounds belonging to different classes. The results indicated that Brazilian VOOs have high total phenolic content because the values were comparable with those from high-quality VOOs produced in other countries. VOOs from Coratina, Arbosana and Grappolo presented the highest total phenolic content. These data will be useful in the development and improvement of Brazilian VOO.
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To evaluate the influence of light-activation of second, third and fourth increments on degree of conversion (DC) and microhardness (KHN) of the top (T) and bottom (B) surface of the first increment. Forty samples (n = 5) were prepared. In groups 1-4, after each increment light-activation (multiple irradiation), T and B of the first increment were measured in DC and KHN. In groups 5-8, only the first increment was made (single irradiation) and measurements of DC and KHN were taken at 15 min intervals. The light-activation modes were (XL) 500 mW/cm(2) × 38 s (G1/G5); (S) 1000 mW/cm(2) × 19 s (G2/G6), (HP) 1400 mW/cm(2) × 14 s (G3/G7); (PE) 3200 mW/cm(2) × 6 s (G4/G8). Data for DC and KHN were analyzed separately by using PROC MIXED for repeated measures and Tukey-Kramer test (α = 0.05). For KHN, B showed lower values than T. PE resulted in lower values of KHN in B surface. For single and multiple irradiations, T and B of first measurement showed the lowest KHN and the fourth measurement showed the highest, with significant difference between them. For single irradiation, first and second increments presented similar KHN, different from the third and fourth increment, which did not differ between them. For multiple irradiations, the second light-activation resulted in KHN similar to first, third and fourth increments. For DC, except QTH, T presented higher DC than B. The light-activation of successive increments was not able to influence the KHN and DC of the first increment.
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To evaluate the occurrence of severe obstetric complications associated with antepartum and intrapartum hemorrhage among women from the Brazilian Network for Surveillance of Severe Maternal Morbidity. Multicenter cross-sectional study. Twenty-seven obstetric referral units in Brazil between July 2009 and June 2010. A total of 9555 women categorized as having obstetric complications. The occurrence of potentially life-threatening conditions, maternal near miss and maternal deaths associated with antepartum and intrapartum hemorrhage was evaluated. Sociodemographic and obstetric characteristics and the use of criteria for management of severe bleeding were also assessed in these women. The prevalence ratios with their respective 95% confidence intervals adjusted for the cluster effect of the design, and multiple logistic regression analysis were performed to identify factors independently associated with the occurrence of severe maternal outcome. Antepartum and intrapartum hemorrhage occurred in only 8% (767) of women experiencing any type of obstetric complication. However, it was responsible for 18.2% (140) of maternal near miss and 10% (14) of maternal death cases. On multivariate analysis, maternal age and previous cesarean section were shown to be independently associated with an increased risk of severe maternal outcome (near miss or death). Severe maternal outcome due to antepartum and intrapartum hemorrhage was highly prevalent among Brazilian women. Certain risk factors, maternal age and previous cesarean delivery in particular, were associated with the occurrence of bleeding.
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Dystrophin-deficient muscles have repeated cycles of necrosis and regeneration, being susceptible to injury induced by muscle contractions. Some studies have demonstrated that tendons are also affected in mdx mice, based especially on the changes in biomechanical properties arising from the respective linked muscles. However, most studies have focused only on alterations in the myotendinous junction. Thus, the purpose of this work was to study biochemical and morphological alterations in the Achilles tendons of 60-day-old mdx mice. Hydroxyproline quantification, showed higher collagen concentration in the mdx mice as compared with the control. No difference between the tendons of both groups was found in the noncollagenous proteins dosage, and in the amount of collagen type III detected in the western blotting analysis. The zymography for gelatinases detection showed higher amounts of metaloproteinase-2 (active isoform) and of metalloproteinase-9 (latent isoform) in the mdx mice. Measurements of birefringence, using polarization microscopy, showed higher molecular organization of the collagen fibers in the tendons of mdx mice in comparison to the control group, with presence of larger areas of crimp. Ponceau SS-stained tendon sections showed stronger staining of the extracellular matrix in the mdx groups. Toluidine blue-stained sections showed more intense basophilia in tendons of the control group. In morphometry, a higher number of inflammatory cells was detected in the epitendon of mdx group. In conclusion, the Achilles tendon of 60-day-old mdx mice presents higher collagen concentration and organization of the collagen fibers, enhanced metalloproteinase-2 activity, as well as prominent presence of inflammatory cells and lesser proteoglycans.