The Influence of Calcium Chloride on the Setting Time, Solubility, Disintegration, and pH of Mineral Trioxide Aggregate and White Portland Cement with a Radiopacifier

This study evaluated the influence of addition of 10% calcium chloride (CaCl(2)) on the setting time, solubility, disintegration, and pH of white MTA (WMTA) and white Portland cement (WPC). A test of the setting time was performed following the #57 ADA specifications and a test of the final setting time according to the ASTM. For the solubility tests disintegration and pH, Teflon rings were filled with the cements and weighed after setting. After 24 h in a desiccator, they were once again weighed. Thereafter, they were immersed in MiliQ water for 24 and 72 h and 7, 14, and 28 days, with maintenance in the desiccator and weighing between periods. The pH of water in which the rings were immersed was measured immediately after contact with them and in the other periods. The addition of CaCl(2) provided a significant reduction (50%) in the initial setting time of cements. The final setting time of WMTA was reduced in 35.5% and the final setting time of WPC in 68.5%. The WMTA with CaCl(2) absorbed water and gained weight with time, except for in the 24-h period. The addition of CaCl(2) to the WPC reduced its solubility. The addition of CaCl(2) increased the pH of WMTA in the immediate period and at 24 and 72 h and for WPC in the immediate period and at 24 h. The addition of CaCl(2) to WMTA and WPC reduced the setting times and solubility of both and increased the pH of cements in the initial periods. (J Endod 2009;35:550-554)

Perinatal lead exposure affects nitric oxide and cyclooxygenase pathways in aorta of weaned rats

Perinatal Pb exposure may modulate arterial tone through nitric oxide (NO) and cyclooxygenase products. To investigate this, Wistar dams received 1000 ppm of Pb or sodium acetate (control) in drinking water during pregnancy and lactation. Curves were constructed in phenylephrine-precontracted intact and/or denuded rings of thoracic aortas of weaned (23-day-old) male pups from their responses to N-omega-nitro-L-arginine methyl ester (L-NAME, NO synthase inhibitor) and ACh in the absence or presence of indomethacin (10(-5)M, cyclooxygenase inhibitor) or L-NAME (3 x 10(-7)M and 3 x 10(-4)M). Blood lead concentration and systolic blood pressure (SBP) were higher in intoxicated than control pups (blood lead mu g/dl: control < 3.0, Pb 58.7 +/- 6.5*; SBP mmHg: control 111.4 +/- 2.3, Pb 135.5 +/- 2.4*). In L-NAME-treated rings maximal responses increased in Pb-exposed rats, and were higher in intact than in denuded aortas (contraction [% of phenylephrine] intact: control 184.3 +/- 23.7, Pb 289.1 +/- 18.3*; denuded: control 125.1 +/- 4.5, Pb 154.8 +/- 13.3*). ACh-induced relaxation in intact aortas from Pb-exposed rats presented rightward shift in L-NAME presence (EC50 x 10(-7)M: control 1.32 [0.33-5.18], Pb 4.88 [3.56-6.69]*) but moved left under indomethacin (EC50 x 10(-7)M: control 8.95 [3.47-23.07], Pb 0.97 [0.38-2.43]*). *p < 0.05 significant relative to the respective control; N = 7-9. Endothelium removal abolished ACh-induced relaxation. Perinatal Pb exposure caused hypertension associated with alterations in the production and/or release of basal and stimulated endothelium-derived relaxing factors-NO and constricting cyclooxygenase products. These findings may help explain the contribution of NO and cyclooxygenase products to the etiology and/or maintenance of Pb-induced hypertension and could ultimately lead to therapeutic advantages in plumbism.

Spermiogenesis and spermatozoa ultrastructure in Salminus and Brycon, two primitive genera in Characidae (Teleostei : Ostariophysi : Characiformes)

In Salminus, spermiogenesis is cystic and gives origin to a type I aquasperm. Spermatid differentiation is characterized by chromatin condensed into thick fibres, nuclear rotation, nuclear fossa formation, cytoplasmic channel formation, mitochondrial fusion producing long and ramified mitochondria, and the presence of several membranous concentric rings around the plasma membrane that encircles the cytoplasmic channel. In Salminus and Brycon, spermatozoa are very similar. They exhibit a spherical nucleus and chromatin condensed into fibre clusters, and a deep nuclear fossa. They show a long midpiece with few elongate mitochondria at the initial region and a cytoplasmic channel completely encircled by one or two membranous concentric rings. The flagellar axis is perpendicular to the nucleus and exhibits the classic axoneme (9 + 2). The very strong similarity observed between Salminus and Brycon spermatozoa supports the hypothesis that these subfamilies are likely to have a monophyletic origin.

Competition and phylogeny determine community structure in Mullerian co-mimics

Until recently, the study of negative and antagonistic interactions (for example, competition and predation) has dominated our understanding of community structure, maintenance and assembly(1). Nevertheless, a recent theoretical model suggests that positive interactions (for example, mutualisms) may counterbalance competition, facilitating long-term coexistence even among ecologically undifferentiated species(2). Mullerian mimics are mutualists that share the costs of predator education(3) and are therefore ideally suited for the investigation of positive and negative interactions in community dynamics. The sole empirical test of this model in a Mullerian mimetic community supports the prediction that positive interactions outweigh the negative effects of spatial overlap(4) (without quantifying resource acquisition). Understanding the role of trophic niche partitioning in facilitating the evolution and stability of Mullerian mimetic communities is now of critical importance, but has yet to be formally investigated. Here we show that resource partitioning and phylogeny determine community structure and outweigh the positive effects of Mullerian mimicry in a species-rich group of neotropical catfishes. From multiple, independent reproductively isolated allopatric communities displaying convergently evolved colour patterns, 92% consist of species that do not compete for resources. Significant differences in phylogenetically conserved traits (snout morphology and body size) were consistently linked to trait-specific resource acquisition. Thus, we report the first evidence, to our knowledge, that competition for trophic resources and phylogeny are pivotal factors in the stable evolution of Mullerian mimicry rings. More generally, our work demonstrates that competition for resources is likely to have a dominant role in the structuring of communities that are simultaneously subject to the effects of both positive and negative interactions.

Male and female reproductive morphology in the inseminating genus Astroblepus (Ostariophysi: Siluriformes: Astroblepidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo morfo-anatômico de folhas de Jacaratia spinosa (Aubl.) A.DC. (Caricaceae)

Aspectos morfológicos e anatômicos da folha de Jacaratia spinosa (Aubl.) A.DC. (Caricaceae) foram estudados com detalhe. O limbo foliar possui organização dorsiventral, estômago anomocíticos, glândulas, laticíferos do tipo articulado anastomosado e epiderme papilosa na face abaxial. A venação é bronquidódroma terminando em alças no bordo foliar.

Influence of acute pancreatitis on the in vitro responsiveness of rat mesenteric and pulmonary arteries

Background: Acute pancreatitis is an inflammatory disease characterized by local tissue injury and systemic inflammatory response leading to massive nitric oxide (NO) production and haemodynamic disturbances. Therefore, the aim of this work was to evaluate the vascular reactivity of pulmonary and mesenteric artery rings from rats submitted to experimental pancreatitis.Male Wistar rats were divided into three groups: saline (SAL); tauracholate (TAU) and phospholipase A(2) (PLA(2)). Pancreatitis was induced by administration of TAU or PLA(2) from Naja mocambique mocambique into the common bile duct of rats, and after 4 h of duct injection the animals were sacrificed. Concentration-response curves to acetylcholine (ACh), sodium nitroprusside (SNP) and phenylephrine (PHE) in isolated mesenteric and pulmonary arteries were obtained. Potency (pEC(50)) and maximal responses (E(MAX)) were determined. Blood samples were collected for biochemical analysis.Results: In mesenteric rings, the potency for ACh was significantly decreased from animals treated with TAU (about 4.2-fold) or PLA(2) (about 6.9-fold) compared to saline group without changes in the maximal responses. Neither pEC(50) nor E(MAX) values for Ach were altered in pulmonary rings in any group. Similarly, the pEC(50) and the E(MAX) values for SNP were not changed in both preparations in any group. The potency for PHE was significantly decreased in rat mesenteric and pulmonary rings from TAU group compared to SAL group (about 2.2- and 2.69-fold, for mesenteric and pulmonary rings, respectively). No changes were seen in the E(MAX) for PHE. The nitrite/nitrate (NO(x)(-)) levels were markedly increased in animals submitted to acute pancreatitis as compared to SAL group, approximately 76 and 68% in TAU and PLA(2) protocol, respectively.Conclusion: Acute pancreatitis provoked deleterious effects in endothelium-dependent relaxing response for ACh in mesenteric rings that were strongly associated with high plasma NO(x)(-) levels as consequence of intense inflammatory responses. Furthermore, the subsensitivity of contractile response to PHE in both mesenteric and pulmonary rings might be due to the complications of this pathological condition in the early stage of pancreatitis.

Estudos sobre estrutura, ciclo de vida e comportamento de Sardinella brasiliensis (Steindachner, 1879), na área entre 22ºS e 28ºS, Brasil: 2. determinação da idade individual e crescimento dos otólitos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudos sobre estrutura, ciclo de vida e comportamento de Sardinella brasiliensis (Steindachner, 1879), na área entre 22ºs e 28ºs, Brasil: 1. morfologia dos otólitos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Inhibition of myotoxic activity of Bothrops asper myotoxin II by the anti-trypanosomal drug surarnin

Suramin, a synthetic polysulfonated compound, developed initially for the treatment of African trypanosomiasis and onchocerciasis, is currently used for the treatment of several medically relevant disorders. Suramin, heparin, and other polyanions inhibit the myotoxic activity of Lys49 phospholipase A(2) analogues both in vitro and in vivo, and are thus of potential importance as therapeutic agents in the treatment of viperid snake bites. Due to its conformational flexibility around the single bonds that link the central phenyl rings to the secondary amide backbone, the symmetrical suramin molecule binds by an induced-fit mechanism complementing the hydrophobic surfaces of the dimer and adopts a novel conformation that lacks C2 symmetry in the dimeric crystal structure of the suramin-Bothrops asper myotoxin II complex. The simultaneous binding of suramin at the surfaces of the two monomers partially restricts access to the nominal active sites and significantly changes the overall charge of the interfacial recognition face of the protein, resulting in the inhibition of myotoxicity. (c) 2005 Elsevier Ltd. All rights reserved.

CYCLIC CODES THROUGH B[X], B[X; 1/kp Z(0)] and B[X; 1/p(k) Z(0)]: A COMPARISON

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Constructions of codes through the semigroup ring B[X; 1/2(2)Z(0)] and encoding

For any finite commutative ring B with an identity there is a strict inclusion B[X; Z(0)] subset of B[X; Z(0)] subset of B[X; 1/2(2)Z(0)] of commutative semigroup rings. This work is a continuation of Shah et al. (2011) [8], in which we extend the study of Andrade and Palazzo (2005) [7] for cyclic codes through the semigroup ring B[X; 1/2; Z(0)] In this study we developed a construction technique of cyclic codes through a semigroup ring B[X; 1/2(2)Z(0)] instead of a polynomial ring. However in the second phase we independently considered BCH, alternant, Goppa, Srivastava codes through a semigroup ring B[X; 1/2(2)Z(0)]. Hence we improved several results of Shah et al. (2011) [8] and Andrade and Palazzo (2005) [7] in a broader sense. Published by Elsevier Ltd

The CMS experiment at the CERN LHC

The Compact Muon Solenoid (CMS) detector is described. The detector operates at the Large Hadron Collider (LHC) at CERN. It was conceived to study proton-proton (and lead-lead) collisions at a centre-of-mass energy of 14 TeV (5.5 TeV nucleon-nucleon) and at luminosities up to 10(34)cm(-2)s(-1) (10(27)cm(-2)s(-1)). At the core of the CMS detector sits a high-magnetic-field and large-bore superconducting solenoid surrounding an all-silicon pixel and strip tracker, a lead-tungstate scintillating-crystals electromagnetic calorimeter, and a brass-scintillator sampling hadron calorimeter. The iron yoke of the flux-return is instrumented with four stations of muon detectors covering most of the 4 pi solid angle. Forward sampling calorimeters extend the pseudo-rapidity coverage to high values (vertical bar eta vertical bar <= 5) assuring very good hermeticity. The overall dimensions of the CMS detector are a length of 21.6 m, a diameter of 14.6 m and a total weight of 12500 t.

Differential Toxicity of Disperse Red 1 and Disperse Red 13 in the Ames Test, HepG2 Cytotoxicity Assay, and Daphnia Acute Toxicity Test

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

(-)-Kolavenic acid

In the two, almost identical, molecules in the asymmetric unit of the title compound [ systematic name: (E)-3-methyl-5-(1,2,4a, 5-tetramethyl-1,2,3,4,4a,7,8,8a-octahydronaphthalen-1yl) pent-2-enoic acid], C20H32O2, the rings are trans fused. The cyclohexane ring has a chair conformation and the cyclohexene ring a distorted half-boat conformation. The two independent molecules are connected into a dimer via O-H center dot center dot center dot O hydrogen bonds. The dimers are associated into supramolecular chains along c via C-H center dot center dot center dot O contacts.