In situ crosslinkable multi-functional and cell-responsive alginate 3D matrix via thiol-maleimide click chemistry.

In vivo, cells interact with the extracellular matrix (ECM), which provides a multitude of biophysical and biochemical signals that modulate cellular behavior. Inspired by this, we explored a new methodology to develop a more physiomimetic polysaccharide-based matrix for 3D cell culture. Maleimide-modified alginate (AlgM) derivatives were successfully synthesized using DMTMM to activate carboxylic groups. Thiol-terminated cell-adhesion peptides were tethered to the hydrogel network to promote integrin binding. Rapid and efficient in situ hydrogel formation was promoted by thiol-Michael addition "click" chemistry via maleimide reaction with thiol-flanked protease-sensitive peptides. Alginate derivatives were further ionically crosslinked by divalent ions present in the medium, which led to greater stability and allowed longer cell culture periods. By tailoring alginate's biofunctionality we improved cell-cell and cell-matrix interactions, providing an ECM-like 3D microenvironment. We were able to systematically and independently vary biochemical and biophysical parameters to elicit specific cell responses, creating custom-made 3D matrices. DMTMM-mediated maleimide incorporation is a promising approach to synthesizing AlgM derivatives that can be leveraged to produce ECM-like matrices for a broad range of applications, from in vitro tissue modeling to tissue regeneration.

Pyruvic acid as attenuator of water deficit in cotton plants varying the phenological stage.

The lack of water during crop growth causes damage to any production system, especially when it occurs during the initial establishment or beginning of the reproductive stage. Although cotton can be properly managed in regions with water limitation, its yield is affected at different levels according to the genetics of the cultivar adopted. Exogenous application of some organic components has shown a stress-mitigating effect and can be a valuable procedure to enhance the yield of water stress-sensitive cultivars. The objective of this work was to evaluate the benefits of exogenous application of pyruvic acid (100 µM) in cotton plants under water deficit varying the phenological stage of the crop. The experiment was conducted in a greenhouse, where the plants were grown in pots and subjected to seven days of water suspension, initiated individually in stages V2 and B1. Each pot contained two plants. The treatments adopted were: T1 - control, T2 - water suppression; and T3 - water suppression + pyruvate application. The design was randomized blocks in a factorial scheme (3 × 3) with three replicates. The reductions in gas exchange and growth of the cultivars BRS Seridó, CNPA 7MH and FM 966 were more significant in the reproductive stage, especially for FM 966, which was more sensitive. Pyruvate application reduced the effects of water suppression on boll production by 31% in BRS Seridó and 34% in CNPA 7MH and FM 966.

Synthesis of benzoylthiourea derivatives and analysis of their antibacterial performance against planktonic Staphylococcus aureus and its biofilms.

Following the appearance of several antimicrobial agents to control the spread of infections, two major challenges have emerged: (i) the occurrence and blowout of multiresistant bacteria and the increase of chronic diseases and (ii) difficult-to-eradicate infections. In this study, we tested five benzoylthiourea derivatives for their ability to inhibit and stop bacterial growth and evaluated the possible influence of 1,2,4-triazolyl-benzoylthiourea derivative 4 on the formation and eradication of Staphylococcus aureus biofilms. Benzoylthiourea derivatives 4, 6, 10, 11 and 13 were obtained in one or two steps with low cost and subjected to tests to identify their minimum inhibitory concentration (MIC) and minimum bactericidal concentration. In vitro tests were also performed to assess their effects on biofilm formation and in preformed biofilms and scanning electron microscopy was used to visualize the effects on biofilm formation. The 1,2,4-triazolyl-benzoylthiourea derivative 4 showed bacteriostatic activity against the S. aureus HU25 clinical strain with an MIC of 16 µg ml-1 , which is below the toxic concentration (at 2500 µg ml-1 , 62·25% of the cells remained viable). Compound 4 also effectively prevented biofilm formation at the three subinhibitory concentrations tested (1/2 MIC, 1/4 MIC and 1/8 MIC) as confirmed by scanning electron microscopy. For breakdown of formed biofilms, the main influence was at a subinhibitory concentration (1/2 MIC). These findings make compound 4 a strong candidate for studies on the development of new antimicrobial and antibiofilm agents.

Luminescent κ-Carrageenan-Based Electrolytes Containing Neodymium Triflate.

In recent years, the synthesis of polymer electrolyte systems derived from biopolymers for the development of sustainable green electrochemical devices has attracted great attention. Here electrolytes based on the red seaweeds-derived polysaccharide κ-carrageenan (κ-Cg) doped with neodymium triflate (NdTrif3) and glycerol (Gly) were obtained by means of a simple, clean, fast, and low-cost procedure. The aim was to produce near-infrared (NIR)-emitting materials with improved thermal and mechanical properties, and enhanced ionic conductivity. Cg has a particular interest, due to the fact that it is a renewable, cost-effective natural polymer and has the ability of gelling in the presence of certain alkali- and alkaline-earth metal cations, being good candidates as host matrices for accommodating guest cations. The as-synthesised κ-Cg-based membranes are semi-crystalline, reveal essentially a homogeneous texture, and exhibit ionic conductivity values 1⁻2 orders of magnitude higher than those of the κ-Cg matrix. A maximum ionic conductivity was achieved for 50 wt.% Gly/κ-Cg and 20 wt.% NdTrif3/κ-Cg (1.03 × 10-4, 3.03 × 10-4, and 1.69 × 10-4 S cm-1 at 30, 60, and 97 °C, respectively). The NdTrif-based κ-Cg membranes are multi-wavelength emitters from the ultraviolet (UV)/visible to the NIR regions, due to the κ-Cg intrinsic emission and to Nd3+, 4F3/2→4I11/2-9/2.

Maternal apical periodontitis is associated with insulin resistance in adult offspring.

AIM: To investigate the plasma concentrations of glucose, insulin and tumour necrosis factor-α (TNF-α) of rats with maternal apical periodontitis (AP) and to explore the effect of maternal inflammation on the initial steps of insulin signalling and the inflammatory pathway in the gastrocnemius muscle (GM) and periepididymal white adipose tissue (pWAT) of adult offspring. METHODOLOGY: Fifteen female Wistar rats were distributed into a control group (CN), a group with 1 tooth with AP (1AP) and a group with 4 teeth with AP (4AP). Thirty days following induction of AP, female rats from all groups were mated with healthy male rats. When male offspring reached 75 days of age, plasma concentrations of glucose, insulin and TNF-α were quantified. Insulin resistance was evaluated by the homoeostasis model assessment of insulin resistance (HOMA-IR) index. Phosphorylation status of pp185 tyrosine, insulin receptor substrate 1 (IRS-1) serine, IκB kinase α/ß (IKKα/ß) and c-Jun N-terminal kinase (JNK) in the GM and pWAT were measured by Western blot. Analysis of variance was performed, followed by the Tukey's post hoc test. P values <0.05 were considered to be statistically significant. RESULTS: Maternal AP promoted insulin resistance, impaired the initial steps of insulin signalling, significantly increased plasma concentrations of insulin (P < 0.001) and TNF-α (P < 0.05), and enhanced IKKα/ß phosphorylation in the GM and pWAT (P < 0.05) of adult offspring. However, maternal AP did not affect fasting glycaemia and JNK phosphorylation in the GM and pWAT of adult offspring. CONCLUSIONS: Maternal AP was associated with insulin resistance in adult offspring through alterations in insulin signalling and inflammation pathways. The study provides information on the impact of maternal AP on the development of metabolic alterations such as insulin resistance in adult offspring and reinforces the importance of preventing maternal AP in order to maintain the general health of offspring.

Adult weight management across the community: population-level impact of the LOSE IT to WIN IT challenge.

Objective: Excess body weight negatively impacts health, but there are few evaluations of low-intensity weight management challenge programs in defined populations. This study examined weight change in adults who participated in the LOSE IT to WIN IT (LIWI) health challenge in a US community. The community-level impact on body mass index was also explored. Methods: Body weight was analysed over 1 year in the cohort of LIWI enrolees, stratified by participants who were healthy weight or overweight/obese at baseline. Secondarily, a multiple cross-sectional analysis compared the 2.5-year trends in body mass index between community adults who did vs. did not participate in LIWI. Results: LOSE IT to WIN IT participants who were overweight/obese lost a mean (95% confidence interval) 1.6 (1.2, 2.0) kg (~2%) over 1 year (p < 0.001), whereas healthy weight participants lost 0.7 (0.3, 1.1) kg. Across the community, LIWI participants and non-participants both gained 0.4 kg m-2 over the 2.5-year study period (p = 0.884). Conclusions: LOSE IT to WIN IT was modestly effective among enrolees, resulting in a small weight loss of 2% over 1 year among those who were overweight/obese. However, LIWI did not impact weight gain in the community. To slow such community-level weight gain trends, weight management challenges must reach larger fractions of the populations that they target.

Chaotic, informational and synchronous behaviour of multiplex networks.

The understanding of the relationship between topology and behaviour in interconnected networks would allow to charac- terise and predict behaviour in many real complex networks since both are usually not simultaneously known. Most previous studies have focused on the relationship between topology and synchronisation. In this work, we provide analytical formulas that shows how topology drives complex behaviour: chaos, information, and weak or strong synchronisation; in multiplex net- works with constant Jacobian. We also study this relationship numerically in multiplex networks of Hindmarsh-Rose neurons. Whereas behaviour in the analytically tractable network is a direct but not trivial consequence of the spectra of eigenvalues of the Laplacian matrix, where behaviour may strongly depend on the break of symmetry in the topology of interconnections, in Hindmarsh-Rose neural networks the nonlinear nature of the chemical synapses breaks the elegant mathematical connec- tion between the spectra of eigenvalues of the Laplacian matrix and the behaviour of the network, creating networks whose behaviour strongly depends on the nature (chemical or electrical) of the inter synapses.

Anomalous transport induced by nonhyperbolicity.

In this paper we study how deterministic features presented by a system can be used to perform direct transport in a quasisymmetric potential and weak dissipative system. We show that the presence of nonhyperbolic regions around acceleration areas of the phase space plays an important role in the acceleration of particles giving rise to direct transport in the system. Such an effect can be observed for a large interval of the weak asymmetric potential parameter allowing the possibility to obtain useful work from unbiased nonequilibrium fluctuation in real systems even in a presence of a quasisymmetric potential.

Parametric evolution of unstable dimension variability in coupled piecewise-linear chaotic maps.

In the presence of unstable dimension variability numerical solutions of chaotic systems are valid only for short periods of observation. For this reason, analytical results for systems that exhibit this phenomenon are needed. Aiming to go one step further in obtaining such results, we study the parametric evolution of unstable dimension variability in two coupled bungalow maps. Each of these maps presents intervals of linearity that define Markov partitions, which are recovered for the coupled system in the case of synchronization. Using such partitions we find exact results for the onset of unstable dimension variability and for contrast measure, which quantifies the intensity of the phenomenon in terms of the stability of the periodic orbits embedded in the synchronization subspace.

Periodic-orbit analysis and scaling laws of intermingled basins of attraction in an ecological dynamical system.

Chaotic dynamical systems with two or more attractors lying on invariant subspaces may, provided certain mathematical conditions are fulfilled, exhibit intermingled basins of attraction: Each basin is riddled with holes belonging to basins of the other attractors. In order to investigate the occurrence of such phenomenon in dynamical systems of ecological interest (two-species competition with extinction) we have characterized quantitatively the intermingled basins using periodic-orbit theory and scaling laws. The latter results agree with a theoretical prediction from a stochastic model, and also with an exact result for the scaling exponent we derived for the specific class of models investigated. We discuss the consequences of the scaling laws in terms of the predictability of a final state (extinction of either species) in an ecological experiment.

Periodic orbit analysis at the onset of the unstable dimension variability and at the blowout bifurcation.

Many chaotic dynamical systems of physical interest present a strong form of nonhyperbolicity called unstable dimension variability (UDV), for which the chaotic invariant set contains periodic orbits possessing different numbers of unstable eigendirections. The onset of UDV is usually related to the loss of transversal stability of an unstable fixed point embedded in the chaotic set. In this paper, we present a new mechanism for the onset of UDV, whereby the period of the unstable orbits losing transversal stability tends to infinity as we approach the onset of UDV. This mechanism is unveiled by means of a periodic orbit analysis of the invariant chaotic attractor for two model dynamical systems with phase spaces of low dimensionality, and seems to depend heavily on the chaotic dynamics in the invariant set. We also described, for these systems, the blowout bifurcation (for which the chaotic set as a whole loses transversal stability) and its relation with the situation where the effects of UDV are the most intense. For the latter point, we found that chaotic trajectories off, but very close to, the invariant set exhibit the same scaling characteristic of the so-called on-off intermittency.

Effect of europium(III) chloride on the aggregation behavior of sodium dodecyl sulfate.

The effect of EuCl3 on the aggregation processes of sodium dodecyl sulfate was investigated. Electrical conductivity data, combined with Eu(III) luminescence measurements, suggest that the formation of micelles involving EuCl3 and SDS occurs at low SDS concentration; the formation of these mixed aggregates was also monitored by light scattering, which indicates that the addition of EuCl3 to SDS concentration at values below the critical micelle concentration of the pure surfactant results in a much higher light scattering than that found just with SDS micelles. It was also found that the Eu(III)/DS- complexes are formed with a binding ratio which varies between 20 and 4, depending on the initial concentration of Eu(III). As the concentration increases, turbidity occurs initially, but solutions become clear subsequently. In contrast to the behavior of SDS in the presence of aluminum(III), no flocculation was observed. From the analysis of electrical conductivity data and comparison with other systems, it is suggested that growth of aggregates happens, probably with formation of nonspherical systems. At the highest concentrations these may involve just Eu(III) and DS- ions. The effect of temperature on the SDS micellization process was studied. The calculated free energy of SDS micellization is not dependent on the initial EuCl3 but is dependent on the final balance between the presence of counterions in solution (ionic strength) and the temperature.

Effects of ethanol and haloperidol on plasma levels of hepatic enzymes, lipid profile, and apolipoprotein in rats.

This work studied the effects of ethanol in the absence and presence of haloperidol under two experimental conditions. In protocol 1, rats were treated daily with ethanol (4 g/kg, p.o.) for 7 days, and received only haloperidol (1 mg/kg, i.p.) from the 8th day to the 14th day. In protocol 2, animals received ethanol, and the treatment continued with ethanol and haloperidol from the 8th day to the 14th day. Results show increases in alanine transaminase (ALT; 48% and 55%) and aspartate transaminase (AST; 32% and 22%) levels after ethanol or haloperidol (14 days) treatments, as compared with controls. Apolipoprotein A-1 (APO A1) levels were increased by haloperidol, after 7- (148%) but not after 14-day treatments, as compared with controls. Levels of lipoprotein (high-density lipoprotein (HDL-C)) tended to be increased only by ethanol treatment for 14 days. ALT (80%) and AST (43%) levels were increased in the haloperidol plus ethanol group (protocol 2), as compared with controls. However, an increase in APO A1 levels was observed in the haloperidol group pretreated with ethanol (protocol 1), as compared with controls and ethanol 7-day treatments. Triglyceride (TG) levels were increased in the combination of ethanol and haloperidol in protocol 1 (234%) and 2 (106%), as compared with controls. Except for a small decrease in haloperidol groups, with or without ethanol, as related to ethanol alone, no other effect was observed in HDL-C levels. In conclusion, we showed that haloperidol might be effective in moderating lipid alterations caused by chronic alcohol intake.

Contribuiçäo ao estudo da anatomia do sistema de canais radiculares de caninos inferiores utilizando-se de cortes macroscópicos e da diafanizaçäo / Anatomy study of root system of lower canines using macroscopic cuts and clarifying technique

A anatomia dos canais radiculares tem sido tema de estudos desde 1942 e mesmo com as diversas observaçöes descritas por vários autores, permaneceu-se dúvidas a respeito dos aspectos morfológicos internos de vários grupos de dentes. O presente trabalho utilizou-se de 103 (cento e três) caninos interiores extraídos, onde se analisou os aspectos macroscópicos da cavidade pulpar, utilizando-se de cortes sagital, frontal e transversais, assim como da diafanizaçäo. Notamos que, em 100 po cento dos espécimes haviam uma raiz e um único canal radicular, sendo que em 83 por cento das amostras evidenciou-se permeabilidade dentinária. Os canais secundários foram verificados em 47 por cento dos dentes, assim com 3 por cento de canais laterais, 1 por cento canal acessório e 15 por cento co delta apical. fator importante que observamos também foi que, em 42 dos espécimes o forame apical coincidia-se com o ápice radicular; 23 por cento, abria-se para vestibular, 8 por cento, para distal; 8 por cento, para mesial e 4 por cento para lingual

Anti-VP1 and anti-VP2 antibodies detected by immunofluorescence assays in patients with acute human parvovirus B19 infection.

Acute human parvovirus B19 infection is followed by an antibody response to the structural proteins of the viral capsid (VP1 and VP2). We used 80 sera collected from 58 erythema infectiosum and 6 transient aplastic crisis patients to test IgM and IgG antibodies against these two proteins in an immunofluorescence assay (IFA) using Sf9 cells infected with recombinant baculovirus expressing either VP1 or VP2 antigen. Although less sensitive than IgM capture enzyme immunoassay using native antigen (MACEIA), we could detect anti-VP1 or anti-VP2 IgM antibodies by IFA in 49 patients with acute infection (76.6%). Detection of IgG anti-VP1 and anti-VP2 by IFA, however, was as sensitive as IgG detection by indirect enzyme immunoassay. By applying IgG avidity IFA to sera of the 15 IgM IFA negative patients we were able to confirm acute infection in further 12 cases by IFA. Overall, acute infection was confirmed by IFA in 61 (95.3%) of the 64 patients.

In situ corrosion control in industrial water systems.

The main objective of this study was to evaluate the efficacy of a biocide and a corrosion inhibitor against the corrosion of a circulating pipe in a cooling tower. Isothiazolone was tested as the industrial biocide. The results showed that the biocide by itself or combined with a dispersant was not efficient to control corrosion in the industrial system. Corrosion rates of 0.324 mm/year were recorded in both the presence and absence of the biocide. Corrosion control was successfully accomplished by using a corrosion inhibitor. In the latter case the maximum corrosion rate of 0.024 mm/year were obtained.

Marrow stromal cells as a source of progenitor cells for nonhematopoietic tissues in transgenic mice with a phenotype of osteogenesis imperfecta.

Marrow stromal cells from wild-type mice were infused into transgenic mice that had a phenotype of fragile bones resembling osteogenesis imperfecta because they expressed a human minigene for type I collagen. In mice that were irradiated with potentially lethal levels (700 cGy) or sublethal levels (350 cGy), DNA from the donor marrow stromal cells was detected consistently in marrow, bone, cartilage, and lung either 1 or 2.5 mo after the infusions. The DNA also was detected but less frequently in the spleen, brain, and skin. There was a small but statistically significant increase in both collagen content and mineral content of bone 1 mo after the infusion. Similar results were obtained with infusion of relatively large amounts of wild-type whole marrow cells into the transgenic mice. In experiments in which male marrow stromal cells were infused into a female osteogenesis imperfecta-transgenic mouse, fluorescense in situ hybridization assays for the Y chromosome indicated that, after 2.5 mo, donor male cells accounted for 4-19% of the fibroblasts or fibroblast-like cells obtained in primary cultures of the lung, calvaria, cartilage, long bone, tail, and skin. In a parallel experiment in which whole marrow cells from a male mouse were infused into a female immunodeficient rag-2 mouse, donor male cells accounted for 4-6% of the fibroblasts or fibroblast-like cells in primary cultures. The results support previous suggestions that marrow stromal cells or related cells in marrow serve as a source for continual renewal of cells in a number of nonhematopoietic tissues.

Bone fragility in transgenic mice expressing a mutated gene for type I procollagen (COL1A1) parallels the age-dependent phenotype of human osteogenesis imperfecta.

An inbred strain of transgenic mice that expressed a mutated gene for type I procollagen and that developed spontaneous fractures was used to study the effects of age on the phenotype of fragile bones. The mutated gene has been shown to cause depletion of type I collagen in the transgenic mice because it generated shortened pro alpha 1(I) chains that bound to and produced degradation of normal pro alpha 1(I) chains synthesized from the endogenous mouse COL1A1 gene. For this study, femurs from transgenic mice ranging in age from 0.5-24 months were examined. The results demonstrated that the level of expression of the transgene was independent of age. Femurs from the transgenic mice were more fragile than controls at 0.5 and 1.5 months, they were biomechanically normal at 6 months, and then they were more fragile at 24 months. The normal biomechanical properties of the bones from the transgenic mice at 6 months were accompanied by periosteal thickening of the bones together with an increase in the collagen content that was not associated with a proportional increase in mineral content. The results indicated that the effects of age, mechanical stress, and hormonal action produced a biological compensation for the mutated gene by either increasing collagen synthesis of bone, decreasing collagen degradation, or both. The biological compensation was apparently lost by 24 months when the outer diameters of the femurs were again less than in controls, the cortical thickness was about the same as in controls, and both the collagen and mineral contents were less than controls. The results demonstrated that bone fragility in the transgenic mice paralleled the age-dependent phenotype of human osteogenesis imperfecta. Therefore the transgenic mice appeared to be useful models for osteogenesis imperfecta. They also may be useful models for some forms of osteoporosis.

Cultured adherent cells from marrow can serve as long-lasting precursor cells for bone, cartilage, and lung in irradiated mice.

Cells from transgenic mice expressing a human mini-gene for collagen I were used as markers to follow the fate of mesenchymal precursor cells from marrow that were partially enriched by adherence to plastic, expanded in culture, and then injected into irradiated mice. Sensitive PCR assays for the marker collagen I gene indicated that few of the donor cells were present in the recipient mice after 1 week, but 1-5 months later, the donor cells accounted for 1.5-12% of the cells in bone, cartilage, and lung in addition to marrow and spleen. A PCR in situ assay on lung indicated that the donor cells diffusely populated the parenchyma, and reverse transcription-PCR assays indicated that the marker collagen I gene was expressed in a tissue-specific manner. The results, therefore, demonstrated that mesenchymal precursor cells from marrow that are expanded in culture can serve as long-lasting precursors for mesenchymal cells in bone, cartilage, and lung. They suggest that cells may be particularly attractive targets for gene therapy ex vivo.

Binding of integration host factor (IHF) to the ilvGp1 promoter of the ilvGMEDA operon of Escherichia coli K12.

Crude extracts of Escherichia coli K-12 were found to bind DNA restriction fragments containing ilvGp1. Our analysis using a series of restriction fragments and a BamHI linker mutation indicate that a factor binds to ilvGp1 or adjacent to it. Analysis with mutant strains of E. coli K-12 and purified IHF indicate that IHF binds to ilvGp1. Furthermore, both analysis in vivo and in vitro indicate that IHF precludes transcription from ilvGp1.