O professor de biologia e a possibilidade de uso de diferentes abordagens de ensino com materiais midiáticos a fim de desenvolver a criticidade do aluno do ensino médio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

O professor de biologia e a possibilidade de uso de diferentes abordagens de ensino com materiais midiáticos a fim de desenvolver a criticidade do aluno do ensino médio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC

We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.

Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV

The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.

Self-assembly of Tetraurea Calix[4]arenes

We have elaborated a multistep strategy to synthesize ABAB-type tetraureas. There are overall nine steps but they involve very simple chemistry. The sequence starts with a 1,3-dialkylation and this is the step in which a difference between distal phenolic units is introduced. The selective ipso-nitration in the next step is based on the difference in reactivity between free phenolic units and alkylated ones. The direct reaction of tetraamino calixarene with tolylisocyanate appears not to be an appropriate method to synthesize 1,3-ditolylurea calixarenes but can be used to get tetraureas of ABBB- and AABB-types in two steps with yields of about 60%. A complete regioselective dimerization was obtained with mono-loop derivatives in which two adjacent urea residues are covalently connected. As predicted/expected the loop prevents the formation of one regioisomer, and only the dimer in which the open-chain residue slips through the loop is formed. To synthesize mono-loop tetraureas 1,2-diBoc protected tetraamino calixarene was acylated with activated di-urethanes under high dilution conditions. Di-loop compounds were synthesized by two different ways. In the reaction of tetraamine and di-urethanes the yield is about 30-40%. The second method is based on the metathesis reaction within a suitable heterodimer. For this strategy, tetraurea derivatives with residues which have terminal double bonds were prepared. The exclusive formation of the heterodimer with tetratosylurea as template is the key point in this strategy. Metathesis followed by hydrogenation give exceptionally good yields (> 80%) of the loop compounds. All the NMR data for di-loop compounds confirm that the loops prevent the interaction of the urea residues which are connected and thus, as expected, the di-loop derivatives do not form homodimers. The heterodimer between di-loop compounds and tetratolylurea (open-chain tetraureas) was the only species observed for a 1:1 mixture in benzene or chloroform. The rational synthesis of bis-[2]catenanes was a consequence of the selective formation of one regioisomer of mono-loop derivatives and the exclusive formation of heterodimers by di-loop derivatives. The formation of interlocking-ring in the synthesis of bis-[2]catenanes is an additional evidence that one open-chain residue slips through the loop in mono- or di-loop derivatives. Exceptionally good yields in the synthesis of bis-[2]catenanes are due to the high preorganization in the dimer which undergoes the metathesis. This preorganization decreases the number of the wrong connections and favors the new connections to be formed. Although the procedure for working up the reaction mixture should be still improved, these results are promising. A C2-symmetrical bis-[2]catenane was successfully resolved by column chromatography using a chiral stationary phase. Thus it should be possible to separate a larger amount to obtain pure enantiomers for further studies.

Membrane properties and synaptic integration of identified neuronal populations in the developing rodent neocortex

In my PhD work I concentrated on three elementary questions that are essential to understand the interactions between the different neuronal cell populations in the developing neocortex. The questions regarded the identity of Cajal-Retzius (CR) cells, the ubiquitous expression of glycine receptors in all major cell populations of the immature neocortex, and the role of taurine in the modulation of immature neocortical network activity.rnTo unravel whether CR cells of different ontogenetic origin have divergent functions I investigated the electrophysiological properties of YFP+ (derived from the septum and borders of the pallium) and YFP− CR cells (derived from other neocortical origins). This study demonstrated that the passive and active electrophysiological properties as well as features of GABAergic PSCs and glutamatergic currents are similar between both CR cell populations. These findings suggest that CR cells of different origins most probably support similar functions within the neuronal networks of the early postnatal cerebral cortex.rnTo elucidate whether glycine receptors are expressed in all major cell populations of the developing neocortex I analyzed the functional expression of glycine receptors on subplate (SP) cells. Activation of glycine receptors by glycine, -alanine and taurine elicited membrane responses that could be blocked by the selective glycinergic antagonist strychnine. Pharmacological experiments suggest that SP cells express functional heteromeric glycine receptors that do not contain 1 subunits. The activation of glycine receptors by glycine and taurine induced a membrane depolarization, which mediated excitatory effects. Considering the key role of SP cells in immature cortical networks and the development of thalamocortical connections, this glycinergic excitation may influence the properties of early cortical networks and the formation of cortical circuits.rnIn the third part of my project I demonstrated that tonic taurine application induced a massive increase in the frequency of PSCs. Based on their reversal potential and their pharmacological properties these taurine-induced PSCs are exclusively transmitted via GABAA receptors to the pyramidal neurons, while both GABAA and glycine receptors were implicated in the generation of the presynaptic activity. Accordingly, whole-cell and cell-attached recordings from genetically labeled interneurons revealed the expression of glycine and GABAA receptors, which mediated an excitatory action on these cells. These findings suggest that low taurine concentrations can tonically activate exclusively GABAergic networks. The activity level maintained by this GABAergic activity in the immature nervous system may contribute to network properties and can facilitate the activity dependent formation of adequate synaptic projections.rnIn summary, the results of my studies complemented the knowledge about neuronal interactions in the immature neocortex and improve our understanding of cellular processes that guide neuronal development and thus shape the brain.rn

The nociceptive withdrawal reflex: Normative values of thresholds and reflex receptive fields

Assessments of spinal nociceptive withdrawal reflexes can be used in human research both to evaluate the effect of analgesics and explore pain mechanisms related to sensitization. Before the reflex can be used as a clinical tool, normative values need to be determined in large scale studies. The aim of this study was to determine the reference values of spinal nociceptive reflexes and subjective pain thresholds (to single and repeated stimulation), and of the area of the reflex receptive fields (RRF) in 300 pain-free volunteers. The influences of gender, age, height, weight, body-mass index (BMI), body side of testing, depression, anxiety, catastrophizing and parameters of Short-Form 36 (SF-36) were analyzed by multiple regressions. The 95% confidence intervals were determined for all the tests as normative values. Age had a statistically and quantitatively significant impact on the subjective pain threshold to single stimuli. The reflex threshold to single stimulus was lower on the dominant compared to the non-dominant side. Depression had a negative impact on the subjective pain threshold to single stimuli. All the other analyses either did not reveal statistical significance or displayed quantitatively insignificant correlations. In conclusion, normative values of parameters related to the spinal nociceptive reflex were determined. This allows their clinical application for assessing central hyperexcitability in individual patients. The parameters investigated explore different aspects of sensitization processes that are largely independent of demographic characteristics, cognitive and affective factors.

Long-Term outcome in patients with mild traumatic brain injury: A prospective observational study

Mild traumatic brain injury (MTBI) is common; up to 37% of adult men have a history of MTBI. Complaints after MTBI are persistent headaches, memory impairment, depressive mood disorders, and disability. The reported short- and long-term outcomes of patients with MTBI have been inconsistent. We have now investigated long-term clinical and neurocognitive outcomes in patients with MTBI (at admission, and after 1 and 10 years).

ESC/EAS Guidelines for the management of dyslipidaemias: the Task Force for the management of dyslipidaemias of the European Society of Cardiology (ESC) and the European Atherosclerosis Society (EAS)

Cardiovascular disease (CVD) due to atherosclerosis of the arterial vessel wall and to thrombosis is the foremost cause of premature mortality and of disability-adjusted life years (DALYs) in Europe, and is also increasingly common in developing countries.1 In the European Union, the economic cost of CVD represents annually E192 billion1 in direct and indirect healthcare costs. The main clinical entities are coronary artery disease (CAD), ischaemic stroke, and peripheral arterial disease (PAD). The causes of these CVDs are multifactorial. Some of these factors relate to lifestyles, such as tobacco smoking, lack of physical activity, and dietary habits, and are thus modifiable. Other risk factors are also modifiable, such as elevated blood pressure, type 2 diabetes, and dyslipidaemias, or non-modifiable, such as age and male gender. These guidelines deal with the management of dyslipidaemias as an essential and integral part of CVD prevention. Prevention and treatment of dyslipidaemias should always be considered within the broader framework of CVD prevention, which is addressed in guidelines of the Joint European Societies’ Task forces on CVD prevention in clinical practice.2 – 5 The latest version of these guidelines was published in 20075; an update will become available in 2012. These Joint ESC/European Atherosclerosis Society (EAS) guidelines on the management of dyslipidaemias are complementary to the guidelines on CVD prevention in clinical practice and address not only physicians [e.g. general practitioners (GPs) and cardiologists] interested in CVD prevention, but also specialists from lipid clinics or metabolic units who are dealing with dyslipidaemias that are more difficult to classify and treat.