2,581 research outputs found
FĂsica e cultura popular : a poesia do samba na sala de aula
A criatividade Ă© um elemento comum, tanto no trabalho do cientista como do artista e, uma aproximação entre esses dois campos do conhecimento pode facilitar a compreensĂŁo da CiĂȘncia como lugar de construção de conhecimento que estĂĄ baseado, dentre outros aspectos, em concepçÔes prĂ©vias trazidas por aqueles que participam dessa construção. Este trabalho apresenta parte de uma pesquisa que se baseou na aproximação entre a FĂsica e elementos da cultura popular â a poesia do samba â como mediadora da investigação da origem das concepçÔes alternativas de alunos do ensino mĂ©dio sobre a reflexĂŁo da luz, atravĂ©s de um projeto de parceria entre a universidade e escolas, que envolveu alunos de graduação e ensino mĂ©dio e que ocorreu no Ăąmbito das escolas, para estudar a origem das concepçÔes alternativas dos alunos, levando-se em conta as concepçÔes de autores de mĂșsicas populares
Persistent impaired glucose metabolism in a zebrafish hyperglycemia model
AbstractDiabetes mellitus (DM) affects over 10% of the world's population. Hyperglycemia is the main feature for the diagnosis of this disease. The zebrafish (Danio rerio) is an established model organism for the study of various metabolic diseases. In this paper, hyperglycemic zebrafish, when immersed in a 111mM glucose solution for 14days, developed increased glycation of proteins from the eyes, decreased mRNA levels of insulin receptors in the muscle, and a reversion of high blood glucose level after treatment with anti-diabetic drugs (glimepiride and metformin) even after 7days of glucose withdrawal. Additionally, hyperglycemic zebrafish developed an impaired response to exogenous insulin, which was recovered after 7days of glucose withdrawal. These data suggest that the exposure of adult zebrafish to high glucose concentration is able to induce persistent metabolic changes probably underlined by a hyperinsulinemic state and impaired peripheral glucose metabolism
Exploiting the Pyrazolo[3,4-d]pyrimidin-4-one ring system as a useful template to obtain potent adenosine deaminase inhibitors,
A number of pyrazolo[3,4-d]pyrimidin-4-ones bearing either alkyl or arylalkyl substituents in position 2 of
the nucleus were synthesized and tested for their ability to inhibit adenosine deaminase (ADA) from bovine
spleen. The 2-arylalkyl derivatives exhibited excellent inhibitory activity, showing Ki values in the nanomolar/
subnanomolar range. The most active compound, 1-(4-((4-oxo-4,5-dihydropyrazolo[3,4-d]pyrimidin-2-
yl)methyl)phenyl)-3-(4-(trifluoromethyl)phenyl)urea, 14d, was tested in rats with colitis induced by 2,4-
dinitrobenzenesulfonic acid to assess its efficacy to attenuate bowel inflammation. The treatment with 14d
induced a significant amelioration of both systemic and intestinal inflammatory alterations in animals with
experimental colitis. Docking simulations of the synthesized compounds into the ADA catalytic site were
also performed to rationalize the structure-activity relationships observed and to highlight the key
pharmacophoric elements of these products, thus prospectively guiding the design of novel ADA inhibitors
Exploiting the Pyrazolo[3,4-d]pyrimidin-4-one ring system as a useful template to obtain potent adenosine deaminase inhibitors,
A number of pyrazolo[3,4-d]pyrimidin-4-ones bearing either alkyl or arylalkyl substituents in position 2 of
the nucleus were synthesized and tested for their ability to inhibit adenosine deaminase (ADA) from bovine
spleen. The 2-arylalkyl derivatives exhibited excellent inhibitory activity, showing Ki values in the nanomolar/
subnanomolar range. The most active compound, 1-(4-((4-oxo-4,5-dihydropyrazolo[3,4-d]pyrimidin-2-
yl)methyl)phenyl)-3-(4-(trifluoromethyl)phenyl)urea, 14d, was tested in rats with colitis induced by 2,4-
dinitrobenzenesulfonic acid to assess its efficacy to attenuate bowel inflammation. The treatment with 14d
induced a significant amelioration of both systemic and intestinal inflammatory alterations in animals with
experimental colitis. Docking simulations of the synthesized compounds into the ADA catalytic site were
also performed to rationalize the structure-activity relationships observed and to highlight the key
pharmacophoric elements of these products, thus prospectively guiding the design of novel ADA inhibitors
Factors driving sediment compositional change in the distal area of the Ria de Vigo (NW Spain): oceanographic processes vs. paleopollution
We analyze potential Late Holocene metal contamination along a sediment core collected in the distal zone of Ria de Vigo (North Spain). Statistical treatment of the dataset based on a multiproxy approach enabled us to identify and disentangle factors influencing the depositional processes and the preservation of the records of this activity in the area over the last approximate to 3000 years BP. Some layers of the analyzed core have significant enrichment in Cu and a moderate enrichment in Ag, Mo, As, Sb, S, Zn, Ni, Sn, Cd, Cr, Co, Pb, and Li. The enrichment of these elements in some layers of this core may be related to mining activities that have taken place since classical times in the region. Successive phases of pollution were identified along the core KSGX24 related to the Late Bronze Age (approximate to 3000-2450 years BP), Iron Age (approximate to 2450-1850 years BP), Roman times (approximate to 1850-1550 years BP), Middle Ages (approximate to 1250-500 years BP), and industrial and modern (approximate to 250-0 years BP) anthropic activities. The protection of the Cies Islands, the erosive and transport capacity of the rivers in the region, oscillations of the oceanographic and climatic regime, atmospheric contamination, and diagenetic sedimentary processes might have contributed to the accumulation and preservation of this record in the distal region of the Ria de Vigo. The studied core shows that the industrial and preindustrial anthropic impacts caused an environmental liability and contributed to the presence of moderate to heavy pollution of various metals in surface and subsurface sediment layers in the distal sector of the Ria de Vigo, which could be a hazard to biota.info:eu-repo/semantics/publishedVersio
Survival differences between women and men in the non-reproductive cancers: Results from a matched analysis of the surveillance, epidemiology, and end-results program
BackgroundMen with non-reproductive cancers have a discrepant outcome compared to women. However, they differ significantly in the incidence of cancer type and characteristics.MethodsPatients with single primary cancer who were 18 years or older and whose data were gathered and made accessible by the Surveillance, Epidemiology, and End Results (SEER) program were included in this retrospective analysis. Kaplan-Meier curves and Cox regression before and after propensity score matching were performed to analyze the risk survival by sex.ResultsAmong the 1,274,118 patients included [median (range) age, 65 year (18â85+) years; 688,481 (54.9%) male]. The median follow-up was 21 months (0â191). Substantial improvements in survival were observed for both sexes during the years of inclusion analyzed, with no difference between them, reaching a reduction of almost 17% of deaths in 2010, and of almost 28% in 2015, compared to 2004. The women had a median survival of 74 months and overall mortality of 48.7%. Males had a median survival of 30 months (29.67â30.33) with an overall mortality of 56.2%. The PSM showed a reduced difference (6 months shorter median survival and 2.3% more death in men), but no change in hazards was observed compared to the unmatched analysis [adjusted HR: 0.888 (0.864â0.912) vs. 0.876 (0.866â0.886) in unmatched].ConclusionsThe discrepancy in survival between men and women is not explained only by the incidence of more aggressive and more advanced cancers in the former
The pattern of recurrence of adenocarcinoma of the oesophago-gastric junction
Knowledge of the pattern of recurrence of surgically treated cases of adenocarcinoma of the oesophago-gastric junction is important both for better understanding of their biological nature and for future strategic planning of therapy. The aim of this study is to demonstrate and compare the pattern of dissemination and recurrence in patients with Type I and Type II adenocarcinoma of oesophago-gastric junction. A prospective audit of the clinico-pathological features of patients who had undergone surgery with curative intent for adenocarcinoma of oesophago-gastric junction between 1991 and 1996 was undertaken. Patients were followed up by regular clinical examination. Clinical evaluation was supported by ultrasound, computerised tomography, radio-isotope bone scan, endoscopy and laparotomy each with biopsy and histology where appropriate. One hundred and sixty-nine patients with oesophago-gastric junction tumours (94 Type I and 75 Type II) have been followed up for a median of 75.3 (57â133) months. One hundred and three patients developed proven recurrent disease. The median time to recurrence was 23.3 (14.2â32.4) months for Type I and 20.5 (11.6â29.4) for Type II cancers. The most frequent type of recurrence was haematogenous (56% of Type I recurrences and 54% of Type II) of which 56% were detected within 1 year of surgery. The most frequent sites were to liver (27%), bone (18%) brain (11%) and lung (11%). Local recurrence occurred in 33% of Type I cancer and 29% of Type II recurrences. Nodal recurrence occurred in 18 and 25% of Type I and Type II cancer recurrences, most frequently to coeliac or porta hepatis nodes (64%). Only 7% of Type I and 15% of Type II cancer recurrences were by peritoneal dissemination. Type I and Type II adenocarcinoma of the oesophago-gastric junction have a predominantly early, haematogenous pattern of recurrence. There is a need to better identify the group of patients with small metastases at the time of diagnosis who are destined to develop recurrent disease in order that they may be spared surgery and those with micro metastases in order that they can be offered multi-modality therapy including early post operative or neo-adjuvant chemotherapy
Expression of Drosophila Adenosine Deaminase in Immune Cells during Inflammatory Response
Extra-cellular adenosine is an important regulator of inflammatory responses. It is generated from released ATP by a cascade of ectoenzymes and degraded by adenosine deaminase (ADA). There are two types of enzymes with ADA activity: ADA1 and ADGF/ADA2. ADA2 activity originates from macrophages and dendritic cells and is associated with inflammatory responses in humans and rats. Drosophila possesses a family of six ADGF proteins with ADGF-A being the main regulator of extra-cellular adenosine during larval stages. Herein we present the generation of a GFP reporter for ADGF-A expression by a precise replacement of the ADGF-A coding sequence with GFP using homologous recombination. We show that the reporter is specifically expressed in aggregating hemocytes (Drosophila immune cells) forming melanotic capsules; a characteristic of inflammatory response. Our vital reporter thus confirms ADA expression in sites of inflammation in vivo and demonstrates that the requirement for ADA activity during inflammatory response is evolutionary conserved from insects to vertebrates. Our results also suggest that ADA activity is achieved specifically within sites of inflammation by an uncharacterized post-transcriptional regulation based mechanism. Utilizing various mutants that induce melanotic capsule formation and also a real immune challenge provided by parasitic wasps, we show that the acute expression of the ADGF-A protein is not driven by one specific signaling cascade but is rather associated with the behavior of immune cells during the general inflammatory response. Connecting the exclusive expression of ADGF-A within sites of inflammation, as presented here, with the release of energy stores when the ADGF-A activity is absent, suggests that extra-cellular adenosine may function as a signal for energy allocation during immune response and that ADGF-A/ADA2 expression in such sites of inflammation may regulate this role
Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at = 5.02 TeV
Two-particle angular correlations between unidentified charged trigger and
associated particles are measured by the ALICE detector in p-Pb collisions at a
nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum
range 0.7 5.0 GeV/ is examined,
to include correlations induced by jets originating from low
momen\-tum-transfer scatterings (minijets). The correlations expressed as
associated yield per trigger particle are obtained in the pseudorapidity range
. The near-side long-range pseudorapidity correlations observed in
high-multiplicity p-Pb collisions are subtracted from both near-side
short-range and away-side correlations in order to remove the non-jet-like
components. The yields in the jet-like peaks are found to be invariant with
event multiplicity with the exception of events with low multiplicity. This
invariance is consistent with the particles being produced via the incoherent
fragmentation of multiple parton--parton scatterings, while the yield related
to the previously observed ridge structures is not jet-related. The number of
uncorrelated sources of particle production is found to increase linearly with
multiplicity, suggesting no saturation of the number of multi-parton
interactions even in the highest multiplicity p-Pb collisions. Further, the
number scales in the intermediate multiplicity region with the number of binary
nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/161
Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider
Measurements of multi-particle azimuthal correlations (cumulants) for charged
particles in p-Pb and Pb-Pb collisions are presented. They help address the
question of whether there is evidence for global, flow-like, azimuthal
correlations in the p-Pb system. Comparisons are made to measurements from the
larger Pb-Pb system, where such evidence is established. In particular, the
second harmonic two-particle cumulants are found to decrease with multiplicity,
characteristic of a dominance of few-particle correlations in p-Pb collisions.
However, when a gap is placed to suppress such correlations,
the two-particle cumulants begin to rise at high-multiplicity, indicating the
presence of global azimuthal correlations. The Pb-Pb values are higher than the
p-Pb values at similar multiplicities. In both systems, the second harmonic
four-particle cumulants exhibit a transition from positive to negative values
when the multiplicity increases. The negative values allow for a measurement of
to be made, which is found to be higher in Pb-Pb collisions at
similar multiplicities. The second harmonic six-particle cumulants are also
found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find
which is indicative of a Bessel-Gaussian
function for the distribution. For very high-multiplicity Pb-Pb
collisions, we observe that the four- and six-particle cumulants become
consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and
Pb-Pb are measured. These are found to be similar for overlapping
multiplicities, when a gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87
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