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Neste trabalho, recorremos à metodologia da transformada de Laplace a fim de mostrar a sua importância na abordagem de uma classe de equações diferenciais fracionárias. Em particular, apresentamos aplicações desta metodologia ao discutirmos possíveis generalizações de certos problemas físicos no campo da viscoelasticidade linear e osciladores harmônicos, comprovando que o uso do cálculo fracionário em modelagem e resolução de problemas usualmente abordados pelo cálculo de ordem inteira oferece vantagens promissoras para nos fornecer formulações mais consistentes com os dados experimentais.

In this paper, we resort to the Laplace transform method in order to show its efficiency when approaching some types of fractional differential equations. In particular, we present some applications of such methods when applied to possible generalizations of certain physical problems in linear viscoelasticity and harmonic oscillators, proving that fractional calculus is well suited for the modelling and solving of problems usually treated by ordinary integer calculus, with the promissing advantages of being able to provide more accurate theoretical predictions to fit experimental data.

https://doi.org/10.1590/S1806-11173731842 5559 descargas

Efeito de diferentes níveis de sombreamento no crescimento inicial de Unha de gato (Uncaria tomentosa Willd.)
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Lunz, A.M.P

; Silva Júnior, E.C.

; de Oliveira, L.C

Revista Brasileira de Plantas Medicinais

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Dic 2014, Volumen 16 Nº 4 Paginas 866 - 873

Resumen: Pt En | Texto: Pt En | PDF: Pt | PDF: En

A unha de gato (Uncaria tomentosa Willd.) é uma das muitas espécies de plantas com propriedades medicinais utilizadas pelas comunidades nativas da Amazônia para o tratamento de diversas doenças. Suas inúmeras propriedades medicinais têm provocado nos últimos anos o aumento da demanda por essa planta, a qual vem sendo explorada de forma indiscriminada e predatória. O conhecimento agronômico disponível atualmente sobre essa espécie é escasso; dessa forma, o objetivo do presente trabalho foi avaliar o efeito de diferentes níveis de sombreamento no crescimento inicial da Unha de gato. O experimento foi realizado no viveiro da área experimental da Embrapa Acre, no município de Rio Branco, AC, no período de maio de 2009 a junho de 2010. Foram avaliados quatro tratamentos, constituídos por diferentes níveis de sombreamento (30%, 50% e 70%) e pleno Sol, obtidos com tela sombrite preta, com as referidas capacidades de retenção da radiação solar. O delineamento experimental utilizado foi o de blocos casualizados, com oito repetições, contendo duas plantas por parcela. As variáveis analisadas foram: altura da parte aérea, diâmetro do colo, biomassa do sistema radicular, biomassa aérea, biomassa total e partição de biomassa. O crescimento da Unha de gato foi modificado pela intensidade de sombreamento. A altura das plantas e a massa seca das raízes aumentaram linearmente com a intensidade de sombreamento. Sombreamentos entre 55 a 60% proporcionaram melhores crescimentos para as variáveis: diâmetro do coleto, massa seca da parte aérea e massa seca total. Não houve variação na distribuição de massa seca entre a parte aérea e o sistema radicular das plantas em função do sombreamento. Verificou-se que o sombreamento na faixa de 55 a 60% é o mais indicado para o seu crescimento inicial.

Is one among many plant species with medicinal properties, used by the native communities of the Amazon to treat several diseases. Its numerous medicinal properties have caused in recent years an increase in demand and the plant has been exploited in an indiscriminate and predatory way. The agronomic knowledge available on this species is scarce, so the purpose of this study was to evaluate the effect of different levels of shading on early growth of Uncaria tomentosa. The experiment was established in the nursery of Embrapa Acre, in the city of Rio Branco, state of Acre, Brazil, from May 2009 to June 2010. We tested four levels of shading (30%, 50% and 70%) and full sunlight, obtained with black shade screens. The experimental design was a randomized block, with eight replications and two plants per plot. The variables analyzed were: height of shoots, stem diameter, root dry matter, aerial dry matter, total dry matter and dry matter partitioning. The growth of Uncaria tomentosa was modified by the intensity of shading. Plant height and dry weight of the roots increased linearly with the intensity of shading. Shading around 55 to 60% provided better growth for the stem diameter, shoot dry matter and total dry matter. There was no change in the distribution of the dry matter between the shoot and root systems of the plants. For the species Uncaria tomentosa, we found that shading in the range of 55 to 60% is the most indicated for its early growth.

https://doi.org/10.1590/1983-084X/11_216 3747 descargas

Morphology of the male agouti accessory genital glands (Dasyprocta prymnolopha Wagler, 1831)
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Menezes, Danilo J. Ayres de

; Assis Neto, Antonio C.

; Oliveira, Moacir F.

; Farias, E.C.

Pesquisa Veterinária Brasileira

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Sep 2010, Volumen 30 Nº 9 Paginas 793 - 797

Resumen: Pt En | Texto: Pt En | PDF: Pt | PDF: En

A morfologia das glândulas genitais acessórias de cutias foram estudados em 23 animais criados em cativeiros. Vinte animais tiveram suas glândulas genitais dissecadas in situ para as descrições macroscópicas. Para o estudo microscópico foram utilizados três animais. Os fragmentos de cada glândula foram embebidos em parafina, seccionados e corados em hematoxilina e eosina. Foram encontrados quatro pares de glândulas: vesiculares, coaguladoras, próstata e bulbouretrais. As características histológicas da glândula vesicular, coaguladora e próstata mostraram morfologia similar, com epitélio colunar pseudoestratificado. O tipo tuboalveolar da glândula bulbouretral mostrou uma deficiência de tecido conjuntivo, citoplasma pouco corado e presença de vacúolos. Este estudo concluiu que a cutia apresenta as mesmas características morfológicas das glândulas genitais acessórias encontradas em roedores.

The morphology of the accessory genital glands of the male agouti was studied in twenty-three animals that were raised in captivity. Twenty animals had their genital glands dissected in situ for macroscopic description. The samples of each gland were recovered, embedded in paraffin, sliced and stained by Hematoxylin-Eosin technique. It was founded four pairs of glands: the vesicular glands, the coagulating glands, the prostate and the bulbourethral glands. Histological characteristics of the vesicular, coagulating and prostate glands showed similar morphology, within the pseudostratified columnar epithelium. The tubulo-alveolar type of the bulbourethral glands showed a lack of connective tissue among the tubules, a small amount of red stained presented it the cytoplasm, and the presence of vacuoles in the tissue. This study concluded that the agouti showed to have similar morphological aspect described in the others species of rodents.

3316 descargas

Intrinsic denervation of the colon is associated with a decrease of some colonic preneoplastic markers in rats treated with a chemical carcinogen
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Vespúcio, M.V.O.

; Turatti, A.

; Modiano, P.

; Oliveira, E.C. de

; Chicote, S.R.M.

; Pinto, A.M.P.

; Garcia, S.B.

Brazilian Journal of Medical and Biological Research

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Abr 2008, Volumen 41 Nº 4 Paginas 311 - 317

Resumen: En | Texto: En | PDF: En

Denervation of the colon is protective against the colon cancer; however, the mechanisms involved are unknown. We tested the hypothesis that the denervated colonic mucosa could be less responsive to the action of the chemical carcinogen dimethylhydrazine (DMH). Three groups of 32 male Wistar rats were treated as follows: group 1 (G1) had the colon denervated with 0.3 mL 1.5 mM benzyldimethyltetradecylammonium (benzalkonium chloride, BAC); G2 received a single ip injection of 125 mg/kg DMH; G3 was treated with BAC + the same dose and route of DMH. A control group (Sham, N = 32) did not receive any treatment. Each group was subdivided into four groups according to the sacrifice time (1, 2, 6, and 12 weeks after DMH). Crypt fission index, ß-catenin accumulated crypts, aberrant crypt foci, and cell proliferation were evaluated and analyzed by ANOVA and the Student t-test. G3 animals presented a small number of aberrant crypt foci and low crypt fission index compared to G2 animals after 2 and 12 weeks, respectively. From the second week on, the index of ß-catenin crypt in G3 animals increased slower than in G2 animals. From the 12th week on, G2 animals presented a significant increase in cell proliferation when compared to the other groups. Colonic denervation plays an anticarcinogenic role from early stages of colon cancer development. This finding can be of importance for the study of the role of the enteric nervous system in the carcinogenic process.

2459 descargas Citado 1 vez en SciELO

Preparation and cytotoxicity of cisplatin-containing liposomes
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Carvalho Júnior, A.D.

; Vieira, F.P.

; De Melo, V.J.

; Lopes, M.T.P.

; Silveira, J.N.

; Ramaldes, G.A.

; Garnier-Suillerot, A.

; Pereira-Maia, E.C.

; De Oliveira, M.C.

Brazilian Journal of Medical and Biological Research

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Ago 2007, Volumen 40 Nº 8 Paginas 1149 - 1157

Resumen: En | Texto: En | PDF: En

We encapsulated cisplatin into stealth pH-sensitive liposomes and studied their stability, cytotoxicity and accumulation in a human small-cell lung carcinoma cell line (GLC4) and its resistant subline (GLC4/CDDP). Since reduced cellular drug accumulation has been shown to be the main mechanism responsible for resistance in the GLC4/CDDP subline, we evaluated the ability of this new delivery system to improve cellular uptake. The liposomes were composed of dioleoylphosphatidylethanolamine (DOPE), cholesteryl hemisuccinate (CHEMS), and distearoylphosphatidylethanolamine-polyethyleneglycol 2000 (DSPE-PEG2000) and were characterized by determining the encapsulation percentage as a function of lipid concentration. Among the different formulations, DOPE/CHEMS/DSPE-PEG liposomes (lipid concentration equal to 40 mM) encapsulated cisplatin more efficiently than other concentrations of liposomes (about 20.0%, mean diameter of 174 nm). These liposomes presented good stability in mouse plasma which was obtained using a 0.24-M EDTA solution (70% cisplatin was retained inside the liposomes after 30 min of incubation). Concerning cytotoxic effects, they are more effective (1.34-fold) than free cisplatin for growth inhibition of the human lung cancer cell line A549. The study of cytotoxicity to GLC4 and GLC4/CDDP cell lines showed similar IC50 values (approximately 1.4 µM), i.e., cisplatin-resistant cells were sensitive to this cisplatin formulation. Platinum accumulation in both sensitive and resistant cell lines followed the same pattern, i.e., approximately the same intracellular platinum concentration (4.0 x 10-17 mol/cell) yielded the same cytotoxic effect. These results indicate that long-circulating pH-sensitive liposomes, also termed as stealth pH-sensitive liposomes, may present a promising delivery system for cisplatin-based cancer treatment. This liposome system proved to be able to circumvent the cisplatin resistance, whereas it was not observed when using non-long-circulating liposomes composed of phosphatidylcholine, phosphatidylserine, and cholesterol.

5991 descargas

A Brazilian family with Brown-Vialetto-van Laere syndrome with autosomal recessive inheritance
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Malheiros, José Augusto

; Camargos, Sarah Teixeira

; Oliveira, José Teotonio de

; Cardoso, Francisco E.C.

Arquivos de Neuro-Psiquiatria

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Mar 2007, Volumen 65 Nº 1 Paginas 32 - 35

Resumen: Pt En | Texto: Pt En | PDF: Pt | PDF: En

Descrevemos a primeira família brasileira com síndrome de Brown-Vialetto-van Laere. Os pacientes são três irmãs e uma sobrinha provenientes de casamentos consangüíneos, o que fortalece a hipótese de transmissão autossômica recessiva. A idade de aparecimento dos sintomas variou entre 12 e 20 anos. A latência entre a perda auditiva e o envolvimento de outros nervos cranianos variou de 3 a 12 anos. O estudo de imagem por ressonância magnética demonstrou atrofia bulbar além de alteração de sinal nas seqüências ponderadas em T2 e FLAIR (fluid attenuated inversion recovery).

We report the first Brazilian family with Brown-Vialetto-van Laere syndrome. The presence of consanguineous marriages and illness affecting three sisters and one niece support an autosomal recessive transmission. The age at onset of the illness ranged from 12 to 20 years old. The time interval between hearing loss and involvement of other cranial nerves varied from 3 to 12 years. MRI demonstrated bulbar atrophy and also high intensity signal at T2 weighted and fluid attenuated inversion recovery (FLAIR) sequences.

3647 descargas

Trypanosoma cruzi infection and/or administration of the nonsteroidal anti-inflammatory nimesulide increase the number of colonic crypts overexpressing metallothioneins in rat colon carcinogenesis
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Escalante, R.D.

; de Oliveira, Ê.C.

; Cunha, F.Q.

; Vespúcio, M.V.O.

; Ribeiro-Silva, A.

; Aprilli, F.

; Garcia, S.B.

Brazilian Journal of Medical and Biological Research

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Jul 2006, Volumen 39 Nº 7 Paginas 895 - 899

Resumen: En | Texto: En | PDF: En

Trypanosoma cruzi infection and nonsteroidal anti-inflammatory drugs inhibit colorectal carcinogenesis by mechanisms not completely known and metallothionein proteins (MTs) may be involved in this process. Sixty-six male Wistar rats weighing 90 to 120 g were randomly divided into seven groups (GI to GVII). GI, GII and GIII animals were subcutaneously infected with 200,000 trypomastigote forms of the Y strain of T. cruzi. After 8 weeks, GI, GII, GIV, and GVI were injected with one weekly subcutaneous dose of 12 mg/kg dimethylhydrazine for 4 weeks. In sequence, GI, GIV and GV were treated with nimesulide (10 mg/kg per dose, five times per week for 8 weeks). Groups I, III, IV, and VI had 12 animals, and each of the other groups had 6 animals. All the animals were euthanized 8 weeks after the last dimethylhydrazine injection. The colons were fixed and processed for MT immunohistochemistry. The index of MT-overexpressing colonic crypts (MTEC) was estimated as the percentage of MT-stained crypts in relation to the total number of crypts scored. Five hundred crypts per animal were scored. Data were analyzed by the Kruskal-Wallis test followed by the Dunn test. There was an increase in MTEC index in the groups either infected with T. cruzi or treated with nimesulide or both infected and treated when compared to control (401, 809, and 1011%, respectively). We suggest that the increased formation of MTEC may be related to the protection against carcinogenesis provided both by T. cruzi infection and nimesulide.

1764 descargas Citado 1 vez en SciELO

Atherosclerosis in aged mice over-expressing the reverse cholesterol transport genes
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Berti, J.A.

; de Faria, E.C.

; Oliveira, H.C.F.

Brazilian Journal of Medical and Biological Research

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Mar 2005, Volumen 38 Nº 3 Paginas 391 - 398

Resumen: En | Texto: En | PDF: En

We determined whether over-expression of one of the three genes involved in reverse cholesterol transport, apolipoprotein (apo) AI, lecithin-cholesterol acyl transferase (LCAT) and cholesteryl ester transfer protein (CETP), or of their combinations influenced the development of diet-induced atherosclerosis. Eight genotypic groups of mice were studied (AI, LCAT, CETP, LCAT/AI, CETP/AI, LCAT/CETP, LCAT/AI/CETP, and non-transgenic) after four months on an atherogenic diet. The extent of atherosclerosis was assessed by morphometric analysis of lipid-stained areas in the aortic roots. The relative influence (R²) of genotype, sex, total cholesterol, and its main sub-fraction levels on atherosclerotic lesion size was determined by multiple linear regression analysis. Whereas apo AI (R² = 0.22, P < 0.001) and CETP (R² = 0.13, P < 0.01) expression reduced lesion size, the LCAT (R² = 0.16, P < 0.005) and LCAT/AI (R² = 0.13, P < 0.003) genotypes had the opposite effect. Logistic regression analysis revealed that the risk of developing atherosclerotic lesions greater than the 50th percentile was 4.3-fold lower for the apo AI transgenic mice than for non-transgenic mice, and was 3.0-fold lower for male than for female mice. These results show that apo AI overexpression decreased the risk of developing large atherosclerotic lesions but was not sufficient to reduce the atherogenic effect of LCAT when both transgenes were co-expressed. On the other hand, CETP expression was sufficient to eliminate the deleterious effect of LCAT and LCAT/AI overexpression. Therefore, increasing each step of the reverse cholesterol transport per se does not necessarily imply protection against atherosclerosis while CETP expression can change specific athero genic scenarios.

2048 descargas

10.

Hot hypernucleus formation in high-energy photonuclear reactions
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Gonçalves, M.

; Oliveira, E.C. de

; Medeiros, E.L.

; Pina, S. de

; Duarte, S.B.

Brazilian Journal of Physics

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Sep 2004, Volumen 34 Nº 3a Paginas 919 - 923

Resumen: En | Texto: En | PDF: En

The probability of a compound residual hot hypernucleus formation at the end of pre-equilibrium phase of high energy photonuclear reactions is calculated with a time dependent Monte Carlo Multicollisional Cascade (MCMC) approach. The emission of hadrons during the rapid phase of the reaction is discussed and characteristics of the residual nucleus are obtained. Results for mass and charge distributions of the formed hot hypernucleus are shown and its excitation energy is discussed.

1001 descargas

11.

pp-Blast: a "pseudo-parallel" Blast
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Osório, E.C.

; Souza, J.E. de

; Zaiats, A.C.

; Oliveira, P.S.L. de

; Souza, S.J. de

Brazilian Journal of Medical and Biological Research

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Abr 2003, Volumen 36 Nº 4 Paginas 463 - 464

Resumen: En | Texto: En | PDF: En

We have developed a software called pp-Blast that uses the publicly available Blast package and PVM (parallel virtual machine) to partition a multi-sequence query across a set of nodes with replicated or shared databases. Benchmark tests show that pp-Blast running in a cluster of 14 PCs outperformed conventional Blast running in large servers. In addition, using pp-Blast and the cluster we were able to map all human cDNAs onto the draft of the human genome in less than 6 days. We propose here that the cost/benefit ratio of pp-Blast makes it appropriate for large-scale sequence analysis. The source code and configuration files for pp-Blast are available at http://www.ludwig.org.br/biocomp/tools/pp-blast.

2098 descargas

12.

QUANTIFICAÇÃO DE LACTOSE EM QUEIJOS MINAS FRESCAL
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Caruso, E.C.

; Oliveira, A.J. de

Scientia Agricola

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1999, Volumen 56 Nº 1 Paginas 243 - 246

Resumen: Pt En | Texto: Pt En | PDF: Pt | PDF: En

O principal objetivo deste trabalho foi verificar a aplicabilidade do método de Acton na determinação de lactose em queijo tipo Minas Frescal e, para isso estudou-se a porcentagem de recuperação de lactose adicionada a amostras dos queijos, em diferentes situações. As recuperações variam de 99,1% e 103,7% , e os melhores resultados em torno de 100%, obtidos para as amostras preparadas contendo até 40 <FONT FACE="Symbol">m</font>g de lactose / ml. Os queijos tipo Minas Frescal, de três lotes diferentes com três queijos por lote, foram adquiridos no comércio de Piracicaba, SP aos dois dias de fabricação e nesse mesmo dia, analisados para o teor de lactose. Os resultados variaram de 2,36% a 2,47% no lote 1; 2,68% a 3,03% no lote 2 e 2,19% a 2,48% no lote 3, mostrando, assim, boa uniformidade dentro dos lotes e pequena variação entre estes, mas, todos os valores apresentaram-se dentro das faixas comumente encontradas para este tipo de queijo.

The main objective of this work was to study the applicability of the method of Acton to estimate the lactose concentration in Minas Frescal cheese. Recovery experiments were carried out, with recoveries for lactose ranging from 99.1% to 103.7%., for samples containing up to 40<FONT FACE="Symbol">m</font>g lactose/ml. Cheese samples were purchased randomly in Piracicaba, SP, Brasil with two days of shelf life, from three batches, with three samples per batch. Lactose was determined in the same day and its concentration varied from 2.36% to 2.47% for batch 1; 2.58% to 3.03% for batch 2; and from 2.19% to 2.48% for batch 3. A high uniformity was observed among batches, with little variation among samples. All values were within the range tipically found for this kind of cheese.

5726 descargas

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