69 research outputs found

    Amplitude Damping for single-qubit System with single-qubit mixed-state Environment

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    We study a generalized amplitude damping channel when environment is initially in the single-qubit mixed state. Representing the affine transformation of the generalized amplitude damping by a three-dimensional volume, we plot explicitly the volume occupied by the channels simulatable by a single-qubit mixed-state environment. As expected, this volume is embedded in the total volume by the channels which is simulated by two-qubit enviroment. The volume ratio is approximately 0.08 which is much smaller than 3/8, the volume ratio for generalized depolarizing channels.Comment: 13 pages, 2 figures incluided V2: homepage address is included in reference V3: version to appear in J. Phys. A: Mathematical and Theoretica

    Phytochemical screening, cytotoxicity and acute toxicity of Annona vepretorum Mart (Annonaceae) leaf extracts

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    Purpose: To investigate the phytochemistry, cytotoxicity and acute toxicity of leaf extracts from Annona vepretorum.Methods: The crude extracts were obtained by maceration with hexane and  methanol. The crude methanol extract was suspended in a 3:7 (v/v) mixture of methanol (MeOH) and water (H2O) and partitioned with hexane, chloroform (CHCl3) and ethyl acetate (AcOEt) in ascending order of polarity to obtain the respective  extracts. In the investigation of phytochemical profile, the extracts were evaluated on thin layer chromatography (TLC) plates of silica gel. Cytotoxicity was tested using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) (MTS) assays against tumor cell lines, viz,HCT-116 (colon), SF-295 (brain), HL-60 (leukemic) and Sarcoma-180. Acute toxicity study was performed by administration of a single oral dose of 2 g/kg body weight of the extracts to mice and the animals were observed for 14 days.Results: Phytochemical screening results showed that A. vepretorum extracts contain alkaloids, flavonoids and terpenes. Methanol and chloroform extracts exhibited high cytotoxic activity against HCT-116, HL-60 and Sarcoma-180. Moreover, the extracts displayed low toxicity in mice, as no deaths and pronounced toxic effects were observed.Conclusion: A. vepretorum contains a variety of secondary metabolites which may confer on this species high cytotoxic activity. In addition, the oral administration of the extracts produced low toxicity in mice.Keywords: Annonaceae, Annona vepretorum, Phytochemistry, Tumor cell lines, Acute toxicit

    Immunomodulatory and neuroprotective effect of cryopreserved allogeneic mesenchymal stem cells on spinal cord injury in rats

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    This study aimed to evaluate the immunomodulatory and neuroprotective effects of allogeneic and cryopreserved mesenchymal stem cells (MSCs) on spinal cord injury. A total of 120 rats were distributed into the following groups: negative control (NC) - without injury, positive control (PC) - with injury without treatment, and group treated with MSC (GMSC) - with injury and treated. Motor function was evaluated by the BBB test at 24, 48, and 72 h and at 8 and 21 postoperative days. Spinal cords were evaluated by histopathology and immunohistochemistry to determine the expression of CD68, NeuN, and GFAP. IL-10, TNF-alpha, IL-1 beta, TGF-beta, BDNF, GDNF, and VEGF expression was quantified by RT-PCR. The GMSC presented higher scores for motor function at 72 h and 8 and 21 days after injury, lower expression of CD68 at 8 days, and lower expression of GFAP at 21 days compared to the PC. In addition, higher expression of NeuN and lower degeneration of the white matter occurred at 21 days. The GMSC also showed higher expression of IL-10 24 h after injury, GDNF at 48 h and 8 days, and VEGF at 21 days. Moreover, lower expression of TNF-alpha was observed at 8 and 21 days and TGF-beta at 24 h and 21 days. There were no differences in the expression of IL-1 beta and BDNF between the GMSC and PC. Thus, cryopreserved MSCs promote immunomodulatory and neuroprotective effects in rats with spinal cord injury by increasing IL-10, GDNF, and VEGF expression and reducing TNF-alpha and TGF-beta expression.Fundacao de Amparo a Pesquisa do Estado de Minas Gerais (FAPEMIG)CAPESVeterinary SchoolLaboratory of Molecular Biology of the Department of Immunology and Biochemistry of the Institute of Biological SciencesUniv Uberaba, Dept Med Ver, Uberaba, MG, BrazilUniv Fed Minas Gerais, Escola Med Vet, Belo Horizonte, MG, BrazilUniv Fed Minas Gerais, Inst Ciencias Biol, Dept Bioquim & Imunol, Belo Horizonte, MG, BrazilUniv Estadual Santa Cruz, Dept Ciencias Biol, Ilheus, BA, BrazilUniv Estadual Santa Cruz, Dept Ciencias Agr & Ambientais, Ilheus, BA, BrazilUniv Fed Sao Paulo, Dept Biociencias, Santos, SP, BrazilUniv Fed Sao Paulo, Dept Biociencias, Santos, SP, BrazilWeb of Scienc

    Tratamento de ferida cirúrgica cutânea em ratos com óleo-resina de copaíba (copaíba reticulata).

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    Foi avaliada a atividade cicatrizante do óleo-resina de copaíba ?in natura? em feridas cirúrgicas cutâneas induzidas em ratos. Setenta e dois ratos foram distribuídos em três grupos: Grupo Controle Negativo (GCN), Grupo Controle Positivo (GCP) e Grupo Óleo-resina de Copaíba (GOC). A avaliação da hiperemia por escore na macroscopia mostrou que a chance de um animal apresentar um grau de hiperemia baixo quando tratado com o óleo-resina de copaíba é 1,46 vezes maior que um animal tratado com ácidos graxos essenciais e 2,14 vezes maiores que a chance de um animal tratado com óleo mineral. Com relação ao infiltrado inflamatório na microscopia a probabilidade de ser menor ocorre no GOC em comparação com os GCN e GCP. Em relação ao tempo de reepitelização, a chance de um animal apresentar uma reepitelização mais lenta tratado com ácidos graxos essenciais é de 1,2 vezes a chance de um animal tratado com óleo-resina de copaíba. A análise histológica mostrou que o tecido cicatricial após o tratamento com óleo-resina de copaíba apresentou maior contração da ferida e consequentemente redução do tamanho da ferida visto pela aproximação de anexos da pele no corte histológico. Concluiu-se que o tratamento com óleo-resina de copaíba proporciona maior contração da ferida e aproximação dos anexos da pele
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