PREDIÇÃO DA ATIVIDADE DE ÁGUA E RELAÇÃO ENTRE A ATIVIDADE DE ÁGUA E A DEPRESSÃO DO PONTO DE CONGELAMENTO DE SUCOS DE FRUTAS

This work proposes to determine the water activity and the freezing point depression of tangerine, pineapple and lemon juices at various concentrations (10-55oBrix) and to achieve a correlation between these properties. The freezing point depression was determined with a LAKTRON cryoscope and common laboratory materials. The water activity was determined with a DECAGON CX-2 hygrometer in the temperature range of 15 to 30oC. With the results, the adjustment to CHEN (1987) water activity prediction equation to non-electrolyte mixtures was verified, through the calculation of the variation coefficient (CV). Being CV smaller than 3% for the proposed model, it can be said that the experimental data have adjusted well to the prediction equation. The water activity and the freezing point depression was correlated for tangerine, pineapple and lemon juices and r2 values were higher than 99%. Therefore, it is possible to obtain the water activity by knowing the freezing point depression of studied juices.

Quantum-state protection in cavities

We show how an initially prepared quantum state of a radiation mode in a cavity can be preserved for a long time using a feedback scheme based on the injection of appropriately prepared atoms. We present a feedback scheme both for optical cavities, which can be continuously monitored by a photodetector, and for microwave cavities, which can be monitored only indirectly via the detection of atoms that have interacted with the cavity field. We also discuss the possibility of applying these methods for decoherence control in quantum information processing.

Controlling the decoherence of a ''meter'' via stroboscopic feedback

We propose a simple modification of the experimental scheme employed by Brune rt ni. [Phys. Rev. Lett. 79, 4887 (1996)] for the generation and detection of a Schrodinger cat state, in which the decoherence of the cat state can be significantly slowed down using an appropriate feedback.

Protecting Schrodinger cat states using feedback

A feedback model based on direct photodetection and micromaser-like atomic injection is proposed for the preservation of quantum coherence in a cavity. We show that in this way it is possible to slow down significantly the decoherence of Schrodinger cat states.

The draft genome of Ciona intestinalis: Insights into chordate and vertebrate origins

The first chordates appear in the fossil record at the time of the Cambrian explosion, nearly 550 million years ago. The modern ascidian tadpole represents a plausible approximation to these ancestral chordates. To illuminate the origins of chordate and vertebrates, we generated a draft of the protein-coding portion of the genome of the most studied ascidian, Ciona intestinalis. The Ciona genome contains similar to16,000 protein-coding genes, similar to the number in other invertebrates, but only half that found in vertebrates. Vertebrate gene families are typically found in simplified form in Ciona, suggesting that ascidians contain the basic ancestral complement of genes involved in cell signaling and development. The ascidian genome has also acquired a number of lineage-specific innovations, including a group of genes engaged in cellulose metabolism that are related to those in bacteria and fungi.

Possível interferência da antitoxina tetânica pré-existente, na vacinação antitetânica

Estudou-se qual a possível interferência no desenvolvimento da imunidade antitetânica ativa em cobaias e camundongos, filhos de fêmeas vacinadas contra o tétano em diferentes épocas durante o período da prenhês. Verificou-se que a vacinação das fêmeas, em gestação não interferiu, negativamente, no desenvolvimento da imunidade ativa dos animais filhos, quando submetidos à vacinação ao redor de 60 dias após o nascimento. A presença de baixos níveis de anticorpos circulantes, recebidos congenitamente, parece ter, em determinadas condições, estimulado a resposta imunitária quando, posteriormente, os animais filhos foram vacinados contra o tétano. Sugere-se que o complexo antígeno-anticorpo formado seja capaz de melhorar a resposta imunitária induzida pelo toxóide.

Synthesis, Antimicrobial and Antiproliferative Activity of Novel Silver(I) Tris(pyrazolyl)methanesulfonateand 1,3,5-Triaza-7-phosphadamantane Complexes

Five new silver(I) complexes of formulas [Ag(Tpms)] (1), [Ag(Tpms)-(PPh3)] (2), [Ag(Tpms)(PCy3)] (3), [Ag(PTA)][BF4] (4), and [Ag(Tpms)(PTA)] (5) {Tpms = tris(pyrazol-1-yl)methanesulfonate, PPh3 = triphenylphosphane, PCy3 = tricyclohexylphosphane, PTA = 1,3,5-triaza-7-phosphaadamantane) have been synthesized and fully characterized by elemental analyses, H-1, C-13, and P-31 NMR, electrospray ionization mass spectrometry (ESI-MS), and IR spectroscopic techniques. The single crystal X-ray diffraction study of 3 shows the Tpms ligand acting in the N-3-facially coordinating mode, while in 2 and 5 a N2O-coordination is found, with the SO3 group bonded to silver and a pendant free pyrazolyl ring. Features of the tilting in the coordinated pyrazolyl rings in these cases suggest that this inequivalence is related with the cone angles of the phosphanes. A detailed study of antimycobacterial and antiproliferative properties of all compounds has been carried out. They were screened for their in vitro antimicrobial activities against the standard strains Enterococcus faecalis (ATCC 29922), Staphylococcus aureus (ATCC 25923), Streptococcus pneumoniae (ATCC 49619), Streptococcus pyogenes (SF37), Streptococcus sanguinis (SK36), Streptococcus mutans (UA1S9), Escherichia coli (ATCC 25922), and the fungus Candida albicans (ATCC 24443). Complexes 1-5 have been found to display effective antimicrobial activity against the series of bacteria and fungi, and some of them are potential candidates for antiseptic or disinfectant drugs. Interaction of Ag complexes with deoxyribonucleic acid (DNA) has been studied by fluorescence spectroscopic techniques, using ethidium bromide (EB) as a fluorescence probe of DNA. The decrease in the fluorescence of DNA EB system on addition of Ag complexes shows that the fluorescence quenching of DNA EB complex occurs and compound 3 is particularly active. Complexes 1-5 exhibit pronounced antiproliferative activity against human malignant melanoma (A375) with an activity often higher than that of AgNO3, which has been used as a control, following the same order of activity inhibition on DNA, i.e., 3 > 2 > 1 > 5 > AgNO3 >> 4.

Inquérito soroepidemiológico para infecções por fungos causadores de micoses sistêmicas na Reserva Indígena Xacriabá, Estado de Minas Gerais

A Reserva Indígena Xacriabá situa-se no norte do Estado de Minas Gerais, próxima do município de Manga e do vale do Rio São Francisco. A população índia é miscigenada com brancos e negros e exerce atividades agrícolas e pecuária. Amostras de sangue foram coletadas de 180 habitantes da Reserva (85 homens e 95 mulheres), com 15 a 84 anos de idade, testando-se o soro pelo método da contraimunoeletroforese com antígenos de Paracoccidioides brasiliensis, Histoplasma capsulatum, Cryptococcus neoformans e Candida albicans. Verificou-se soros reagentes em, respectivamente, 5%, 3,9%, 7,2% e 6,7% do total de amostras. Os indivíduos reativos com antígenos de P. brasiliensis e H. capsulatum eram predominantemente mulheres e tinham idade menor e títulos médios mais elevados de anticorpos do que os reativos com outros antígenos.Os resultados são sugestivos da ocorrência de paracoccidiodomicose-infecção e de histoplasmose-infecção, nas primeiras décadas de vida dos habitantes, na área da Reserva Indígena Xacriabá.

Hidatidose policística: relato de dois casos procedentes de Sena Madureira, Acre, na Amazônia brasileira

Dois casos de hidatidose policística (HP) são relatados, oriundos do mesmo município da região amazônica brasileira (Sena Madureira, Acre). Ambos tiveram a mesma apresentação e evolução clínica ao longo de dois anos de acompanhamento. Inicialmente os pacientes queixaram-se de dor abdominal no andar superior ou no hipocôndrio direito e apresentaram icterícia obstrutiva, febre, aumento de volume abdominal e emagrecimento. Por exame de imagem, além de esplenomegalia, cistos múltiplos e coalescentes foram detectados no fígado. Amostras de soro foram reagentes por contraimunoeletroforese. O tratamento com albendazol resultou em melhora parcial, com alívio sintomático e redução no tamanho das lesões. Este relato reforça a importância de estudos clínico-epidemiológicos da hidatidose policística na região amazônica brasileira, especialmente no município de Sena Madureira, onde outros pacientes com HP podem estar sem diagnóstico.

Inquérito sorológico da infecção pelo Echinococcus sp no município de Sena Madureira, AC

Foi realizado no município de Sena Madureira, Acre, um inquérito soroepidemiológico para avaliar o contato de indivíduos com o Echinococcus sp. Escolheu-se duas populações distintas, uma residente na área urbana e a outra na área rural do município, distribuída em comunidades ribeirinhas da região. Foram avaliados no total 1.064 indivíduos, dos quais 851 pertencentes à área urbana e 213 à área rural. O estudo foi dividido em duas partes: inquérito sorológico, no qual foram coletadas e enviadas amostras de sangue ao Laboratório de Sorologia do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo, onde foram realizados os testes imunológicos pela técnica de contraimunoeletroforese; inquérito epidemiológico para avaliação individual, além de as condições de moradia e hábitos dos indivíduos. A prevalência sorológica na área rural foi 6%, enquanto na urbana fomos 3,5%. A prevalência geral foi 4%. Quando analisada a possibilidade da existência de outros hospedeiros intermediários no ciclo do Echinococcus vogeli, foram encontrados resultados que sugerem ser o porco doméstico o mais provável.

Efficacy of voriconazole in experimental rat paracoccidioidomycosis

INTRODUCTION: Amphotericin B, azole or sulfamide drugs are used for treatment of patients with paracoccidioidomycosis. Among the azole drugs, voriconazole was active in vitro against Paracoccidioides brasiliensis and showed efficacy in the treatment of patients infected with this fungus.In the present study the antifungal activity of voriconazole and of other drugs was compared in a rat model of paracoccidioidomycosis. METHODS: Wistar rats were inoculated intravenously with the BOAS strain of P. brasiliensis and antifungal drugs were administered to the animals by gavage at the following doses (mg/kg weight/day): voriconazole (5 to 20), ketoconazole (12 to 15), fluconazole (6), itraconazole (4), and sulfamethoxazole-trimethoprim (120 to 150). The antifungal activity of the drugs was assessed by determining the P. brasiliensis colony forming units in the lungs and spleen of the animals at the end of treatment and by a survival study. RESULTS: Voriconazole reduced the total tissue fungal burden of P. brasiliensis, particularly at doses of ≥10mg/kg weight/day but its antifungal activity was less intense than that of fluconazole, itraconazole and sulfamethoxazole-trimethoprim. The mean survival of animals treated with the last three drugs, 29.1±10.7, 26.1± 10.1 and 28.4±9.6 days, respectively, was higher than that achieved with voriconazole 10mg/kg weight/day (18.5±8.3 days) and that observed in untreated animals (15.7±3.6 days). CONCLUSIONS: At doses similar to those used for clinical treatment, voriconazole showed lower antifungal activity in experimental rat paracoccidioidomycosis than that obtained with itraconazole and sulfamethoxazole-trimethoprim.

In vitro activity of antimicrobial combinations against multidrug-resistant Pseudomonas aeruginosa

Introduction Pseudomonas aeruginosa isolates related to nosocomial infections are often resistant to multiple antibacterial agents. In this study, antimicrobial combinations were evaluated to detect in vitro synergy against clinical isolates of P. aeruginosa. Methods Four clinical P. aeruginosa isolates were selected at random among other isolates from inpatients treated at the public University hospital in Ribeirão Preto, SP, Brazil. Two isolates were susceptible to imipenem (IPM-S) and several other antimicrobials, while the other two isolates were imipenem and multidrug resistant (IPM-R). The checkerboard method was used to assess the interactions between antimicrobials. Results Combinations of imipenem or other anti-Pseudomonas drugs with complementary antibiotics, such as aminoglycosides, fosfomycin and rifampin, reached synergy rates of 20.8%, 50%, 62.5% and 50% for the two IPM-S and two IPM-R Pseudomonas isolates, respectively. Imipenem, piperacillin-tazobactam and ceftazidime yielded a greater synergy rate than cefepime or ciprofloxacin. Synergist combinations were more commonly observed when the complementary drug was tobramycin (65%) or fosfomycin (57%). Conclusions Some antibacterial combinations led to significant reductions of the minimum inhibitory concentrations of both drugs, suggesting that they could be clinically applied to control infections caused by multidrug-resistant P. aeruginosa.

Serological diagnosis of paracoccidioidomycosis in HIV-coinfected patients

Paracoccidioidomycosis should be differentiated from other opportunistic diseases in human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients who live in Latin America. Laboratory investigation can begin with serological tests, which are rapid and efficient. In the present study, double immunodiffusion (DID), counterimmunoelectrophoresis (CIEP) and an enzyme linked immunosorbent assay (ELISA) tests were assessed for the detection of anti-Paracoccidioides brasiliensis antibodies in 40 patients coinfected with HIV. The results were compared to those obtained for 75 non-HIV-infected patients with endemic paracoccidioidomycosis. Anti-P. brasiliensis antibodies were detected in 65% (DID), 79% (CIEP) and 95% (ELISA) of the patients with HIV/AIDS, significantly lower rates than those detected in cases of endemic paracoccidioidomycosis, which were 89%, 99% and 100%, respectively. The reactive sera of HIV-infected patients also showed lower anti-P. brasiliensis antibody titres than those of non-HIV-infected patients. Despite the lower intensity of the specific humoral response, serological tests are useful for the diagnosis of opportunistic paracoccidioidomycosis in the HIV/AIDS population. We suggest optimization of the laboratory diagnosis by combining the ELISA test with CIEP or DID.