66 research outputs found

    Stability and activity of Zn/MCM-41 materials in toluene alkylation: Microwave irradiation vs continuous flow

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    Zn/MCM-41 mesoporous materials have been prepared via classic wet impregnation, employing zinc nitrate as precursor and tested for activity and stability in the Friedel-Crafts alkylation of toluene with benzyl chloride under microwave irradiation and continuous flow. The modified materials were characterized by means of a number of analytical techniques, and surface and textural properties were thoroughly checked. Materials containing the highest Zn loading (15 wt %) provided full conversion after 5 minutes reaction under microwave irradiation (300 W, 120 °C). Materials were proved to be stable and reusable for several cycles with an optimum performance under continuous flow conditions.Fil: Carraro, Paola María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Tecnología Química. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Tecnología Química; ArgentinaFil: Goldani, Bruna S.. Universidade Federal de Pelotas; BrasilFil: Alves, Diego. Universidade Federal de Pelotas; BrasilFil: Sathicq, Angel Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Eimer, Griselda Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Tecnología Química. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Tecnología Química; ArgentinaFil: Romanelli, Gustavo Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Luque, Rafael. Universidad de Córdoba; España. Rudn University; Rusi

    BK Virus Encephalitis in HIV-Infected Patients: Case Report and Review

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    Encephalitis and meningitis due to BKPyV are unusual and emerging condition. Only a few cases of BKPyV encephalitis have been reported in hematopoietic stem cell transplant recipients, with the majority of cases presenting with concurrent hemorrhagic cystitis and HIV-infected patients. The authors report two HIV-infected patients with the diagnosis of BKPyV encephalitis and discuss the main clinical, diagnostic, and therapeutic aspects of this infection in patients with AIDS. Physicians should be aware to recognize the main clinical features and diagnose BKPyV central nervous infection in the setting of AIDS

    International scientific collaboration in HIV and HPV: a network analysis.

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    Research endeavours require the collaborative effort of an increasing number of individuals. International scientific collaborations are particularly important for HIV and HPV co-infection studies, since the burden of disease is rising in developing countries, but most experts and research funds are found in developed countries, where the prevalence of HIV is low. The objective of our study was to investigate patterns of international scientific collaboration in HIV and HPV research using social network analysis. Through a systematic review of the literature, we obtained epidemiological data, as well as data on countries and authors involved in co-infection studies. The collaboration network was analysed in respect to the following: centrality, density, modularity, connected components, distance, clustering and spectral clustering. We observed that for many low- and middle-income countries there were no epidemiological estimates of HPV infection of the cervix among HIV-infected individuals. Most studies found only involved researchers from the same country (64%). Studies derived from international collaborations including high-income countries and either low- or middle-income countries had on average three times larger sample sizes than those including only high-income countries or low-income countries. The high global clustering coefficient (0.9) coupled with a short average distance between researchers (4.34) suggests a "small-world phenomenon." Researchers from high-income countries seem to have higher degree centrality and tend to cluster together in densely connected communities. We found a large well-connected community, which encompasses 70% of researchers, and 49 other small isolated communities. Our findings suggest that in the field of HIV and HPV, there seems to be both room and incentives for researchers to engage in collaborations between countries of different income-level. Through international collaboration resources available to researchers in high-income countries can be efficiently used to enroll more participants in low- and middle-income countries

    Epidemiological aspects and characterization of the resistance profile of Fusarium spp. in patients with invasive fusariosis

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    Introduction. The remarkable intrinsic resistance of Fusarium species to most antifungal agents results in high mortality rates in the immunocompromised population. Aims. This study aimed to investigate the epidemiology, clinical features and antifungal susceptibility of Fusarium isolates in patients with invasive fusariosis. Methodology. A total of 27 patients admitted to a referral hospital from January 2008 to June 2017 were evaluated. Antifungal susceptibility testing of isolates was performed by broth microdilution according to the Clinical and Laboratory Standards Institute guidelines. Results. Haematological malignancy was the predominant underlying condition, with an incidence of invasive fusariosis of 14.8 cases per 1000 patients with acute lymphoid leukaemia and 13.1 cases per 1000 patients with acute myeloid leukaemia. The Fusarium solani species complex (FSSC) was the most frequent agent group, followed by the Fusarium oxysporum species complex (FOSC). Voriconazole showed the best activity against Fusarium, followed by amphotericin B. Itraconazole showed high minimum inhibitory concentration values, indicating in vitro resistance. Clinical FSSC isolates were significantly (P<0.05) more resistant to amphotericin B and voriconazole than FOSC isolates. Conclusion. The present antifungal susceptibility profiles indicate a high incidence of fusariosis in patients with haematological malignancy. Species- and strain-specific differences in antifungal susceptibility exist within Fusarium in this setting

    Tuberculous meningitis: evaluation of polymerase chain reaction (PCR) as a diagnostic tool – a pilot study.

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    Meningite é uma forma grave e potencialmente fatal de tuberculose. O diagnóstico envolve a detecção de bacilos álcool-ácido resistentes no líquido cefalorraquidiano por microscopia ou cultura. Entretanto, a dificuldade de detectar o organismo representa um desafio ao diagnóstico. O uso da reação em cadeia da polimerase (PCR) na abordagem diagnóstica de meningite causada por Mycobacterium tuberculosis (MTB) tem sido relatado como um método rápido e preciso, com diversos kits comerciais disponíveis. Como alternativa, algumas instituições vêm desenvolvendo testes in house com baixo custo. Em nossa instituição, usamos PCR in house para tuberculose. O desempenho de nossa PCR para o diagnóstico de meningite causada por MTB foi analisado em 148 pacientes consecutivos, usando a cultura do MBT como padrão-ouro. A sensibilidade da PCR no líquido cefalorraquidiano para o diagnóstico de meningite causada por MTB foi de 50%, especificidade de 98,6% e concordância coma cultura de 96% (kappa = 0,52). O desempenho de nossa PCR é semelhante ao obtido com os kits comerciais disponíveis.Meningitis is a severe and potentially fatal form of tuberculosis. The diagnostic workup involves detection of acid-fast bacilli in the cerebrospinal fluid by microscopy or culture. However the difficulty in detecting the organism poses a challenge to diagnosis. Use of polymerase chain reaction (PCR) in the diagnostic approach to Mycobacterium tuberculosis (MTB) meningitis has been reported as a fast and accurate method, with several commercial kits available. As an alternative, some institutions have been developing inexpensive in-house assays. In our institution, we use an in-house PCR for tuberculosis. The performance of our PCR for the diagnosis of MTB meningitis was analyzed in 148 consecutive patients, using MTB culture as the gold standard. Sensitivity of cerebrospinal fluid PCR for the diagnosis of MTB meningitis was 50%, specificity was 98.6%, and concordance with culture was 96% (kappa = 0.52). The performance of our PCR is similar to that obtained with the available commercial kits

    Meningite tuberculosa : avaliação da reação em cadeia da polimerase como ferramenta diagnóstica : um estudo piloto

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    Meningitis is a severe and potentially fatal form of tuberculosis. The diagnostic workup involves detection of acidfast bacilli in the cerebrospinal fluid by microscopy or culture. However the difficulty in detecting the organism poses a challenge to diagnosis. Use of polymerase chain reaction (PCR) in the diagnostic approach to Mycobacterium tuberculosis (MTB) meningitis has been reported as a fast and accurate method, with several commercial kits available. As an alternative, some institutions have been developing inexpensive in-house assays. In our institution, we use an inhouse PCR for tuberculosis. The performance of our PCR for the diagnosis of MTB meningitis was analyzed in 148 consecutive patients, using MTB culture as the gold standard. Sensitivity of cerebrospinal fluid PCR for the diagnosis of MTB meningitis was 50%, specificity was 98.6%, and concordance with culture was 96% (kappa = 0.52). The performance of our PCR is similar to that obtained with the available commercial kits.Meningite é uma forma grave e potencialmente fatal de tuberculose. O diagnóstico envolve a detecção de bacilos álcool-ácido resistentes no líquido cefalorraquidiano por microscopia ou cultura. Entretanto, a dificuldade de detectar o organismo representa um desafio ao diagnóstico. O uso da reação em cadeia da polimerase (PCR) na abordagem diagnóstica de meningite causada por Mycobacterium tuberculosis (MTB) tem sido relatado como um método rápido e preciso, com diversos kits comerciais disponíveis. Como alternativa, algumas instituições vêm desenvolvendo testes in house com baixo custo. Em nossa instituição, usamos PCR in house para tuberculose. O desempenho de nossa PCR para o diagnóstico de meningite causada por MTB foi analisado em 148 pacientes consecutivos, usando a cultura do MBT como padrão-ouro. A sensibilidade da PCR no líquido cefalorraquidiano para o diagnóstico de meningite causada por MTB foi de 50%, especificidade de 98,6% e concordância coma cultura de 96% (kappa = 0,52). O desempenho de nossa PCR é semelhante ao obtido com os kits comerciais disponíveis

    Avaliaçao da funçao renal após a terapia de ressincronizaçao cardíaca

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    OBJETIVO: A insuficiência renal crônica (IRC), presente em metade dos portadores de insuficiência cardíaca (IC), está associada ao aumento de mortalidade nessa populaçao. A terapia de ressincronizaçao cardíaca (TRC), que traz benefícios aos pacientes com IC, também pode melhorar a IRC. O objetivo deste estudo foi avaliar a funçao renal após a TRC. MÉTODO: Estudo de coorte, retrospectivo, de pacientes que se submeteram a TRC de julho de 2004 a maio de 2010, para analisar a taxa de filtraçao glomerular (TFG) pré-operatória e seis meses após a TRC. RESULTADOS: Foram incluídos 67 pacientes, com idade média de 68 anos, 70% dos quais eram renais crônicos nao dialíticos. A média da creatinina prévia à TRC foi de 1,47 mg/dl e seu valor após a TRC foi de 1,35 mg/dl (p2) e após a TRC (54,3 ml/min/1,73 m2), com valor de p=0,144. Entretanto, quando analisadas as TFG nos subgrupos, verificou-se melhora importante da funçao renal nos pacientes que apresentavam TFG menor antes da TRC. Naqueles em estágio 3 da funçao renal, observou-se acréscimo de 7,2 ml/min/1,73 m2 após a TRC; o que representa uma melhora da funçao renal de 15,45%. Nos que estavam em estágio 4, o ganho foi de 11,7 ml/min/1,73 m2 após a TRC, um incremento de 48,34%. CONCLUSAO: A TRC proporcionou melhora da TFG nos pacientes com IRC moderada a severa, porém nao apresentou impacto na funçao renal dos pacientes com TFG inicial >60 ml/min/1,73 m2
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