Risikoanalyse durch eine wirkungsbezogenen Analytik mit der instrumentellen Hochleistungs-Dünnschichtchromatographie in der Lebensmittelüberwachung

Zusammenfassung.: Als wirkungsbezogene Analytik wird die Kopplung von biochemischen bzw. biologischen Testverfahren an chemisch/physikalische oder chromatographische Verfahren bezeichnet. So lassen sich mittels der Dünnschichtchromatographie die aufgetrennten Komponenten direkt auf dem Chromatogramm physikalisch-chemisch detektieren und quantifizieren. Durch die Kopplung von biochemischen (z.B. enzymatischen Hemmtests) oder biologischen Testverfahren können toxikologisch wirksame Substanzen in situ nachgewiesen werden. Mit diesen biologischen Testsystemen können - direkt auf dem Chromatogramm auf der Dünnschichtplatte - Fungizide, Antibiotika und Lumnineszenz-Hemmstoffen nachgewiesen werden; ein neues molekularbiologisches Testverfahren ermöglicht den qualitativen und quantitativen Nachweis von Hormonen. Mit biochemischen und biologischen Detektionsverfahren können Wirkstoffe in Lebensmittelproben sowie bei der Reinheitskontrolle und in der Metabolismusforschung von Chemikalien nachgewiesen werden. Außerdem können die detektierten Wirkstoffe durch ihre Migrationsstrecke und ihr UV-Spektrum charakterisiert oder auch identifiziert werden. Pflanzliche Lebensmittel wurden mit der wirkungsbezogenen Analytik auf die Gegenwart von Pestiziden hin untersucht. Biochemische und biologische Detektionsverfahren auf dem Dünnschichtchromatogramm sind sehr selektiv und sensitiv und schließen damit die Lücke zwischen biologischen in vitro-Testverfahren und instrumenteller Analytik. Die Detektion von Wirkungsäquivalenten ist als Screening-Verfahren zunächst unabhängig von Referenzsubstanzen. Neben verschiedenen Testverfahren wird ein Konzept zur Risikoanalyse und Risikobewertung vorgestellt, bei dem die wirkungsbezogene Analytik als Bindeglied zwischen Biotests und chemisch/physikalischen Analytik- und Identifizierungsverfahren fungier

Application of direct bioautography and SPME-GC-MS for the study of antibacterial chamomile ingredients

The isolation and characterization of antibacterial chamomile components were performed by the use of direct bioautography and solid phase microextraction (SPME)-GC-MS. Four ingredients, active against Vibrio fischeri, were identified as the polyacetylene geometric isomers cis- and trans-spiroethers, the coumarin related herniarin, and the sesquiterpene alcohol (-)-alpha-bisabolol

A influência de instrumentos de políticas públicas para a conservação – uma ótica sobre o pagamento dos serviços ambientais

Os serviços ecossistêmicos são essenciais para a sobrevivência do ser humano. No entanto, devido ao processo de urbanização, a população perde a sensibilidade para com os recursos ambientais, trazendo como consequências impactos que podem se tornar irreversíveis. Ao tomar consciência da magnitude que esses impactos podem alcançar, o ser humano se vê na necessidade de alterar o entendimento acerca das cidades, desenvolvendo meios para o desenvolvimento sustentável. Atualmente, diversos instrumentos de gestão são utilizados para a conservação dos recursos ambientais, sendo um deles o pagamento por serviço ambiental (PSA). Assim, o objetivo deste trabalho foi levantar e compreender as contribuições do PSA para a configuração do território. A metodologia apresentou natureza exploratória, dividida nas etapas de busca bibliométrica e a análise dos artigos selecionados. Percebendo que se trata de um instrumento estratégico por envolver os três atores principais dentro da governança urbana (gestor público, população e o recurso natural),          notou-se que existe uma hibridização na tipologia de instrumento de política ambiental, além de romper as barreiras entre o rural e urbano. Assim, o PSA passa a fortalecer as relações entre cidadãos e os serviços ecossistêmicos, sendo uma excelente resposta para as demandas das agendas globais atuais

O papel das instituições subnacionais na aderência da agenda de integração hídrica: lições da governança hídrica metropolitana de Curitiba

A escassez hídrica global tratada há décadas por documentos internacionais, é também reconhecida, ainda que com baixa aderência, nas agendas ambientais subnacionais. Conceitos como o Gerenciamento Integrado de Recursos Hídricos (GIRH) e Serviços Ecossistêmicos (SE) são relevantemente preconizados a nível internacional pela comunidade científica para serem aplicados pelas instituições no nível local. Este artigo propõe uma análise da adesão destes conceitos para a governança da água na Região Metropolitana de Curitiba (RMC). Primeiramente foram elencados os planos de maior relevância no gerenciamento da água na governança relativa ao Estado do Paraná e ao município de Curitiba, bem como suas respectivas atribuições com relação à manutenção desse recurso e suas escalas de atuação. As instituições envolvidas na gestão dos recursos hídricos na RMC dialogam de alguma forma com a agenda internacional? Por meio de uma análise documental, relacionamos as medidas adotadas pelos diferentes atores de modo a subsidiar uma análise da inserção dos conceitos de GIRH e SE nas suas respectivas atuações. Com isto buscou-se entender as possíveis implicações para o gerenciamento da água dentro das especificidades de governança paranaense e curitibana, e como as instituições e sua relação com o meio ambiente podem ter consequências sobre a disponibilidade de água com qualidade na RMC

A small-molecule inhibitor of TRPC5 ion channels suppresses progressive kidney disease in animal models

Progressive kidney diseases are often associated with scarring of the kidney’s filtration unit, a condition called focal segmental glomerulosclerosis (FSGS). This scarring is due to loss of podocytes, cells critical for glomerular filtration, and leads to proteinuria and kidney failure. Inherited forms of FSGS are caused by Rac1-activating mutations, and Rac1 induces TRPC5 ion channel activity and cytoskeletal remodeling in podocytes. Whether TRPC5 activity mediates FSGS onset and progression is unknown. We identified a small molecule, AC1903, that specifically blocks TRPC5 channel activity in glomeruli of proteinuric rats. Chronic administration of AC1903 suppressed severe proteinuria and prevented podocyte loss in a transgenic rat model of FSGS. AC1903 also provided therapeutic benefit in a rat model of hypertensive proteinuric kidney disease. These data indicate that TRPC5 activity drives disease and that TRPC5 inhibitors may be valuable for the treatment of progressive kidney diseases.National Institutes of Health (U.S.) (Grant DK095045)National Institutes of Health (U.S.) (Grant DK099465)National Institutes of Health (U.S.) (Grant DK103658)National Institutes of Health (U.S.) (Grant DK083511)National Institutes of Health (U.S.) (Grant DK093746

Observations of mixed-species bird flocks at Kichwa Tembo Camp, Kenya

Mixed-species foraging flocks were studied at Kichwa Tembo Camp on the edge of the Masai Mara National Reserve in Kenya between July and September 2004. Observations were made on 29 mixed-species flocks, in which 24 species participated. African Paradise-Flycatcher Terpsiphone viridis, Black-backed Puffback Dryoscopus cubla, Grey-backed Camaroptera Camaroptera brachyura, Collared Sunbird Hedydipna collars and Cabanis's Greenbul Phyllastrephus cabanisi were the most common participants in mixed-species flocks, as well as among the most frequently encountered bird species overall. The Black-backed Puffback was identified as the nuclear species in flocks due to their abundance and frequency with which they were followed by other species. Mixed-species flocks represent another niche dimension in this diverse bird community, but few of these species could be described as flock specialists; most of the birds observed in mixed-species flocks in this study were opportunistic attendant species, including the African Pygmy-Kingfisher Ispidina picta, not previously described as joining mixed-species flocks

Numerical simulation of diffusion-controlled droplet growth: Dynamical correlation effects

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Decay and Fission Hindrance of Two- and Four-Quasiparticle K Isomers in (254)Rf

Two isomers decaying by electromagnetic transitions with half-lives of 4.7(1.1) and 247(73)μs have been discovered in the heavy Rf254 nucleus. The observation of the shorter-lived isomer was made possible by a novel application of a digital data acquisition system. The isomers were interpreted as the Kπ=8-, ν2(7/2+[624],9/2-[734]) two-quasineutron and the Kπ=16+, 8-ν2(7/2+[624],9/2-[734])⊗ - 8-π2(7/2-[514],9/2+[624]) four-quasiparticle configurations, respectively. Surprisingly, the lifetime of the two-quasiparticle isomer is more than 4 orders of magnitude shorter than what has been observed for analogous isomers in the lighter N=150 isotones. The four-quasiparticle isomer is longer lived than the Rf254 ground state that decays exclusively by spontaneous fission with a half-life of 23.2(1.1)μs. The absence of sizable fission branches from either of the isomers implies unprecedented fission hindrance relative to the ground state

Molecular genetic analysis of podocyte genes in focal segmental glomerulosclerosis—a review

This review deals with podocyte proteins that play a significant role in the structure and function of the glomerular filter. Genetic linkage studies has identified several genes involved in the development of nephrotic syndrome and contributed to the understanding of the pathophysiology of glomerular proteinuria and/or focal segmental glomerulosclerosis. Here, we describe already well-characterized genetic diseases due to mutations in nephrin, podocin, CD2AP, alpha-actinin-4, WT1, and laminin β2 chain, as well as more recently identified genetic abnormalities in TRPC6, phospholipase C epsilon, and the proteins encoded by the mitochondrial genome. In addition, the role of the proteins which have shown to be important for the structure and functions by gene knockout studies in mice, are also discussed. Furthermore, some rare syndromes with glomerular involvement, in which molecular defects have been recently identified, are briefly described. In summary, this review updates the current knowledge of genetic causes of congenital and childhood nephrotic syndrome and provides new insights into mechanisms of glomerular dysfunction

Genetics of focal segmental glomerulosclerosis

The recent advances in understanding the pathophysiology of focal segmental glomerulosclerosis (FSGS) and molecular function of glomerular filtration barrier come directly from genetic linkage and positional cloning studies. The exact role and function of the newly discovered genes and proteins are being investigated by in vitro and in vivo mechanistic studies. Those genes and proteins interactions seem to change susceptibility to kidney disease progression. Better understanding of their exact role in the development of FSGS may influence future therapies and outcomes in this complex disease