Oral contraceptives in the treatment of Darier-White disease - a case report and review of the literature

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Influence of the generation of mesopores on the hydroisomerization activity and selectivity of n-hexane over Pt/mordenite

The activity and selectivity of hydroisomerization of n-hexane over Pt/mordenite is strongly influenced by acid leaching. The activity increases and the selectivity changes to favor primary products. Leaching selectively modifies the mordenite structure, making more sites accessible for reaction and facilitating desorption of reaction products. It is argued that the activity of untreated mordenite is limited by mass transfer effects. These effects largely vanish after modification of the zeolite structure by generation of a 3-D micropore structure as well as mesopores. The alleviation of intracrystalline diffusion limitation is the major factor in activity enhancement after acid leaching of Pt/mordenite

Rapid adaptive divergence of life-history traits in response to abiotic stress within a natural population of a parthenogenetic nematode

Sexual reproduction is acknowledged to facilitate adaptation to novel environments while asexual eukaryotes are often regarded as having low adaptive potential. This view has been challenged in a number of studies, but the adaptive potential of asexual populations in the field is poorly documented. We investigated the response of natural populations of the parthenogenetic nematode Acrobeloides nanus to imposed divergent selective pressures. For this purpose, we employed a replicated evolution experiment in the field. After 20 years of evolution under abiotic stress and control conditions, life-history traits were assessed in reaction norm- and reciprocal transplant experiments. Both these experiments indicated adaptive divergence within the population of A. nanus. Namely, the transplant experiment demonstrated that in the stressed soil environment, body growth rate was more reduced in the nematodes originating from the control treatment. In the reaction norm experiment, survival and reproduction were higher under test conditions corresponding to the native environment of the nematodes. The differences in the analysed traits are discussed in the context of life-history theory. Overall, our results strongly support high adaptive potential of A. nanus and suggest that population structure and distribution of asexual species is shaped by local adaptation events

Influence of lytic polysaccharide monooxygenase active site segments on activity and affinity

In past years, new lytic polysaccharide monooxygenases (LPMOs) have been discovered as distinct in their substrate specificity. Their unconventional, surface-exposed catalytic sites determine their enzymatic activities, while binding sites govern substrate recognition and regioselectivity. An additional factor influencing activity is the presence or absence of a family 1 carbohydrate binding module (CBM1) connected via a linker to the C-terminus of the LPMO. This study investigates the changes in activity induced by shortening the second active site segment (Seg2) or removing the CBM1 from Neurospora crassa LPMO9C. NcLPMO9C and generated variants have been tested on regenerated amorphous cellulose (RAC), carboxymethyl cellulose (CMC) and xyloglucan (XG) using activity assays, conversion experiments and surface plasmon resonance spectroscopy. The absence of CBM1 reduced the binding affinity and activity of NcLPMO9C, but did not affect its regioselectivity. The linker was found important for the thermal stability of NcLPMO9C and the CBM1 is necessary for efficient binding to RAC. Wild-type NcLPMO9C exhibited the highest activity and strongest substrate binding. Shortening of Seg2 greatly reduced the activity on RAC and CMC and completely abolished the activity on XG. This demonstrates that Seg2 is indispensable for substrate recognition and the formation of productive enzyme-substrate complexes.</p