911. |
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912. |
- Mikoláš, Martin, et al.
(författare)
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Protect old-growth forests in Europe now
- 2023
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075. ; 380:6644, s. 466-466
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Tidskriftsartikel (refereegranskat)
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913. |
- Moldowan, JM, et al.
(författare)
-
Biogeochemical evidence for dinoflagellate ancestors in the Early Cambrian
- 1998
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Ingår i: SCIENCE. - : AMER ASSOC ADVANCEMENT SCIENCE. - 0036-8075. ; 281:5380, s. 1168-1170
-
Tidskriftsartikel (refereegranskat)abstract
- Dinoflagellates are single-celled organisms that reflect the ecological conditions in modern oceans and Lakes. Ultrastructural data and molecular phylogeny suggest that they originated in the Neoproterozoic, yet dinoflagellate ancestors are classified onl
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914. |
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915. |
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916. |
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917. |
- Orton, G, et al.
(författare)
-
Earth-based observations of the Galileo probe entry site
- 1996
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Ingår i: SCIENCE. - : AMER ASSOC ADVANCEMENT SCIENCE. - 0036-8075. ; 272:5263, s. 839-840
-
Tidskriftsartikel (refereegranskat)abstract
- Earth-based observations of Jupiter indicate that the Galileo probe probably entered Jupiter's atmosphere just inside a region that has less cloud cover and drier conditions than more than 99 percent of the rest of the planet. The visual appearance of the
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918. |
- Park, Hee-Sung, et al.
(författare)
-
Design and evolution of new catalytic activity with an existing protein scaffold.
- 2006
-
Ingår i: Science. - 1095-9203. ; 311:5760, s. 535-8
-
Tidskriftsartikel (refereegranskat)abstract
- The design of enzymes with new functions and properties has long been a goal in protein engineering. Here, we report a strategy to change the catalytic activity of an existing protein scaffold. This was achieved by simultaneous incorporation and adjustment of functional elements through insertion, deletion, and substitution of several active site loops, followed by point mutations to fine-tune the activity. Using this approach, we were able to introduce beta-lactamase activity into the alphabeta/betaalpha metallohydrolase scaffold of glyoxalase II. The resulting enzyme, evMBL8 (evolved metallo beta-lactamase 8), completely lost its original activity and, instead, catalyzed the hydrolysis of cefotaxime with a (kcat/Km)app of 1.8 x 10(2) (mole/liter)(-1) second(-1), thus increasing resistance to Escherichia coli growth on cefotaxime by a factor of about 100.
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919. |
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920. |
- Poinar, HN, et al.
(författare)
-
Molecular coproscopy: Dung and diet of the extinct ground sloth Nothrotheriops shastensis
- 1998
-
Ingår i: SCIENCE. - : AMER ASSOC ADVANCEMENT SCIENCE. - 0036-8075. ; 281:5375, s. 402-406
-
Tidskriftsartikel (övrigt vetenskapligt)abstract
- DNA from excrements can be amplified by means of the polymerase chain reaction. However, this has not been possible with ancient feces. Cross-Links between reducing sugars and amino groups were shown to exist in a Pleistocene coprolite from Gypsum Cave, N
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