Poly(alanine) end-capped poly(propylene glycol)−poly(ethylene glycol)−poly(propylene glycol) (PA−PLX−PA) aqueous solutions underwent sol-to-gel transition as the temperature increased. On the basis of FTIR spectra, circular dichroism spectra, 13C NMR spectra, transmission electron microscopic images, fluorescence spectra, and dynamic light scattering studies, increases in the β-sheet conformation of the polyalanine (PA) and dehydration of the poly(propylene glycol)−poly(ethylene glycol)−poly(propylene glycol) (PLX) were suggested as the sol-to-gel transition mechanism. The sol-to-gel transition temperature could be controlled by molecular parameters of the PA−PLX−PA such as molecular weight of PA, molecular weights of PLX, and l-Ala/dl-Ala ratio. The PA−PLX−PA was significantly degraded in the subcutaneous layer of rats over 15 days; however, it was stable in phosphate buffer saline over the same period of time. Poly(propylene glycol)/poly(ethylene glycol) block copolymers suffer from short gel duration for biomedical applications, whereas the current polypeptide-based polymer is unique in that it shows prolonged (>15 days) gel duration and the sol-to-gel transition involves the secondary structural change of the polypeptide.

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As WWW grows at an increasing speed, a classifier targeted at hypertext has become in high demand. While document categorization is quite a mature, the issue of utilizing hypertext structure and hyperlinks has been relatively unexplored. In this paper, we propose a practical method for enhancing both the speed and the quality of hypertext categorization using hyperlinks. In comparison against a recently proposed technique that appears to be the only one of the kind, we obtained up to 18.5% of improvement in effectiveness while reducing the processing time dramatically. We attempt to explain through experiments what factors contribute to the improvement.

The tyrosine kinase Fyn is a member of the Src family kinases which are important in many integrin-mediated cellular processes including cell adhesion and migration. Fyn has multiple phosphorylation sites which can affect its kinase activity. Among these phosphorylation sites, the serine 21 (S21) residue of Fyn is a protein kinase A (PKA) recognition site within an RxxS motif of the amino terminal SH4 domain of Fyn. In addition, S21 is critical for Fyn kinase-linked cellular signaling. Mutation of S21A blocks PKA phosphorylation of Fyn and alters its tyrosine kinase activity. Expression of Fyn S21A in cells lacking Src family kinases (SYF cell) led to decreased tyrosine phosphorylation of focal adhesion kinase resulting in reduced focal adhesion targeting, which slowed lamellipodia dynamics and thus cell migration. These changes in cell motility were reflected by the fact that cells expressing Fyn S21A were severely deficient in their ability to assemble and disassemble focal adhesions. Taken together, our findings indicate that phosphorylation of S21 within the pPKA recognition site (RxxS motif) of Fyn regulates its tyrosine kinase activity and controls focal adhesion targeting, and that this residue of Fyn is critical for transduction of signals arising from cell-extracellular matrix interactions.

Hydroxy fatty acids are used as starting materials for the production of secondary metabolites and signalling molecules as well as in the manufacture of industrial fine chemicals. However, these compounds are usually difficult to produce from renewable biomass by chemical means. In this study, linoleate double bond hydratases of Lactobacillus acidophilus NBRC 13951 were cloned for the first time. These enzymes were highly specific for the hydration of the C‐9 or the C‐12 double bond of unsaturated fatty acids (e.g., linoleic acid). Thereby, the enzymes allowed the selective production of hydroxy fatty acids such as 13‐hydroxy‐cis‐9‐octadecenoic acid and 10‐hydroxy‐cis‐12‐octadecenoic acid from linoleic acid. In addition, the hydroxy fatty acids were further converted into industrially relevant carboxylic acids (e.g., 12‐hydroxy‐cis‐9‐dodecenoic acid, α,ω‐tridec‐9‐enedioic acid) and lactones (i.e., δ‐decalactone, γ‐dodecelactone) via whole‐cell biocatalysis using an enzyme cascade. This study thus contributes to the preparation of hydroxy fatty acids, unsaturated carboxylic acids, and lactones from renewable unsaturated fatty acids.magnified image

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The EC95 of remifentanil for smooth emergence from anesthesia was 2.51 ng/mL after transsphenoidal hypophysectomy.

Folic acid, a water soluble B vitamin, plays an important role in cellular metabolic activities, such as functioning as a cofactor in one-carbon metabolism for DNA and RNA synthesis as well as nucleotide and amino acid biosynthesis in the body. A lack of dietary folic acid can lead to folic acid deficiency and result in several health problems, including macrocytic anemia, elevated plasma homocysteine, cardiovascular disease, birth defects, carcinogenesis, muscle weakness, and walking difficulty. However, the effect of folic acid deficiency on skeletal muscle development and its molecular mechanisms are unknown. We, therefore, investigated the effect of folic acid deficiency on myogenesis in skeletal muscle cells and found that folic acid deficiency induced proliferation inhibition and cell cycle breaking as well as cellular senescence in C2C12 myoblasts, implying that folic acid deficiency influences skeletal muscle development. Folic acid deficiency also inhibited differentiation of C2C12 myoblasts and induced deregulation of the cell cycle exit and many cell cycle regulatory genes. It inhibited expression of muscle-specific marker MyHC as well as myogenic regulatory factor (myogenin). Moreover, immunocytochemistry and Western blot analyses revealed that DNA damage was more increased in folic acid-deficient medium-treated differentiating C2C12 cells. Furthermore, we found that folic acid resupplementation reverses the effect on the cell cycle and senescence in folic acid-deficient C2C12 myoblasts but does not reverse the differentiation of C2C12 cells. Altogether, the study results suggest that folic acid is necessary for normal development of skeletal muscle cells.