The use of a tourniquet during total knee arthroplasty was effective for reducing blood loss and avoiding excessive postoperative inflammation and muscle damage. The use of a tourniquet was related to slightly more postoperative pain but did not affect postoperative recovery.

Strontium (Sr):calcium (Ca) ratios in otoliths of the eels Anguilla japonica and A. marmorata caught in 4 Taiwanese rivers were examined to reconstruct their migratory environmental history. In all sampling locations, each eel species preferred a different environment and all were differently distributed in the river. A. japonica was more abundant than A. marmorata in the lower reach, accounting for 76 to 86% of the eel population. In contrast, A. marmorata was more abundant than A. japonica in the upper reach, accounting for 76 to 100% of the eel population. A. japonica consisted of diversified migratory contingents, including freshwater, brackish-water and seawater eels, but A. marmorata tended to reside in freshwater and seemed to avoid seawater during the yellow eel stage. This disparity in migratory behaviors and habitat use between species may reflect interspecific competition and adaptive radiation. The flexible migratory behavior and adaptation to different salinities of A. japonica may be an advantageous evolutional fitness when facing competition, heavy fishing pressure and environmental stress. The freshwater-restricted A. marmorata is more easily threatened by both fishing pressure and continuous habitat degradation than A. japonica.

Dynamic solvation at binding and active sites is critical to protein recognition and enzyme catalysis. We report here the complete characterization of ultrafast solvation dynamics at the recognition site of photoantenna molecule and at the active site of cofactor/ substrate in enzyme photolyase by examining femtosecondresolved fluorescence dynamics and the entire emission spectra. With direct use of intrinsic antenna and cofactor chromophores, we observed the local environment relaxation on the time scales from a few picoseconds to nearly a nanosecond. Unlike conventional solvation where the Stokes shift is apparent, we observed obvious spectral shape changes with the minor, small, and large spectral shifts in three function sites. These emission profile changes directly reflect the modulation of chromophore's excited states by locally constrained protein and trapped-water collective motions. Such heterogeneous dynamics continuously tune local configurations to optimize photolyase's function through resonance energy transfer from the antenna to the cofactor for energy efficiency and then electron transfer between the cofactor and the substrate for repair of damaged DNA. Such unusual solvation and synergetic dynamics should be general in function sites of proteins.function-site solvation | ultrafast dynamics | spectral tuning | protein rigidity and flexibility | femtosecond-resolved emission spectra D ynamic solvation in binding and active sites plays a critical role in protein recognition and enzyme reaction, and such local motions optimize spatial configurations and minimize energetic pathways (1-11). These dynamics involve local constrained protein and trapped-water motions within angstrom distance and occur on ultrafast time scales (6,7,10,11). Typically, extrinsic dye molecules or synthetic amino acids were used as local optical probes to label function sites, and the local relaxations were observed, ranging from femtoseconds to nanoseconds (5,(12)(13)(14). Such labeling of bulky dye molecules usually induces significant local perturbations, and direct characterization with intrinsic chromophores in proteins eliminates those interferences and reveals intact environment responses (4, 7, 15-21), as recently examined in green fluorescence proteins (21). We have recently studied a series of flavoproteins using intrinsic flavin molecule as the optical probe (10, 22, 23) and especially found the important functional role of local solvation in photolyase (10).Photolyase, a flavoprotein and a photoenzyme, repairs damaged DNA caused by UV irradiation. Two types of structurally similar photolyases are specific for two major UV-induced DNA lesions of cyclobutane pyrimidine dimer (CPD) and (6-4) photoproduct (24). The CPD photolyase contains two noncovalently bound chromophores, a pterin molecule in the form of methenyltetrahydrofolate (MTHF) in the binding site as the photoantenna for energy efficiency and a fully reduced flavin adenine dinucleotide (FADH − ) at the active site as the catalytic cofactor for repair of d...

We measured femtosecond transient absorption of dye solutions and TiO 2 films sensitized with two zinc porphyrins (PE1 and PE4) to investigate the interfacial dynamics of electron transfer in relation to the dependence of cell performance on the length of the linker (

Flavoproteins are unique redox coenzymes and the dynamic solvation at their function sites is critical to the understanding of their electron-transfer properties. Here, we report our complete characterization of the function-site solvation of holoflavodoxin in three redox states and of the binding-site solvation of apoflavodoxin. Using intrinsic flavin cofactor and tryptophan residue as the local optical probes with two site-specific mutations, we observed distinct ultrafast solvation dynamics at the function site in the three states and at the related recognition site of the cofactor, ranging from a few to hundreds of picoseconds. The initial ultrafast motion in 1-2.6 ps reflects the local water-network relaxation around the shallow, solvent-exposed function site. The second relaxation in 20-40 ps results from the coupled local water-protein fluctuation. The third dynamics in hundreds of picoseconds is from the intrinsic fluctuation of the loose loops flanking the cofactor at the function site. These solvation dynamics with different amplitudes well correlate with the redox states from the oxidized form, to the more rigid semiquinone and to the much looser hydroquinone. This observation of the redox control of local protein conformation plasticity and water network flexibility is significant and such an intimate relationship is essential to the biological function of interprotein electron transfer.

We used an electron probe microanalyzer (EPMA) to determine the migratory environmental history of the catadromous grey mullet Mugil cephalus from the Sr:Ca ratios in otoliths of 10 newly recruited juveniles collected from estuaries and 30 adults collected from estuaries, nearshore (coastal waters and bay) and offshore, in the adjacent waters off Taiwan. Mean (± SD) Sr:Ca ratios at the edges of adult otoliths increased significantly from 6.5 ± 0.9 × 10 -3 in estuaries and nearshore waters to 8.9 ± 1.4 × 10 -3 in offshore waters (p < 0.01), corresponding to increasing ambient salinity from estuaries and nearshore to offshore waters. The mean Sr:Ca ratios decreased significantly from the core (11.2 ± 1.2 × 10 -3 ) to the otolith edge (6.2 ± 1.4 × 10 -3 ) in juvenile otoliths (p < 0.001). The mullet generally spawned offshore and recruited to the estuary at the juvenile stage; therefore, these data support the use of Sr:Ca ratios in otoliths to reconstruct the past salinity history of the mullet. A life-history scan of the otolith Sr:Ca ratios indicated that the migratory environmental history of the mullet beyond the juvenile stage consists of 2 types. In Type 1 mullet, Sr:Ca ratios range between 4.0 × 10 -3 and 13.9 × 10 -3, indicating that they migrated between estuary and offshore waters but rarely entered the freshwater habitat. In Type 2 mullet, the Sr:Ca ratios decreased to a minimum value of 0.4 × 10 -3 , indicating that the mullet migrated to a freshwater habitat. Most mullet beyond the juvenile stage migrated from estuary to offshore waters, but a few mullet less than 2 yr old may have migrated into a freshwater habitat. Most mullet collected nearshore and offshore were of Type 1, while those collected from the estuaries were a mixture of Types 1 and 2. The mullet spawning stock consisted mainly of Type 1 fish. The growth rates of the mullet were similar for Types 1 and 2. The migratory patterns of the mullet were more divergent than indicated by previous reports of their catadromous behavior.

No abstract

Intrinsic absorption and subsequent heat generation have long been issues for metal-based plasmonics. Recently, thermo-plasmonics, which takes the advantage of such a thermal effect, is emerging as an important branch of plasmonics. However, although significant temperature increase is involved, characterization of metal permittivity at different temperatures and corresponding thermo-derivative are lacking. Here we measure gold permittivity from 300K to 570K, which the latter is enough for gold annealing. More than one order difference in thermo-derivative is revealed between annealed and unannealed films, resulting in a large variation of plasmonic properties. In addition, an unusual increase of imaginary permittivity after annealing is found. Both these effects can be attributed to the increased surface roughness incurred by annealing. Our results are valuable for characterizing extensively used unannealed nanoparticles, or annealed nanostructures, as building blocks in future thermo-nano-plasmonic systems.