524 research outputs found
Improved Crystalline Quality of Si\u3csub\u3e1-x\u3c/sub\u3eGe\u3csub\u3ex\u3c/sub\u3e Formed by Low-temperature Germanium Ion Implantation
Improvement of crystalline quality in Si1-xGex formed by germanium ion implantation has been found. Endâofârange defects were drastically reduced in number by lowering the substrate temperature during implantation with doses on the order of 1016 cmâ2. This improvement was confirmed by electrical characterization of pân junctions formed in the SiGe layer as well as by transmission electron microscopy
Central Anatolian terrestrial sand dunes: enhancing carbon sequestration by indigenous vegetation
Assessment of the changes in natural resource quality requires long term monitoring. This study outlines the changes achieved in soils and vegetation quality in a sand dune area of Central Turkey maintained since 1960s
FUNCTIONAL DIFFERENCES IN THE HAMSTRING MUSCLES DURING SPRINTING
The purpose of this study was to demonstrate the respective activation of the biceps femoris (BF), semitendinosus (ST), and semimembranosus (SM) muscles during overground sprinting. Lower extremity kinematics and the electromyographic (EMG) activities of the BF, ST, and SM muscles were recorded for 13 male sprinters performing overground sprinting at maximum effort. Mean normalized EMG activity was calculated in the early stance, late stance, middle swing, and late swing phases. The peak activation time during the stance and latter half of the swing phases was also calculated. Significantly different characteristics for EMG activation and different occurrences of peak activation of the BF, ST, and SM were found within the gait cycle, indicating that the activation demand of each hamstring muscle differs during sprinting
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Crystal structures of TdsC, a dibenzothiophene monooxygenase from the thermophile Paenibacillus sp A11-2, reveal potential for expanding its substrate selectivity
Sulfur compounds in fossil fuels are a major source of environmental pollution, and microbial desulfurization has emerged as a promising technology for removing sulfur under mild conditions. The enzyme TdsC from the thermophile Paenibacillus sp. A11-2 is a two-component flavin-dependent monooxygenase that catalyzes the oxygenation of dibenzothiophene (DBT) to its sulfoxide (DBTO) and sulfone (DBTO2) during microbial desulfurization. The crystal structures of the apo and flavin mononucleotide (FMN)-bound forms of DszC, an ortholog of TdsC, were previously determined, although the structure of the ternary substrateâFMNâenzyme complex remains unknown. Herein, we report the crystal structures of the DBTâFMNâTdsC and DBTOâFMNâTdsC complexes. These ternary structures revealed many hydrophobic and hydrogen-bonding interactions with the substrate, and the position of the substrate could reasonably explain the two-step oxygenation of DBT by TdsC. We also determined the crystal structure of the indole-bound enzyme because TdsC, but not DszC, can also oxidize indole, and we observed that indole binding did not induce global conformational changes in TdsC with or without bound FMN. We also found that the two loop regions close to the FMN-binding site are disordered in apo-TdsC and become structured upon FMN binding. Alanine substitutions of Tyr-93 and His-388, which are located close to the substrate and FMN bound to TdsC, significantly decreased benzothiophene oxygenation activity, suggesting their involvement in supplying protons to the active site. Interestingly, these substitutions increased DBT oxygenation activity by TdsC, indicating that expanding the substrate-binding site can increase the oxygenation activity of TdsC on larger sulfur-containing substrates, a property that should prove useful for future microbial desulfurization applications
THE KINEMATICS OF OVERGROUND SPRINTING IN TRACK AND FIELD ATHLETES WITH PREVIOUS HAMSTRING INJURIES
The purpose of this study was to examine the kinematic characteristics of lower extremity and long head of the biceps femoris (BFlh) muscle length during overground sprinting in track and field athletes with previous unilateral hamstring strain injuries. Ten male college sprinters with a history of hamstring injury performed a maximum effort sprint on an athletic track. Three-dimensional kinematic data were recorded during sprinting, and the hip and knee joint angles and musculotendon length of the biceps femoris muscle were calculated. The previously injured limb displayed delayed peak hip flexion and increased knee flexion compared with the uninjured limb, placing the BFlh muscle at decreased length during the terminal swing phase of sprinting
Comparison of Hi-C results using in-solution versus in-nucleus ligation.
BACKGROUND: Chromosome conformation capture and various derivative methods such as 4C, 5C and Hi-C have emerged as standard tools to analyze the three-dimensional organization of the genome in the nucleus. These methods employ ligation of diluted cross-linked chromatin complexes, intended to favor proximity-dependent, intra-complex ligation. During development of single-cell Hi-C, we devised an alternative Hi-C protocol with ligation in preserved nuclei rather than in solution. Here we directly compare Hi-C methods employing in-nucleus ligation with the standard in-solution ligation. RESULTS: We show in-nucleus ligation results in consistently lower levels of inter-chromosomal contacts. Through chromatin mixing experiments we show that a significantly large fraction of inter-chromosomal contacts are the result of spurious ligation events formed during in-solution ligation. In-nucleus ligation significantly reduces this source of experimental noise, and results in improved reproducibility between replicates. We also find that in-nucleus ligation eliminates restriction fragment length bias found with in-solution ligation. These improvements result in greater reproducibility of long-range intra-chromosomal and inter-chromosomal contacts, as well as enhanced detection of structural features such as topologically associated domain boundaries. CONCLUSIONS: We conclude that in-nucleus ligation captures chromatin interactions more consistently over a wider range of distances, and significantly reduces both experimental noise and bias. In-nucleus ligation creates higher quality Hi-C libraries while simplifying the experimental procedure. We suggest that the entire range of 3C applications are likely to show similar benefits from in-nucleus ligation
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