Objective To determine the association between joint structure and gait in patients with knee osteoarthritis (OA). Methods IMI-APPROACH recruited 297 clinical knee OA patients. Gait data was... Show moreObjective To determine the association between joint structure and gait in patients with knee osteoarthritis (OA). Methods IMI-APPROACH recruited 297 clinical knee OA patients. Gait data was collected (GaitSmart®) and OA-related joint measures determined from knee radiographs (KIDA) and MRIs (qMRI/MOAKS). Patients were divided into those with/without radiographic OA (ROA). Principal component analyses (PCA) were performed on gait parameters; linear regression models were used to evaluate whether image-based structural and demographic parameters were associated with gait principal components. Results Two hundred seventy-one patients (age median 68.0, BMI 27.0, 77% female) could be analyzed; 149 (55%) had ROA. PCA identifed two components: upper leg (primarily walking speed, stride duration, hip range of motion [ROM], thigh ROM) and lower leg (calf ROM, knee ROM in swing and stance phases). Increased age, BMI, and radiographic subchondral bone density (sclerosis), decreased radiographic varus angle deviation, and female sex were statistically signifcantly associated with worse lower leg gait (i.e. reduced ROM) in patients without ROA (R2=0.24); in ROA patients, increased BMI, radiographic osteophytes, MRI meniscal extrusion and female sex showed signifcantly worse lower leg gait (R2=0.18). Higher BMI was signifcantly associated with reduced upper leg function for non-ROA patients (R2=0.05); ROA patients with male sex, higher BMI and less MRI synovitis showed signifcantly worse upper leg gait (R2=0.12). Conclusion Structural OA pathology was signifcantly associated with gait in patients with clinical knee OA, though BMI may be more important. While associations were not strong, these results provide a signifcant association between OA symptoms (gait) and joint structure. Show less
Biological molecules, especially the proteins, have a special and important function. We study their structure to understand their functions, and further make application, like the medical... Show moreBiological molecules, especially the proteins, have a special and important function. We study their structure to understand their functions, and further make application, like the medical research. The routine method is diffraction, but not work for molecules which cannot grow into crystal and molecules which their crystal are too small. Cryo-EM technique provides another way to solve their structures through their images, it does not need crystals. Meanwhile, electron diffraction can work small crystals (micro- and nano-crystals) after the sample preparation was improved. Hence, we try to build a method that can restore the structure from the crystal’s image. We collect images of protein nano-crystal, and these images were processed to enhance their contrast. The key step is to find the orientations of these images in the procedure of reconstruction, therefore, we create a method that calculates these orientations. Nano-crystals, which cannot be used in diffraction method, then can be used in this method. Show less
The first massive elliptical galaxies were already in place when the Universe was only 3 billions years old. Surprisingly, they are more compact in comparison to their present-day counterparts. In... Show moreThe first massive elliptical galaxies were already in place when the Universe was only 3 billions years old. Surprisingly, they are more compact in comparison to their present-day counterparts. In this thesis these recent findings are assessed by measuring the stellar kinematics of massive z=2 galaxies from spectra obtained with X-Shooter on the Very Large Telescope. This thesis work shows that high-redshift galaxies are truly very massive and structurally very different from present-day galaxies, yet they follow the same scaling relations. Show less
In this thesis the prospects of electron diffraction and imaging techniques are discussed to solve the structure of three dimensional nano-crystals. These crystals are beyond the scope of current X... Show moreIn this thesis the prospects of electron diffraction and imaging techniques are discussed to solve the structure of three dimensional nano-crystals. These crystals are beyond the scope of current X-ray techniques. Show less
Hoogendijk, M.G.; Potse, M.; Linnenbank, A.C.; Verkerk, A.O.; Ruijter, H.M. den; Amersfoorth, S.C.M. van; ... ; Coronel, R. 2010
UVDE is a repair enzyme discovered for the first time in the fission yeast Schizaromyces pombe. The initial biochemical characterization of this enzyme showed that its substrate specificity... Show moreUVDE is a repair enzyme discovered for the first time in the fission yeast Schizaromyces pombe. The initial biochemical characterization of this enzyme showed that its substrate specificity includes not only UV lesions, but also abasic sites and some nucleotide mismatches. The mechanism, however, of UVDE damage recognition and DNA cleavage was not clarified. S. pombe UVDE was seen to require Mn2+ and Mg2+ for its function, but the utilization of divalent metals in its cleavage reaction was empirical and without a clear vision of the nature, the number and the exact role of the metal cofactors. UVDE homologues were found in many fungal species and in a number of bacteria such as Bacillus subtilis and Thermus thermophilus. Although the S. pombe UVDE was partially characterized, no information was available for the substrate specificity or the cofactor requirements its bacterial homologues Show less
