RESUMO
Recent developments in the instrumentation and data analysis of synchrotron small-angle X-ray scattering (SAXS) on biomolecules in solution have made biological SAXS (BioSAXS) a mature and popular tool in structural biology. This article reports on an advanced endstation developed at beamline 13A of the 3.0â GeV Taiwan Photon Source for biological small- and wide-angle X-ray scattering (SAXS-WAXS or SWAXS). The endstation features an in-vacuum SWAXS detection system comprising two mobile area detectors (Eiger X 9M/1M) and an online size-exclusion chromatography system incorporating several optical probes including a UV-Vis absorption spectrometer and refractometer. The instrumentation and automation allow simultaneous SAXS-WAXS data collection and data reduction for high-throughput biomolecular conformation and composition determinations. The performance of the endstation is illustrated with the SWAXS data collected for several model proteins in solution, covering a scattering vector magnitude q across three orders of magnitude. The crystal-model fittings to the data in the q range â¼0.005-2.0â Å-1 indicate high similarity of the solution structures of the proteins to their crystalline forms, except for some subtle hydration-dependent local details. These results open up new horizons of SWAXS in studying correlated local and global structures of biomolecules in solution.
RESUMO
Multiple particle-tracking techniques were used to quantify the thermally driven motion of ensembles of naked polystyrene (0.5 µm diameter) microbeads in order to determine the microrheological characteristics around the gut mucosa. The microbeads were introduced into living ex vivo preparations of the wall of the terminal ileum and proximal colon of the brushtail possum (Trichosurus vulpecula). The fluid environment surrounding both the ileal villi and colonic mucosa was heterogeneous; probably comprising discrete viscoelastic regions suspended in a continuous Newtonian fluid of viscosity close to water. Neither the viscosity of the continuous phase, the elastic modulus (G') nor the sizes of viscoelastic regions varied significantly between areas within 20 µm and areas more than 20 µm from the villous mucosa nor from the tip to the sides of the villous mucosa. The viscosity of the continuous phase at distances further than 20 µm from the colonic mucosa was greater than that at the same distance from the ileal villous mucosa. Furthermore, the estimated sizes of viscoelastic regions were significantly greater in the colon than in the ileum. These findings validate the sensitivity of the method and call into question previous hypotheses that a contiguous layer of mucus envelops all intestinal mucosa and restricts diffusive mass transfer. Our findings suggest that, in the terminal ileum and colon at least, mixing and mass transfer are governed by more complex dynamics than were previously assumed, perhaps with gel filtration by viscoelastic regions that are suspended in a Newtonian fluid.
Assuntos
Colo/citologia , Íleo/ultraestrutura , Microvilosidades/fisiologia , Trichosurus/fisiologia , Animais , Fluorescência , Íleo/fisiologia , Técnicas In Vitro , Microscopia de Vídeo , Microesferas , Poliestirenos , Reologia/métodos , Trichosurus/anatomia & histologia , ViscosidadeAssuntos
Carcinoma de Células Escamosas/cirurgia , Neoplasias Bucais/cirurgia , Reabilitação Bucal , Recidiva Local de Neoplasia/cirurgia , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Seguimentos , Humanos , Metástase Linfática , Neoplasias Bucais/mortalidade , Neoplasias Bucais/patologia , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/patologia , Taxa de SobrevidaAssuntos
Carcinoma de Células Escamosas/terapia , Neoplasias Bucais/terapia , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Terapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/mortalidade , Neoplasias Bucais/patologia , Estadiamento de Neoplasias , Prognóstico , Taxa de SobrevidaRESUMO
We compared the objective and subjective evaluations of the results after correction of the earposition by the method of Converse with the results by the method of Reichert and Mustarde. The mean values obtained by the method of Converse correspond to the mean normal values. The patients are very satisfied with their results. A comparison of the results of these three methods do not show any aggravating differences.