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Biomedical subjects

Hui Ma

Publications and source records attributed to Hui Ma.

42 records · Page 3Linked to original sources
PubMed2003

[Direct upconversion sensitization luminescence comparison of the ErYb co-doped oxyfluoride fluoride pentaphosphate glass].

This paper investigates the direct upconversion sensitization luminescence of the ErYb co-doped oxyfluoride glass (ErYb: FOG), fluoride glass (ErYb: ZBLAN) and pentaphosphate noncrystalline (ErYb: PP) excited by a 966 nm diode laser. The splendid upconversion luminescence phenomenon is found. It is resulted from that the Yb3+ concentration in rather high, the energy transfer among Er(3+)-Yb3+ and Yb(3+)-Yb3+ ions is rather strong. An important fact is found that the direct upconversion sensitization luminescence of ErYb: FOG is about 100-100,000 times greater than that of ErYb: PP. And meanwhile it is interesting that the upconversion luminescence intensity of ErYb: FOG is near to that of ErYb: ZBLAN. It is significant to enhance the comprehensive level of up-conversion luminescence.

Energy Transfer↗
PubMed2003

[Integrated methods for assessing auditory nerve-auditory pathway integrity].

OBJECTIVE: To evaluate the feasibility and value of integrated methods to assess auditory pathway integrity. METHOD: Twenty-four cases of bilateral profoundly-deafened individuals who were considered as the candidates of cochlear implantation were included in this study. Auditory pathway integrity from these candidates of cochlear implantation were assessed with the integrated methods established by our team, which consist of 5 categories including 1. audiological test; 2. radiological imaging study; 3. ear-canal electric audiometry; 4. response to sound in daily life; and 5. speech development. RESULT: Twenty-three candidates who meet the criteria of auditory nerve-auditory pathway integrity received cochlear implantation with improved hearing and speech development postoperatively. The remainder one of the 24 candidates was diagnosed as bilateral absence of auditory nerve. The fault of cochlear implantation was avoided. CONCLUSION: The integrated methods for assessing auditory pathway integrity is feasible and valuable. Auditory nerve-auditory pathway integrity should be considered and included as one of the most important criteria for cochlear implantation candidate.

Acoustic Stimulation↗
PubMed2002

Regulated SUMOylation and ubiquitination of DdMEK1 is required for proper chemotaxis.

MEK1, which is required for aggregation and chemotaxis in Dictyostelium, is rapidly and transiently SUMOylated in response to chemoattractant stimulation. SUMOylation is required for MEK1's function and its translocation from the nucleus to the cytosol and cortex, including the leading edge of chemotaxing cells. MEK1 in which the site of SUMOylation is mutated is retained in the nucleus and does not complement the mek1 null phenotype. Constitutively active MEK1 is cytosolic and is constitutively SUMOylated, whereas the corresponding nonactivatable MEK1 is not SUMOylated and nuclear. MEK1 is also ubiquitinated in response to signaling. A MEK1-interacting, ubiquitin E3 ligase RING domain-containing protein controls nuclear localization and MEK1 ubiquitination. These studies provide a pathway regulating the localization and function of MEK1.

Amino Acid Sequence↗
PubMed2002

[Effects and mechanism of ischemic preconditioning on the survival of axial flaps in rats].

OBJECTIVE: This study was to develop a new method that can improve flap survival. METHODS: A long skin flap spanning the full length of the rat dorsum was used to make a bilateral skin tube, which was based on the lateral thoracic artery proximally, and the deep circumflex iliac artery distally. The animals were randomly divided into 3 groups of 8 rats in each group: the control and two experimental groups with elevation of the tube (the proximal pedicle divided) immediately or 24 hours following ischemic preconditioning. All tube flaps were observed for 3 days postoperatively and the surviving flap area was measured as a percentage of the whole flap using the paper template technique. Heat shock protein 70 in the three groups was examined by means of immunohistochemistry. RESULTS: There was an overall statistical significance in comparison of flap survival of the preconditioned flaps with that of the controls. There was no statistical significance between the two preconditioned groups. Heat shock protein 70 (HSP70) was demonstrated immunohistochemically in the preconditioned skin flap but not in the control skin flap. CONCLUSION: Ischemic preconditioning can improve skin flap survival and the contents of HSP70. It is suggest that the mechanism be related to the function of HSP70.

Animals↗
PubMedDate not supplied

Tracking deforming aortas in two-photon autofluorescence images and its application on quantitative evaluation of aorta-related drugs.

This paper describes a novel approach to an objective measurement of aorta samples of rats and a quantitative evaluation of aorta-related drugs. Two-photon fluorescence microscopy is used for recording image sequences of deforming aorta. Time sequence snake models are used to track the structural deformations of aorta walls caused by drug stimulation of the elastic lamina in the aorta. Several objective and quantitative biomarkers extracted from these models are used as diagnostic indicators. In a preliminary study, the technique was successfully used for evaluating the effect of a newly developed drug-human erythrocyte-derived depressing factor quantitatively and objectively.

Animals↗