Biomedical subjects

C-W Chang

Publications and source records attributed to C-W Chang.

3 recordsLinked to original sources

PubMed2006

Coupled waveguide-surface plasmon resonance biosensor with subwavelength grating.

This study develops a coupled waveguide-surface plasmon resonance (CWSPR) biosensor with a subwavelength grating structure for the real-time analysis of biomolecular interactions. In the proposed optical metrology system, normally incident white light is coupled into the waveguide layer through the subwavelength grating structure thereby enhancing the wave vector which excites the surface plasmons on the metal sensing surface. The proposed CWSPR biosensor not only retains the same sensing sensitivity as that of a conventional surface plasmon resonance device, but also yields a sharper dip in the reflectivity spectrum and therefore provides an improved measurement precision. Moreover, the metrology setup overcomes the limitations of the conventional Kretschmann attenuated total reflection approach and is less sensitive to slight variations in the angle of the incident light. The experimental results confirm that the current CWSPR biosensor provides a straightforward yet powerful technique for real-time biomolecular interaction analysis.

Biopolymers↗

PubMed2005

Cervical myelopathy induced by pseudogout in ligamentum flavum and retro-odontoid mass: a case report.

STUDY DESIGN: Retrospective case study. OBJECTIVES: Report a rare case of cervical myelopathy induced by calcium pyrophosphate dehydrate (CPPD) deposition in multiple cervical levels. SETTING: An area teaching hospital in Taiwan. METHOD: A patient with cervical myelopathy was evaluated by computerized tomography (CT) scan and magnetic resonance (MR) image. CPPD deposition known as pseudogout was diagnosed and approved by a polarized microscope. RESULT: A prominent hypertrophy of ligmentum flavum and a retro-odontoid bulging mass induced cord compression were found in CT scan and MR image. CPPD deposition was confirmed by the histological examinations in the ligamentum flavum at the spinal levels of C3-C6. After decompression surgery of spine and comprehensive rehabilitation, the patient's neurological symptoms subsided and her neurological functions improved leading to a good prognosis. CONCLUSION: CPPD deposition in cervical spine occurring at multiple levels is rare. Image studies with CT scan and MR are complementary in the diagnosis of CPPD-induced myelopathy. Surgical decompression is always required and expected to have a good outcome.

Aged↗

PubMed2005

Relation between the axial length and lenticular progressive myopia.

PURPOSE: To investigate the possible risk factors associated with lenticular progressive myopia and to compare the differences between patients with lenticular progressive myopias and senile cataracts. METHODS: We retrospectively reviewed cases that had been diagnosed as lenticular progressive myopia with a discrete nuclear sclerotic cataract and progressive myopic changes in one hospital from January 1998 to February 2003. A total of 47 eyes of 35 patients were enrolled in this study. In all, 32 eyes of 29 cases of common senile cataract receiving cataract extraction surgery during the study period were randomly chosen (every four cases in time sequence within a 2-month period by two ophthalmologists' clinic in 2002) as the control group. We compared the preoperative refraction status, keratometry (K-values) and axial lengths between these two groups. The possible ocular or systemic associating diseases were also investigated in the study group. RESULTS: In the lenticular progressive myopia group, the mean age at surgery (52.9+/-9.2 years) is younger than that in the senile cataract group (68.1+/-7.3 years). The mean axial length in the study group (25.68+/-1.93 mm) is statistically significant longer than that in the control group (22.97+/-0.83 mm) (P<0.0001). Besides, patients with lenticular progressive myopia had significantly lower mean K-values (43.25+/-1.42 diopters) than patients with senile cataracts (44.25+/-1.28 diopters) (P<0.01). There were no other ocular or systemic diseases closely associated with lenticular progressive myopia. CONCLUSIONS: Patients with nuclear cataract combined with lenticular progressive myopia have longer axial length than patients with senile cataract. The longer axial length may be one of the important risk factors predisposing to lenticular progressive myopia.

Adult↗