Biomedical subjects

Jian-Jun He

Publications and source records attributed to Jian-Jun He.

4 recordsLinked to original sources

PubMed2006

[In situ analysis of distribution of immunocompetent cells in tumor's local draining lymph nodes].

AIM: To observe the distribution of immunocompetent cells (ICCs) in tumor's local draining lymph nodes (LDLN) at different stages of disease including non-metastasis, micro-metastasis and late metastasis. METHODS: 71 LDLN from 22 breast cancer, 28 LDLN from 7 gastric carcinoma were analysed by using catalyzed signal amplification (CSA) immunohistochemical staining. Monoclonal antibodies (mAbs) to perforin, granzyme B, CD8, CD56, CD68, S-100, CD134 and CD25 were used to detect the amount and functional change of ICCs. RESULTS: Paracortical hyperplasia and sinus histocytosis was mainly observed in tumor's LDLN. As it was reported, the density of S100(+) dendritic cells (DCs) was decreased as the draining lymph nodes became tumor-containing from the status of tumor free (P<0.05), and the morphology of DCs turned to be inactivated. As the lymph nodes were invaded by tumors, the densities of CD134(+) lymphocytes and CD25(+) cells were significantly increased (P<0.01). Furthermore, there was a significant trend of decreasing in the number of activated cytotoxic T lymphocytes (granzyme B(+) cells) in LDLN as tumor progressed from non/micro-metastasis, early metastasis to advanced stage metastasis (P<0.01). There was no obvious difference in distribution of ICC between non/micro-metastasis sentinel lymph nodes and non-sentinel lymph nodes. CONCLUSION: The dynamic change of the ICCs in LDLN implied that immune response of tumor bearing host tends to be inhibited with the progress of tumors.

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PubMed2005

Compact silicon-on-insulator-based multimode interference coupler with bilevel taper structure.

A novel compact silicon-on-insulator- (SOI-)based multimode interference (MMI) coupler with bilevel taper structures was designed. The MMI section and the S-bend sections of the input-output waveguides are deeply etched. The input-output waveguides connecting to single-mode fibers or other photonic light circuits are etched shallowly to yield single-mode operation. A bilevel taper is introduced in the transition region between the shallowly and deeply etched regions. It is predicted theoretically that this design will not only improve the quality of the self-imaging in the MMI section but will also make the structure compact. Both the excess loss and the nonuniformity of the MMI coupler are reduced. By use of a three-dimensional beam propagation method, the performance of a 1 x 4 MMI coupler based on a SOI is simulated as a numerical example of the novel design. The simulated nonuniformity and the excess loss are approximately 0.0285 and 0.2 dB, respectively.

Journal Article↗

PubMed2005

Fast analysis method for polarization-dependent performance of a concave diffraction grating with total-internal-reflection facets.

A fast simulation method for a waveguide-based concave grating with total-internal-reflection (TIR) facets is presented using the Kirchhoff-Huygens principle. Unlike the conventional scalar method, modifications are made to take into account the influence of the Goos-Hänchen (GH) shift. The simple method is in good agreement with a numerical method based on rigorous coupled-wave analysis for a wide range of practical device parameters and can provide an insightful physical explanation for the numerical results. It is shown that the GH shift is a main contributing factor for the loss and the polarization-dependent loss of an etched diffraction grating demultiplexer with TIR facets.

Journal Article↗

PubMed2004

Analysis and design of a concave diffraction grating with total-internal-reflection facets by a hybrid diffraction method.

A novel hybrid diffraction method is introduced to simulate the diffraction and imaging of a planar-integrated concave grating that has total internal reflection (TIR) facets. The Kirchhoff-Huygens diffraction formula is adopted to simulate the propagation of the lightwave field in the free-propagation region, and a rigorous coupled-wave analysis is used to calculate the polarization-dependent diffraction by the grating. The hybrid diffraction method can be used to analyze accurately the imaging properties as well as the polarization-dependent diffraction characteristics of a concave grating. The dependence of several merit parameters of a concave grating with TIR facets on its basic geometric parameters is studied. Compared with one with metallic echelle facets, a concave grating with TIR facets shows a much lower polarization-dependent loss. Since more performance specifications can be considered in the design of a concave grating than with the conventional scalar method, design error can be reduced greatly with the present hybrid diffraction method.

Journal Article↗