Biomedical subjects

C T Zhou

Publications and source records attributed to C T Zhou.

12 recordsLinked to original sources

PubMed2006

X-wave solutions of complex Ginzburg-Landau equations.

A solution in the form of X-wave patterns of the complex Ginzburg-Landau equation with a harmonic background inhomogeneity is obtained. The pattern can be attributed to the effects of the harmonic potential and the boundary configuration and size. By varying the harmonic of the background potential, the competition among three types of wave patterns: spiral, X, and target, is investigated by following the evolution of the Fourier modes.

Journal Article↗

PubMed2006

Stabilizing long-period orbits via symbolic dynamics in simple limiter controllers.

We present an efficient approach to determine the control parameter of simple limiter controllers by using symbolic dynamics of one-dimensional unimodal maps. By applying addition- and subtraction-symbol rules for generating an admissible periodic sequence, we deal with the smallest base problem of the digital tent map. The proposed solution is useful for minimizing the configuration of digital circuit designs for a given target sequence. With the use of the limiter controller, we show that one-dimensional unimodal maps may be robustly employed to generate the maximum-length shift-register sequences. For an arbitrary long Sarkovskii sequence, the control parameters are analytically given.

Journal Article↗

PubMed2006

Synchronization in nonidentical complex Ginzburg-Landau equations.

A cross-correlation coefficient of complex fields has been investigated for diagnosing spatiotemporal synchronization behavior of coupled complex fields. We have also generalized the subsystem synchronization way established in low-dimensional systems to one- and two-dimensional Ginzburg-Landau equations. By applying the indicator to examine the synchronization behavior of coupled Ginzburg-Landau equations, it is shown that our subsystem approach may be of better synchronization performance than the linear feedback method. For the linear feedback Ginzburg-Landau equation, the nonidentical system exhibits generalized synchronization characteristics in both amplitude and phase. However, the nonidentical subsystem may exhibit complete-like synchronization properties. The difference between complex fields for driven and response systems gives a linear scaling with the change of their parameter difference.

Journal Article↗

PubMed2006

A note on chaotic unimodal maps and applications.

Based on the word-lift technique of symbolic dynamics of one-dimensional unimodal maps, we investigate the relation between chaotic kneading sequences and linear maximum-length shift-register sequences. Theoretical and numerical evidence that the set of the maximum-length shift-register sequences is a subset of the set of the universal sequence of one-dimensional chaotic unimodal maps is given. By stabilizing unstable periodic orbits on superstable periodic orbits, we also develop techniques to control the generation of long binary sequences.

Algorithms↗

PubMed2005

Comparison between constant feedback and limiter controllers.

Using symbolic dynamics of the one-dimensional unimodal map, the chaos stabilization mechanics of the feedback and limiter control schemes are considered. For feedback control, it is found that the control strength can be efficiently obtained from the superstable parameter of the embedded periodic orbits, and the scaling of the control-space period-doubling bifurcation cascade still obeys the Feigenbaum law. For Sarkovskii orbits, the scaling is also consistent with that of the original chaotic system. For limiter control, a single critical point in the unimodal map is extended to a superstable periodic window and a simple approach for determining the value of the control plateau is found. The scaling in the control space of the period-doubling bifurcation cascade is indeed superexponential. A different scaling for the fine structure of the Sarkovskii sequence is also found. Simple one-dimensional unimodal maps can also be used to generate maximum-length shift-register sequences.

Journal Article↗

PubMed2000

[Experimental study of abnormal cell proliferation and differentiation in rat tongue carcinogenesis induced by 4NQO].

OBJECTIVE: To clarify the phenotypic characteristics of abnormal cell proliferation and differentiation in oral carcinogenesis. METHODS: The expressions of gp230, a marker of epithelium cell differentiation, and proliferating cell nuclear antigen (PCNA) in rat tongue carcinogenesis induced by 4-nitroquinoline-1-oxide (4NQO) were detected by LSAB immunohistochemical staining. RESULTS: With the progress of oral carcinogenesis abnormal proliferation and differentiation patterns were indicated by reduced expression of gp230 and increased expression of PCNA. CONCLUSION: Oral carcinogenesis is the result of mucosa epithelium cell aberrant proliferation and differentiation.

English Abstract↗

PubMed2000

[Histologic study on impeding leukoplakia carcinogenesis of golden hamster cheek pouch about Erigeron breviscapus (Vant) Hand-Mazz].

OBJECTIVE: To observe the effect of Erigeron breviscapus (Vant) Hand Mazz (HEr) in impeding oral leukoplakia carcinogenesis, and to seek effective Chinese herb medicine that can impede precarcinoma of oral mucosas. METHODS: 132 golden hamsters were randomly divided into model group (60 animals), HEr group (60 animals), and control group 12 animals. Salley's leukoplakia carcinogenesis model of golden hamster cheek pouch was used in this study. HEr was injected into the stomach to impede evolution of carcinogenesis. Pathological specimens were observed via naked eye and light microscope between model group and HEr group. Results were compared. RESULTS: Observation via naked-eye showed that leukoplakia rate of HEr group (18.2%) was lower than that of model group (27.3%). Observation via light microscope showed that carcinogenesis rate descended one fold and displasia rate descended 0.4 fold in HEr group. CONCLUSION: HEr has exact effect in impeding leukoplakia carcinogenesis.

English Abstract↗

PubMed2000

[Observation on alpha-SMA during Erigeron Breviscapus (Vant) Hand-Mazz obstructs the evolution of carcinogenesis of golden hamster cheek pouch].

OBJECTIVE: To observe dynamically that Erigeron Breviscapus (Vant) Hand-Mazz (HEr) affects the expression of alpha-smooth muscle actin (alpha-SMA). To discuss the probable mechanism of obstructing leukoplakia carcinogenesis of this medicine. METHODS: 120 golden hamsters were randomly divided into model group (48), HEr group (48) and control group (6). HEr was applied to obstruct the evolution of carcinogenesis of golden hamster cheek pouch. Immunohistochemistry was used to detect the expression level of alpha-SMA with cheek pouch specimen that besmears DMBA in 4-9 weeks. Results were compared with model group. RESULTS: Vessel density dyed with alpha-SMA continuously of HEr group was 65.76 significantly higher than that of model group 42.12 (P<0.001). High classification cases in HEr group were much more than model group when cases were divided into five groups as follow: 100%, 50%, 20%, 10%, 3% (P<0.01). CONCLUSION: HEr can raise the expression level of alpha-SMA exactly during the evolution of leukoplakia carcinogenesis of golden hamster, which shows that this medicine obstructs carcinogenesis by keeping the normal physiological function of vascular myoepithelial cell and integrity of vascular basement membrane.

English Abstract↗

PubMed2000

[Study of resisting leukoplakia canceration and angiogenesis of Herba Erigerontis].

OBJECTIVE: To evaluate the effect of resisting canceration of Herba Erigerontis HEr and that of angiogenesis; seek the mechanism of angiogenesis. METHODS: 150 golden hamsters were randomly divided into model group (66 animals), HEr group (66) and control group (18). Carcinomatous conversions of golden hamster cheek pouches induced by Sally way and interrupted by Herba Erigerontis. Ink perfusion, analysis of images, resin cast form of micro vessel, alpha-SMA detection and histopathological examination were applied to observe their changing patterns. RESULTS: The rate of leukoplakia canceration of Herba Erigerontis group was 50% lower than that of model group. The rate of normal cells was about four times more than that of model. alpha-SMA of Herba Erigerontis 65.76 was higher than that of model (P<0.001). There was no significant difference between angeion vessel area and density (P>0.05). Nevertheless, the resin cast form of micro-vessel showed that its configuration and spacious arrangement was similar to control group. CONCLUSION: Herba Erigerontis has the function of preventing leukoplakia canceration absolutely. Maybe its mechanism is to upregulate the expression of alpha-SMA. It has no obvious effect of angio-hyperplasia and expansion in the course of leukoplakia canceration. However, it has the protecting function to angio-configuration and spacious arrangement and the integrity of angeion vessed wall. Probably its mechanism is promoting blood circulation by removing blood stasis and benign angiogenesis so as to resist canceration.

English Abstract↗

PubMed1998

[Flow cytometry dynamic study binding to bromodeoxyuridine in golden hamster cheek pouch premalignancy]

OBJECTIVE:In order to study cellular dynamicfeatures in carcinoma and premalignancy originated inepithelial tissue. METHODS: The golden hamster pouch premalignant model with dimethylbenzanthracence(DMBA) smeared was established by Salley and detected with flow cytometry(FCM) binding to bromodeoxyuridine(BRDU),30 Syrian golden hamsters were grouped and done contrast study. RESULTS: The cellular lesions were aggravated gradually along with extention of smeared DMBA microstopically,FCM detective results demonstrated that the detective rate of Sporiod cell between contrast and smeared group had significant difference. Even though mild dysplsia presented microscopically FCM detective result and significant difference. CONCLUSION: The study suggests that golden hamster cheek pouch premalignancy has cellular dynamicfeatures of dysplasia.

Journal Article↗

PubMed1998

[Developmental carcinogenesis in the cheek pouch of the hamster induced by DMBA using on light microscope]

OBJECTIVE:In this study that the DMBA was applicated to induce the premalignantal changes of the cheek pouches of 89 hamsters in various stage,the result was shown that the slight epithelial displasia was occured 3 weeks later,the medium displasia was occured 5 weeks later,and the severe displasia or the carcinoma in situ was occured 6-9 weeks later.It is suggested that the suitable experimental period of the hamster's carcinogenesis is during 1-3 weeks.

Journal Article↗

PubMed1996

[Analysis of the clinic with pathology and detection using IGSS of 201 cases of discoid lupus erythematosus]

Clinic pathology and detection using IGSS of 201 cases of discoid lupus erythematosus (DLE) were studied in this paper.The results showed:1.DLE usually occured on the low lip(60%);2.Suffering from gastrointestinal disease were the first symptom(25%DLE cases was confirmed by mild dysplasia,3 cases of carcinoma.1 cases Combined of DLE and lichen planus(LP);4.Immunogold-silver Staining (IGSS) was applied to detect immune complex.The result indicated that Fg,immunoglobins and complement C3 deposited at basal membrane zone of DLE.It is illustrated that DLE is an autoimmune disease which is caused by many kinds of factors and may be cancerous.Coexistence of DLE and LP suggested that they may be at different stages of the same disease.Its mechanism will be further studied.

Journal Article↗