An analysis technique of steady state and stability for closed-loop PWM DC/DC switching converters is presented. Using this method, the closed-loop switching converter is transformed into an open-loop system. By means of the fact that in steady state, the two boundary values are equal in one switching period. The exponential matrix is evaluated by precise time-domain-integration method, and then the related curve between feedback duty cycle and the input one is obtained. Not only can the steady-state duty cycle be found from the curve, but also the stability and stable domain of the system. Compared with other methods, it features with simplicity and less calculation, and fit for numerical simulation and analysis for closed-loop switching converters. The simulation results of examples indicate the correctness of the presented method.

Genetically modified organisms, as a high-tech product, break through the limitation of different organisms and create new organisms through gene implanting from other kinds of organisms. They not only bring great benefits to human beings but also bring some ethical issues including the effect on environment,the effect on human health,and the respect to hatural law.Moreover,this article argues some ethical issues during the process of commercialization and sale including how to maintain the consumers' benefits,the protection on researchers through potent right,the precautionary principle and label issues.

In the report of the definition and classification subcommittee of the International Dry Eye WorkShop (2007), inflammation was emphasized specially, and anti-inflammation therapy was also included in the treatment recommendations by severity level. Inflammation has been highly valued in the pathogenesis of dry eye recently. The management of dry eye through anti-inflammation therapy is also a hot point in recent years. What is the role of inflammation in the development of dry eye? This article mainly reviews the advancement of the study about their relevance in recent years.

Objective To investigate the biological features of epidermal growth factor receptor inhibitor AG1478 on cervical carcinoma cell. Methods The proliferation of HeLa cells under AG1478 stimulation was determined by CCK8 assay. The expression of EGFR downstream signaling protein and apoptotic relative protein were examined by Western blot and transcription of apotosis?related genes were measured by RT?qPCR in AG 1478 treated HeLa cells. Nuclear transport of phosphorylated ERK were measured through ICC assay. TUNEL assay was used to determine early stage of apoptosis. Results CCK8 assay showed that AG1478 inhibit the proliferation of HeLa cells and also block phosphorylated level of EGFR ,ERK and AKT. Furthermore ,nuclear transport of phosphorylated ERK upon EGF stimulation were blocked and pro?apoptotic proteins were up?regluated with activat ed cleaved Caspases. Conclusion AG1478 inhibited the proliferation and induced apoptosis in HeLa cells and it could be a potential therapeutic drug for cervical carcinoma.

Analysis was conducted and rights concerning teachers,students and patients in practice teaching was defined from the perspectives of medicine,pedagogy,ethnics and law through investigating on reasons leading to problems and conflicts in medical universities' practice right.Effective solutions were proposed from the examination of doctor' s qualification,law and pedagogy.Standardization and legalization of clinical teaching was promoted from the perspective of ethnics.

OBJECTIVE: To investigate the differential gene expression profiles in patients with blood stasis syndrome by oligonucleotide microarray technique. METHODS: Sixteen patients with blood stasis syndrome were divided into patients with coronary heart disease (CAD) (n=8) and non-CAD patients (n=8) by using coronary angiography. The sex- and age-matched eight healthy persons were enrolled as control group. Venous bloods were collected for extracting RNA. Test-3 chip was first employed to examine the quality of samples. Then the samples were hybridized with Affymetrix U133 Plus 2.0 array to compare the gene expression profiles among the three groups. Gene-array scanner and gene chip operating software were applied to screen hybridization signals and analyze gene expression respectively. Based on the comparison of the three groups of samples, the differential genes related with blood stasis syndrome were analyzed by Gene Ontology (GO) and pathway, and confirmed by real-time reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Forty-eight differential genes were found being associated with blood stasis syndrome, including 26 up-regulated genes and 22 down-regulated genes. Five of the forty-eight genes (10.4%) were related to inflammatory reaction and immune response through the GO analysis. In the pathway analysis, five of ten significant pathways were referred to inflammation and immune response. The results of real-time RT-PCR proved the accuracy of the gene chip. CONCLUSION: Inflammatory- and immune-related genes have a remarkable predominance in blood stasis syndrome gene expression profiles, which may explain the function of inflammation and immune response in the occurrence and development of blood stasis syndrome.

Objective To investigate the expressions of matrix metalloproteinase 2 (MMP 2), matrix metalloproteinase 7 (MMP 7), and tissue inhibitor of matalloproteinase 2 (TIMP 2) in lung carcinoma tissue and their significance Methods The expressions of MMP 2, MMP 7, and TIMP 2 in 74 cases of lung carcinoma tissues and 20 cases of peri cancerous normal lung tissues were detected by immunohistochemical method, and the correlation between the expressions of these proteins and the clinicopathological parameters and the prognosis was analyzed Results MMP 2 and MMP 7 expressions in lung carcinoma tissues were significantly higher than those in peri cancerous normal lung tissues ( P 0 05), and the expression of TIMP 2 was significantly lower in lung carcinomas with lymph node metastasis than that in lung carcinomas without lymph node metastasis ( P

Objective To explore the pathogenesis of autism by observation of changes of brain-derived neurotrophic factor(BDNF) positive neurons and the morphology of pyramidal cells in hippocampal CA1 region,and provide theoretical evidence for the therapeutic schedule.Methods Animal model of autism was obtained by Schneider method.Using the immunohistochemistry methods and image analysis,the number of BDNF positive neurons was examined in hippocampal CA1 region of the autism model rats and the normal rats,and the changes of pyramidal cell were observed in hippocampal CA1 region after HE staining.Results The numbers of BDNF positive neurons in the hippocampal CA1 region of the autism model rats were more than those of the normal rats (5.00 ±1.60 vs 3.00 ± 1.04,t =3.63,P =0.0015).The morphology of pyramidal cells showed that the pyramidal cells of the autism model rats in hippocampal CA1 region had apoptosis.Conclusion The occurrence of autism may be related to the changes of BDNF and the morphology of pyramidal cells in hippocampal CA1 region.

The efficacy of traditional Chinese medicine(TCM) is the summary for the effects of traditional Chinese medicine.The effect of traditional Chinese medical pharmacology is studying the interaction mechanism between TCM and body,using the modern technical methods and guiding by TCM theories.Most efficacies of TCM are identical with pharmacological effects.The clinical use of TCM pharmacy will give a full play of treatment only by guided with the theory of the concept of the whole and treatment based on syndrome differentiation and integrated with the efficacy of TCM and the principal compatibility of medicine.

The morbidity and mortality of tumors of digestive system is much higher in recent years .Realizing diagnosis of early phase tumors can improve the surgical resection rate and prolong survival time of patients .Compared with traditional diagnosis methods, multiphoton microscopy has got an obvious improvement in the penetration depth .Furthermore, phototoxicity and photo-bleaching has been largely reduced .Combining with the second harmonic microscopy , the change of collagen fibers can be observed in the organization.MPM can achieve early diagnosis of cancer at the cellular level .Therefore, multiphoton microscopy , with the imaging characteristics of unique high resolution , real-time, nondestructive , deeply spectral resolution , is of great potential in the diagnosis of early stage tumors of digestive system .Based on the latest research results , this review summarizes the latest progress of multiphoton microscopy diagnosing early phase of gastrointestinal tumor .