With the development of Wide-band wireless communications,MAC protocol in IEEE 802.11 can't satisfy user-individual quality of service(QoS) guarantees effectively and can't support high-speed mobility.A novel ...With the development of Wide-band wireless communications,MAC protocol in IEEE 802.11 can't satisfy user-individual quality of service(QoS) guarantees effectively and can't support high-speed mobility.A novel algorithm for channel allocation in Wide-band WLAN and an improved resource reservation mechanism applied into IEEE 802.11 MAC protocol are proposed in this article.The simulated results indicate that the advanced protocol makes the system throughput improved and delay decrease.Moreover,the improved system shows an excellent performance in the environment with high-speed mobility.展开更多
There is evidence to suggest that follicle-stimulating hormone （FSH） can facilitate the neovascularization of ovarian cancers by increasing vascular endothelial growth factor （VEGF） expression in cancer cells, alt...There is evidence to suggest that follicle-stimulating hormone （FSH） can facilitate the neovascularization of ovarian cancers by increasing vascular endothelial growth factor （VEGF） expression in cancer cells, although the underlying molecular mechanism of this process is not well known. Therefore, we investigated the effect of FSH on VEGF expression in the ovarian cancer cell lines SKOV-3 and ES-2. Treatment with FSH significantly increased VEGF expression in a dose- and time-dependent manner. In addition, FSH treatment enhanced the expression of survivin and hypoxlainducible factor-1 （HIF-1α）. Knockdown of survivin or HIF-1α suppressed VEGF expression, but only knockdown of survivin inhibited FSH-stimulated VEGF expression. Pretreatment with LY294002, a phosphoinositide 3-kinase （PI3K）/AKT inhibitor, neutralized the enhanced expression of survivin induced by FSH, but treatment with U0126, a mitogen-activated protein kinase/extracellular signal-regulated kinase inhibitor, had no such effect. We further showed that ovarian serous cystadenocarcinoma samples had much higher incidence of positive AKT and phosphorylated AKT （pAKT） protein staining than did benign ovarian cystadenoma samples （p 〈 0.01）. The 5-year survival rate was only about 15% in patients with ovarian serous cystadenocarcinoma who had AKT and pAKT expression, whereas it was about 80% in those who did not have AKT or pAKT expression. Taken together, these results indicate that FSH increases the expression of VEGF by upregulating the expression of survivin, which is activated by the PI3K/AKT signaling pathway. Understanding the role of the PI3K/AKT pathway in FSH-stimulated expression of survivin and VEGF will be beneficial for evaluating the prognosis for patients with ovarian serous cystadenocarcinoma and for pursulug effective treatment against this disease.展开更多
文摘With the development of Wide-band wireless communications,MAC protocol in IEEE 802.11 can't satisfy user-individual quality of service(QoS) guarantees effectively and can't support high-speed mobility.A novel algorithm for channel allocation in Wide-band WLAN and an improved resource reservation mechanism applied into IEEE 802.11 MAC protocol are proposed in this article.The simulated results indicate that the advanced protocol makes the system throughput improved and delay decrease.Moreover,the improved system shows an excellent performance in the environment with high-speed mobility.
文摘There is evidence to suggest that follicle-stimulating hormone （FSH） can facilitate the neovascularization of ovarian cancers by increasing vascular endothelial growth factor （VEGF） expression in cancer cells, although the underlying molecular mechanism of this process is not well known. Therefore, we investigated the effect of FSH on VEGF expression in the ovarian cancer cell lines SKOV-3 and ES-2. Treatment with FSH significantly increased VEGF expression in a dose- and time-dependent manner. In addition, FSH treatment enhanced the expression of survivin and hypoxlainducible factor-1 （HIF-1α）. Knockdown of survivin or HIF-1α suppressed VEGF expression, but only knockdown of survivin inhibited FSH-stimulated VEGF expression. Pretreatment with LY294002, a phosphoinositide 3-kinase （PI3K）/AKT inhibitor, neutralized the enhanced expression of survivin induced by FSH, but treatment with U0126, a mitogen-activated protein kinase/extracellular signal-regulated kinase inhibitor, had no such effect. We further showed that ovarian serous cystadenocarcinoma samples had much higher incidence of positive AKT and phosphorylated AKT （pAKT） protein staining than did benign ovarian cystadenoma samples （p 〈 0.01）. The 5-year survival rate was only about 15% in patients with ovarian serous cystadenocarcinoma who had AKT and pAKT expression, whereas it was about 80% in those who did not have AKT or pAKT expression. Taken together, these results indicate that FSH increases the expression of VEGF by upregulating the expression of survivin, which is activated by the PI3K/AKT signaling pathway. Understanding the role of the PI3K/AKT pathway in FSH-stimulated expression of survivin and VEGF will be beneficial for evaluating the prognosis for patients with ovarian serous cystadenocarcinoma and for pursulug effective treatment against this disease.
