ABSTRACT
In this paper, a novel direction-of-arrival (DOA) estimation for unknown (anonymous) emitter signal (ES) based on time reversal (TR) and coprime array (CA) is proposed. The resolution and accuracy of DOA estimation are enhanced from two aspects: one is from the view of array arrangement: the new distribution of CA is designed to reduce the holes, increase the degree of freedom (DOF) and apertures by rotating and translating only one subarray, which simplifies the operation. The other one is from the view of the algorithm: a neoteric DOA estimation algorithm with noise suppression based on TR, Capon and adaptive neuro-fuzzy inference system (ANFIS) is proposed for solving the wide sidelobe, multipath effect, low resolution and accuracy produced by conventional algorithms, in particular, those cannot work effectively under the existed hole condition. Furthermore, the resubmitting distorted noise and channel noise are suppressed effectively, which is not taken into considered in the conventional Capon algorithm. Simulation results including the resolution, accuracy, root mean square error (RMSE), Cramér-Rao lower bound (CRLB) and the compared analyses on uniform linear array (ULA), nested array (NA) and minimum redundancy array(MRA) demonstrate the performance advantages of the proposed DOA estimation algorithm even at very low signal-to-noise ratio (SNR) condition.
ABSTRACT
Previous studies have showed that bile acids (BAs) play essential roles in the progression of various human cancers, and the G-protein coupled bile acid receptor-1 (Gpbar-1, or TGR5), a receptor of BAs, has been reported to connect BAs with cancers. However, little is known about the prognostic role of TGR5 in pancreatic cancer. In this study, we found that the expression of TGR5 was significantly higher in the cancerous tissues than the adjacent normal tissues by immunohistochemical staining (81.6% vs. 36.8%). Meanwhile, TGR5 was positively correlated with lymph node metastasis (P=0.021) and advanced stage (P=0.011). Finally, univariate analysis showed that patients with high TGR5 expression (P<0.001), lymph node metastasis (P=0.002) and advanced tumor stage (P=0.008) had decreased overall survival, and Cox proportional hazards regression analysis confirmed that TGR5 expression was an independent predictor of the overall survival of patients with pancreatic cancer (P=0.019). Our findings suggested that TGR5 might serve as an important predictor of poor survival in pancreatic cancer.
ABSTRACT
OBJECTIVE: To study the depletion of cardiac troponin T in Rats of early myocardial ischaemia. METHODS: Immunohistochemical method (LSAB) was used and the depletion area of CTnT in myocardial ischaemia were measured by the computer image analysis. RESULTS: There is obviously depletion of CTnT after 15 min in myocardial ischaemia of rats, the mean of CTnT depletion of myocardial ischaemic group is significant difference compared with that of the control group (P < 0.01), and the depletion area increased with the prolongagtion of ischaemic time. CONCLUSION: The depletion of CTnT is one of sensitive signs of early myocardial ischaemia.
