Analysis of Ultrasonic Machining Characteristics under Dynamic Load.

This research focuses on the load characteristics of piezoelectric transducers in the process of longitudinal vibration ultrasonic welding. We are primarily interested in the impedance characteristics of the piezoelectric transducer during loading, which is studied by leveraging the equivalent circuit theory of piezoelectric transducers. Specifically, we propose a cross-value mapping method. This method can well map the load change in ultrasonic welding to the impedance change, aiming to obtain an equivalent model of impedance and load. The least-squares strategy is used for parameter identification during data fitting. Extensive simulations and physical experiments are conducted to verify the proposed model. As a result, we can empirically find that the result from our model agrees with the impedance characteristics from the real-life data measured by the impedance meter, indicating its potential for real practice in controller research and transducer design.

The acute and regulatory phases of time-course changes in gill mitochondrion-rich cells of seawater-acclimated medaka (Oryzias dancena) when exposed to hypoosmotic environments.

The recent model showed that seawater (SW) mitochondrion-rich (MR) cells with hole-type apical openings secrete Cl(-) through the transporters including the Na(+), K(+)-ATPase (NKA), Na(+), K(+), 2Cl(-) cotransporter (NKCC), and cystic fibrosis transmembrane conductance regulator (CFTR). The present study focused on the dynamic elimination of the Cl(-) secretory capacity and illustrated different phases (i.e., acute and regulatory phases) of branchial MR cells in response to hypoosmotic challenge. Time-course remodeling of the cell surfaces and the altered expressions of typical ion transporters were observed in the branchial MR cells of SW-acclimated brackish medaka (Oryzias dancena) when exposed to fresh water (FW). On the 1st day post-transfer, rapid changes were shown in the acute phase: the flat-type MR cells with large apical surfaces replaced the hole-type cells, the gene expression of both Odnkcc1a and Odcftr decreased, and the apical immunostaining signals of CFTR protein disappeared. The basolateral immunostaining signals of NKCC1a protein decreased throughout the regulatory phase (>1day post-transfer). During this period, the size and number of NKA-immunoreactive MR cells were significantly reduced and elevated, respectively. Branchial NKA expression and activity were maintained at constant levels in both phases. The results revealed that when SW-acclimated brackish medaka were transferred to hypoosmotic FW for 24h, the Cl(-) secretory capacity of MR cells was eliminated, whereas NKCC1a protein was retained to maintain the hypoosmoregulatory endurance of the gills. The time-course acute and regulatory phases of gill MR cells showed different strategies of the euryhaline medaka when subjected to hypoosmotic environments.

DRI-Net: segmentation of polyp in colonoscopy images using dense residual-inception network.

Colorectal cancer is a common malignant tumor in the gastrointestinal tract, which usually evolves from adenomatous polyps. However, due to the similarity in color between polyps and their surrounding tissues in colonoscopy images, and their diversity in size, shape, and texture, intelligent diagnosis still remains great challenges. For this reason, we present a novel dense residual-inception network (DRI-Net) which utilizes U-Net as the backbone. Firstly, in order to increase the width of the network, a modified residual-inception block is designed to replace the traditional convolutional, thereby improving its capacity and expressiveness. Moreover, the dense connection scheme is adopted to increase the network depth so that more complex feature inputs can be fitted. Finally, an improved down-sampling module is built to reduce the loss of image feature information. For fair comparison, we validated all method on the Kvasir-SEG dataset using three popular evaluation metrics. Experimental results consistently illustrates that the values of DRI-Net on IoU, Mcc and Dice attain 77.72%, 85.94% and 86.51%, which were 1.41%, 0.66% and 0.75% higher than the suboptimal model. Similarly, through ablation studies, it also demonstrated the effectiveness of our approach in colorectal semantic segmentation.

The Predictive Value of N-Terminal Probrain Natriuretic Peptide for Infection in Patients With Acute Myocardial Infarction.

Background: Infections increase the risk of poor outcomes in patients with ST-elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI). However, predicting patients at a high risk of developing infection remains unclear. Moreover, the value of N-terminal probrain natriuretic peptide (NT-proBNP) for predicting infection is still unknown. Thus, we aimed to assess the relationship between NT-proBNP and the following development of infection, and clinical adverse outcomes in patients with STEMI undergoing PCI. Methods: STEMI patients undergoing PCI were consecutively enrolled from January 2010 to July 2016 and divided into groups according to baseline NT-proBNP levels: tertiles T1 (<988 pg/mL), T2 (988-3520 pg/mL), and T3 (≥3520 pg/mL). The primary endpoint was infection during hospitalization. Results: A total of 182 (27%) patients developed in-hospital infection. The incidence of infection increased from T1 to T3 (10.5, 17.7, and 54.5%, P < 0.001). NT-proBNP was an independent risk factor (adjusted odds ratio = 1.39, 95% confidence interval (CI) = 1.12-1.73, P = 0.003) and presented accurately predicting infection (area under curve = 0.774). Multivariate cox analysis showed that NT-proBNP was a significant risk factor for major adverse clinical events (MACE) at follow-up (adjusted HR = 1.92, 95% CI = 1.61-2.29, P < 0.001). Conclusion: The baseline NT-proBNP level has a good predictive value for infection and MACE in STEMI patients undergoing PCI.

Comparison of the preventive efficacy of rosuvastatin versus atorvastatin in post-contrast acute kidney injury in patients with ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention.

Statins have been shown to reduce the risk of post-contrast acute kidney injury (PC-AKI) in patients undergoing percutaneous coronary intervention (PCI). However, the preventive effect of rosuvastatin versus atorvastatin on PC-AKI in patients with ST-segment elevation myocardial infarction (STEMI) undergoing PCI remains unclear. Patients with STEMI undergoing PCI between January 2010 and May 2016 were consecutively enrolled. A total of 1300 included patients were divided into two groups according to the statin type (atorvastatin: n = 1040; rosuvastatin: n = 260). The primary endpoint was PC-AKI defined as an absolute increase of ≥ 0.5 mg/dL in the level of serum creatinine or an increase of ≥ 25 % over baseline within 48-72 h after contrast media exposure. In total, 245 (18.8 %) patients developed PC-AKI. The atorvastatin and rosuvastatin groups had similar rates of PC-AKI (19.1 % vs. 17.7 %, p = 0.595), in-hospital mortality (4.1 % vs. 3.8 %, p = 0.833), and major adverse clinical events (MACE). Multivariate logistic regression analysis revealed that rosuvastatin treatment had an effect similar to atorvastatin regarding PC-AKI (odds ratio [OR] = 0.97, 95 % confidence interval [CI], 0.66-1.43, p = 0.874). Propensity score analyses and subgroup analysis demonstrated similar results for PC-AKI. Kaplan-Meier survival curves and Cox proportional regression showed that the atorvastatin and rosuvastatin groups had no differences regarding follow-up mortality. Rosuvastatin exerted a similar preventive effect against PC-AKI and showed similar levels of in-hospital and follow-up all-cause mortality and in-hospital MACE compared with atorvastatin in patients with STEMI undergoing PCI.

Predictive value of the Canada Acute Coronary Syndrome risk score for post-acute myocardial infarction infection.

BACKGROUND: Although rare, infection in patients with ST-elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI) significantly increases mortality. Therefore, it is important to identify patients at high risk of infection. We aimed to validate the value of the Canada Acute Coronary Syndrome (C-ACS) risk score for predicting infection in such patients. METHODS: We conducted a prospective cohort study. Consecutive patients with STEMI undergoing PCI at our hospital from January 2010 to June 2016 were enrolled . C-ACS risk score was calculated based on the following clinical parameters (1 point for each): age ≥ 75 years, Killip class >1, systolic blood pressure <100 mmHg, and heart rate > 100 beats/min. The primary outcome was development of post-acute myocardial infarction (P-AMI) infection. RESULTS: A total of 2198 patients were enrolled, of whom 424 (18.5%) developed infection. The incidence of infection, in-hospital mortality, and major adverse clinical events (MACE) were significantly higher in those with a C-ACS risk score ≥2. After adjusting for potential risk factors, C-ACS risk score remained a significant predictor of P-AMI infection (odds ratio [OR] = 2.27, 95% confidence interval [CI] = 1.92-2.67, p < 0.001), in-hospital mortality, and MACE. Receiver operating characteristic curves demonstrated the C-ACS risk score had good predictive value for P-AMI infection (area under the curve = 0.783, 95% CI = 0.759-0.806, P < 0.001), in-hospital mortality and MACE. CONCLUSIONS: The C-ACS risk score was a good predictor of P-AMI infection, and other clinical outcomes.

Effects of TNF-α on penile structure alteration in rats with hyperprolactinemia.

This study aimed to investigate the effects of anti-tumor necrosis factor (TNF)-α antibody (Ab) on alteration of penile structure in the hyperprolactinemia (hyperPRL) rat model. HyperPRL was induced in 8-week-old male Sprague-Dawley rats by allografting anterior pituitary (AP) glands under the renal capsule (+AP rats). Rats implanted with cerebral cortex (CX) were used as sham control (+CX rats). At 6 weeks post implantation, rats received either a single intra-testicular dose of TNF-α Ab (12.5 µg/kg) or testosterone replacement (2 doses of testosterone enanthate [TE], 3 mg/kg), and they were sacrificed 1 week later. Blood and penile tissue was collected for analysis. Compared to +CX rats, the +AP group had lower serum testosterone concentration and neuronal nitric oxide synthase (nNOS) expression, but exhibited a higher ratio of collagen III/I in the corpus cavernosum. Smooth muscle content exhibited no significant changes. At 1 week post TNF-α Ab injection, the collagen III/I ratio in the +AP group was decreased, and the smooth muscle content and nNOS expression increased significantly. These findings were comparable to those observed in +AP rats receiving TE. Testicular TNF-α suppresses testosterone release, which in turn results in the erectile dysfunction (ED) seen in hyperPRL. Intra-testicular TNF-α Ab treatment is as effective as testosterone supplementation on penile structure normalization in the hyperPRL model.