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Abstract Background We aimed to investigate the relationship between the perioperative hemodynamic parameters and the occurrence of cardiac surgery-associated acute kidney injury. Methods A retrospective study was performed in patients who underwent cardiac surgery at a tertiary referral teaching hospital. Acute kidney injury was determined according to the KDIGO criteria. We investigated the association between the perioperative hemodynamic parameters and cardiac surgery-associated acute kidney injury to identify the independent hemodynamic predictors for acute kidney injury. Subgroup analysis was further performed in patients with chronic hypertension. Results Among 300 patients, 29.3% developed acute kidney injury during postoperative intensive care unit period. Multivariate logistic analysis showed the postoperative nadir diastolic perfusion pressure, but not mean arterial pressure, central venous pressure and mean perfusion pressure, was independently linked to the development of acute kidney injury after cardiac surgery (odds ratio 0.945, P = 0.045). Subgroup analyses in hypertensive subjects (n = 91) showed the postoperative nadir diastolic perfusion pressure and peak central venous pressure were both independently related to the development of acute kidney injury (nadir diastolic perfusion pressure, odds ratio 0.886, P = 0.033; peak central venous pressure, odds ratio 1.328, P = 0.010, respectively). Conclusions Postoperative nadir diastolic perfusion pressure was independently associated with the development of cardiac surgery-associated acute kidney injury. Furthermore, central venous pressure should be considered as a potential hemodynamic target for hypertensive patients undergoing cardiac surgery.

Background: Nocturnal heart block often occurs in patients with obstructive sleep apnoea (OSA). It is more likely to be undiagnosed in heart block patients who are ignorant of the symptoms of sleep disorder. Berlin Questionnaire (BQ) is a highly reliable way to discover the risk factors of OSA, whereas the validity in sleep-related heart block patients is uncertain. We performed an observational study to address these issues and confirmed the potential protective effect of continuous positive airway pressure (CPAP).Methods: Patients who were previously diagnosed with nocturnal heart block with R-R pauses exceeding 2 seconds were retrospective screened from the ECG centre of Zhongshan hospital. These recruited participants completed Berlin Questionnaire and underwent polysomnography synchronously with 24-hour Holter monitoring. A cross-sectional analysis was performed to confirm the association between nocturnal arrhythmia and OSA, as well as to assess the diagnostic accuracy of the BQ. Subsequently, subjects diagnosed with OSA (apnoea-hypopnoea index > 5) underwent 3 consecutive days of CPAP therapy. On the third day, patients repeated 24-hour Holter monitoring within the institution of CPAP.Results: The symptoms of disruptive snoring and hypersomnolence in 72 enrolled patients were more related to the occurrence of nocturnal heart block (r = 0.306, 0.226, respectively, p = 0.015, 0.019) than syncope (r = 0.134, p = 0.282) and palpitations (r = 0.106, p = 0.119), which were prominent trait of our study population. The sensitivity, specificity, positive and negative predictive value of the BQ at a cut-off point of 5 of AHI for detecting OSA in heart block patients was 81.0 %, 44.4 %, 91.07 % and 25 %. Nocturnal heart block does not appear to occur exclusively in severe sleep apnoea. The frequent occurrence of arrhythmias in prominent oxygen desaturation supports the correlation between them. CPAP therapy resulted in significant decrease in the average number of episodes of heart block, from 148.58 ± 379.44 to 16.07 ± 58.52 (p < 0.05), same to the change of the longest RR pausing time (from 4.38 ± 2.95 s to 0.57 ± 1.05 s, p = 0.169) in 51 patients. The optimal therapy pressure to make the observed arrhythmia disappeared is 12 cm H2O.Conclusion: Concerning high prevalence of OSA in heart block patients, BQ provided an economical and efficient screening method for OSA. For better management, CPAP therapy is feasible to prevent heart blocks avoiding unnecessary concomitant pacemaker implantation. [ABSTRACT FROM AUTHOR]

In this paper, the width and gap of etching transistors in TFT-LCD panels were measured using sub-pixel accuracy estimation, and the accuracy was tested in a noisy environment. The concept of line width measurement was introduced in terms of line distance and defect measurement based on the low and high spatial frequency distribution change of TFT-LCD panel image. Some patterns do not need to have the line width and distance measured, while others have different measurement requirements. The conductor border of a pattern is normally an area with a flat change of grey scale, but we are still able to find an accurate measurement with the proposed method. In the TFT-LCD testing pattern, there are circular etching structures, and for measurement we focus on the position of the center of the circle and the size of the radius. This method can be used quickly and accurately for measuring the TFT short, ITO open, marking, spot particle or scratching on the panel caused by over etching. [ABSTRACT FROM AUTHOR]

In this paper a new electroporation (EP) system is developed, which includes an EP microchip and a logic circuit, which combined with electrophoresis (ES), can provide site-specific enhancement of gene concentration. In this ES-EP microchip, an arc planar electrode provides the ES function for DNA attraction, and interdigitated array electrodes provide appropriate electric fields for the EP on the chip surface. In addition, the adherent cells can be manipulated in situ without detachment of the ES-EP microchip, which performs the "Lab on a chip". Experimental results have shown that the efficiency of gene transfection with an attracting-electric field (35.89%) becomes much higher than that without an attracting-electric field (16.62%). Cell numbers as low as 10(4) cells, and DNA as little as 4 microg are sufficient for evaluating the phenotypic effects following the over-expression of the introduced genes on the ES-EP microchip. The proposed system has the advantages of portability, cost-effectiveness, a high transfection rate and ease of operation.

We developed a new electroporation system, including a microchip and a logic circuit, and combining with the function of electrophoresis, which can site-specific enhancement of the gene concentration. We have demonstrated that the electroporation microchip could enhance and target in vitro gene transfection for cell lines. In this micro-device, the outer electrodes could provide the electrophoresis function for DNA attraction, and the inner electrodes could provide appropriate electric fields for the electroporation on the chip surface. The electrostatic force can be designed into specific regions, where the DNA plasmids are attracted to provide the region-targeting function. This study successfully demonstrates that the electrostatic force can attract DNA plasmids to the cell surface and highly enhance the gene delivery. Experimental results showed that the efficiency of gene transfection with an attracting-electric field become much higher than that without an attracting-electric field. Furthermore, the adherent cells could be manipulated in situ without detachment by this EP microchip. The system has several advantages of portable, cost-effective, high transfection rate and easy operation.