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This paper proposes a novel passive micromixer design for mixing enhancement by forming a large three-dimensional (3-D) flow vortex in a counterflow microfluidic system. The counterflow fluids are self-driven by surface tension to perform mixing in an open chamber. The chamber design consists of two rectangular bars to house the chamber and to form two opening inlets from opposite directions. The best design is selected from various versions of mixing chambers. The mixing effectiveness is tremendously increased by folds of contacting surface between two fluids induced and enhanced due to the stretching of two fluid contacting interfaces by the formation of a 3-D large size vortex structure inside the mixing chamber itself with unaccountable numbers of fluid layers. Both numerical simulations and experiments are performed and compared to identify the design parameters for maximum utilization in this microfluidic system, such as the length of rectangular bar, microchannel wall height, and mixing chamber size. Compared to traditional micromixers operated by two-dimensional (2-D) vortex, this passive mixer can greatly enhance mixing efficiency and reduce mixing time by tenfold from around 10 s to less than 10 ms by 3-D effective chaotic flow structures in a more compact size. This mixing chamber is also suitable for an H-shape digital fluidic system for parallel mixing process in different mixing ratio simultaneously as a lab-on-a-chip system.[1509]

Summary Tranexamic acid is an effective treatment to reduce blood loss. We performed a retrospective observational study to evaluate safety in unilateral total knee arthroplasty. We utilised Taiwan's national health insurance database to identify relevant patients and to retrieve information on peri‐operative blood transfusions and tranexamic acid administration within 60 days of follow‐up. We examined changes in the rate of transfusions and adverse events with respect to tranexamic acid administration using logistic regression. We observed a total of 226,719 knee arthroplasty cases during 2010–2019. Transfusion and tranexamic acid administration rates were 38.9% (88,258) and 42.9% (97,237), respectively. Tranexamic acid was associated with a 50% decrease in blood transfusions (RR: 0.50, 95%CI: 0.48–0.51). After propensity‐score matching, tranexamic acid was not associated with pulmonary embolism; deep vein thromboembolism; artery vein thromboembolism; acute myocardial infarction; ischaemic stroke; or in‐hospital mortality, but was significantly associated with acute kidney injury. Patients with existing chronic kidney disease suffered a high absolute risk of kidney injury irrespective of tranexamic acid administration (832 per 10,000, 95%CI 797–869). Tranexamic acid was also associated with surgical site infection. There was strong interaction between blood transfusion; tranexamic aid administration; and development of surgical site infection. In conclusion, tranexamic acid use was associated with decreased blood transfusion and was not associated with thromboembolic events. However, careful consideration is required before use in patients with pre‐existing renal disease. Further, our observed interaction between patients given tranexamic acid who subsequently require transfusion requires careful consideration with respect to enhanced prophylaxis against surgical site infection.

Understanding the dopant diffusion in a device is one of the major challenges in advance ULSI semiconductor technology of nowadays. Recently, applications of electron holography in transmission electron microscopy to map 2D dopant distribution in the phase image have shown considerable promise [1]. However, the preparation of samples for analysis is a crucial aspect of the application of electron holography to semiconductor materials.The non-interferometric method, involving the so-called Transport of Intensity Equation (TIE) [2], have potentially a practical method for quantifying 2D p-n junctions as used in electron holography. The phase retrieval procedure with TIE has been successfully applied in different fields [3][4][5]. Here, we propose that TIE can be solved with a two-step de-convolution process using the maximum entropy method (MEM) is a sensitive phase trivial method that potentially provides comparable results as those obtained using electron holography.The p-n junctions for this investigation were made on a p-type Si wafer by implanting arsenic ions at 2 KeV to a dose of 9x10 14 cm -2 , then annealing at 1075 °C. Thin cross section of the device suitable for TEM observation was prepared by regular procedure and experimental images were obtained using a JEOL 2010F FEGTEM at 200kV. Figure 1(a)-(e) shows a series of cross-sectional TEM images of an n-MOS (As doped) transistor. The images were separated by a step size of 1510.4 nm. The Figure 2 presents the structure of n-MOS which demonstrated in the paper. The compositions and expected doping regions also indicated in the schematic. Figure 3 (a)-(b) show the reconstructed phase image by TIE/MEM method. The main characteristics of the n-MOS device were reconstructed as shown in phase image. The source and drain areas of the device are clearly visible by the increase in contrast. Because of the phase shift of the electron wave is proportional to inner potential of the material which electron wave passes through. Therefore, the whiter contrast suggests that the potential is higher than the dark regions. It's reasonable that the potential in the doped n-type (As doped) region is higher than the p-type (B doped) silicon substrate.The maximum entropy de-convolution method (MEM) is employed to solve the transport of intensity equation (TIE) for phase retrieval problems. The results establish that TIE/MEM can become an efficient and potentially a practical method for quantifying 2D p-n junctions as used in electron holography.

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