No abstract

The pH-sensitive organic electrochemical transistors are expected to be widely used in wearable electronic devices for in-situ physiological monitoring. However, the unclear current-voltage relationship seriously hinders its development in design, optimization, and application. In the current work, the current-voltage characteristic of pH-sensitive organic electrochemical transistors is constructed by combining the electrochemical equilibrium equation with the series model of differential capacitances formed at gate electrode/electrolyte and semiconductor channel/electrolyte interface. Moreover, a pH-sensitive organic electrochemical transistor is constructed by using poly (3,4- ethylenedioxythiophene)/polystyrene sulfonate as the semiconductor layer material and modifying the gate electrode with pH-sensitive polymer (poly (3,4-ethylenedioxythiophene)/bromothymol blue). The effectiveness of the theoretical model is verified by investigating the output, transfer, and pH response characteristics of the pH-sensitive organic electrochemical transistor. The experimental results show that the detection sensitivity could be up to 0.22 mA·pH·unit^-1, and the pH response is gate-bias dependent. Then, a polynomial indicating the gate bias effect is introduced to modify the current-voltage characteristic equation. The goodness of fitting the theoretical model to the experimental results of transfer curves is found to be 0.998. The comparison of experimental and theoretical results of the gate bias corresponding to the peak transconductance and pH sensitivity responding to gate bias could also verify the effectiveness of the modified theoretical model. The results could provide theoretical support for the design and manufacture of pH-sensitive organic electrochemical transistors bases flexible biosensors.

The development of donor-speci c antibodies (DSAs) against human leukocyte antigens (HLA) is a major problem during haplo-identical hematopoietic stem cell transplantation (haplo-HSCT). There is currently no recommended treatment option to remove DSAs. Thus, we conducted a prospective, single-arm study where we combined low-dose splenic irradiation with plasmapheresis and rituximab as a new treatment protocol to reduce DSAs before haplo-HSCT. Nineteen patients were enrolled in this prospective study and matched controls treated with the same protocol, but without splenic irradiation, were simultaneously collected from DSA patients. The aim of this study is to explore the safety and e cacy of our outlined treatment protocol made up of splenic irradiation, plasmapheresis, and rituximab. We found that DSA levels decreased signi cantly after transplantation in both groups, however they decreased more greatly in patients treated additionally with splenic irradiation than those in control group. De novo DSAs were not detected after transplantation in the splenic irradiation group but detected in 5 patients from the control group. At follow-up, we found that patients in splenic irradiation group achieved superior overall survival (OS) and progress free survival (PFS) compared to those in control group. We concluded that adding low-dose splenic irradiation to routine protocol is feasible.