Ti3C2Tx MXene Paper-Based Wearable and Degradable Pressure Sensor for Human Motion Detection and Encrypted Information Transmission.

Paper-based flexible sensors are of great significance for promoting the development of green wearable electronic devices due to their good degradability and low cost. In this work, a paper-based wearable pressure sensor with a sandwich structure is proposed, which is assembled from a sensing layer printed with Ti3C2Tx MXene ink, an interdigitated electrode printed in the same simple and economical way, and two polyethylene terephthalate films. The demonstrated paper-based pressure sensor exhibits excellent sensitivity in a wide pressure sensing range, as well as cyclic stability at a certain pressure. The sensor can be attached to the human body's surface to monitor various pressure-related physical activities. Using a self-designed mobile phone APP, the special pressure signals collected from the sensor can be transmitted and translated, and an intelligent and encrypted information transmission system can be established. Since only ordinary printing paper and Ti3C2Tx MXene ink are used, the pressure sensor is easy to prepare, economical, and environmentally friendly, and it can be degraded by stirring in water without generating electronic waste. It can be foreseen that the proposed sensor shows bright application potential in the sustainable development of healthcare and human-computer interaction fields.

Dual-Layer All-Textile Flexible Pressure Sensor Coupled by Silver Nanowires with Ti3C2-Mxene for Monitoring Athletic Motion during Sports and Transmitting Information.

At present, wearable flexible pressure sensors have broad application prospects in fields such as motion monitoring and information transmission. However, it is still a challenge to design flexible pressure sensors with high sensitivity over a large sensing range and simple fabrication. Here, we use a simple "dipping-drying" method to fabricate a fabric-based flexible pressure sensor by coupling silver nanowires (AgNWs) with Ti3C2-MXene. The interaction between MXene and AgNWs helps realize a dual-layer sensing network, achieving good synergistic effects between pressure sensitivity and sensing range. The effects of the material combination and dip-coating sequence on the sensor's performance are systematically studied. The results show that the sensor was impregnated sequentially with AgNWs solution, and the MXene solution has the highest sensitivity (0.168 kPa-1) over a wide range (190 kPa). Meanwhile, it has the advantages of low response hysteresis and detection limit, as well as good linearity and durability. We further demonstrate the application of this sensor in human physiological signal monitoring and motion pattern recognition. It can also encrypt and transmit information according to different pressing states. In addition, the proposed pressure sensor array exhibits spatial resolution detection capabilities, laying the foundation for applications in the fields of motion monitoring and human-computer interaction.

Highly sensitive surface plasmon resonance temperature sensor based on a hollow core fiber multilayer structure.

A surface plasmon resonance (SPR) temperature sensor based on a hollow core fiber (HCF) is designed in this paper. The sensor is composed of a multi-mode fiber (MMF)-HCF-MMF structure, and the self-made HCF is deposited successively with a thin layer of Au film (50 nm in thickness), gold nanoparticles (10 nm in diameter) and polydimethylsiloxane (PDMS). A series of theoretical and experimental investiagtions are conducted, and the results are as follows: the proposed sensing structure only with Au film can effectively excite the SPR effect, with a sensitivity of (2200 ± 100) nm / RIU in the refractive index (RI) range of 1.3334-1.3811; after adding AuNPS, the sensitivity of the sensor is effectively improved, the sensitivity can be increased to (3100 ± 100) nm / RIU, and after the PDMS coating, temperature sensing can be realized due to its unique temperature-sensitive characteristics, a linear sensitivity of (-2.1 ± 0.1) nm / °C is realized in the temperature range of 25 °C to 100 °C. The sensor has the advantages of simple structure, wide application, large measurement range, high sensitivity, good stability and repeatability. Meanwhile, the internal air hole of HCF leaves a preparation channel for dual-parameter measurement. It has broad application prospect in medical treatment, environmental monitoring and manufacturing industry.

Flexible Pressure Sensor Decorated with MXene and Reduced Graphene Oxide Composites for Motion Detection, Information Transmission, and Pressure Sensing Performance.

Although fiber-based flexible piezoresistive pressure sensors have received extensive attention because of their simple fabrication and easy integration, the common practice of using a single material as the sensing layer often leads to unsatisfactory sensitivity and a limited sensing range. Herein, we exploit the combination of reduced graphene oxide (rGO) and two-dimensional transition-metal carbides and nitrides (MXene), use a polyester filament (PET) as the fiber matrix, and fabricate an MX/rGO PET-based flexible pressure sensor using the "dipping-drying" method. A systematic study is conducted concerning the effect of the dip-coating sequence and material combination on the sensor's resistance and sensitivity, which reveals that MX/rGO PET has the smallest resistance and the highest sensitivity (1.24 kPa-1). A series of tests are conducted to evaluate the pressure sensing characteristics of the MX/rGO PET-based pressure sensor, confirming its good linearity, fast response speed, low detection limit, and stable performance. In addition, the sensor has been successfully used to monitor various human joint activities and physiological signals such as breathing, demonstrating great application potential in the field of personal health care. To further enhance the practical utility, an APP has been designed to analyze and display the collected signals, and the constructed sensor network also provides an ingenious method for information encryption and transmission via pressure sensing. In all, the MX/rGO PET-based pressure sensor proposed in this work is expected to provide a competitive scheme for wearable flexible electronic devices in information transmission and human-computer interaction in the future.

The effect of preoperative oral carbohydrate on the time to colostrum and amount of vaginal bleeding after elective cesarean section.

OBJECTIVE: To investigate the effect of oral carbohydrate at 2 h before elective cesarean section on postoperative recovery indicators such as the time to colostrum and vaginal bleeding. METHODS: Women undergoing elective cesarean section under spinal-epidural anesthesia, aged 20-40 years, with a body mass index (BMI) of 19-30 kg/m2 and an American Society of Anesthesiology (ASA) score of II were randomized to the oral carbohydrate group (the OC group), the oral placebo group (the OP group), or the control group (the C group). The OC group underwent oral carbohydrate preloading (300 mL/bottle), the OP group orally consumed 300 mL of distilled water, and the C group was forbidden from drinking or eating on the day of the operation. The time to colostrum, vaginal bleeding, time to exhaust, and complications were recorded. RESULTS: A total of 38 participants in the OC group, 37 in the OP group, and 37 in the C group completed the study. Compared with the OP group and the C group, the OC group produced colostrum significantly earlier, had a lower amount of 24-h vaginal bleeding, and had a higher 24-h consumption of analgesics. Compared with OP and OC groups, the C group took longer to exhaust. No significant intergroup difference was observed for any other indicator. CONCLUSION: Oral carbohydrates loading 2 h before elective cesarean section significantly reduces the time to produce colostrum and the amount of vaginal bleeding, which contributes to postoperative recovery.

Preheating of streamlined liner of pharyngeal airway (SLIPA) reduced the related complications: a randomized control study.

This study was designed to verify whether preheating could decrease the complications that may be associated with the use of streamlined liner of pharyngeal airway (SLIPA). We evaluated the incidence of sore throat, maximum sealing pressure, hoarseness and blood stains after preheating of SLIPA. Eighty patients scheduled for hysteroscopic surgery to whom the SLIPA was considered suitable were randomly allocated to preheating group or control group. The SLIPA in preheating group was placed in the incubator at 42 °C. The control group temperature was 24 °C. The mean maximum sealing pressure and duration of insertion were compared. Patients were interviewed at recovery room about sore throat and other complications. There were statistical differences in incidence of sore throat, severity of sore throat and blood stains between groups. However there was no statistical difference in the maximum sealing pressure. Our results suggest preheating of the SLIPA decreased the complications related with the insertion of SLIPA. Clinical Trials.gov Identifier NCT02539485.

Comparison of intubation conditions and apnea time after anesthesia induction with propofol/remifentanil combined with or without small dose of succinylcholine.

BACKGROUND: Many scholars are seeking for an anesthesia induction regimen to meet the requirements of both intubation and instant recovery of spontaneous breathing in case of "cannot intubate, cannot ventilate" to prevent severe consequences. This study aims to investigate whether the combination use of remifentanil 1 µg/kg and small dose of succinylcholine (0.6 mg/kg) is superior to single use of remifentanil 1.5 µg/kg in improving intubation conditions and shortening apnea time under anesthesia induction with propofol. METHODS: Sixty patients undergoing selective gynecological laparoscopic operation under general anesthesia were included into the prospective randomized controlled trial. After sufficient preoxygenation, all patients received propofol for anesthesia induction, and patients in group S were managed with remifentanil 1 µg/kg and succinylcholine 0.6 mg/kg, while those in group C were treated with remifentanil 1.5 µg/kg and normal saline. Tracheal intubation was conducted 60 s later, and mechanical ventilation was not performed until spontaneous breathing emerged. The intubation conditions were evaluated, and the apnea time between induction and breathing recovery was recorded. RESULTS: One patient (3.70%) in group S was graded as poor in intubation conditions, which was significantly fewer than 12 patients in group C (P<0.001). There was no significant difference in apnea time between two groups (245.50 ± 53.71 vs 251.12 ± 70.71, P=0.750). No patient experienced hypoxic event with SpO2<90% before recovery of spontaneous breathing. CONCLUSIONS: Compared with single use of remifentanil 1.5 µg/kg, the combination use of remifentanil 1 µg/kg and succinylcholine 0.6 mg/kg may offer better intubation conditions and may not prolong apnea time under anesthesia induction with propofol 2 mg/kg.

2,4-Dichloro-6-nitro-benzoic acid.

The title compound, C(7)H(3)Cl(2)NO(4), was prepared by the reaction of 2,4-dichloro-6-nitro-toluene with 20% HNO(3) solution at 430 K. The carboxyl and nitro groups are twisted by 82.82 (12) and 11.9 (2)°, respectively, with respect to the benzene ring. The crystal structure is stabilized by O-H⋯O hydrogen bonding between carboxyl groups and weak C-H⋯O hydrogen bonding between the nitro group and the benzene ring of an adjacent mol-ecule.