ABSTRACT
Ionic polymer sensors (IPSs) have broad application prospects in health monitoring, environmental perception, and human-computer interaction. The performance of IPSs with chemically prepared electrodes is generally superior to that with physically prepared electrodes due to the area difference of the electric double layer (EDL), but the effects of the electrode characteristics prepared by chemical methods on the performance of IPSs have not been revealed. Therefore, in this paper, we studied the impact of the characteristics of chemically prepared electrodes on the performance of IPSs and realized the performance optimization of IPSs through electrode characteristic regulation. By controlling the matrix surface roughening, immersion reduction plating (IRP) cycles, and electroplating (EP) time, the sensing performances of IPS samples with different electrode interface roughnesses, electrode penetration depths, and surface resistances were investigated, respectively. The experimental results indicated that the response voltage of the IPS can be improved by increasing the electrode interface roughness and the electrode penetration depth and reducing the surface resistance. In addition, we have proven that the sensing performance of the IPS is determined by its intrinsic capacitance characteristics. Through coupling electrode characteristic regulations such as roughening and increasing IRP cycles and EP time, a high-performance IPS was obtained, and its response amplitude was improved by 237.8%. The obtained high-performance sensor has been applied in human motion detection, which has good potential to develop wearable devices with high stability for physiological activity monitoring.
ABSTRACT
In the past decade, the development of medical health and human-computer interfaces has put forward requirements for the non-contact application of flexible electronics. Among them, flexible humidity sensors play an important role in the field of non-contact sensing by virtue of their rapid response to humidity changes. In this paper, a flexible paper-based humidity sensor with high performance was fabricated by embedded Au@AgNWs electrodes on filter paper through spraying and electroplating (EP) methods. Benefitting from the moisture-sensitive properties of the paper and the tight integration of the electrodes into the filter paper, the sensor shows the humidity monitoring range of 33-100% RH, large response value of I/I0 = 1958, excellent linearity of R2 = 0.99662 and hysteresis performance under the low excitation voltage of only DC 1 V. In addition, the good biocompatibility of the paper-based humidity sensor endows it with multifunctional applications for breath detection, non-contact applications and food security monitoring. Easy access to raw materials and convenient preparation methods of this work provide new ideas for the development and commercialization of flexible humidity sensors.
ABSTRACT
Ionic polymer-metal composites (IPMCs) have attracted attention in recent years due to their integration of actuation and sensing functions. As one of the main sensing functions of IPMCs, humidity sensing has been of consistent interest in wearable health monitors and artificial skin. However, there are still some technical challenges in that classical IPMCs have poor humidity sensing performance due to their dense surface electrode, and IPMCs are damaged easily due to an electrode/membrane mismatch. In this work, through the spraying and electrodepositing process, we developed an efficient method to rapidly prepare a Au-shell-Ag-NW (silver nanowire)-based IPMC with high strength, low surface resistance and excellent humidity sensing performance. Meanwhile, we optimized the preparation method by clarifying the influence of solvent type and electrodepositing time on the performance of the Au-shell-Ag-NW-based IPMC, thus effectively improving the humidity sensing effect and strength of the IPMC. Compared with previous research, the humidity electrical response (~9.6 mV) of the Au-shell-Ag-NW-based IPMC is at least two orders of magnitude higher than that of the classical IPMC (~0.41 mV), which is mainly attributed to the sparse gap structure for promoting the exchange of water molecules in the environment and Nafion membrane, a low surface resistance (~3.4 Ohm/sq) for transmitting the signal, and a seamless connection between the electrode and Nafion membrane for fully collecting the ion charges in the Nafion membrane. Additionally, the Au-shell-Ag-NW-based IPMC could effectively monitor the human breathing process, and the humidity sensing performance did not change after being exposed to the air for 4 weeks, which further indicates that the Au-shell-Ag-NW-based IPMC has good application potential due to its efficient preparation technology, high stability and good reproducibility.
ABSTRACT
Splenic artery steal syndrome (SASS) has been considered a life-threatening complication to liver transplant recipients. Herein we timely diagnosed a case of SASS with deteriorating liver function. SASS was screened by routine Doppler ultrasonography (DUS) and multidetector computed tomography and was ultimately diagnosed by selective celiac trunk angiography. The patient was rescued by splenic artery embolization. In this case, routine DUS was useful to screen SASS. Signs of high-resistance hepatic artery waveform and low diastolic flow were highly suspected of SASS. This case also indicated that portal hyperperfusion was a cause of graft dysfunction in SASS. The study was in accordance with the Helsinki Congress and the Declaration of Istanbul, no prisoners were used, and participants were neither paid nor coerced in this study. Furthermore, we reviewed the recent literatures on the advances in the diagnosis and treatment of SASS. These studies suggest that splenic artery embolization may be a safe and effective technique to treat SASS. In addition, identification of recipients at high risk of SASS with preoperative computed tomography scans and DUS is recommended. Banding or ligation the splenic artery may be useful to prevent SASS and other potential complications after liver transplantation.
Subject(s)
Embolization, Therapeutic , Liver Transplantation , Vascular Diseases , Humans , Splenic Artery/diagnostic imaging , Liver Transplantation/adverse effects , Living Donors , Hepatic Artery/diagnostic imaging , Vascular Diseases/diagnosisABSTRACT
Ionic flexible sensors (IFS) usually consist of an ionomer matrix and two conductive electrodes, the failure of which mostly originates from interfacial debonding between matrix and electrode layers. To improve electrode's adhesion and impedance matching with matrix, polymer binder or plasmonic heating technology is used to enhance the adhesion of electrodes, but there are technical challenges such as high resistance and harsh conditions. Herein, inspired by biological hair, we proposed a reliable and facile method to form AgNWs@Au-embedded Nafion flexible electrodes (AN FEs) for IFS without rigorous temperature and harsh conditions. Through integrating the spraying and electrodepositing Au method, we achieved that the AgNWs are partly embedded in the matrix layer for forming the embedded layer, similar to the root of biological hair, which is used to fix the FEs and collect the ion charges. The other parts of AgNWs exposed on the surface form the conductive mesh layer for transmitting the signal, analogous to the tip of biological hair. Compared with other AgNWs FEs, AN FEs exhibit high adhesion (â¼358 kPa) and low sheet resistance (â¼ 3.7 Ω/â¡), and high stabilities after 100 washing cycles, 200 s H2O2 corrosion or 1500s HCl corrosion. A self-powered IFS prepared by AN FEs can achieve dual sensing of mechanical strain and ambient humidity and still has promising sensing performance after being exposed to air for 2 months, which further indicates potential applications of the prepared FEs in next-generation multifunctional flexible electronic devices.
Subject(s)
Nanowires , Electrodes , Fluorocarbon Polymers , Hydrogen Peroxide , Ions , Polymers , SilverABSTRACT
Background: To evaluate the feasibility and efficacy of sequential portal vein embolization (PVE) and radiofrequency ablation (RFA) (PVE+RFA) as a minimally invasive variant for associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) stage-1 in treatment of cirrhosis-related hepatocellular carcinoma (HCC). Methods: For HCC patients with insufficient FLR, right-sided PVE was first performed, followed by percutaneous RFA to the tumor as a means to trigger FLR growth. When the FLR reached a safe level (at least 40%) and the blood biochemistry tests were in good condition, the hepatectomy was performed. FLR dynamic changes and serum biochemical tests were evaluated. Postoperative complications, mortality, intraoperative data and long-term oncological outcome were also recorded. Results: Seven patients underwent PVE+RFA for FLR growth between March 2016 and December 2019. The median baseline of FLR was 353 ml (28%), which increased to 539 (44%) ml after 8 (7-18) days of this strategy (p < 0.05). The increase of FLR ranged from 40% to 140% (median 47%). Five patients completed hepatectomy. The median interval between PVE+RFA and hepatectomy was 19 (15-27) days. No major morbidity ≥ III of Clavien-Dindo classification or in-hospital mortality occurred. One patient who did not proceed to surgery died within 90 days after discharge. After a median follow-up of 18 (range 3-50) months, five patients were alive. Conclusion: Sequential PVE+RFA is a feasible and effective strategy for FLR growth prior to extended hepatectomy and may provide a minimally invasive alternative for ALPPS stage-1 for treatment of patients with cirrhosis-related HCC.
ABSTRACT
BACKGROUND: The future liver remnant (FLR) faces a risk of poor growth in patients with cirrhosis-related hepatocellular carcinoma (HCC) after stage-1 radiofrequency-assisted ALPPS (RALPPS). The present study presents a strategy to trigger further FLR growth using supplementary radiofrequency ablation (RFA) and percutaneous ethanol injection (PEI). METHODS: At RALPPS stage-1 the portal vein branch was ligated, followed by intraoperative RFA creating a coagulated avascular area between the FLR and the deportalized lobes. During the interstage period, patients not achieving sufficient liver size (≥ 40%) within 2-3 weeks underwent additional percutaneous RFA/PEI of the deportalized lobes (rescue RFA/PEI) in an attempt to further stimulate FLR growth. RESULTS: Seven patients underwent rescue RFA/PEI after RALPPS stage-1. In total five RFAs and eight PEIs were applied in these patients. The kinetic growth rate (KGR) was highest the first week after RALPPS stage-1 (10%, range - 1% to 15%), and then dropped to 1.5% (0-9%) in the second week (p < 0.05). With rescue RFA/PEI applied, KGR increased significantly to 4% (2-5%) compared with that before the rescue procedures (p < 0.05). Five patients proceeded to RALPPS stage-2. Two patients failed: In one patient the FLR remained at a constant level even after four rescue PEIs. The other patient developed metastasis. Except one patient died after RALPPS stage-2, no severe complications (Clavien-Dindo ≥ IIIb) occurred among remaining six patients. CONCLUSIONS: Rescue RFA/PEI may provide an alternative to trigger further growth of the FLR in patients with cirrhosis-related HCC showing insufficient FLR after RALPPS stage-1. Trial registration Retrospectively registered.
Subject(s)
Carcinoma, Hepatocellular , Catheter Ablation , Liver Neoplasms , Radiofrequency Ablation , Carcinoma, Hepatocellular/complications , Carcinoma, Hepatocellular/surgery , Ethanol , Hepatectomy , Humans , Ligation , Liver Cirrhosis/complications , Liver Neoplasms/complications , Liver Neoplasms/surgery , Portal Vein/surgeryABSTRACT
OBJECTIVE: To establish a three-dimensional image of the penile suspensory ligament, and explore a stereoscopic and multi angle observation method of patient' s penile suspensory ligament. METHODS: This study selected the patients with small penis from our hospital as subjects. The participants were conducted on magnetic resonance imaging (MRI) examination before operation. Afterwards, the results of MRI were imported into 3D reconstruction software (MIMICS 10.0), and the suspensory ligament of penis, the pubic symphysis and other related structures were reconstructed for observation. RESULTS: The pubic symphysis, penis and corpus spongiosum can be quite clearly displayed in the thin-section MRI images. In addition, penile suspensory with patchy distribution can be visible between lower part of ligament pubic symphysis and corpus cavernosum. Finally, we can reconstruct the three-dimensional structures through MIMICS 10.0, and then precisely describe the suspensory ligament's start-stop point, the angle with cavernous body of penis and the attached area in the corpus cavernosum penis. CONCLUSION: Based on the MRI 3D reconstruction of deep penile suspensory ligament and adjacent structures, we can carry out dynamic, three-dimensional multi angle observation of patients deep penile suspensory ligament, and can use the reconstructed image to provide certain theory basis for the judgement of the corpus cavernosum penis extension length and penile suspensory ligament depth before penis extension operation.