Multifunctional hydrogels with properties including transparency, flexibility, self-healing, and high electrical conductivity have attracted great attention for their potential application to soft ...electronic devices. The presence of an ionic species can make hydrogels conductive in nature. However, the conductivity of hydrogels is often influenced by temperature, due to the change of the internal nano/microscopic structure when temperature reaches the sol–gel phase transition temperature. In this regard, by introducing a novel surface-capacitive sensor device based on polymers with lower critical solution temperature (LCST) behavior, near-perfect stimulus discriminability of touch and temperature may be realized. Here, we demonstrate a multimodal sensor that can monitor the location of touch points and temperature simultaneously, using poly(N-isopropylacrylamide) (PNIPAAm) in hybrid poly(vinyl alcohol) (PVA) and sodium tetraborate decahydrate cross-linked hydrogels doped with poly(sodium acrylate) (SA) w/w/w = 5:2.7:1–3. This multimodal sensor exhibits a response time of 0.3 s and a temperature coefficient of resistance of −0.58% K–1 from 20 to 40 °C. In addition, the LCST behavior of PNIPAAm-incorporated PVA/SA gels is investigated. Incorporation of LCST polymers into high-end hydrogel systems may contribute to the development of temperature-dependent soft electronics that can be applied in smart windows.
Health self-monitoring systems that can automatically recognize health information and respond in real-time through wearable sensors and artificial intelligence are one of the major development ...issues of the fourth industrial revolution. To realize such health self-monitoring systems, it is essential to develop wearable sensors that can detect biophysical signals from the human body. Organic sensors based on organic semiconductors or conductive materials are receiving a lot of attention as wearable sensors for health self-monitoring systems due to the advantages of their flexibility, stretchability, low cost, and light weight. Here, we review recent developments in organic sensors for health monitoring and methods for improving their performance.
This review describes the development status of organic sensors for health-monitoring systems and the strategies to enhance their performance.
Novel ZnO/TiO(2) composite nanofibers were fabricated by an electrospinning method and showed excellent antimicrobial activity against gram-negative Escherichia coli and gram-positive Staphylococcus ...aureus under UV irradiation and in the absence of light.
Background
Leptin and its receptor play a role in several disease processes such as pancreatitis and heart disease. However, their association with gallbladder mucocele (GBM) in dogs has not been ...reported.
Hypothesis/Objectives
To evaluate differences in the expression of leptin and leptin receptor between dogs with and without GBM.
Animals
Twenty‐five healthy dogs, including 9 laboratory beagle dogs, and 22 client‐owned dogs with GBM.
Methods
Serum leptin concentration was determined in blood samples of all dogs by ELISA. Canine gallbladder samples were collected from 9 dogs with GBM that underwent surgery for therapeutic purposes and from 9 healthy laboratory beagle dogs as a normal control group. Samples were analyzed for leptin and leptin receptor mRNA by real‐time polymerase chain reaction.
Results
Serum leptin concentration was significantly higher in dogs with GBM than in healthy dogs (medians of 7.03 and 2.18 ng/mL, respectively; P < .001). Patients with GBM that had undergone surgery had significantly higher serum leptin concentrations than those that had not (medians of 12.2 and 4.09 ng/mL, respectively; P = .001). However, no difference in serum leptin concentration was found between dogs with GBM with or without endocrinopathies. The mRNA expression levels of leptin and its receptor were significantly increased in the gallbladder tissues of dogs with GBM.
Conclusions and Clinical Importance
Dysregulation of leptin might be involved in the pathophysiology of GBM, and leptin concentrations might be associated with GBM severity.
Soft electronic materials are key elements for realizing wearable, attachable, and stick-on electronics. The development of deformable and stretchable electrodes is a key research area as they are ...one of the most important components for soft electronic devices. Recently, significant progress in the development of deformable and stretchable electrodes has been achieved with organic materials offering electrical tunability, simple mechanical implementation, and desirable chemical and optical properties. In this review, we present recent progress in the design of stretchable electronics based on deformable conducting materials, including their fabrication and conductivity properties and the methods that are employed to enhance performance. In addition, we review the development status of organic- and carbon- based conductive materials and their hybrid composites being used for electronic applications, including carbon nanotubes, graphene, metal composites, conductive polymers, hybrid composites, and ion gel composites. The structural aspects, such as wavy or mesh configurations, of stretchable electrodes and other high-performance conducting materials are investigated intensively. Many stretchable electrodes show great potential for use in future electronics such as electronic skin (e-skin) and stretchable displays, which require reversible deformation and a high degree of operational stability.
Objectives
To measure serum leptin concentration in dogs with pituitary‐dependent hyperadrenocorticism and varying degrees of cholestatic disease and determine whether serum levels differed between ...dogs with pituitary‐dependent hyperadrenocorticism and those with gall bladder mucocoele.
Materials and Methods
Client‐owned healthy dogs (n=20), dogs diagnosed with gall bladder mucocoele (n=20) and dogs diagnosed with pituitary‐dependent hyperadrenocorticism (n=60) were enrolled. Only dogs of normal body condition score were included. Dogs with pituitary‐dependent hyperadrenocorticism were divided into three groups according to the severity of cholestatic disease: normal gall bladder (n=20), cholestasis (n=20) and gall bladder mucocoele (n=20). Serum leptin levels were measured using sandwich enzyme‐linked immunosorbent assay.
Results
Serum concentrations of leptin were similar between dogs with gall bladder mucocoele and those with pituitary‐dependent hyperadrenocorticism accompanied by gall bladder mucocoele; these concentrations were significantly higher than those in healthy control dogs. In dogs with pituitary‐dependent hyperadrenocorticism, circulating leptin concentration significantly increased with the severity of cholestasis: higher in the cholestasis group than the normal gall bladder group and higher in the gall bladder mucocoele group than the cholestasis group.
Clinical Significance
Elevated circulating leptin concentration was associated with canine pituitary‐dependent hyperadrenocorticism and gall bladder mucocoele. Homeostatic imbalance of leptin concentration might be associated with severity of cholestatic disease in pituitary‐dependent hyperadrenocorticism.
Poly(3,4-ethylenedioxythiophene) nanotubes (PEDOT NTs) flexible membrane was successfully fabricated by vapor deposition polymerization (VDP) mediated electrospinning for ammonia gas detection. PVA ...nanofibers (NFs) were electrospun as a core part and polyvinyl alcohol (PVA)/PEDOT coaxial nanocables (NCs) were prepared by VDP method via EDOT monomer adsorption onto the electrospun PVA NFs as templates. To obtain the PEDOT NTs membrane, the PVA NFs were removed from PVA/PEDOT coaxial NCs with distilled water. PVA/PEDOT coaxial NCs and PEDOT NTs had the conductivities of 71 and 61
S
cm
−1 and were applied as a transducer for ammonia gas detection in the range of 1–100 parts per million (ppm) of NH
3 gas. They exhibited the minimum detectable level of
ca. 5 parts per million (ppm) and fast response time (less than 1
s) towards ammonia gas. In a recovery time, the PEDOT NTs membrane sensor was
ca. 30
s and shorter compared to that of the membrane sensor based on the PVA/PEDOT NCs (
ca. 50
s). In addition, sensor performance of PEDOT NTs membrane was also undertaken as a function of membrane thickness. Thick membrane sensor (30
μm) had the enhanced sensitivity and the sensitivity on the membrane thickness was in the order of 30
μm
>
20
μm
>
10
μm at 60
ppm of NH
3 gas.
Soft electronic devices are key components of flexible or wearable smart electronics. Chemical sensors based on organic field-effect transistors (OFETs) show great promise because of their high ...sensitivity, low cost, fast response, flexible applications, and signal amplification via gate voltage tuning. In addition, the sensor response can be made highly selective by incorporating specific functional groups or recognition elements. The response magnitude of an OFET sensor depends strongly on the surface area of the active layer that interacts with the analyte. In this study, two strategies including nanostructuring and surface functionalization have been explored to enhance the performance and sensitivity of OFET sensors. We describe the fabrication of highly flexible, electrospun poly(3,3-didodecylquaterthiophene)/calix8arene (PQT-12)/C8A sensors employing semiconducting polymer nanofibers (NFs) as the active layer. The resulting bendable and flexible PQT-12/C8A OFET sensors show high sensitivity to ethanol (192%) and toluene (229%) and moderate sensitivity to n -hexane (121%) with a minimum detectable level of 10 ppm. In addition, the PQT-12/C8A NF sensors are electrically stable under typical operating conditions with a bending radius down to 0.5 mm. This work demonstrates a viable approach for the fabrication of flexible OFETs for use as wearable sensors and health-monitoring devices.
The recurrence rate of choledocholithiasis in the general population has been reported to exceed 10%. The incidence of cholelithiasis was reported to be higher in patients following gastrectomy than ...that in the general population. However, there is no study for recurrent choledocholithiasis incidence in patients following gastrectomy. This study aimed to evaluate the recurrence rate of choledocholithiasis and identify risk factors for recurrent choledocholithiasis in patients following gastrectomy. A retrospective analysis was performed on patients with gastrectomy history who underwent choledocholithiasis removal in Kyungpook National University Hospital between January 2011 and December 2019. Choledocholithiases were treated by endoscopic retrograde cholangiopancreatography (ERCP) (n = 41) or percutaneous transhepatic biliary drainage (PTBD) (n = 90). The gastrectomy type was classified as subtotal gastrectomy with Billroth I (18.3%), Billroth II (45.0%), and total gastrectomy with Roux-en-Y (36.6%). During a median follow-up period of 31.5 (range, 6–105) months, choledocholithiasis recurrence was noted in 19 of 131 patients (14.5%). In subgroup analysis, the ERCP group (24.4%) had higher choledocholithiasis recurrence than the PTBD group (10.0%). Stone removal modality (ERCP), no use of balloon sphincteroplasty, and the presence of periampullary diverticulum were significant risk factors for recurrent choledocholithiasis. In multivariate analysis, ERCP (hazard ratio (HR), 3.597; 95% confidence interval (CI): 1.264–10.204) CBD stricture (HR, 3.823; 95% CI: 1.118–13.080) and no use of balloon sphincteroplasty (HR, 4.830; 95% CI: 1.669–13.889) were risk factors for recurrent choledocholithiasis following stone removal. The incidence of CBD stones in patients who underwent gastrectomy is similar to that of the general population. ERCP, CBD stricture, and no use of balloon sphincteroplasty are potential risk factors for recurrent CBD stones following gastrectomy. When we consider PTBD disadvantages, the ERCP procedure with active use of balloon sphincteroplasty is recommended to decrease recurrent CBD stones.
Polymer-based pressure sensors play a key role in realizing lightweight and inexpensive wearable devices for healthcare and environmental monitoring systems. Here, conductive core/shell polymer ...nanofibers composed of poly(vinylidene fluoride-co-hexafluoropropene) (PVDF-HFP)/poly(3,4-ethylenedioxythiophene) (PEDOT) are fabricated using three-dimensional (3D) electrospinning and vapor deposition polymerization methods, and the resulting sponge-like 3D membranes are used to create piezoresistive-type pressure sensors. Interestingly, the PEDOT shell consists of well-dispersed spherical bumps, leading to the formation of a hierarchical conductive surface that enhances the sensitivity to external pressure. The sponge-like 3D mats exhibit a much higher pressure sensitivity than the conventional electrospun 2D mats due to their enhanced porosity and pressure-tunable contact area. Furthermore, large-area, wireless, 16 × 10 multiarray pressure sensors for the spatiotemporal mapping of multiple pressure points and wearable bands for monitoring blood pressure have been fabricated from these 3D mats. To the best of our knowledge, this is the first report of the fabrication of electrospun 3D membranes with nanoscopically engineered fibers that can detect changes in external pressure with high sensitivity. The developed method opens a new route to the mass production of polymer-based pressure sensors with high mechanical durability, which creates additional possibilities for the development of human–machine interfaces.
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