An Enhanced Soft Vibrotactile Actuator Based on ePVC Gel with Silicon Dioxide Nanoparticles.

In this paper, we propose a soft vibrotactile actuator made by mixing silicon dioxide nanoparticles and plasticized PVC gel. The effect of the silicon dioxide nanoparticles in the plasticized PVC gel for the haptic performance is investigated in terms of electric, dielectric, and mechanical properties. Furthermore, eight soft vibrotactile actuators are prepared as a function of the content. Experiments are conducted to examine the haptic performance of the prepared eight soft vibrotactile actuators and to find the best weight ratio of the plasticized PVC gel to the nanoparticles. The experiments should show that the plasticized PVC gel with silicon dioxide nanoparticles improves the haptic performance of the plasticized PVC gel-based vibrotactile actuator, and the proposed vibrotactile actuator can create a variety of haptic sensations in a wide frequency range.

Crack-Enhanced Microfluidic Stretchable E-Skin Sensor.

We reported the development of a transparent stretchable crack-enhanced microfluidic capacitive sensor array for use in E-skin applications. The microfluidic sensor was fabricated through a simple lamination process involving two silver nanowire (AgNW)-embedded rubbery microfluidic channels arranged in a crisscross fashion. The sensing performance was optimized by testing a variety of sensing liquids injected into the channels. External mechanical stimuli applied to the sensor induced the liquid to penetrate the deformed microcracks on the rubber channel surface. The increased interfacial contact area between the liquid and the nanowire electrodes increased the capacitance of the sensor. The device sensitivity was strongly related to both the initial fluid interface between the liquid and crack wall and the change in the contact length of the liquid and crack wall, which were simulated using the finite element method. The microfluidic sensor was shown to detect a wide range of pressures, 0.1-140 kPa. Ordinary human motions, including substantial as well as slight muscle movements, could be successively detected, and 2D color mappings of simultaneous external load sensing were collected. Our simple method of fabricating the microfluidic channels and the application of these channels to stretchable e-skin sensors offers an excellent sensing platform that is highly compatible with emerging medical and electronic applications.

Clinical utility of des-γ-carboxyprothrombin kinetics as a complement to radiologic response in patients with hepatocellular carcinoma undergoing transarterial chemoembolization.

PURPOSE: Serial α-fetoprotein (AFP) measurements are useful for assessing tumor responses to numerous therapies for hepatocellular carcinoma (HCC). This study tested the predictive value of changes in des-γ-carboxy prothrombin (DCP), in parallel with AFP, as an indicator of HCC response after transarterial chemoembolization. MATERIALS AND METHODS: The study group consisted of 327 patients with HCC initially seropositive for DCP (≥ 40 mAU/mL) and/or AFP (≥ 100 ng/mL) who underwent repeated chemoembolization as first-line therapy. Radiologic responses were measured based on modified Response Evaluation Criteria In Solid Tumors guidelines. Serologic response was defined as a decrease of at least 50% in DCP or AFP level from baseline. Radiologic-serologic correlation and disease progression and survival according to serologic responses were analyzed. RESULTS: Before treatment, 129 patients (39%) had high DCP alone, 66 (20%) had high AFP alone, and 58 (18%) had high levels of both. Radiologic and serologic responses were achieved in 88.2% and 91.4% of patients with high DCP levels and in 89.5% and 91.1% of those with high AFP levels, respectively. Serologic response based on AFP or DCP was significantly correlated with radiologic response, and this was confirmed by landmark analysis (P < .001). DCP and AFP responders had better times to progression and overall survival than nonresponders (P < .001). Cox models revealed that both serologic responses were independent estimates of survival (hazard ratios, 0.11 for DCP and 0.14 for AFP; P < .001). CONCLUSIONS: After transarterial chemoembolization for HCC, DCP response may be a useful surrogate endpoint of immediate and prolonged clinical outcomes, along with AFP response.

Predictable factors of histologic discrepancy of gastric cancer between the endoscopic forceps biopsy and endoscopic treatment specimen.

BACKGROUND/AIMS: Recently, variable gastrointestinal track tumors including early stage malignancies are treated by endoscopic procedure. However, the discrepancy of histologic diagnosis may sometimes exist between the pretreatment forceps biopsy results and those of post treatment specimen. So the prediction of malignant lesion is important in the aspect of treatment selection. In this study, we investigated the predictable factors of the histologic discrepancy through the clinical, endoscopic features of the lesion diagnosed as adenocarcinoma in the post-endoscopic treatment specimen after the adenoma was diagnosed by the endoscopic forceps biopsy. METHODS: From March 2005 to April 2009, 129 gastric tumor lesions (129 patients) which were not diagnosed as malignancy and treated with endoscopic procedure were enrolled retrospectively. We compared the pretreatment endoscopic forceps biopsy results and post-treatment specimen biopsy results, then, analyzed the tumor characteristics. RESULTS: Twenty-one cases (16.3%) were diagnosed as malignancy after endoscopic treatment. Especially, discrepancy occurred more frequently in depressed lesions than in flat or elevated lesions (41.7% vs. 13.7%, p=0.012), and in lesions diagnosed as high grade adenomas than low or moderate grade adenomas (33.3% vs. 11.1%. p=0.004). CONCLUSIONS: In cases of depressed type lesions in the pretreatment endoscopy or those diagnosed as high grade adenoma in the pretreatment forceps biopsy, we should consider combined malignant lesion. Therefore, treatment modalities ensuring accurate diagnosis and potentially curative resection, should be carefully selected and performed in cases which have these features.

Non-ischemic cardiomyopathy attributed to adult myotonic dystrophy.

In patients with myotonic dystrophy (MD), impairment of the conduction system is a common and progressive finding. However, only a few cases of MD with cardiomyopathy have been reported. Herein we report a case of MD with progressive non-ischemic cardiomyopathy and severe electrocardiographic abnormalities.