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1.
Micromachines (Basel) ; 14(9)2023 Sep 17.
Article in English | MEDLINE | ID: mdl-37763945

ABSTRACT

Conversion of ambient energy to usable electrical energy is attracting attention from researchers since providing a maintenance-free power source for the sensors is critical in any IoT (Internet of Things)-based system and in SHM (structural health monitoring). Continuous health monitoring of structures is advantageous since the damage can be identified at inception and the necessary action taken. Sensor technology has advanced significantly, and MEMS (microelectromechanical systems)-based low-power sensors are available for incorporating into large structures. Relevant signal conditioning and transmission modules have also evolved, making them power-efficient and miniaturized. Various micro wireless sensor nodes (WSN) have also been developed in recent years that require very little power. This paper describes the applications of a novel tunable piezoelectric vibration energy harvester (PVEH) for providing autonomous power to low-power MEMS sensors for use in IoT and remote SHM. The novel device uses piezoelectric material and an ionic polymer-metal composite (IPMC) and enables electrical tuning of the resonant frequency using a small portion of the power generated.

2.
Polymers (Basel) ; 15(3)2023 Jan 31.
Article in English | MEDLINE | ID: mdl-36772033

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.

3.
Nanomaterials (Basel) ; 13(3)2023 Jan 24.
Article in English | MEDLINE | ID: mdl-36770434

ABSTRACT

The present study aims to use enhanced ionic polymer-metal composites (IPMC) as an artificial muscle (a soft-active actuator) to restore eyelid movement of patients with ptosis. The previous eyelid movement mechanisms contained drawbacks, specifically in the lower eyelid. We used finite element analysis (FEA) to find the optimal mechanism among two different models (A and B). In addition to common electrodes of IPMC (gold and platinum), the bovine serum albumin (BSA) and microcrystalline cellulose (MCC) polymers, with optimal weight percentages of carbon nanotube (CNT) nanofiller, were also utilized as non-metallic electrodes to improve the efficiency of the IPMC actuator. In both models, IPMC with nanocomposite electrodes had higher efficiency as compared to the metallic electrodes. In model A, which moved eyelids indirectly, IPMC with MCC-CNT electrode generated a higher force (25.4%) and less stress (5.9 times) as compared to IPMC with BSA-CNT electrode. However, the use of model A (even with IPMCs) with nanocomposite electrodes can have limitations such as possible malposition issues in the eyelids (especially lower). IPMC with MCC-CNT nanocomposite electrode under model B, which moved eyelids directly, was the most efficient option to restore eyelid movement. It led to higher displacements and lower mechanical stress damage as compared to the BSA-CNT. This finding may provide surgeons with valuable data to open a window in the treatment of patients with ptosis.

4.
Polymers (Basel) ; 14(17)2022 Aug 26.
Article in English | MEDLINE | ID: mdl-36080568

ABSTRACT

As emerging smart polymers, ionic polymer-metal composites (IPMCs) are playing more and more important roles as promising candidates for next-generation actuators in terms of academic interest and industrial applications. It is reported that the actuation behaviors of IPMCs are dependent on the electrochemical kinetic process between metal/polymer interfaces to a great extent. Thus, the fabrication of tailored metal/polymer interface electrodes with large surface areas and superior interface characteristics is highly desirable in improving the actuation performance of IPMCs, which is still technologically critical for IPMCs. In this contribution, we developed a novel fabrication technology for carbon/metal composite electrodes with a superior interface structure and characteristics to optimize the actuation behaviors of IPMCs by exploiting the synergistic effect of combining a sulfonated multi-walled carbon nanotube (SCNT)/Nafion hybrid layer with nanodispersed Pd particles. The improved IPMCs showed significantly enhanced capacitance characteristics and highly facilitated charge-discharge processes. Moreover, their actuation behaviors were greatly improved as expected, including approximately 2.5 times larger displacement, 3 times faster deformation speed, 4 times greater output force, and 10 times higher volume work density compared to those of the IPMCs with traditional electrode structures. The advantages of the developed SCNT/Pd-IPMCs will greatly facilitate their applicability for artificial muscles.

5.
Micromachines (Basel) ; 13(8)2022 Aug 11.
Article in English | MEDLINE | ID: mdl-36014211

ABSTRACT

Electroactive polymer (EAP) is a polymer that reacts to electrical stimuli, such as voltage, and can be divided into electronic and ionic EAP by an electrical energy transfer mechanism within the polymer. The mechanism of ionic EAP is the movement of the positive ions inducing voltage change in the polymer membrane. Among the ionic EAPs, an ionic polymer-metal composite (IPMC) is composed of a metal electrode on the surface of the polymer membrane. A common material for the polymer membrane of IPMC is Nafion containing hydrogen ions, and platinum, gold, and silver are commonly used for the electrode. As a result, IPMC has advantages, such as low voltage requirements, large bending displacement, and bidirectional actuation. Manufacturing of IPMC is composed of preparing the polymer membrane and plating electrode. Preparation methods for the membrane include solution casting, hot pressing, and 3D printing. Meanwhile, electrode formation methods include electroless plating, electroplating, direct assembly process, and sputtering deposition. The manufactured IPMC is widely demonstrated in applications such as grippers, micro-pumps, biomedical, biomimetics, bending sensors, flow sensors, energy harvesters, biosensors, and humidity sensors. This paper will review the overall field of IPMC by demonstrating the categorization, principle, materials, and manufacturing method of IPMC and its applications.

6.
Membranes (Basel) ; 12(7)2022 Jun 25.
Article in English | MEDLINE | ID: mdl-35877854

ABSTRACT

This work presents the development of a cost-effective electric-stimulus-responsive bending actuator based on a sulfonated polyvinyl chloride (SPVC)-phosphotungstic acid (PTA) ionic polymer-metal composite (IPMC), using a simple solution-casting method followed by chemical reduction of platinum (Pt) ions as an electrode. The characterizations of the prepared IPMC were performed using Fourier-transform infrared (FTIR) spectroscopy, Scanning electron microscopy (SEM), X-ray diffraction (XRD) techniques, Thermogravimetric analysis (TGA), and Energy-dispersive X-ray (EDX) analysis. Excellent ion-exchange capacity (IEC) and proton conductivity (PC), with values of ca. 1.98 meq·g-1 and ca. 1.6 mS·cm-1, respectively, were observed. The water uptake (WU) and water loss (WL) capacities of the IPMC membranes were measured at 25 °C, and found to have maxima of ca. 48% for 10 h, and ca. 36% at 6 V DC for almost 9 min, respectively. To analyze the actuation performance of the developed membrane, tip displacement and actuation force measurements were conducted. Tip displacement was found to be ca. 15.1 mm, whereas bending actuation was found to be 0.242 mN at 4 V DC. The moderate water loss, good proton conductivity (PC), high thermal stability, and good electrochemical properties of the developed IPMC membrane actuator position it as a cost-effective alternative to highly expensive conventional perfluorinated polymer-based actuators.

7.
Int J Mol Sci ; 23(7)2022 Mar 24.
Article in English | MEDLINE | ID: mdl-35408883

ABSTRACT

As a new type of flexible smart material, ionic polymer-metal composite (IPMC) has the advantages of being lightweight and having fast responses, good flexibility, and large deformation ranges. However, IPMC has the disadvantages of a small driving force and short lifespan. Based on this, this paper firstly analyzes the driving mechanism of IPMC. Then, it focuses on the current preparation technology of IPMC from the aspects of electroless plating and mechanical plating. The advantages and disadvantages of various preparation methods are analyzed. Due to the special driving mechanism of IPMC, there is a problem of short non-aqueous working time. Therefore, the modification research of IPMC is reviewed from the aspects of the basement membrane, working medium, and electrode materials. Finally, the current challenges and future development prospects of IPMC are discussed.


Subject(s)
Metals , Polymers , Electrodes , Ions , Technology
8.
Anticancer Res ; 42(5): 2645-2655, 2022 May.
Article in English | MEDLINE | ID: mdl-35489761

ABSTRACT

BACKGROUND/AIM: This study evaluated the efficacy of adjuvant chemotherapy (AC) for intraductal papillary mucinous carcinoma (IPMC). PATIENTS AND METHODS: We retrospectively analyzed patients who underwent pancreatectomy for invasive IPMC from January 2007 to June 2020. We evaluated outcomes of AC in the entire cohort and in patients with known prognostic factors. RESULTS: A total of 51 patients with invasive IPMC underwent surgery, of which 35 received AC. In the entire cohort, there was no significant difference in median overall survival (OS) between the AC and surgery alone (SA) group [hazard ratio (HR)=0.54; p=0.232]. For patients with poorly differentiated adenocarcinoma, median OS was significantly longer in the AC group (HR=0.27; p=0.022). For patients with lymph node metastasis, median OS was significantly higher in the AC group (HR=0.07; p<0.001). CONCLUSION: AC may be effective for selected invasive IPMC patients.


Subject(s)
Adenocarcinoma, Mucinous , Adenocarcinoma, Papillary , Adenocarcinoma , Carcinoma, Pancreatic Ductal , Pancreatic Intraductal Neoplasms , Pancreatic Neoplasms , Adenocarcinoma/pathology , Adenocarcinoma, Mucinous/drug therapy , Adenocarcinoma, Mucinous/surgery , Adenocarcinoma, Papillary/pathology , Carcinoma, Pancreatic Ductal/drug therapy , Carcinoma, Pancreatic Ductal/surgery , Chemotherapy, Adjuvant , Humans , Neoplasm Invasiveness , Pancreatic Neoplasms/drug therapy , Pancreatic Neoplasms/surgery , Retrospective Studies , Pancreatic Neoplasms
9.
Polymers (Basel) ; 14(4)2022 Feb 10.
Article in English | MEDLINE | ID: mdl-35215581

ABSTRACT

Herein, we present new approaches for developing sulfonated polyether ether ketone (SPEEK) and polyaniline-based (PANI) actuator formed by film-casting and chemical reduction of Pt electrodes. We have thoroughly studied the synthesis of SPEEK and characterized it by different analytical techniques. The ion-exchange capacity (IEC) and proton conductivity of SPEEK-PANI polymer membrane were calculated to be 1.98 mmol g-1 and 1.97 × 10-3 S cm-1, respectively. To develop an IPMC actuator, SPEEK was combined with PANI through in-situ polymerization method. SEM and XRD were used to check the morphology of the given SPEEK-PANI-Pt membrane. In addition, FT-IR and EDX techniques confirmed the molecular structure and chemical conformation of SPEEK-PANI polymer membrane. Pt electrode layers homogeneously dispersed on the IPMC membrane surface, which was demonstrated by smooth SEM micrographs. The actuation functioning, including the high bending deflection, proton conductivity, current density and IEC of IPMC actuator based on SPEEK-PANI-Pt, was obtained owing to its strong electrochemical and electromechanical characteristics. Synergistic combinations of SPEEK and PANI produced membrane that are flexible, mechanically strong and robust. The developed materials have immense capability as actuators for various applications including in biomimetics and robotics.

10.
Polymers (Basel) ; 13(23)2021 Nov 26.
Article in English | MEDLINE | ID: mdl-34883640

ABSTRACT

Flexible polymer-based actuators, often also called artificial muscles, are an essential part of biomimetic systems that mimic the movement principles of animal world creatures. The most used electrode material to force the actuator move is an ensemble of noble metal nanoparticles in the electroactive polymer surface. Noble metal electrodes have enough electrical conductivity and elasticity and are not subjected to oxidation. However, high cost of such electrodes and their tendency to cracking dictate the need for searching other materials, primarily carbon ones. The review considers several options for this search. For example, carbon nanotubes and graphene have excellent properties at the level of a single individually taken nanotube or graphene sheet. However, conservation of these properties in structurally imperfect film electrodes requires a separate study. In addition, there are problems of compatibility of such electrodes with the polymers that requires cumbersome technologies, e.g., hot pressing, which complicates the production of the actuator as a whole. The review concerns the technology options of manufacturing actuators and the results obtained on their basis, both including hot pressing and avoiding this procedure. In particular, the required level of the graphene oxide reduction in hydrazine provides sufficient adhesion at rather high electrical conductivity of the graphene film. The ability to simultaneous achieving these properties is a nontrivial result, providing the same level of actuation as with expensive noble metal electrodes. Actuators that additionally require greater lifetime resource should be obtained in other ways. Among them are using the graphdiyne electrodes and laser processing of the graphene electrodes.

11.
Polymers (Basel) ; 13(18)2021 Sep 09.
Article in English | MEDLINE | ID: mdl-34577942

ABSTRACT

Throat sensing has received increasing demands in recent years, especially for oropharyngeal treatment applications. The conventional videofluoroscopy (VFS) approach is limited by either exposing the patient to radiation or incurring expensive costs on sophisticated equipment as well as well-trained speech-language pathologists. Here, we propose a smart and non-invasive throat sensor that can be fabricated using an ionic polymer-metal composite (IPMC) material. Through the cation's movement inside the IPMC material, the sensor can detect muscle movement at the throat using a self-generated signal. We have further improved the output responses of the sensor by coating it with a corrosive-resistant gold material. A support vector machine algorithm is used to train the sensor in recognizing the pattern of the throat movements, with a high accuracy of 95%. Our proposed throat sensor has revealed its potential to be used as a promising solution for smart healthcare devices, which can benefit many practical applications such as human-machine interactions, sports training, and rehabilitation.

12.
Nanotechnology ; 32(38)2021 Jul 02.
Article in English | MEDLINE | ID: mdl-34144550

ABSTRACT

Ionic polymer metal composite (IPMC) always takes big risks of electrode cracking and peeling, which lead to energy wasting, waterloss, and uneven electric field distribution, thus hamper its commercial applications. To address this issue, we propose a facile and effective technique to repair the electrode fatigue by coating polyvinylpyrrolidone (PVP) encapsulated Ag nanoparticles (PVP@AgNPs) on the long-term used IPMC surface. To improve the electrochemical stability, the silver nanoparticles (Ag NPs) with a diameter of ∼34 nm are encapsulated by a 1.3 nm thick PVP film, thus forming a shell-core structure to resist corrosion from the electrolyte solution. Physiochemical investigations reveal that, PVP@AgNPs closely attach to the interior and exterior surfaces of the original Pt nanograin electrode, thus refreshing its electronic conductivity; the repaired IPMC actuator exhibits better electromechanical properties compared to its precursor actuator: 7.62 folds in displacement output, 9.38 folds in force output, and 9.73 folds in stable working time.

13.
Pancreatology ; 21(2): 390-396, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33487577

ABSTRACT

BACKGROUND: Intraductal papillary mucinous neoplasm (IPMN) is reported as a high-risk factor for pancreatic cancer (PC) that includes IPMN-derived cancers (IPMC) and the development of invasive pancreatic ductal adenocarcinoma (PDAC) concomitant with IPMN. Since invasive IPMC and PDAC exhibit different oncological behaviors, their differentiation is clinically important. We aimed to investigate the use of contrast-enhanced harmonic endoscopic ultrasound (CEH-EUS) for the differential diagnosis between invasive IPMC and PDAC. METHODS: This study involved 183 consecutive patients with PC (invasive IPMC: 42, PDAC concomitant with IPMN: 9, without IPMN: 132) who underwent CEH-EUS preoperatively. While investigating the patterns, enhanced effects in the solid part of the tumor were compared with those in the surrounding pancreatic parenchyma after administration of Sonazoid® and evaluated as hyperenhanced, isoenhanced, or hypoenhanced. We retrospectively compared the enhanced pattern of CEH-EUS by using multiphasic analysis and clinicopathological factors between invasive IPMC and PDAC. RESULTS: In multiphase evaluations at 20, 40 and 60 s in CEH-EUS, 75.2% (106/141) of PDACs were hypoenhanced (-) at ≥2 of the 3 time points, with significant differences from those of invasive IPMC (P < 0.001). The solid tumor diameter was significantly larger in PDAC than in invasive IPMC, and the tumor stage and preoperative serum carbohydrate antigen 19-9 level were higher. After propensity score matching of stage and solid tumor diameter, contrast enhancement patterns were significantly more persistent in invasive IPMC than in PDAC (P = 0.0013). CONCLUSIONS: Multiphase evaluation using CEH-EUS is a useful method for differentiating between invasive IPMC and PDAC.


Subject(s)
Contrast Media/pharmacology , Endosonography/methods , Pancreatic Intraductal Neoplasms/diagnostic imaging , Adult , Aged , Aged, 80 and over , Diagnosis, Differential , Female , Humans , Image Enhancement/methods , Male , Middle Aged , Retrospective Studies
14.
Micromachines (Basel) ; 11(12)2020 Dec 17.
Article in English | MEDLINE | ID: mdl-33348797

ABSTRACT

The article is devoted to the development and creation of a multiphysics simulator that can, on the one hand, simulate the most significant physical processes in the IPMC actuator, and on the other hand, unlike commercial products such as COMSOL, can use computing resources economically. The developed mathematical model is an adjoint differential equation describing the transport of charged particles and water molecules in the ion-exchange membrane, the electrostatic field inside, and the mechanical deformation of the actuator. The distribution of the electrostatic potential in the interelectrode space is located by means of the solution of the Poisson equation with the Dirichlet boundary conditions, where the charge density is a function of the concentration of cations inside the membrane. The cation distribution was obtained by means of the solution of the equation system, in which the fluxes of ions and water molecules are described by the modified Nernst-Planck equations with boundary conditions of the third kind (the Robin problem). The cantilever beam forced oscillation equation in the presence of resistance (allowing for dissipative processes) with assumptions of elasticity theory was used to describe the actuator motion. A combination of the following computational methods was used as a numerical algorithm for the solution: the Poisson equation was solved by a direct method, the modified Nernst-Planck equations were solved by the Newton-Raphson method, and the mechanical oscillation equation was solved using an explicit scheme. For this model, a difference scheme has been created and an algorithm has been described, which can be implemented in any programming language and allows for fast computational experiments. On the basis of the created algorithm and with the help of the obtained experimental data, a program has been created and the verification of the difference scheme and the algorithm has been performed. Model parameters have been determined, and recommendations on the ranges of applicability of the algorithm and the program have been given.

15.
Surg Today ; 50(1): 50-55, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31807871

ABSTRACT

The current treatment strategy for intraductal papillary mucinous neoplasms (IPMNs), based on the international consensus guideline, has been accepted widely. However, reported outcomes after surgical resection for IPMN show that once the tumor progresses to invasive intraductal papillary mucinous carcinoma (IPMC), recurrence is not uncommon. The surgical treatment for IPMN is invasive and sometimes followed by complications. Therefore, the best timing for resection might be at the point when high-grade dysplasia (HGD) is evident. According to previous reports, main duct type IPMN has a high malignant potential and its surgical resection is universally accepted, whereas, the incidence of HGD/invasive IPMC in branch duct and mixed type IPMNs is thought to be lower. In addition to mural nodules and a dilated main pancreatic duct, cytology and measurement of the carcinoembryonic antigen level in the pancreatic juice might be useful to differentiate HGD/invasive IPMC from low-grade dysplasia. The nomogram proposed recently to predict the risk of HGD/invasive IPMC in IPMN patients might help surgeons decide on the best treatment strategy, depending on the patient's age and general condition. Second resection for high-risk lesions in the remnant pancreas might improve the survival of IPMN patients.


Subject(s)
Pancreas/surgery , Pancreatectomy/methods , Pancreatic Intraductal Neoplasms/surgery , Pancreatic Neoplasms/surgery , Age Factors , Biomarkers, Tumor/metabolism , Carcinoembryonic Antigen/metabolism , Humans , Lymph Node Excision , Neoplasm Grading , Neoplasm Invasiveness , Neoplasm Recurrence, Local , Pancreatic Intraductal Neoplasms/diagnosis , Pancreatic Intraductal Neoplasms/mortality , Pancreatic Intraductal Neoplasms/pathology , Pancreatic Juice/metabolism , Pancreatic Neoplasms/diagnosis , Pancreatic Neoplasms/mortality , Pancreatic Neoplasms/pathology , Reoperation , Risk , Survival Rate , Treatment Outcome
16.
Sensors (Basel) ; 19(18)2019 Sep 14.
Article in English | MEDLINE | ID: mdl-31540032

ABSTRACT

Ionic polymer-metal composites (IPMC) are smart material transducers that bend in response to low-voltage stimuli and generate voltage in response to bending. IPMCs are mechanically compliant, simple in construction, and easy to cut into desired shape. This allows the designing of novel sensing and actuation systems, e.g., for soft and bio-inspired robotics. IPMC sensing can be implemented in multiple ways, resulting in significantly different sensing characteristics. This paper will review the methods and research efforts to use IPMCs as deformation sensors. We will address efforts to model the IPMC sensing phenomenon, and implementation and characteristics of different IPMC sensing methods. Proposed sensing methods are divided into active sensing, passive sensing, and self-sensing actuation (SSA), whereas the active sensing methods measure one of IPMC-generated voltage, charge, or current; passive methods measure variations in IPMC impedances, or use it in capacitive sensor element circuit, and SSA methods implement simultaneous sensing and actuation on the same IPMC sample. Frequency ranges for reliable sensing vary among the methods, and no single method has been demonstrated to be effective for sensing in the full spectrum of IPMC actuation capabilities, i.e., from DC to ∼100 Hz. However, this limitation can be overcome by combining several sensing methods.

17.
Sensors (Basel) ; 19(9)2019 May 07.
Article in English | MEDLINE | ID: mdl-31067676

ABSTRACT

As an excellent transducer, ionic polymer-metal composites (IPMCs) can act as both an actuator and a sensor. During its sensing process, many factors, such as the water content, the cation type, the surface electrode, and the dimensions of the IPMC sample, have a considerable impact on the IPMC sensing performance. In this paper, the effect of dimensions focused on the Pd-Au typed IPMC samples with various thicknesses, widths, and lengths that were fabricated and their deformation sensing performances were tested and estimated using a self-made electromechanical sensing platform. In our experiments, we employed a two-sensing mode (both current and voltage) to record the signals generated by the IPMC bending. By comparison, it was found that the response trend was closer to the applied deformation curve using the voltage-sensing mode. The following conclusions were obtained. As the thickness increased, IPMC exhibited a better deformation-sensing performance. The thickness of the sample changed from 50 µm to 500 µm and corresponded to a voltage response signal from 0.3 to 1.6 mV. On the contrary, as the length increased, the sensing performance of IPMC decreased when subjected to equal bending. The width displayed a weaker effect on the sensing response. In order to obtain a stronger sensing response, a thickness increase, together with a length reduction, of the IPMC sample is a feasible way. Also, a simplified static model was proposed to successfully explain the sensing properties of IPMC with various sizes.

18.
Clin J Gastroenterol ; 12(6): 621-625, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31123981

ABSTRACT

Pulmonary lepidic metastasis from intraductal papillary mucinous carcinoma (IPMC) of the pancreas is extremely rare. The patient was a 50s-year old male who was hospitalized in the department of respiratory in our hospital for the evaluation of ground-glass opacities in both lungs on computed tomography (CT) imaging. Steroid therapy was administered, as interstitial pneumonia was suggested; however, there was no improvement. A transbronchial lung biopsy (TBLB) revealed the possibility of distant lung metastases. Abdominal CT revealed pancreatic cystic lesions; the patient was, therefore, referred to our department for further evaluation. Endoscopic ultrasound revealed large multi-cystic lesion with mural nodule and wall thickness. A subsequent pancreatic juice cytology under endoscopic retrograde cholangiopancreatography revealed adenocarcinoma. As this was consistent with the pathological findings shown on TBLB, IPMC metastasis to the lung was diagnosed. In this case, it was considered that pulmonary lepidic metastasis from IPMC by CT imaging and pathological findings. Although the cases of pulmonary lepidic metastasis from gastrointestinal cancer are rare, we should consider these pathological conditions when pneumonia-like infiltration observed on imaging studies does not respond to treatment.


Subject(s)
Adenocarcinoma, Mucinous/secondary , Adenocarcinoma, Papillary/secondary , Carcinoma, Pancreatic Ductal , Lung Neoplasms/secondary , Pancreatic Neoplasms , Cholangiopancreatography, Endoscopic Retrograde , Endosonography , Humans , Lung Neoplasms/diagnostic imaging , Male , Middle Aged , Multimodal Imaging , Tomography, X-Ray Computed
19.
Polymers (Basel) ; 11(1)2019 Jan 08.
Article in English | MEDLINE | ID: mdl-30960074

ABSTRACT

Ionic polymer metal composites (IPMCs) with various thicknesses of 1, 2, 4, and 6 nafion films (denoted as 1-film, 2-film, 4-film and 6-film, respectively) are fabricated, and their characterization and actuation performances are then investigated. The effects of the thickness of the IPMCs on their morphology, surface resistance, and water uptake capability are studied. Their actuation performances are further evaluated by examining the tip force and displacement in terms of the length and the thickness of the IPMCs, under a direct current (DC) power of 3.0 or 4.5 V. In comparison with the 1-film, the 2-film shows a six-fold increase in the maximum tip force, but the response time increases from 2 to 9 s. The 4-film doubles the maximum tip force of the 2-film at 21 s. On the other hand, a reduction of the length of the IPMC from 30 to 15 mm also results in a double-maximum tip force, but this never increases the response time. Repeated actuations of the IPMCs with various thicknesses are performed by three actuation methods of no treatment, treatment in deionized water, and treatment in a NaCl solution. The relationships between the repeated actuation methods and actuations of the IPMCs with various thicknesses are also investigated.

20.
Mol Clin Oncol ; 10(5): 511-515, 2019 May.
Article in English | MEDLINE | ID: mdl-30967945

ABSTRACT

As a result of recent advances in diagnostic techniques and treatment modalities, the number of patients diagnosed with multiple primary malignancies has been increasing. We report the case of a 79-year-old male with multiple primary malignancies of three histological types in six different organs: Stomach, prostate, colon, urinary bladder, facial skin and pancreas, in chronological order. The first malignancy was upper gastric cancer diagnosed in 1998. The second and third malignancies were prostate cancer and ascending colon cancer, which were diagnosed in 2010. The fourth malignancy was bladder cancer diagnosed in 2011. The fifth and sixth malignancies were squamous cell skin cancer of the right cheek and intraductal papillary mucinous carcinoma (IPMC), respectively, diagnosed in 2014. The gastric cancer, colon cancer, bladder cancer, skin cancer and IPMC were surgically resected. The prostate cancer was treated by anti-androgen therapy. The patient died of local recurrence of IPMC in August 2016. Although multiple primary malignancies are not uncommon, diagnosis of six primary malignancies in a single patient, as reported in the present study, is extremely rare. It is important to understand the characteristics of multiple primary malignancies in order to administer suitable treatment and determine relevant follow-up plans for patients with cancer.

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