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Tumor hypoxia is correlated with increased resistance to chemotherapy and poor overall prognoses across a number of cancer types. We present here a cancer cell-selective and hypoxia-responsive probe (fol-BODIPY) designed on the basis of density functional theory (DFT)-optimized quantum chemical calculations. The fol-BODIPY probe was found to provide a rapid fluorescence "off-on" response to hypoxia relative to controls, which lack the folate or nitro-benzyl moieties. In vitro confocal microscopy and flow cytometry analyses, as well as in vivo near-infrared optical imaging of CT26 solid tumor-bearing mice, provided support for the contention that fol-BODIPY is more readily accepted by folate receptor-positive CT26 cancer cells and provides a superior fluorescence "off-on" signal under hypoxic conditions than the controls. Based on the findings of this study, we propose that fol-BODIPY may serve as a tumor-targeting, hypoxia-activatable probe that allows for direct cancer monitoring both in vitro and in vivo.

Simultaneous MR-PET imaging is a fusion of MRI using various parameters and PET images using various nuclides. In this paper, we performed analysis on the fitting degree between MRI and simultaneous MR-PET images and between PET and simultaneous MR-PET images. For the fitness analysis by neural network learning, feature parameters of experimental images were extracted by discrete wavelet transform (DWT), and the extracted parameters were used as input data to the neural network. In comparing the feature values extracted by DWT for each image, the horizontal and vertical low frequencies showed similar patterns, but the patterns were different in the horizontal and vertical high frequency and diagonal high frequency regions. In particular, the signal value was large in the T1 and T2 weighted images of MRI. Neural network learning results for fitting degree analysis were as follows. 1. T1-weighted MRI and simultaneous MR-PET image fitting degree: Regression (R) values were found to be Training 0.984, Validation 0.844, and Testing 0.886. 2. Dementia-PET image and Simultaneous MR-PET Image fitting degree: R values were found to be Training 0.970, Validation 0.803, and Testing 0.828. 3. T2-weighted MRI and concurrent MR-PET image fitting degree: R values were found to be Training 0.999, Validation 0.908, and Testing 0.766. 4. Brain tumor-PET image and Simultaneous MR-PET image fitting degree: R values were found to be Training 0.999, Validation 0.983, and Testing 0.876. An R value closer to 1 indicates more similarity. Therefore, each image fused in the simultaneous MR-PET images verified in this study was found to be similar. Ongoing study of images acquired with pulse sequences other than the weighted images in the MRI is needed. These studies may establish a useful protocol for the acquisition of simultaneous MR-PET images.

In this paper, we propose a method for determining degree of malignancy on digital mammograms using artificial intelligence deep learning. Digital mammography is a technique that uses a low-energy X-ray of approximately 30 KVp to examine the breast. The goal of digital mammography is to detect breast cancer in an early stage by identifying characteristic lesions such as microcalcifications, masses, and architectural distortions. Frequently, microcalcifications appear in clusters that increase ease of detection. In general, larger, round, and oval-shaped calcifications with uniform size have a higher probability of being benign; smaller, irregular, polymorphic, and branching calcifications with heterogeneous size and morphology have a higher probability of being malignant. The experimental images for this study were selected by searching for "mammogram" in the NIH database. The images were converted into JPEG format of 256 X 256 pixels and saved. The stored images were segmented, and edge detection was performed. Most of the lesion area was low frequency, but the edge area was high frequency. DCT was performed to extract the features of the two parts. Similarity was determined based on DCT values entered into the neural network. These were the findings of the study: 1) There were 6 types of images representing malignant tumors. 2) There were 2 types of images showing benign tumors. 3) There were two types of images demonstrating tumors that could worsen into malignancy. Medical images like those used in this study are interpreted by a radiologist in consideration of pathological factors. Since discrimination of medical images by AI is limited to image information, interpretation by a radiologist is necessary. To improve the discrimination ability of medical images by AI, extracting accurate features of these images is necessary, as is inputting clinical information and accurately setting targets. Study of learning algorithms for neural networks should be continued. We believe that this study concerning recognition of cancer on digital breast images by AI deep learning will be useful to the radiomics (radiology and genomics) research field.

This study evaluated PSNR of server display monitor and client display monitor of DSA system. The signal is acquired and imaged during the surgery and stored in the PACS server. After that, distortion of the original signal is an important problem in the process of observation on the client monitor. There are many problems such as noise generated during compression and image storage/transmission in PACS, information loss during image storage and transmission, and deterioration in image quality when outputting medical images from a monitor. The equipment used for the experiment in this study was P's DSA. We used two types of monitors in our experiment, one is P’s company resolution 1280×1024 pixel monitor, and the other is W’s company resolution 1536×2048 pixel monitor. The PACS Program used MARO-view, and for the experiment, a PSNR measurement program using Visual C++ was implemented and used for the experiment. As a result of the experiment, the PSNR value of the kidney angiography image was 26.958dB, the PSNR value of the lung angiography image was 28.9174 dB, the PSNR value of the heart angiography image was 22.8315dB, and the PSNR value of the neck angiography image was 37.0319 dB, and the knee blood vessels image showed a PSNR value of 43.2052 dB, respectively. In conclusion, it can be seen that there is almost no signal distortion in the process of acquiring, storing, and transmitting images in PACS. However, it suggests that the image signal may be distorted depending on the resolution and performance of each monitor. Therefore, it will be necessary to evaluate the performance of the monitor and to maintain the performance.

Dengue virus (DENV) is a major infectious viral pathogen that affects millions of individuals worldwide every year, causing a potentially fatal syndrome, while no commercial antiviral drugs are yet available. To develop an antiviral against dengue fever, it is necessary to understand the relationship between DENV and host cells, which could provide a basis for viral dynamics and identification of inhibitory drug targets. In this study, we designed DiD-loaded and BODIPY-ceramide-encapsulated DENV-polymersome hybrid nanovesicles (DENVSomes) prepared by an extrusion method, which trigger red fluorescence in the endosome and green in the Golgi. DENVSome monitors the dynamics of host cell-virus interaction and tracking in living cells with novel state-of-the-art imaging technologies that show images at high resolution. Also, DENVSome can be exploited to screen whether candidate antiviral drugs interact with DENVs. Consequently, we successfully demonstrated that DENVSome is an efficient tool for tracking and unraveling the mechanisms of replication and drug screening for antiviral drugs of DENV.

Herein, lipid-coated polyaniline (LiPAni) nanoparticles were fabricated to monitor the redox state of cancer cells. To confirm the characteristics of LiPAni, we firstly analyzed the size and chemical structures of the LiPAni nanoparticles. The absorbance properties of the LiPAni nanoparticles were observed to vary with the pH conditions. Furthermore, cell viability tests conducted with breast cancer cell lines showed that the cell viability of the cells with LiPAni nanoparticles was dramatically increased compared to those with the Tween80-coated polyaniline nanoparticles (TPAni) as a control. Subsequently, the colors of the LiPAni nanoparticles were observed and analyzed using spectroscopic methods. Finally, in order to investigate the more accurate sensing of the redox state using the color changes of the LiPAni nanoparticles with cancer cell lines, dark field microscopic images and scattering spectra were recorded at the single nanoparticle scale. For the TPAni nanoparticles, there was only a change in brightness and no change in color, but for the LiPAni nanoparticles, there was a change of color from yellow to pink in the dark field images.

Tumor hypoxia is correlated with increased resistance to chemotherapy and poor overall prognoses across a number of cancer types. We present here a cancer cell-selective and hypoxia-responsive probe (

We have successfully fabricated a nanocomposite, which is composed of polyaniline (PAni) and pyrene butyric acid (Pyba) via a solvent shift method, which was self-doped at a neutral pH value. This PAni nanocomposite can act as a fine nanoagent expressing absorbance, fluorescence, and Raman properties according to the surrounding pH values.

Real-time quantitative and qualitative analyses of metastasis-associated proteases are critical for precise diagnosis and novel therapeutic treatment of advanced cancers. However, conventional methods based on DNA, peptides, and proteins require sophisticated chemistry and additional processes to expose detection moieties, and they lack elements of temporal control, which limit their applicability. We designed unique protease-activatable polymersomes (PeptiSomes) for high sensitivity, in situ quantitative analysis of activating membrane-type 1 matrix metalloproteinases (MT1-MMP, MMP14). To do this, we first synthesized an amphiphilic block polymer–peptide and a copolypeptide based on mPEG-b-pLeu and MT1-peptide-b-pLeu, respectively. Amphiphilic self-assembled PeptiSomes in water were capable of disassembling and releasing the encapsulated self-quenched fluorescence dye (calcein) via enzymatic activation by MT1-MMP. Our PeptiSome system may potentially prevent the initiation and progression of cancer metastasis. Furthermore, the PeptiSome approach described here is likely to facilitate the development of rapid protease assay techniques and further extend the role of proteases as metastasis indicators and therapeutic targets.

Although islet cell transplantation has emerged as a promising treatment for type 1 diabetes, it remains an unmet clinical application due to the need for immunosuppression to prevent islet elimination and autoimmunity. To solve these problems, we developed novel nanoencapsulation of neonatal porcine islet-like cell clusters (NPCCs) with cell-mimic polymersomes (PSomes) based on PEG-b-PLA (poly(ethylene glycol)-b-poly(dl-lactic acid)). To accomplish this, we first formulated NHS-, NH2-, COOH-, and m(methoxy)-PSomes. This coating utilizes interactions involving NPCC surfaces and PSomes that have covalent bonds, electrostatic interactions, and hydrogen bonds. We extended the range of applicability by comparing the binding affinity of electrostatic attraction and hydrogen bonding, as well as covalent bonds. Our protocol can be used as an efficient hydrogen bonding method because it reduces cell membrane damage as well as the use of covalent bonding methods. We verified the selective permeability of NHS-, NH2-, COOH-, and m-PSome-shielded NPCCs. Furthermore, we showed that a novel nanoencapsulation did not affect insulin secretion from NPCCs. This study offers engineering advances in islet encapsulation technologies to be used for cell-based transplantation therapies.

Small animal positron emission tomography (PET) is a noninvasive imaging modality that enables in vivo imaging and quantification of the biological processes of small experimental animals. We have developed a small animal PET that utilizes a high-resolution multiplexed readout and charge signal transmission (CST) method. The small animal PET was composed of six detector blocks consisting of SiPMs and LYSO arrays. Six detector blocks were mounted on a PET gantry having an inner diameter of 76 mm, outer diameter of 112 mm, and axial length of 40.8 mm. The charge signals of SiPM output were transmitted to the input of multiplexed readout using 4 m flexible flat cables. The multiplexed readout was composed of six main boards, each of which included 36 detector boards, to reduce the number of readout channels by a factor of 36, with a multiplexing ratio of 144:4. The performance of the small animal PET was evaluated using NEMA NU 4-2008 standards, and its imaging capability was demonstrated by in vivo mouse imaging studies. The average energy and time resolutions were 13.2% ± 0.3% and 3.8 ns, respectively. The spatial resolution at the center of the transaxial FOV was 1.1 mm, and the peak sensitivity at the center of the axial FOV was 1.5%. The peak noise equivalent count (NEC) rate and scatter fraction were 21.1 kcps at 18.2 MBq and 21%, respectively. The acquired images demonstrated high quality tracer uptake patterns of small experimental animals. The results of performance evaluation and animal imaging indicate that the small animal PET developed in this study can provide high-quality small animal imaging with cost-effectiveness and compactness.

The cancer stem cell (CSC) hypothesis postulates that cancer cells overexpressing CD44 are marked as CSCs that cause tumorigenesis and recurrence. This hypothesis suggests that CD44 is a potential therapeutic target that can interfere with CSCs qualities. MicroRNA-34a (miR-34a) is a promising candidate for CD44 repression-based cancer therapy as it has been reported to inhibit proliferation, metastasis, and survival of CD44-positive CSCs. Here, we used nanovesicles containing PLI/miR complexes (NVs/miR) to systemically deliver miR-34a and induce miR-34a-triggered CD44 suppression in orthotopically and subcutaneously implanted tumors in nude mice. Poly(l-lysine-graft-imidazole) (PLI) condenses miRs and is functionally modified to deliver miRs to the site of action by buffering effect of imidazole residues under endosomal pH. Indeed, NVs/miR consisting of PEGylated lipids enveloping PLI/miR complexes greatly reduced inevitable toxicity of polycations by compensating their surface charge and markedly improved their in vivo stability and accumulation to tumor tissue compared to PLI/miR polyplexes. Our NVs-mediated miR-34a delivery system specifically increased endogenous target miR levels, thereby attenuating proliferation and migration of gastric cancer cells by repressing the expression of CD44 with decreased levels of Bcl-2, Oct 3/4 and Nanog genes. Our strategy led to a greater therapeutic outcome than PLI-based delivery with highly selective tumor cell death and significantly delayed tumor growth in CD44-positive tumor-bearing mouse models, thus providing a fundamental therapeutic window for CSCs.

The development of a synchronized delivery and imaging system for small interfering RNA (siRNA) is required for the clinical application of RNA interference (RNAi) in cancer treatment. Herein, we report a pH-responsive, magnetic nanoparticle-based siRNA delivery system that can facilitate the safe and efficient delivery and visualization of therapeutic siRNA by high-resolution magnetic resonance (MR) imaging. Cationic poly-l-lysine-graft-imidazole (PLI) with a reactive silane moiety was stably immobilized onto the surface of the assembled manganese ferrite nanoparticles (MFs) through an emulsion process, ensuring high water solubility, enhanced MR contrast effect, and endosome-disrupting functionality. The synthesized nanovectors were then complexed with siRNA targeting the CD44 gene via electrostatic interactions to verify the specific gene-silencing effect. The imidazolized magnetic nanovector (ImMNV) architectures developed here facilitated improved cellular internalization and exhibited a high level in vitro downregulation compared to non-imidazolized MNVs in metastatic breast cancer cells.

We presented an anisotropic plasma etching technique by reactive ion etcher (RIE) as a new pretreatment method of fabrication of ionic polymer-metal composite (IPMC). We already found that the new technique provided large displacement to the fabricated IPMC in the presence of low applied voltage. However, we did not examine the optimum condition for the anisotropic plasma etching. In this research, we tried to figure out optimum treatment condition of film in etcher. Nafion (by DuPont) films were etched using various etching time and shadow masks with various slit and space sizes. The etched samples were plated with Pt at top and bottom side by Oguro's reduction method. The surface morphology of fabricated IPMCs was characterized by SEM. And, we've measured surface resistance, bending displacement, and driving force in order to check the IPMC properties out. Here, we found that optimum condition for pre-treatment of Nafion was 1 min for etching time under shadow mask with 200 microm slit and 100 microm space.

SIMULTANEOUS functional and anatomical imaging using PET-MR system has been reported to be useful in preclinical research to investigate various in vivo biological processes [1-3]. The purpose of this study was to develop a MR compatible small animal PET insert and to evaluate the performance of the developed PET and the influence of the PET on MRI performance.

Smart drug delivery systems that are triggered by environmental conditions have been developed to enhance cancer therapeutic efficacy while limiting unwanted effects. Because cancer exhibits abnormally high local acidities compared to normal tissues (pH 7.4) due to Warburg effects, pH-sensitive systems have been researched for effective cancer therapy. Chitosan-based intelligent theragnosis nanocomposites, N-naphthyl-O-dimethymaleoyl chitosan-based drug-loaded magnetic nanoparticles (N Chitosan-DMNPs), were developed in this study. N Chitosan-DMNPs are capable of pH-sensitive drug release with MR-guided images because doxorubicin (DOX) and magnetic nanocrystals (MNCs) are encapsulated into the designed N-naphthyl-O-dimethymaleoyl chitosan (N-nap-O-MalCS). This system exhibits rapid DOX release as acidity increases, high stability under high pH conditions, and sufficient capacity for diagnosing and monitoring therapeutic responses. These results demonstrate that N Chitosan-DMNPs have potential as theragnosis nanocomposites for effective cancer therapy.

Mobile multi-hop relay (MMR) network is known to have the strength of easy installation and convenient management because of its self-organizing and self-healing characteristics. However, MMR is also known to be vulnerable to security problems for the very same reason. In this paper, we propose a new hybrid authentication algorithm for IEEE 802.16j MMR network service. The proposed scheme uses centralized authentication when a mobile station (MS) or a relay station (RS) initially joins the MMR network, and uses distributed authentication for hop-by-hop authentication between the mobile nodes. We analyze the procedure of the proposed scheme in detail, and examine its usefulness when applied to the MMR network. The proposed scheme can be used in any mobile multi-hop network as well as IEEE 802.16j MMR network.

Plasma etching was performed to improve displacement and response speed of IPMC actuator through homogeneous roughening and anisotropic surface treatment. We found that the anisotropic surface treatment by plasma etching of Nafion in the pre-treatment process gave the response speed and displacement of resulting IPMC which was 2 times faster and 1.5 times larger than those manufactured by the sandblasting, respectively.

Aim To analyse several reference structures using axial computed tomography (CT) imaging of the temporal bone, which may reflect pneumatization of the entire temporal bone by statistical correlation to the actual volume of the temporal bone measured using three-dimensional reconstruction. Materials and methods One hundred and sixteen temporal bones were studied, comprising 48 with normal findings and 68 sides showing chronic otitis media or temporal bone fracture. After measuring the volume of temporal bone air cells by the volume rendering technique using three-dimensional reconstruction images, classification of temporal bone pneumatization was performed using various reference structures on axial images to determine whether significant differences in the volume of temporal bone air cells could be found between the groups. Results When the sigmoid sinus at the level of the malleoincudal complex was used in the classification, there were statistically significant differences between the groups that correlated with the entire volume of the temporal bone. Grouping based on the labyrinth and the ascending carotid artery showed insignificant differences in volume. Furthermore, there was no significant correlation between the cross-sectional area of the antrum and the entire volume of the temporal bone. Conclusion The degree of pneumatization of temporal bone can be estimated easily by the evaluation of the air cells around the sigmoid sinus on axial CT images.