Chitosan-based intelligent theragnosis nanocomposites enable pH-sensitive drug release with MR-guided imaging for cancer therapy

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 (NChitosan-DMNPs), were developed in this study. NChitosan-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 NChitosan-DMNPs have potential as theragnosis nanocomposites for effective cancer therapy.     

The development of a fully integrated micro-channel fuel processor using low temperature co-fired ceramic (LTCC)

A fully integrated micro-channel fuel processor system consisting of vaporizer, steam reformer, heat exchanger and preferential CO oxidation (PROX) was developed using low temperature co-fired ceramic (LTCC). To fabricate a compact all-in-one system, each substrate was stacked to build a multilayered type fuel processor. A CuO/ZnO/Al₂O₃ catalyst and Pt-based catalyst prepared by wet impregnation were deposited inside the micro-channel of steam reformer and PROX, respectively. The performance of the fully integrated micro-channel reformer was measured at various conditions such as the ratio of the feed flow rate, the ratio of H₂O/CH₃OH and the operating temperature of the reactor. In parallel with the experiments, 3-D fluid dynamics simulation (Fluent) was conducted to verify the micro-reformer performance. The fully integrated micro-channel reformer has the dimensions of W: 130 mm × D: 50 mm × H: 3 mm. The fuel processor produced the gas composition of 71% H₂ and 25% CO₂, and more than 93% of methanol conversion was achieved at 300 °C and 2 cm³/h of the feed flow rate when CO concentration was maintained below 100 ppm by PROX.     

Cryptanalysis of flexible remote password authentication scheme of ICN'01

The weakness of Woei-Jiunn Tsaur's (see ICN 2001, p.174-83, 2001) flexible user authentication scheme for multi-server Internet services is demonstrated. We show that Tsaur's authentication scheme is vulnerable to the off-line guessing attack, i.e. we show that the user's additional two secret keys do not strengthen the security of Tsaur's scheme.     

Synthesis and Characterization of Cobalt-Doped WS<Subscript>2</Subscript> Nanorods for Lithium Battery Applications

Cobalt-doped tungsten disulfide nanorods were synthesized by an approach involving exfoliation, intercalation, and the hydrothermal process, using commercial WS₂ powder as the precursor and n-butyllithium as the exfoliating reagent. XRD results indicate that the crystal phase of the sample is 2H-WS₂. TEM images show that the sample consists of bamboo-like nanorods with a diameter of around 20 nm and a length of about 200 nm. The Co-doped WS₂ nanorods exhibit the reversible capacity of 568 mAh g⁻¹ in a voltage range of 0.01–3.0 V versus Li/Li⁺. As an electrode material for the lithium battery, the Co-doped WS₂ nanorods show enhanced charge capacity and cycling stability compared with the raw WS₂ powder.     

Cysteine-Encapsulated Liposome for Investigating Biomolecular Interactions at Lipid Membranes

The development of a strategy to investigate interfacial phenomena at lipid membranes is practically useful because most essential biomolecular interactions occur at cell membranes. In this study, a colorimetric method based on cysteine-encapsulated liposomes was examined using gold nanoparticles as a probe to provide a platform to report an enzymatic activity at lipid membranes. The cysteine-encapsulated liposomes were prepared with varying ratios of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and cholesterol through the hydration of lipid films and extrusions in the presence of cysteine. The size, composition, and stability of resulting liposomes were analyzed by scanning electron microscopy (SEM), dynamic light scattering (DLS), nuclear magnetic resonance (NMR) spectroscopy, and UV-vis spectrophotometry. The results showed that the increased cholesterol content improved the stability of liposomes, and the liposomes were formulated with 60 mol % cholesterol for the subsequent experiments. Triton X-100 was tested to disrupt the lipid membranes to release the encapsulated cysteine from the liposomes. Cysteine can induce the aggregation of gold nanoparticles accompanying a color change, and the colorimetric response of gold nanoparticles to the released cysteine was investigated in various media. Except in buffer solutions at around pH 5, the cysteine-encapsulated liposomes showed the color change of gold nanoparticles only after being incubated with Triton X-100. Finally, the cysteine-encapsulated liposomal platform was tested to report the enzymatic activity of phospholipase A₂ that hydrolyzes phospholipids in the membrane. The hydrolysis of phospholipids triggered the release of cysteine from the liposomes, and the released cysteine was successfully detected by monitoring the distinct red-to-blue color change of gold nanoparticles. The presence of phospholipase A₂ was also confirmed by the appearance of a peak around 690 nm in the UV-vis spectra, which is caused by the cysteine-induced aggregation of gold nanoparticles. The results demonstrated that the cysteine-encapsulated liposome has the potential to be used to investigate biological interactions occurring at lipid membranes.     

A study of improving overlay accuracy by applying a new outlier handling method in FPD manufacturing

As the pixel size of display devices has been reduced, overlay accuracy between layers needs to be more improved in flat panel display (FPD) manufacturing. However, because of large substrate size and non-uniform processes in FPD manufacturing, an improvement of overlay accuracy has been a challenging work. As an effort to improve overlay accuracy, overlay error correction, which is a kind of feedback control similar to one in semiconductor manufacturing, has also been applied in the photo lithography processes for FPD. However, its characteristics and problems were not technically well investigated as much as in semiconductor manufacturing. This paper investigates one of the problems encountered in the practice of the overlay error correction: outliers in the measurement of overlay errors. Such outliers can cause undesirable effects on overlay accuracy, if used for the overlay error correction. In order to systematically cope with such outliers, a new framework is proposed for detecting and handling outliers as well as for verifying the result. In the consideration of the proposed framework, a new outlier detecting and handling method is also proposed. This method is based on a robust regression technique and is compared with others through simulation to confirm its better performance.     

Redox-sensitive colorimetric polyaniline nanoprobes synthesized by a solvent-shift process

We have synthesized water-stable polyaniline nanoparticles coated with triarmed polyethylene glycol chains using a solvent-shift method and confirmed their colloidal size and aqueous solubility. Furthermore, we have demonstrated that the polyaniline nanoparticles can be doped with biological dopants to produce distinct color changes allowing the detection of live cancer cells.      

Cancer Diagnosis by Terahertz Molecular Imaging Technique

We obtained the diagnostic images of cancerous tumors by employing the THz molecular imaging (TMI) technique which measured the THz response change by surface plasmon resonance induced on the surface of nanoparticles with a irradiation of near-infrared (NIR) beam. To demonstrate the principle of the TMI technique, THz images of tissues with nanoprobes were observed and compared with THz only images. The sensitivity of TMI was further enhanced by adopting a THz differential measurement technique, which was realized by modulating the NIR beams. By employing this differential TMI technique, the diagnostic images of cancerous tumors were obtained ex vivo and in vivo in the preclinical stage. These images indicated the feasibility of applying the differential TMI technique in the clinical stage.     

Secure and Efficient Code Encryption Scheme Based on Indexed Table

Software is completely exposed to an attacker after it is distributed because reverse engineering is widely known. To protect software, techniques against reverse engineering are necessary. A code encryption scheme is one of the techniques. A code encryption scheme encrypts the binary executable code. Key management is the most important part of the code encryption scheme. However, previous schemes had problems with key management. In an effort to solve these problems in this paper, we survey the previous code encryption schemes and then propose a new code encryption scheme based on an indexed table. Our scheme provides secure and efficient key management for code encryption.