Discrimination of Copper Molten Marks through a Fire Reproduction Experiment Using Microstructure Features.

The copper molten marks at a fire site provide important clues for determining the causes of fire. Four factors have been presented to quantitatively discriminate copper molten marks, namely the fraction of (001) component perpendicular to the demarcation line, the grain aspect ratio, the fraction of Σ3 boundaries, and the fraction of maximum grain size. However, only laboratory-level results of these parameters have been presented, and their applicability in actual fires is yet to be verified. In this study, a fire reproduction experimental system was configured to generate molten marks similar to those in actual fire sites. The molten marks were measured by electron backscatter diffraction and applied to the four discriminant factors. The results obtained similar characteristics to those of the laboratory unit, confirming the applicability of the four discriminant factors. Discriminant equations and processes that can distinguish the primary and secondary arc beads were derived using the molten marks generated in the laboratory and reproduction experiments. Furthermore, a probabilistic discrimination method and classification model developed by machine learning were proposed. Therefore, the use of the discriminants in actual fires can improve the reliability of the statistics and prevent the recurrence of similar fires.

Potential Method to Distinguish Copper Molten Marks Using Boundary and Grain Characteristics.

The microstructure of molten marks changes according to ambient temperatures, when a short circuit occurs. Investigation of microstructural changes is important for understanding the properties of copper and examining the cause of a fire. In this study, the boundary characteristics and grain-size distribution of molten marks-primary-arc beads (PABs), which short-circuited at room temperature (25 °C), and secondary-arc beads (SABs), which short-circuited at high temperatures (600 °C, 900 °C)-were compared using electron backscatter diffraction. The distribution of Σ3 boundaries was compared, and it was found that SABs have a higher fraction of Σ3 boundaries than PABs. Moreover, it was confirmed that the ratio of maximum grain size (area) to the total area of the molten mark in SABs is larger than that in PABs. Thus, reliable discriminant factors were suggested, such as the fraction of Σ3 boundaries and normalized maximum grain size, which can distinguish PABs and SABs. The four discriminant factors, such as the (001)//LD, GAR, fraction of Σ3 boundaries, and fraction of maximum grain size to the total molten-mark area, were verified using the machine learning of t-SNE and Pearson correlation analyses.

Simultaneously Improved Cubic Phase Stability and Li-Ion Conductivity in Garnet-Type Solid Electrolytes Enabled by Controlling the Al Occupation Sites.

Here, we, for the first time, report on the simultaneous enhancement in cubic phase stability and Li-ion conductivity of garnet-type solid electrolytes (SEs) by adding excess Li/Al. The excess Al/Li creates very large grains of up to 170 µm via the segregation of Al at the grain boundaries and enables preferential Al occupation at 96h sites over 24d sites, a behavior contrary to previous observations. The resulting SE shows improved Li-ion conductivity due to the large grain size and less blocking Li pathway caused by different preferential Al occupation. Surprisingly, it is observed that the cubic phase of the garnet-type SE is transformed to the tetragonal phase on the surface and in the bulk under the applied voltage, and the preferential Al occupation enables its cubic phase stability. Under battery operating conditions, the LLZO SE with excess Li/Al can maintain high ionic conductivity due to the cubic phase stability and large grain size. We clearly demonstrate that the cubic phase stability and ionic conductivity of LLZO can be simultaneously improved by excess Li/Al without any post-treatments. The findings and understanding will provide new insights into practical use of the garnet-type SEs for advanced all solid-state batteries.

Anticancer drug-incorporated layered double hydroxide nanohybrids and their enhanced anticancer therapeutic efficacy in combination cancer treatment.

OBJECTIVE: Layered double hydroxide (LDH) nanoparticles have been studied as cellular delivery carriers for anionic anticancer agents. As MTX and 5-FU are clinically utilized anticancer drugs in combination therapy, we aimed to enhance the therapeutic performance with the help of LDH nanoparticles. METHOD: Anticancer drugs, MTX and 5-FU, and their combination, were incorporated into LDH by reconstruction method. Simply, LDHs were thermally pretreated at 400°C, and then reacted with drug solution to simultaneously form drug-incorporated LDH. Thus prepared MTX/LDH (ML), 5-FU/LDH (FL), and (MTX + 5-FU)/LDH (MFL) nanohybrids were characterized by X-ray diffractometer, scanning electron microscopy, infrared spectroscopy, thermal analysis, zeta potential measurement, dynamic light scattering, and so forth. The nanohybrids were administrated to the human cervical adenocarcinoma, HeLa cells, in concentration-dependent manner, comparing with drug itself to verify the enhanced therapeutic efficacy. CONCLUSION: All the nanohybrids successfully accommodated intended drug molecules in their house-of-card-like structures during reconstruction reaction. It was found that the anticancer efficacy of MFL nanohybrid was higher than other nanohybrids, free drugs, or their mixtures, which means the multidrug-incorporated LDH nanohybrids could be potential drug delivery carriers for efficient cancer treatment via combination therapy.

Inorganic nanomedicines and their labeling for biological imaging.

In this review, we are going to demonstrate the recent progresses in inorganic nanomaterial-based nanomedicines and their labeling for effective biological imaging. Nanomaterials which are classified according to their dimensionality, from zero- to three-dimensions can be utilized as nanomedicines including drug delivery, therapy and diagnosis. In the following section, the labeling of nanomaterials with various contrasting agents are introduced. Various labeling agents like fluorescence, quantum dots, upconversion nanoparticles, magnetic particles and radioisotopes can be tagged on nanomaterials for effective imaging such as optical, magnetic resonance, computed tomography, positron emission tomography and etc. The labeling of contrasting agent on nanomedicine can be summarized into intercalation, surface modification, embedment and combination depending on how and where the label is tagged. Through these approaches, multimodal biological imaging and multifunctional nanomedicine could be suggested.

Anticancer activity of ferulic acid-inorganic nanohybrids synthesized via two different hybridization routes, reconstruction and exfoliation-reassembly.

We have successfully prepared nanohybrids of biofunctional ferulic acid and layered double hydroxide nanomaterials through reconstruction and exfoliation-reassembly routes. From X-ray diffraction and infrared spectroscopy, both nanohybrids were determined to incorporate ferulic acid molecules in anionic form. Microscopic results showed that the nanohybrids had average particle size of 150 nm with plate-like morphology. As the two nanohybridization routes involved crystal disorder and random stacking of layers, the nanohybrids showed slight alteration in z-axis crystallinity and particle size. The zeta potential values of pristine and nanohybrids in deionized water were determined to be positive, while those in cell culture media shifted to negative values. According to the in vitro anticancer activity test on human cervical cancer HeLa cells, it was revealed that nanohybrids showed twice anticancer activity compared with ferulic acid itself. Therefore we could conclude that the nanohybrids of ferulic acid and layered double hydroxide had cellular delivery property of intercalated molecules on cancer cell lines.

Porous SnO2/layered titanate nanohybrid with enhanced electrochemical performance for reversible lithium storage.

A porous hybrid of titanate nanosheets with SnO(2) nanoparticles has been realized by an exfoliation and reassembling route. The present nanohybrid shows a large reversible capacity of 860 mA h g(-1) with a good capacity retention (about 60% retention of the initial capacity after 50 cycles).

Surface passivation of CeO2 catalyst and its ultraviolet screening effect.

A new strategy was attempted to fabricate CeO2 nanoparticles using the surface fluorination technique to control the particle size and suppress the catalytic activity. The fluorinated CeO2 nanoparticles are fully characterized with XRD, XANES, UV-vis spectroscopy, HR-TEM, XPS along with the evaluation of photo and thermal catalytic activities. XRD patterns were not affected by surface fluorination. That is to say, the crystalline structure of CeO2 was not deteriorated upon fluorination. The TEM analysis showed that the fluorinated CeO2 nanoparticles with the primary particle size of 7 nm could be prepared. According to the X-ray absorption near edge structure (XANES) analysis, overall XANES spectrum was not changed upon fluorination, suggesting that the local structure of fluorinated CeO2 resembled that of the starting CeO2 nanoparticles. It was also revealed that both photo and thermal catalytic activities could be almost totally suppressed at the fluorination level of ca. 6.0 wt%. It is suggested that the selective surface fluorination with fluoride could lead to fluorinated CeO2 nanoparticles, which could be applied to new fields such as the cosmetics industries.

Amorphous tungstate precursor route to nanostructured tungsten oxide film with electrochromic property.

Electrochromic tungsten oxide (WO3) films on ITO glass were fabricated by spin-coating with a tungsten peroxy acid solution, which was prepared by adding an equivolume mixture of hydrogen peroxide and glacial acetic acid to tungsten metal powder. The structural evolution of the tungstate precursor upon heat treatment was studied by X-ray diffraction (XRD) and X-ray absorption near edge structure (XANES) analyses, which indicated that the as-synthesized tungstate transformed into nanocrystalline WO3 upon heating. It is, therefore, quite clear that as-synthesized tungstate can be a good precursor for electrochromic WO3 films. A series of WO3 thin films were prepared on ITO glass by spin-coating with different concentrations of tungsten peroxy acid solution and then post-annealing at various temperatures. Depending on the concentration of the tungstate coating solution (200-500 mg mL(-1)) and the annealing temperature (100-300 degrees C), the thickness and WO3 content as well as the electrochromic properties of WO3 films can be controlled. As a result, the optimum fabrication conditions were determined to be a tungstate solution concentration of 300-400 mg mL(-1) and a post-annealing temperature of 200 degrees C. Finally, an inorganic-inorganic hybrid electrochromic device (ECD) composed of optimized WO3 and Prussian Blue (PB) with desirable coloration efficiency was successfully developed.

A dual-polymer electrochromic device with high coloration efficiency and fast response time: poly(3,4-(1,4-butylene-(2-ene)dioxy)thiophene)-polyaniline ECD.

A new dual-polymer electrochromic device (ECD) composed of poly(3,4-(1,4-butylene-(2-ene)dioxy)thiophene) (PBueDOT) and polyaniline (PANI) with a hydrophobic molten salt electrolyte has been developed. To build this system, an alkylenedioxy ring in the BueDOT backbone was expanded to include a strongly electron-donating alkylenedioxy bridge, and the thickness and surface morphology of the corresponding PBueDOT film were controlled systematically. Not only the dual-electrochromic-polymer-electrode system, but also the expanded alkylenedioxy ring in the BueDOT backbone, synergistically improved the electrochromic performance. From the coloration efficiency (CE) value calculations, we found that the CE was enhanced up to 930 cm(2) C(-1). Furthermore, these ECDs showed an extremely fast response time of less than 80 ms.

Norepinephrine induces VEGF expression and angiogenesis by a hypoxia-inducible factor-1α protein-dependent mechanism.

A growing number of studies have demonstrated that physiological factors can influence the progression of several cancers via cellular immune function, angiogenesis and metastasis. Recently, stress-induced catecholamines have been shown to increase the expression of various cancer progressive factors, including vascular endothelial growth factor (VEGF), matrix metalloproteinases and interleukins. However, a detailed mechanism remains to be identified. In this study, we investigated the role of adrenergic receptors and hypoxia-inducible factor (HIF)-1α protein in catecholamine-induced VEGF expression and angiogenesis. Treatment of the cells with norepinephrine (NE) or isoproterenol induced VEGF expression and HIF-1α protein amount in a dose-dependent manner. Induction of VEGF expression by NE was abrogated when the cells were transfected with HIF-1α-specific siRNA. Similarly, adenylate cyclase activator forskolin and cyclic AMP-dependent protein kinase A inhibitor H-89 enhanced and decreased HIF-1α protein amount, respectively. More importantly, conditioned medium of NE-stimulated cancer cells induced angiogenesis in a HIF-1α protein-dependent manner. In addition, pretreatment of cells with propranolol, a ß-adrenergic receptor (AR) blocker, completely abolished induction of VEGF expression and HIF-1α protein amount by NE in all of the tested cancer cells. However, treatment with the α1-AR blocker prazosin inhibited NE-induced HIF-1α protein amount and angiogenesis in SK-Hep1 and PC-3 but not MDA-MB-231 cells. Collectively, our results suggest that ARs and HIF-1α protein have critical roles in NE-induced VEGF expression in cancer cells, leading to stimulation of angiogenesis. These findings will help to understand the mechanism of cancer progression by stress-induced catecholamines and design therapeutic strategies for cancer angiogenesis.

Enhanced lithium storage capacity and cyclic performance of nanostructured TiO2-MoO3 hybrid electrode.

New porous heterostructure of TiO(2)-MoO(3) nanohybrids have been successfully synthesized via an exfoliation and reassembling method: the hybridization between TiO(2) and MoO(3) gives rise to a remarkable enhancement of the reversible capacity of 420 mAhg(-1).

Porous organo-functionalized silica/clay hybrids.

Two negatively charged species of silica nanoparticles and exfoliated clay nanosheets have been successfully assembled into highly porous frameworks through a direct hybridization reaction with the help of a surface modification technique. In order to create attractive Coulombic interaction between two components, the surface of silica was modified with positively chargeable aminosilane coupling agents. Without any additional post-calcination, as-prepared hybrid materials are highly porous with the BET specific surface area of 480 m2/g.

One step route to the fabrication of arrays of TiO2 nanobowls via a complementary block copolymer templating and sol-gel process.

Highly dense, ordered arrays of a titania (TiO2) nanomaterial with a bowl-shape morphology are generated by using poly(styrene-block-ethylene oxide) (PS-b-PEO) block copolymers as templates combined with a sol-gel process. Porous organic-inorganic hybrid films with titania nanodomains incorporated in the PEO domains can be produced by one step spin-coating. By manipulating the relative composition of the precursor ingredients, a simple protocol to fabricate hexagonally packed arrays of nanobowls is defined. Addition of a second inorganic precursor into the common solution leads to arrays of composite Au-TiO2 nanobowls. Such organic-inorganic hybrids and pure titania nanostructures with controlled shape and size exhibit unique photophysical properties.

Enhanced contrast of electrochromic full cell systems with nanocrystalline PEDOT-prussian blue.

Poly-(3,4-ethylenedioxythiophene) (PEDOT) is an ideal polymer for electrochromic (EC) devices due to its fast response time, high conductivity, and facile fabrication in a doped form except its demerit like an optical contrast limitation. In this study, we developed a simple way to overcome low coloration efficiency of PEDOT through fabricating a complementary PEDOT and prussian blue full cell system. Fundamental properties of EC displays, such as optical contrast, coloration efficiency, and switching speed, could be successfully optimized by controlling the deposition time and applied voltage during EDOT polymerization. In particular, UV transmittance spectra indicated that the optical contrast was enhanced up to 31 approximately 99% at the wavelength of 600 nm. Scanning electron microscopy images showed that the optimized PEDOT and prussian blue films were deposited on ITO glass substrate with an uniform thickness of approximately 180 nm and approximately 190 nm, respectively. Moreover, according to the circuit analysis, the average response time of electric current for the optimized full cell system was about 400 ms. It is, therefore, concluded that such a full cell system could have high potential applications as smart windows and/or optical devices.