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Biochemical systems in living cells have their optimum concentration ratio among each constituent element to maintain their functionality. However, in the case of the biochemical system with complex interactions and feedbacks among elements, their activity as a system greatly changes by the concentration shift of the entire system irrespective of the concentration ratio among elements. In this study, by using a transcription-translation (TX-TL) system as the subject, we illustrate the principle of the nonlinear relationship between the system concentration and the activity of the system. Our experiment and simulation showed that shifts of the system concentration of TX-TL by dilution and concentration works as a switch of activity and demonstrated its ability to emerge a biochemical system to confer the permeability of small molecules to liposomes. These results contribute to the creation of artificial cells using the switch and provide an insight into the birth of the origin of life.

Here, we report on the design and function of a membrane nanopore through a DNA origami square tube with a cross-section of 100 nm2 . When the nanopore is added onto the giant vesicle membrane, the permeation of hydrophilic fluorescent molecules was observed. It can be sealed by the existence of the four specific single strand DNAs. A controllable artificial nanopore should help to communicate the vesicle components with their environment

An isothermal amplification circuit for specific DNA molecules was implemented in giant unilamellar vesicles. Using this circuit, over 5000-fold amplification of output DNAs was achieved, and the amplification behaviour depended on the concentration of input signal DNAs in a cell-sized compartment. Moreover, initiation of the amplification by photo-stimulation was demonstrated.

The most common way to fabricate DNA nanostructures is to mix individually synthesized DNA oligomers in one pot. However, if DNA nanostructures could be produced through enzymatic reactions, they could be applied in various environments, including in vivo. Herein, an enzymatic method developed to construct a DNA nanostructure from a simple motif called a T-motif is reported. A long, repeated structure was replicated from a circular template by rolling circle amplification and then cleaved into T-motif segments by restriction enzymes. These motifs have been successfully assembled into a ladder-like nanostructure without purification or controlled annealing. This approach is widely applicable to constructing a variety of DNA nanostructures through enzymatic reactions.

Cell-sized liposomes and droplets coated with lipid layers have been used as platforms for understanding live cells, constructing artificial cells, and implementing functional biomedical tools such as biosensing platforms and drug delivery systems. However, these systems are very fragile, which results from the absence of cytoskeletons in these systems. Here, we construct an artificial cytoskeleton using DNA nanostructures. The designed DNA oligomers form a Y-shaped nanostructure and connect to each other with their complementary sticky ends to form networks. To undercoat lipid membranes with this DNA network, we used cationic lipids that attract negatively charged DNA. By encapsulating the DNA into the droplets, we successfully created a DNA shell underneath the membrane. The DNA shells increased interfacial tension, elastic modulus, and shear modulus of the droplet surface, consequently stabilizing the lipid droplets. Such drastic changes in stability were detected only when the DNA shell was in the gel phase. Furthermore, we demonstrate that liposomes with the DNA gel shell are substantially tolerant against outer osmotic shock. These results clearly show the DNA gel shell is a stabilizer of the lipid membrane akin to the cytoskeleton in live cells.

Investigations into the refolding of DNA origami leads to the creation of reconstructable nanostructures and deepens our understanding of the sustainability of life. Here, we report the refolding of the DNA origami structure inside a micron-sized compartment. In our experiments, conventional DNA origami and truss-type DNA origami were annealed and purified to remove the excess staples in a test tube. The DNA origami was then encapsulated inside of a micron-sized compartment of water-in-oil droplets, composed of neutral surfactants. The re-annealing process was then performed to initiate refolding in the compartment. The resulting 100-nm-sized DNA nanostructures were observed using atomic force microscopy (AFM), and the qualities of their structures were evaluated based on their shape. We found that the refolding of the DNA origami structure was favored inside the droplets compared with refolding in bulk solution. The refolded structures were able to fold even under &ldquo, quick&rdquo, one-minute annealing conditions. In addition, the smaller droplets (average diameter: 1.2 &micro, m) appeared to be more advantageous for the refolding of the origamis than larger droplets. These results are expected to contribute to understanding the principles of life phenomena based on multimolecular polymer self-assembly in a micron-sized compartment, and for the production and maintenance of artificially designed molecules.

Flexible macroporous silicone gels were prepared using methyltrimethoxysilane and dimethyldimethoxysilane as coprecursors via a two-step reaction catalyzed by acetic acid and ammonia solution. A sheet-shaped material was integrated with the gel by immersing the mesh in the sol during the reaction. The mesh reinforced sheet having a thickness of several millimeters was resistant to bending and pulling and easy to handle, though the physical properties such as hydrophobicity and oleophilicity possessed by the bulk surface were not lost. The composite sheets are used for various applications such as water–oil separation, manipulation of water droplets by adsorption on hydrophobic surfaces, and preparation of giant vesicle dispersions by taking advantage of surface properties and porosity.

Giant vesicles were efficiently produced by squeezing a lipid (l-α-phosphatidylcholine from egg yolk)-coated marshmallow-like flexible macroporous silicone monolith in a buffer. The mean diameter of the obtained vesicles was 2 μm, showing a wide distribution, up to tens of micrometers, which was similar to that of vesicles formed by a natural swelling method. It was possible to prepare vesicle dispersions on a scale from several microliters to several hundred milliliters. A protein synthesis system (PURE system) contained in vesicles prepared using this method functioned effectively. Our absorbing-squeezing method is expected to help in studies that use giant vesicles such as artificial cells and drug delivery systems.

We propose a method to control the diffusion speed of DNA molecules with a target sequence in a polymer solution. The interaction between solute DNA and diffusion-suppressing DNA that has been anchored to a polymer matrix is modulated by the concentration of the third DNA molecule called the competitor by a mechanism called toehold exchange. Experimental results show that the sequence-specific modulation of the diffusion coefficient is successfully achieved. The diffusion coefficient can be modulated up to sixfold by changing the concentration of the competitor. The specificity of the modulation is also verified under the coexistence of a set of DNA with noninteracting base sequences. With this mechanism, we are able to control the diffusion coefficient of individual DNA species by the concentration of another DNA species. This methodology introduces a programmability to a DNA-based reaction-diffusion system.

Automobile bumper is a most important part in the aspect of safety, which protects the passengers from front and rear collision. Initially, metals were used as bumper to avoid the collision. In this modern era, the development of polymer and its composite plays an effective role in reducing the weight without sacrificing the functionality. However, the awareness of the available light weight polymer materials was not explored successfully by the industries. Hence, an attempt was made to carry out the systematic review on automobile bumper and its materials. Polypropylene (PP) is one of the widely used polymers in developing various automobile parts including automobile bumpers. The required mechanical properties of bumpers were not achieved successfully with the PP. Hence, the different concentration of various micro and nano fillers such as Multi walled carbon nanotubes (MWCNT), Single walled carbon nanotubes (SWNT), carbon black, glass fiber, carbon fiber, nanoclay, etc., were reinforced with PP to achieve the sufficient mechanical properties. One of our study shows that the reinforcement of 1.5 wt% of MWCNT enhanced the mechanical properties significantly, where the tensile strength, flexural strength, flexural modulus, and Young׳s modulus was found to be enhanced by 42.8, 33.7, 17.4, and 16%, respectively compared to pure PP. It was observed that various fillers were used with PP matrix to achieve the required mechanical properties, however the optimum filler concentration is still a concern. It is concluded that more research should be carried out to avoid the muddle in choosing filler and reinforcement concentration before practical usage.

An analytical method to determine fumonisin B1 (FB1), B2 (FB2) and B3 (FB3) in pet foods using a liquid chromatography-electrospray ionization-mass spectrometer (LC-ESI-MS) was developed, and an inter-laboratory study was conducted in eleven laboratories. FB1, FB2 and FB3 were extracted with aqueous acetonitrile. The extract was purified by a multifunctional column, MultiSep 211 Fum, and analysed by LC-ESI-MS. The limit of quantification of fumonisins was estimated to be 0.2 mg/kg for dry and semi-dry pet foods, and 0.1 mg/kg for wet pet food. The calibration curve showed linearity in the range of 0.1-5 ng of fumonisins (0.02-1.0 μg/ml). The values of the mean recovery for FB1 at 0.1-1.0 mg/kg were 93.3-107% and of the relative standard deviation less than 7.9%. These values were 87.3-102 and 8.6% for FB2 and 90.8-102 and 8.6% for FB3, respectively. The mean recovery, repeatability, reproducibility and the Horwitz ratio for FB1 from the inter-laboratory validation study were 92.9-98.9%, 2.6-4.6%, 6.8-10% and 0.41-0.54, respectively. The values for FB2 were 91.5-94.7%, 2.7-5.9%, 6.8-8.9% and 0.33-0.55, respectively, and the values for FB3 were 90.1-94.3%, 3.3-5.9%, 7.3-9.5% and 0.44-0.57, respectively.

A simple method of preparation giant vesicles by squeezing out with a buffer from flexible porous monoliths impregnated with lipids was reported.

We constructed a rotary DNA origami device and tested its stepping operation on a mica substrate by sequential strand displacement with four different sets of signal DNA strands. This work paves the way for building a variety of dynamic rotary DNA nanodevices which respond to multiple signals.

We show electric control of unzipping and shearing dehybridization of a DNA duplex anchored to a hydrogel. Tensile force is applied by electrophoresing (25 V cm−1) gold nanoparticles pulling the DNA duplex. The pulled DNA strand is gradually released from the hydrogel. The unzipping release rate is faster than shearing; for example, 3-fold for a 15 base pair duplex, which helps to design electrically driven DNA devices.

Temporal variations in the stable isotopic compositions of nitrate dissolved in stream water eluted from a cool–temperate forested watershed (8 ha) were measured to quantify the biogeochemical effects of clear-cutting of trees and subsequent strip-cutting of the understory vegetation, dwarf bamboo (Sasa senanensis), with special emphasis on changes in the fate of atmospheric nitrate that had been deposited onto the watershed based on Δ17O values of nitrate. A significant increase in stream nitrate concentration to 15 μmol L−1 in spring of 2004 was correlated with a significant increase in the Δ17O values of nitrate. Additionally, the high Δ17O values of +14.3‰ suggest that the direct drainage of atmospheric nitrate accounted for more than 50% of total nitrate exported from the forested watershed peaking in spring. Similar increases in both concentrations and Δ17O values were also found in spring of 2005. Conversely, low Δ17O values less than +1.5‰ were observed in other seasons, regardless of increases in stream nitrate concentration, indicating that the majority of nitrate exported from the forested watershed during seasons other than spring was remineralized nitrate: those retained in the forested ecosystem as either organic N or ammonium and then been converted to nitrate via microbial nitrification. When compared with the values prior to strip-cutting, the annual export of atmospheric nitrate and remineralized nitrate increased more than 16-fold and fourfold, respectively, in 2004, and more than 13-fold and fivefold, respectively, in 2005. The understory vegetation (Sasa) was particularly important to enhancing biological consumption of atmospheric nitrate., Published by Copernicus Publications on behalf of the European Geosciences Union.

Injection molded composites are becoming more widespread in recent years because of their high quality and low cost. However, compared to synthetic fiber composites, it is difficult to maintain a constant fiber volume fraction and uniform distribution for natural fiber composites during the direct injection process. This is mainly because natural fibers are more easily twisted during feeding into the injection machine, owing to their rough surfaces. These feeding difficulties are particularly due to the low bulk densities of natural fibers, especially natural fillers. Additional challenges to the injection process include the concentration and, especially for natural filler reinforced composite. To address these problems, the current study investigates the mechanical properties and morphologies of polypropylene (PP) reinforced by wood powder. Two pre-molding processes, dry-blending and compounding, were compared, and the effects of an additive (crystalline polyalpha olefin (CPAO)) on the mechanical properties of the wood/PP composites were investigated. This investigation is based on tensile, three point bending, and Izod impact tests, and scanning electron microscope (SEM) observation of the fracture surfaces. Results indicated that the composites molded through compounding exhibited better mechanical properties than the samples molded through the direct dry-blending process. In addition, the tensile and bending properties of the composites produced through compounding were found to increase with the addition of CPAO content, because of improved wood powder distribution in the PP matrix.

Oral mucositis is one of the most common side-effects of 5-fluorouracil (5-FU)-based chemotherapy. The objective of this study was to evaluate the effects of irsogladine maleate (IM) on fluorouracil-induced oral mucositis through a double-blind, placebo controlled trial.Patients (N = 66) were randomly assigned to receive either placebo or IM (4 mg/day for 14 consecutive days). The incidence and maximum severity of fluorouracil-induced oral mucositis and safety of the irsogladine dosing regimen were evaluated.A cohort of 33 patients received placebo and 33 patients received IM. The incidence of oral mucositis was significantly lower for IM than for placebo (27% versus 73%; P0.001 by chi-square test). Specific adverse events considered related to IM were not found.IM significantly reduced the incidence and maximum severity of oral mucositis in patients treated with 5-FU-chemotherapy.

Aims To determine whether the carotenoid production improves stress tolerance of lactic acid bacteria, the cloned enterococcal carotenoid biosynthesis genes were expressed in Lactococcus lactis ssp. cremoris MG1363, and the survival rate of carotenoid-producing engineered MG1363 strain under stress condition was investigated. Methods and Results We cloned carotenoid biosynthesis genes from yellow-pigmented Enterococcus gilvus. The cloned genes consisted of crtN and crtM and its promoter region were inserted into the shuttle vector pRH100, and the resulting plasmid was named pRC. The cloned crtNM was expressed using pRC in noncarotenoid-producing L. lactis ssp. cremoris MG1363. The expression of crtNM led to the production of C30 carotenoid 4,4′-diaponeurosporene. After exposure to 32 mmol l−1 H2O2, low pH (1.5, acidified with HCl), 20% bile acid and 12 mg ml−1 lysozyme, the survival rates of the MG1363 strain harbouring pRC were 18.7-, 6.8-, 8.8- and 4.4-fold higher, respectively, than those of MG1363 strain harbouring the empty vector pRH100. Conclusions The expression of carotenoid biosynthesis genes from Ent. gilvus improves the multistress tolerance of L. lactis. Significance and Impact of the study First report of the improvement of multistress tolerance of lactic acid bacteria by the introduction of genes for carotenoid production.

Proteoliposomes were directly prepared by synthesizing membrane proteins with the use of minimal protein synthesis factors isolated from Escherichia coli (the PURE system) in the presence of liposomes. Connexin-43 (Cx43), which is a water-insoluble integral membrane protein that forms a hexameric complex in membranes, was cotranslationally integrated with an essentially uniform orientation in liposomes. The addition of liposomes following protein expression (post-translational presence of liposomes) did not lead to the integration of Cx43 into the liposome membranes. The amount of integrated Cx43 increased as the liposome concentration increased. The presence of liposomes did not influence the total amount of synthesized Cx43. The Cx43 integrated into the liposome membranes formed open membrane pores. These results indicate that the liposomes act in a chaperone-like manner by preventing Cx43 from aggregating in solution, because of integration into the bilayer, and also by functionalization of the integrated Cx43 in the membrane. This is the first report that cell-free-synthesized water-insoluble membrane protein is directly integrated with a uniform orientation as a functional oligomer into liposome membranes. This simple proteoliposome preparation procedure should be a valuable approach for structural and functional studies of membrane proteins. Structured digital abstract • MINT-7900670: Cx-43 (uniprotkb:P08050) and Cx-43 (uniprotkb:P08050) bind (MI:0407) by cross-linking study (MI:0030)

Stimuli-responsive DNA gels that can undergo a sol-gel transition in response to photo-irradiation provide a way to engineer functional gel material with fully designed DNA base sequences. We propose an X-shaped DNA motif that turns into a gel by hybridization of self-complementary sticky ends. By embedding a photo-crosslinking artificial base in the sticky-end sequence, repetitive gel-sol transitions are achieved through UV irradiation at different wavelengths. The concentration of the DNA motif necessary for gelation is as low as 40 μm after modification of the geometrical properties of the motif. The physical properties, such as swelling degree and diffusion coefficient, were assessed experimentally.

Gardenia yellow powders A, B and C, containing geniposide at 0.284%, 0.938% and 2.783%, respectively, were administered orally to male and female SD rats as 3% feed admixtures for 13-weeks to evaluate any potential toxicity. Mean geniposide intake values were 5.72, 18.9 and 56.3 mg/kg/day in groups receiving these feed admixtures, respectively. All animals survived the duration of the study. The following findings were evident in the gardenia yellow C group: chromatouria, slightly increased plasma total bilirubin, blackish brown discoloration of the kidneys and liver, brown pigments in the proximal tubular epithelium of the kidneys. Slightly increased plasma total bilirubin was considered to be due to interference of metabolite of geniposide with the system of measurement and not to be a toxic effect since there were no related changes in histopathology of the liver or in any blood chemistry parameters. Other findings were limited to pigmentations or discolorations attributable to metabolites of geniposide. No treatment-related effects were evident on body weight, food consumption, ophthalmology, hematology or organ weights in any group. Therefore, it was concluded that 3-month ingestion of the gardenia yellow powder containing geniposide at 2.783% (approximately 60 mg/kg/day as geniposide intake) does not cause any severe toxic effects.

Large-pore hexagonal SBA-15 molecular sieves partially substituted with iron(III) have been synthesized for the first time in highly acidic media. The degree of iron(III) incorporation into SBA-15 can easily be controlled by a simple adjustment of the molar ratio of water and hydrochloric acid. All the materials have been characterized by XRD, N2 adsorption, UV−Vis DRS, ESR, and XANES spectroscopy. The characterization of the FeSBA-15 materials by UV−Vis DRS, ESR, and XANES spectroscopies suggests that the iron atoms are highly dispersed and mostly occupy isolated tetrahedral sites. XANES studies revealed that the proportion of tetrahedrally coordinated Fe atoms decreases with decreasing nSi/nFe ratios. Benzylation of benzene (or substituted benzenes) using benzyl chloride as the alkylating agent over FeSBA-15 with different nSi/nFe ratios was investigated as was the same reaction using AlSBA-15 as catalyst. The influence of parameters such as reaction temperature, reactant feed ratio, and the presence of...

Checkpoint kinase 1 (Chk1) is a cell cycle regulator and a heat shock protein 90 (Hsp90) client. It is essential for cell proliferation and survival. In this report, we analyzed the mechanisms of Chk1 regulation in U87MG glioblastoma cells using Geldanamycin (GA), which interferes with the function of Hsp90. GA reduced Chk1 protein level but not its mRNA level in glioblastoma cells. Co-treatment with GA and cycloheximide (CHX), a protein synthesis inhibitor, induced a decrease of half-life of the Chk1 protein to 3h and resulted in Chk1 down-regulation. CHX alone induced only 32% reduction of Chk1 protein even after 24h. These findings indicated that reduction of Chk1 by GA was due to destabilization and degradation of the protein. In addition, GA-induced down-regulation of Chk1 was reversed by MG132, a specific proteasome inhibitor. And it was revealed that Chk1 was ubiquitinated by GA. These results have indicated that degradation of Chk1 by GA was mediated by the ubiquitin-proteasome pathway in U87MG glioblastoma cells.

We report here a novel carrier of quantum dots (QDs) for intracellular labeling. Monodisperse hybrid nanoparticles (38 nm in diameter) of QDs were prepared by simple mixing with nanogels of cholesterol-bearing pullulan (CHP) modified with amino groups (CHPNH 2 ). The CHPNH 2 –QD nanoparticles were effectively internalized into the various human cells examined. The efficiency of cellular uptake was much higher than that of a conventional carrier, cationic liposome. These hybrid nanoparticles could be a promising fluorescent probe for bioimaging.

Hippocalcin is a member of the neuronal calcium sensor (NCS) protein family that is highly expressed in hippocampal pyramidal cells and moderately expressed in the neurons of cerebral cortex, cerebellum and striatum. Here we examined the physiological roles of hippocalcin using targeted gene disruption. Hippocalcin-deficient (−/−) mice displayed no obvious structural abnormalities in the brain including hippocampal formation at the light microscopic level. Deletion of hippocalcin did not result in up-regulation of the hippocalcin-related proteins; neural visinin-like Ca 2+ -binding proteins (NVP) 1, 2, and 3. The synaptic excitability of hippocampal CA1 neurons appeared to be normal, as estimated by the shape of field excitatory postsynaptic potentials elicited by single- and paired-pulse stimuli, and by tetanic stimulation. However, N -methyl- d -aspartate stimulation- and depolarization-induced phosphorylation of cAMP-response element-binding protein (CREB) was significantly attenuated in −/− hippocampal neurons, suggesting an impairment in an activity-dependent gene expression cascade. In the Morris water maze test, the performance of −/− mice was comparable to that of wild-type littermates except in the probe test, where −/− mice crossed the previous location of the platform significantly less often than +/+ mice. Hippocalcin-deficient mice were also impaired on a discrimination learning task in which they needed to respond to a lamp illuminated on the left or right side to obtain food reinforcement. No abnormalities were observed in motor activity, anxiety behavior, or fear learning. These results suggest that hippocalcin plays a crucial role in the Ca 2+ -signaling pathway that underlies long-lasting neural plasticity and that leads to spatial and associative memory.

(13)C-detected experiments are still limited by their inherently lower sensitivity, as compared to the equivalent (1)H-detected experiments. Improving the sensitivity of (13)C detection methods remains a significant area of NMR research that may provide better means for studying large macromolecular systems by NMR. In this communication, we show that (13)C-detected experiments are less sensitive to the salt concentration of the sample solution than (1)H-detected experiments. In addition, acquisition can be started with anti-phase coherence, resulting in higher sensitivity due to the elimination of the final INEPT transfer step.

By collision of 120 keV Ar8+ with planar hydrocarbons, ethylene and benzene, dissociation of multiply ionized target molecules was studied, focusing attention on the possibility that all the fragment ions are ejected, or tend to be ejected, in a single plane. The trajectories of fragment ions were determined by position-sensitive time-of-flight measurements and the angular correlation of the initial velocity vectors was compared to the results of a reference non-planar molecule, ethane. To eliminate ambiguity due to the contribution of the residual gases, dissociation of ethylene-d4 and benzene-d6 was also examined. The results indicate that the initial velocity direction of the fragments indeed tends to be confined in a single plane when the target molecules are planar. That is, the angular correlation of fragment ions conserves the information on the molecular structure even for considerably large molecules.

Three isomers of difluorobenzene were multiply ionized by low-energy collisions with Ar8+, and their subsequent dissociation was studied using position-sensitive time-of-flight (TOF) measurements combined with a coincidence technique. The vector correlation of the velocities of the two F+ fragment ions was examined and found to be sensitive to the structure.

Structurally diverse organophosphonate inhibitors targeting the active site of the enzyme were used to investigate the relationship of the active site and the dimer interface of wild-type protease in solution. Positional scanning synthetic combinatorial libraries revealed Kaposi's sarcoma-associated herpesvirus protease to be highly specific, even at sites distal to the peptide bond undergoing hydrolysis. Specificity results were used to synthesize a hexapeptide diphenylphosphonate inhibitor of Kaposi's sarcoma-associated herpesvirus protease. The transition state analog inhibitors covalently phosphonylate the active site serine, freezing the enzyme structure during catalysis. An NMR-based assay was developed to monitor the native monomer-dimer equilibrium in solution and was used to demonstrate the effect of protease inhibition on the quaternary structure of the enzyme. NMR, circular dichroism, and size exclusion chromatography analysis showed that active site inhibition strongly regulates the binding affinity of the monomer-dimer equilibrium at the spatially separate dimer interface of the protease, shifting the equilibrium to the dimeric form of the enzyme. Furthermore, inhibitor studies revealed that the catalytic cycles of the spatially separate active sites are independent. These results ( i ) provide direct evidence that peptide bond hydrolysis is integrally linked to the quaternary structure of the enzyme, ( ii ) establish a molecular mechanism of protease activation and stabilization during catalysis, and ( iii ) highlight potential implications of substoichiometric inhibition of the viral protease in developing herpesviral therapeutics.

Continuous emulsion copolymerizations of styrene(St) and methyl methacrylate(MMA) were carried out at 50°C in a single continuous stirred tank reactor (CSTR) using sodium lauryl sulfate as emulsifier and potassium persulfate as initiator, respectively. The effect of operational variables such as the initiator and emulsifier concentrations in the feed and the mean residence time on the kinetic behavior was examined with the weight ratio of St/MMA in the monomer feed fixed at 1.0. It was found that 1) oscillation in monomer conversion takes place, although its amplitude is comparatively small compared with that usually observed in the continuous emulsion polymerization of vinyl acetate in a CSTR, 2) the (time‐average) steady‐state total monomer conversion is proportional to the 1.7 power of the emulsifier, to the − 0.2 power of the initiator concentrations and to the 1.0 power of the mean residence time, and 3) the (time‐average) steady‐state number of polymer particles produced is proportional to the 2.5 p...

We have studied the spontaneous formation of giant liposome from dry lipid film under an aqueous solution of long DNA molecules, T4DNA 165 kbp. The number density of DNAs entrapped inside liposomes formed with 10 mM Mg2+ solution is one order of magnitude higher than that in the bulk solution. In addition, DNA molecules assume a somewhat shrunken conformation in phospholipid solution containing Mg2+. The mechanism of the enhanced uptake of DNA into cell-sized liposomes is discussed in relation to the local increase in osmotic pressure due to DNA molecules attached to the membrane surface through Mg2+.

Research has been carried out on the use of glass fibers (hereafter referred to as “GF”) to form a beam structure of GF reinforced thermoplastic composites. GF is generally supplied in lengths 0.2 to 0.6 mm and dispersed in a discontinuous form in a matrix resin in conventional GF reinforced thermoplastic composites. We have successfully developed a method to form a beam structure in which the GF are apparently joined in the matrix resin by utilizing the fact that polymers with a high affinity for GF migrate to the interface of the GF. That is, by adding a small quantity of resin having a higher heat resistance than the matrix resin and having an excellent affinity for GF, we have been successful in joining the fibers by selectively migrating this small quantity of resin to the interface with the GF. This beam structure material was found to have a heat distortion temperature (HDT) significantly higher than that of conventional GF reinforced thermoplastic composites. By applying this concept to glass fiber reinforced polystyrene (GFPS), the HDT of GFPS improved from 100°C - 110°C to 200°C - 250°C.

In this paper we investigate self-diffusion of Ti and Al along interfaces present in the lamellar L10 TiAl by atomistic computer modeling. The interactions between the atoms are described by central-force many-body potentials. The approach adopted is similar to that used in earlier atomistic modeling of bulk diffusion in TiAl [1, 2]. Both the formation and migration of vacancies is examined. The interfaces studied are the three types of γ–γinterfaces: ordinary twin, pseudotwin and 120° rotational fault. For the latter two interfaces the diffusion was investigated not only for the stoichiometric case but also when the interfaces possess a surplus of titanium in the form of a layer with the composition and structure of Ti3Al, as was found in an earlier Monte Carlo study of titanium segregation to these interfaces. The calculations suggest that the diffusivity along γ–γinterfaces is higher than in the bulk. However, the difference between bulk and interfacial diffusivity is not as drastic as it may be encountered in grain boundaries. At the same time the above mentioned surplus of Ti appears to affect the interfacial diffusion only marginally.

Hyponatremia associated with syndrome of inappropriate secretion of antidiuretic hormone (SIADH) or renal salt-wasting syndrome (RSWS) after platinum-based chemotherapy is not uncommon. However, no reports of RSWS following taxane monotherapy have been previously published. We report a case of a 63-year-old man with esophageal cancer who developed RSWS after docetaxel administration. He was diagnosed as having esophageal cancer and underwent esophagectomy. This was followed by adjuvant chemoradiotherapy consisting of a total dose of 50 Gy plus cisplatin combined with 5-fluorouracil. Two years after primary treatment, he was admitted to our hospital because of severe pain due to bone metastasis and mediastinal lymph node metastases. Ten days following chemotherapy consisting of nedaplatin and 5-fluorouracil, he experienced severe hyponatremia (113 mEq/L) due to SIADH. Subsequently, 7 days following third-line chemotherapy with docetaxel, he again experienced severe hyponatremia (104 mEq/L), this time due to RSWS. He was treated with a sodium supplement, to which he responded well. He recovered from the hyponatremia episode within a few days without any complications. In summary, treatment with docetaxel may lead to RSWS, even in patients with normal renal function. To the best of our knowledge, this is the first reported case of RSWS related to taxane chemotherapy in esophageal cancer. Oncologists should be aware of the possibility that docetaxel could cause RSWS.

Continuous emulsion polymerizations of vinyl acetate were conducted at 50°C in a single continuous Couette–Taylor vortex flow reactor (CCTVFR) using sodium lauryl sulfate as emulsifier and potassium persulfate as initiator. The polymerization can be carried out very smoothly and stably, but the steady-state monomer conversion attained in a CCTVFR is not as high as that in a plug flow reactor (PFR), but only slightly higher than that in a continuous stirred tank reactor (CSTR), even if the Taylor number is adjusted to an optimum value. Also, the effects of operating variables, such as the emulsifier, initiator, and monomer concentrations in the feed and the mean residence time on the kinetic behaviors were almost the same as those observed in a CSTR. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2755–2762, 2002

Continuous emulsion polymerizations of vinyl acetate were carried out at 50 °C in a single continuous stirred-tank reactor using sodium lauryl sulfate as emulsifier and potassium persulfate as initiator. It was found that (1) the so-called limit cycles could take place in monomer conversion, the number of polymer particles and the molecular weight of polymers produced under certain operating conditions, (2) the time-average steady-state monomer conversion was proportional to the 0.31 power of the emulsifier concentration in the feed, to the 0.50 power of the initiator concentration, to the −1.0 power of the monomer concentration, and to the 0.90 power of the mean residence time, and (3) the time-average steady-state number of polymer particles produced was proportional to the 2.1 power of the emulsifier concentration in the feed, to the −0.80 power of the initiator concentration, to the 0 power of the monomer concentration, and to the −0.92 power of mean residence time. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2748–2754, 2002

The effects of boric acid additions on the pH close to the electrode surface, on the hydrogen evolution reaction and on the internal stress in the plated films were studied for the high speed electroplating of nickel from a nickel sulfamate bath at a current density close to the nickel ion limiting current density. The study was carried out at 50 °C and pH 4.0 using a 1.55 M nickel sulfamate plating bath containing boric acid at concentrations ranging from 0 to 0.81 mol L−1. The variation of the internal strain in the plated nickel films was determined in situ using a resistance wire-type strain gauge fitted to the reverse side of the copper electrode substrate. The solution pH at a distance of 0.1 mm from the depositing nickel film was measured in situ using a miniature pH sensor assembly consisting of a thin wire-type antimony electrode and a Ag/AgCl/sat. KCl electrode housed in a thin Luggin capillary. The addition of boric acid was shown to effectively suppress the hydrogen evolution reaction at nickel electrodeposition rates (18.0 A dm−2) close to the limiting current density (~20 A dm−2). Consequently, the solution pH adjacent to the plating metal surface was maintained at a value close to that in the bulk solution and the development of high internal stresses in the deposited nickel films was avoided.

A new class of artificial molecular transport system is constructed by polymeric microspheres. The microspheres are prepared by self-assembly of poly(ethylene glycol)-block-poly(3-dimethyl(methacryloyloxyethyl)ammonium propane sulfonate), PEG-b-PDMAPS, by intermolecular dipole-dipole interaction of sulfobetaine side chains in water. Below the upper critical solution temperature (UCST) of PEG-b-PDMAPS, the microspheres (∼1μm) interact with other microspheres by partial and transit fusion. In order to apply the interaction between microspheres, a 3'-TAMRA-labeled single-stranded DNA oligomer (ssDNA) is encapsulated into a PEG-b-PDMAPS microsphere by thermal treatment. The exchange of ssDNA between microspheres is confirmed by fluorescence resonance energy transfer (FRET) quenching derived from double-stranded formation with complementary 5'-BHQ-2-labeled ssDNA encapsulated in PEG-b-PDMAPS microspheres. The exchange rate of ssDNA is controllable by tuning the composition of the polymer. The contact-dependent transport of molecules can be applied in the areas of microreactors, sensor devices, etc.

Sharp luminescence originating from intra-atomic 4f-4f transition from both Eu and Tb doped GaN was observed at 622 nm which can be assigned to 5 D 0 - 7 F 2 transition of Eu 3+ and at 545 nm which can be assigned to 5 D 4 - 7 F 5 transitions of Tb 3+ . However, the luminescence intensity of Eu 3+ is two orders of magnitude stronger than that of Tb 3+ though the content of the rare earth elements is almost the same. The cause of the difference in the luminescence properties was studied based on the defect-related energy transfer model, and the role of the defects observed by Fourier transform infrared (FTIR) spectra was discussed.

The propagation-rate constant of vinylidene chloride (VDC) was determined at 40 and 50 °C, respectively, by applying the so-called Ugelstad plot to the polymerization-rate data of the seeded and unseeded emulsion polymerizations of VDC. The values of the propagation-rate constant kp thus determined are kp = 64 dm3/mol · s at 50 °C and kp = 52 dm3/mol · s at 40 °C, respectively. From these kp values, the activation energy for propagation reaction was determined to be Ep = 4.2 kcal/mol, which is close to that of vinyl chloride (3.7 kcal/mol). © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1005–1015, 2001

We report a novel rhythmic phenomenon of a single polymer chain between the elongated coil state and the folded compact state under thermodynamically open conditions. It is shown that a T4 DNA molecule (166 kbp) in poly(ethylene glycol) (PEG) solution exhibits rhythmic conformational change at the focus of a continuous wave (CW) Nd:YAG laser beam (1064 nm), where the laser beam plays dual roles: trapping a molecular chain and making a temperature gradient around the focus. The conformational oscillation is discussed in terms of the limit-cycle oscillation of a single polymer chain driven through the dissipation of the photon energy.

Cu(II) and Zn(II) complexes of hyaluronate (Hy) were prepared. The local structures and binding sites were determined by Cu and Zn K-EXAFS and XANES measurements in the solid state. Both metal ions were found to be coordinated to Hy via carboxylate and oxygen atoms and probably O-1. The NH group of the acetamido moiety does not take part in the complexation. Analysis of the EXAFS spectra revealed that the oxygen coordination geometry around the Cu(II) ion (distorted octahedron) and the Cu–O bond length ( r eq =200 pm) in the Cu(II)–Hy complex are not very different from those in the hexaaqua Cu(II) ion (195 pm). The Zn(II)–Hy complex is tetra coordinated in a tetrahedral structure, with an average Zn-O bond length of 202 pm. The non-bonding Cu...C and Zn...C distances were determined to be 315 and 299 pm, respectively. These values and the large Debye–Waller factors indicate the macrochelate coordination mode of the ligand.

Emulsion polymerization of vinylidene chloride was carried out at 50°C using sodium lauryl sulfate as emulsifier and potassium persulfate as initiator, respectively. Contrary to the results so far reported, the stirring rate did not affect the progress of the polymerization and such an abnormal kinetic behavior as the rate of polymerization suddenly drops in the course of polymerization was not observed. The number of polymer particles produced was proportional to the 0.7 power of the concentration of emulsifier forming micelles and to the 0.3 power of the initial initiator concentration, respectively, and was independent of the initial monomer concentration. The rate of polymerization was in proportion to the 0.3 power of the concentration of emulsifier forming micelles, to the 0.5 power of the initial initiator concentration, to the 0.2 power of the initial monomer concentration, and to the 0.45 power of the number of polymer particles, respectively.

The structure change of SrTiO 3 (111) polar surface was studied as a function of atmosphere. Atomic force microscopy (AFM) and coaxitial impact-collision ion-scattering spectroscopy (CAICISS) were used to study the surface structure of the (111) polar surfaces of SrTiO 3 single crystals. From the result of AFM observation, the polar surfaces annealed in oxygen gas had a trench structure, and that annealed in argon gas formed large triangular terraces. The surface annealed in air, i.e. in intermediate oxygen partial pressure, consisted of complicated self-similar triangles with different sizes, forming a fractal shape called Sierpinski's gasket. The time of flight spectra of CAICISS suggested that a Ti 4+ plane was more stable than a SrO 3 4− plane on the substrate surface annealed in oxygen gas, and the Ti 4+ and SrO 3 4− planes almost equally existed on the substrate surface annealed in argon gas. Molecular dynamic calculations at constant temperature and pressure were applied for various SrTiO 3 (111) polar surfaces.

Chemical and morphological characterization of carbon thin films produced by chemical vapor deposition (CVD) of hydrocarbon gases onto a hard carbon substrate has been performed using various surface analytical techniques. Semiquantitative analyses of the surface concentration of C C double bonds have been conducted using near edge X-ray absorption fine structure (NEXAFS) at the C K edge and core level X-ray photoelectron spectroscopy (XPS). NEXAFS spectra of CVD carbon films are similar to those of well-ordered graphite. Rather surprisingly, however, it has been revealed that the CVD carbon films contain less C C double bonds than that of the hard carbon. Intensities of π-π * shake-up satellite of the C 1s XPS peak have been measured, and the results were consistent with those of NEXAFS. Smaller concentrations of C C double bonds can be attributed to the incomplete dehydrogenation due to the relatively low temperature of the CVD treatment. High resolution transmission electron microscope (TEM) images of CVD carbon showed preferential orientation of graphite-like plane units in the direction parallel to the surface, suggesting the formation of large molecules in gas phase reaction prior to deposition.

Femtosecond electron diffraction has been used to probe the photoinduced phase transition in the strongly-correlated system, Me4P[Pt(dmit)2]2, revealing molecular motions involved in this process and breaking new ground in terms of chemical complexity.

To diagnose depth of invasion of early flat and depressed nonpolypoid colorectal cancers with double-contrast barium enema examination.Ninety-seven early nonpolypoid colorectal cancers, initially identified with colonoscopy, were investigated with double-contrast barium enema examination. Depth of invasion in resected specimens obtained with endoscopic mucosal or surgical resection was determined. Cancer confined to the mucosal layer or with focal extension to the submucosal layer was defined as Ca-m; moderate to massive extension of cancer into the submucosal layer was classified Ca-sm.In flat elevated and depressed cancers, converging folds and semilunar deformity were observed significantly more frequently in Ca-sm than in Ca-m tumors (P.05 and P.01, respectively). Sensitivities and specificities of these findings for Ca-sm tumor were 42%, 93% and 86%, 85%, respectively. Deep depression, irregular surface of the depression, and tumor size larger than 20 mm were also predictive findings for depressed Ca-sm tumors (P.05); the specificity of each was 100%. With use of these radiographic predictors, overall accuracy for diagnosing depth of invasion was 85%.Findings on double-contrast barium enema study are highly predictive of depth of invasion of early nonpolypoid colorectal cancer. Radiographic findings of converging folds, semilunar deformity, deep depression, irregular surface of the depression, and tumor size are predictors of Ca-sm tumor.