Thermoreversible Gel-Dispersed Liquid Crystals

A simple model is introduced to describe phase behaviours of binary mixtures of a thermoreversible gel and a low-molecular-weight liquid crystal (LC). We predict novel phase diagrams on the temperature-concentration plane, including sol-gel transition, nematic-isotropic phase transition, and phase separation. At high temperatures, the phase separation between the isotropic sol and gel phases appears. As the temperature decreases, we have the phase separation between nematic sol and isotropic gel phases, in which the nematic domains are dispersed in the isotropic gel phase. We suggest that thermoreversible gelation of reactive molecules mixed with LCs will become one of the new classes of polymer-dispersed liquid crystals.

Enhanced Material Assimilation in a Toroidal Plasma Using Mixed H_{2}+Ne Pellet Injection and Implications to ITER

The ablation and assimilation of cryogenic pure H_{2} and mixed H_{2}+Ne pellets, which are foreseen to be used by the ITER tokamak for mitigating thermal and electromagnetic loads of major disruptions, are observed by spatially and temporally resolved measurements. It is experimentally demonstrated that a small fraction (here ≈5%) of neon added to hydrogenic pellets enhances the core density assimilation with reduced outward transport for the low magnetic-field side injection. This is consistent with theoretical expectations that line radiation increased by doped neon in dense plasmoids suppresses the plasmoid pressure and reduces the E[over →]×B[over →] transport of the ablated material.

Thermoresponsive mobility of liquid crystals and reactive mesogens during photopolymerization-induced phase separation

Molecular interactions between liquid crystals (LCs) and reactive mesogens (RMs) at temperatures across the phase transition regions were comprehensively studied during photopolymerization-induced phase separation (PPIPS) beginning with raw mixtures until the formation of polymer network liquid crystals (PNLCs). Then, the molecules were found to be nonuniformly more and less mobile in response to temperature as PPIPS progressed. Optical birefringence and infrared absorption were carefully measured throughout PPIPS, using 4-cyano-4'-hexylbiphenyl (6CB) and 1,4bis-[4-(3-acryloyloxypropyloxy) benzoyloxy]-2-methylbenzene (RM257) as typical LCs and RMs. Microscopic views of thermoresponsive changes in the molecular orientation order of both LCs and RMs were obtained: LCs and RMs in raw mixtures interacted with one another but uniformly transformed their molecular orientation. Such interactions continuously change to become nonuniform with progress in PPIPS. At the incipient stages of PPIPS, RMs, which are polymerized but not completely networked, inhibit LCs from changing their molecular orientation and vice versa. As PPIPS progresses, some LCs become more mobile and some less mobile owing to RM constraints. The domain configuration of the submicrometer phase separation affects the thermoresponsive mobility of LCs and RMs, that is, LCs become more mobile in LC-richer areas. The quantitative knowledge here provides comprehensive insight that LCs and RMs are mutually constrained and that such interactive behavior varies nonuniformly as PPIPS progresses.

A comprehensive atlas of Aggrecan, Versican, Neurocan and Phosphacan expression across time in wildtype retina and in retinal degeneration

As photoreceptor cells die during retinal degeneration, the surrounding microenvironment undergoes significant changes that are increasingly recognized to play a prominent role in determining the efficacy of therapeutic interventions. Chondroitin Sulphate Proteoglycans (CSPGs) are a major component of the extracellular matrix that have been shown to inhibit neuronal regrowth and regeneration in the brain and spinal cord, but comparatively little is known about their expression in retinal degeneration. Here we provide a comprehensive atlas of the expression patterns of four individual CSPGs in three models of inherited retinal degeneration and wildtype mice. In wildtype mice, Aggrecan presented a biphasic expression, while Neurocan and Phosphacan expression declined dramatically with time and Versican expression remained broadly constant. In degeneration, Aggrecan expression increased markedly in Aipl1-/- and Pde6brd1/rd1, while Versican showed regional increases in the periphery of Rho-/- mice. Conversely, Neurocan and Phosphacan broadly decrease with time in all models. Our data reveal significant heterogeneity in the expression of individual CSPGs. Moreover, there are striking differences in the expression patterns of specific CSPGs in the diseased retina, compared with those reported following injury elsewhere in the CNS. Better understanding of the distinct distributions of individual CSPGs will contribute to creating more permissive microenvironments for neuro-regeneration and repair.

Volume Phase Transitions of Heliconical Cholesteric Gels under an External Field along the Helix Axis

We present a mean field theory to describe cholesteric elastomers and gels under an external field, such as an electric or a magnetic field, along the helix axis of a cholesteric phase. We study the deformations and volume phase transitions of cholesteric gels as a function of the external field and temperature. Our theory predicts the phase transitions between isotropic (I), nematic (N), and heliconical cholesteric (ChH) phases and the deformations of the elastomers at these phase transition temperatures. We also find volume phase transitions at the I-ChH and the N-ChH phase transitions.

Phase transitions of heliconical smectic-C and heliconical nematic phases in banana-shaped liquid crystals

A mean-field theory is introduced to describe heliconical nematic (N_{TB}), heliconical smectic-C (S_{m}C_{TB}), and biaxial heliconical smectic-C (S_{m}C_{TB,b}) phases with mirror symmetry breaking. We extend our previous theories of the N_{TB} phase to the heliconical smectic-C phases, by taking into account one-dimensional spatial ordering of smectic layers. The calculated phase diagrams on the temperature-alkyl chain length plane show a rich variety of phase transitions: first- and second-order N_{TB}-S_{m}C_{TB} transitions, etc., including tricritical, tetracritical, and multicritical points. Our theory is qualitatively consistent with an experimental phase diagram.

Normal- and Reverse-Mode Thermoresponsive Controllability in Optical Attenuation of Polymer Network Liquid Crystals

A simple nonuniform irradiation method for photopolymerization-induced phase separation (PPIPS) was developed to produce unconventional mesoscale domain structures composed of liquid crystal (LC) and reactive mesogen (RM) phases. The LC/RM phase formations and their molecular orientation ordering through PPIPS were comprehensively investigated as a function of LC/RM molar ratio, curing temperature, and the use of uniform or nonuniform irradiation. Then, two different optical-anisotropic structures that can cause normal- or reverse-mode thermoresponsive light attenuation were formed by nonuniform irradiation at different curing temperatures at the same molar ratios. These two structures consist of mesoscale domains organized with multiaxially orientation-ordered LCs and orientation-disordered RMs for normal-mode thermoresponse and uniaxially orientation-ordered LCs and RMs for reverse-mode thermoresponse. Phase-separation nuclei were generated by nonuniform irradiation at the incipient stage during the PPIPS process under nonuniform irradiation and subsequently coalesced to form mesoscale polymer networks while maintaining their molecular orientation order. This is a promising method to overcome the restraint of structural controllability due to intrinsic material properties and thus to provide unconventional optical and photonic devices, such as thermoresponsive smart windows and thermometric sheets.

Improved ECG Signal Analysis Using Wavelet and Feature Extraction

Objectives : Automatic detection of arrhythmias is important for diagnosis of heart problems. However, in ECG signals, there is significant variation of waveforms in both normal and abnormal beats. It is this phenomenon, which makes it difficult to analyse ECG signals. The aim of developing methodology is to distinguish between normal beats and abnormal beats in an ECG signal.

Methods : ECG signals were first decomposed using wavelet transform. The feature vectors were then extracted from these decomposed signals as normalised energy and entropy. To improve the classification of the feature vectors of normal and abnormal beats, the normal beats which occur before and after the abnormal beats were eliminated from the group of normal beats.

Results : With our proposed methods, the normal beats and abnormal beats formed different clusters of vector points. By eliminating normal beats which occur before and after the abnormal beats, the clusters of different types of beats showed more apparent separation.

Conclusions : The combination of wavelet decomposition and the classification using feature vectors of the beats in ECG signals separate abnormal beats from normal beats. The elimination of the normal beats which occur before and after the abnormal beats succeeded in minimising the size of normal beats cluster.

Multiple Bragg Diffractions with Different Wavelengths and Polarizations Composed of Liquid Crystal/Polymer Periodic Phases

We first fabricated holographic polymer-dispersed liquid crystals (HPDLCs) that produce multiple Bragg diffractions with different polarization states for every angle of incidence, through a photopolymerization-induced phase separation by one-time interferential exposure. The polarizations of the Bragg diffractions were well-controlled at individual wavelengths in the fabrication process by the compositional ratio of LCs to monomers. The raw mixtures of extremely low-functionality monomers having very different viscosities were used to reduce the domain size in phase separation and subsequently to form elaborate periodic structures of the LC and polymer phases. A cross-linker (1-vinyl-2-pyrrolidione) and a prepolymer with urethane groups were employed to strengthen the polymer network. Note that the diffractions of our HPDLCs are regarded as not purely but mostly Bragg type, according to the evaluation with the established criteria. The devices, which are monolithic but versatile in diffractive behaviors, have advantages of simple manufacturing and handling.

Impact of surgical margins on survival of 37 dogs with massive hepatocellular carcinoma

AIMS

To compare the survival of dogs with completely resected massive hepatocellular carcinoma (HCC) with that of dogs in which HCC were incompletely excised.

METHODS

A retrospective cohort study was conducted. Dogs that underwent surgical excision of massive HCC between November 2006 and April 2015 were included. Dogs that died in the perioperative period or were lost to follow-up within 2 months after surgery were excluded. Data were collected from the medical records and a single pathologist examined all available histology slides to confirm the diagnosis of HCC. Surgical margins were defined as complete if no neoplastic cells were seen at the edge of excised tissues, based on original histopathology reports. Progression-free survival (PFS) and overall survival (OS) were compared between dogs with complete surgical margins (CM) and those with incomplete margins (IM) using a log-rank test.

RESULTS

Of the 37 dogs included in the study, 25 were allocated to the CM group and 12 to the IM group. Progressive local disease developed after surgery in three dogs in the CM group and seven dogs in the IM group. Three dogs in the CM group and five dogs in the IM group died due to tumour progression. Median PFS was longer for dogs in the CM group (1,000 (95% CI=562-1,438) days) compared to dogs in the IM group (521 (95% CI=243-799) days; p=0.007). OS was also longer for dogs in the CM group (>1,836 days) compared to those in the IM group (median 765 (95% CI=474-1,056) days; p=0.02).

CONCLUSIONS AND CLINICAL RELEVANCE

Compared with complete resection, incomplete resection decreased PFS and OS in dogs with massive HCC. Dogs with incompletely excised HCC should be closely monitored for local recurrence, although median OS was >2 years following incomplete excision. Further prospective studies are warranted to confirm these findings.

Volume phase transitions of cholesteric liquid crystalline gels

We present a mean field theory to describe anisotropic deformations of a cholesteric elastomer without solvent molecules and a cholesteric liquid crystalline gel immersed in isotropic solvents at a thermal equilibrium state. Based on the neoclassical rubber theory of nematic elastomers, we derive an elastic energy and a twist distortion energy, which are important to determine the shape of a cholesteric elastomer (or gel). We demonstrate that when the elastic energy dominates in the free energy, the cholesteric elastomer causes a spontaneous compression in the pitch axis and elongates along the director on the plane perpendicular to the pitch axis. Our theory can qualitatively describe the experimental results of a cholesteric elastomer. We also predict the first-order volume phase transitions and anisotropic deformations of a gel at the cholesteric-isotropic phase transition temperature. Depending on a chirality of a gel, we find a prolate or oblate shape of cholesteric gels.

Exposure to an atomic bomb explosion is a risk factor for in-hospital death after esophagectomy to treat esophageal cancer

Esophagectomy, one of the most invasive of all gastrointestinal operations, is associated with a high frequency of postoperative complications and in-hospital mortality. The purpose of the present study was to determine whether exposure to the atomic bomb explosion at Hiroshima in 1945 might be a preoperative risk factor for in-hospital mortality after esophagectomy in esophageal cancer patients. We thus reviewed the outcomes of esophagectomy in 31 atomic bomb survivors with esophageal cancer and 96 controls (also with cancer but without atomic bomb exposure). We compared the incidences of postoperative complications and in-hospital mortality. Of the clinicopathological features studied, mean patient age was significantly higher in atomic bomb survivors than in controls. Of the postoperative complications noted, atomic bomb survivors experienced a longer mean period of endotracheal intubation and higher incidences of severe pulmonary complications, severe anastomotic leakage, and surgical site infection. The factors associated with in-hospital mortality were exposure to the atomic bomb explosion, pulmonary comorbidities, and electrocardiographic abnormalities. Multivariate analysis revealed that exposure to the atomic bomb explosion was an independent significant preoperative risk factor for in-hospital mortality. Exposure to the atomic bomb explosion is thus a preoperative risk factor for in-hospital death after esophagectomy to treat esophageal cancer.

Phase diagrams of mixtures of a polymer and a cholesteric liquid crystal under an external field

We present a mean field theory to describe phase behaviors in mixtures of a polymer and a cholesteric liquid crystal under an external magnetic or electric field. Taking into account a chiral coupling between a polymer and a liquid crystal under the external field, we examine twist-untwist phase transitions and phase separations in the mixtures. It is found that a cholesteric-nematic phase transition can be induced by not only the external field but also concentration and temperature. Depending on the strength of the external field, we predict cholesteric-paranematic (Ch+pN), nematic-paranematic (N+pN), cholesteric-nematic (Ch+N) phase separations, etc., on the temperature-concentration plane. We also discuss mixtures of a non-chiral nematic liquid crystal and a chiral dopant.

Theory of liquid crystalline micelles

A theory is introduced to describe self-assembly of liquid crystalline AB diblock copolymers, consisting of a homopolymer (A) and a side-chain liquid crystalline polymer (B). We derive the free energy of the liquid crystalline micellar solutions and examine the equilibrium solution properties: critical micelle concentration (CMC), nematic-isotropic phase transition (NIT) of the rigid side-chains inside the micelle core, and phase separations. It is shown that there is a critical micelle size below which the NIT becomes continuous due to a packing effect. We also find re-entrant micellizations near the NIT temperature. The phase diagrams, including binodal, spinodal, CMC, and NIT curves are also examined on the temperature-concentration plane.

Novel biaxial nematic phases of side-chain liquid crystalline polymers

We present a mean field theory to describe biaxial nematic phases of side-chain liquid crystalline polymers, in which rigid side-chains (mesogens) and rigid-backbone chains favor mutually perpendicular orientations. Taking into account both excluded volume and attractive interactions between rigid rods, novel biaxial nematic phases are theoretically predicted. We calculate uniaxial and biaxial orientational order parameters as a function of temperature and the length of backbone chains. We find a first-order biaxial-biaxial phase transition and a first (or second)-order uniaxial-biaxial one, depending on the length of mesogens and backbone chains.

Imaging spectroscopy diagnosis of internal electron temperature and density distributions of plasma cloud surrounding hydrogen pellet in the Large Helical Device

To investigate the behavior of hydrogen pellet ablation, a novel method of high-speed imaging spectroscopy has been used in the Large Helical Device (LHD) for identifying the internal distribution of the electron density and temperature of the plasma cloud surrounding the pellet. This spectroscopic system consists of a five-branch fiberscope and a fast camera, with each objective lens having a different narrow-band optical filter for the hydrogen Balmer lines and the background continuum radiation. The electron density and temperature in the plasma cloud are obtained, with a spatial resolution of about 6 mm and a temporal resolution of 5 × 10(-5) s, from the intensity ratio measured through these filters. To verify the imaging, the average electron density and temperature also have been measured from the total emission by using a photodiode, showing that both density and temperature increase with time during the pellet ablation. The electron density distribution ranging from 10(22) to 10(24) m(-3) and the temperature distribution around 1 eV have been observed via imaging. The electron density and temperature of a 0.1 m plasma cloud are distributed along the magnetic field lines and a significant electron pressure forms in the plasma cloud for typical experimental conditions of the LHD.

Prognostic significance of BAF57 expression in patients with endometrial carcinoma

This study was conducted to elucidate the prognostic significance of BAF57 in patients with endometrial carcinoma. We investigated the relationship between the immunohistochemical expression of BAF57 and various clinicopathological variables in 111 endometrial carcinomas. Both univariate and multivariate regression analyses were performed. The correlations between the BAF57 expression and the other variables including estrogen receptor (ER) and p53 were examined. The high nuclear BAF57 expression was detected in 42 (37.8%) endometrial carcinomas, and 69 (62.2%) endometrial carcinomas were defined as having low nuclear BAF57 expression. The BAF57 expression was significantly associated with the surgical stage, grade of the tumor, myometrial invasion, lympho-vascular space invasion (LVSI) and lymph node metastasis. The 10-year overall survival rates of patients with low and high BAF57 expression were 96.9% and 58.2%, respectively (p<0.001). A multivariate analysis identified BAF57 expression as an independent prognostic factor. The BAF57 expression was significantly correlated with p53 expression (r=0.312, P=0.001), but was not correlated with ER expression (r= -0.141, P=0.14). The high BAF57 expression is an independent marker of poor prognosis of the patients in endometrial carcinomas. The inhibition of BAF57 activity may be one of the candidates for endometrial cancer therapy, especially therapy for aggressive tumors showing overexpression of p53.

Phase diagrams of binary mixtures of liquid crystals and rodlike polymers in the presence of an external field

We theoretically study phase separations in mixtures of a low molecular-weight-liquid crystalline molecule (LC) and a rigid-rodlike polymer (rod) under an external field, such as magnetic or electric fields. By taking into account two orientational order parameters of the rod and the LC, we define four nematic phases (N(0), N(1), N(2), N(3)) on the temperature-concentration plane. Depending on the sign of the dielectric anisotropy Δε(i) of the rod (i = 1) and LC(i = 2), we examine the phase behavior of rod/LC mixtures in the case of Δε(1) > 0, Δε(2) > 0 (a), Δε(1) < 0, Δε(2) > 0 (b), Δε(1) > 0, Δε(2) < 0 (c), and Δε(1) < 0, Δε(2) < 0 (d). We predict a variety of phase separations induced by an external field.

Volume phase transitions of biaxial nematic elastomers

We present a mean-field theory to describe biaxial nematic phases of side-chain liquid crystalline elastomers. Novel biaxial nematic phases are theoretically predicted in a side-chain liquid crystalline polymer and gel, where side chains (mesogens) and rigid-backbone chains favor mutually perpendicular orientations. We calculate uniaxial and biaxial orientational order parameters and examine deformations of the gel and stable biaxial nematic phases of the liquid crystalline gel dissolved in isotropic solvents. We predict first-order uniaxial-biaxial nematic phase transitions of the gel and the volume of the gel is discontinuously changed at the phase transition temperature.

Design and performance of a punch mechanism based pellet injector for alternative injection in the large helical device

A low speed single barrel pellet injector, using a mechanical punch device has been developed for alternative injection in the large helical device. A pellet is injected by the combined operation of a mechanical punch and a pneumatic propellant system. The pellet shape is cylindrical, 3 mm in diameter and 3 mm in length. Using this technique the speed of the pellet can be controlled flexibly in the range of 100-450 m/s, and a higher speed can be feasible for a higher gas pressure. The injector is equipped with a guide tube selector to direct the pellet to different injection locations. Pellets are exposed to several curved parts with the curvature radii R(c) = 0.8 and 0.3 m when they are transferred in guided tubes to the respective injection locations. Pellet speed variation with pressure at different pellet formation temperatures has been observed. Pellet intactness tests through these guide tubes show a variation in the intact speed limit over a range of pellet formation temperatures from 6.5 to 9.8 K. Pellet speed reduction of less than 6% has been observed after the pellet moves through the curved guide tubes.

Late restenosis following sirolimus-eluting stent implantation

OBJECTIVES

This serial angiographic study evaluated the incidence and predictors of late restenosis after sirolimus-eluting stent (SES) implantation.

BACKGROUND

Previous studies showed late restenosis (i.e., late catch-up phenomenon) after implantation of 7-hexanoyltaxol-eluting stents and nonpolymeric, paclitaxel-eluting stents.

METHODS

Between August 2004 and December 2006, SES implantation was performed in 1,393 patients with 2,008 lesions, in whom 8-month and 2-year follow-up coronary angiography were planned.

RESULTS

Of 2,008 lesions, 1,659 (83%) underwent 8-month follow-up angiography (8.3 ± 2.2 months). Restenosis was observed in 122 lesions (7.4%). Coronary angiography 2 years (1.9 ± 0.4 years) after SES deployment was performed in 1,168 lesions (74% of lesions without restenosis at 8-month follow-up angiography). Late restenosis was observed in 83 lesions (7.1%). There was significant decrease in minimum luminal diameter (MLD) between 8-month and 2-year follow-up (2.56 ± 0.56 mm vs. 2.35 ± 0.71 mm, p < 0.001). Multivariate analysis showed in-stent restenosis before SES implantation and MLD at 8-month follow-up as independent predictors of late restenosis.

CONCLUSIONS

Between 8-month and 2-year follow-up after SES implantation, MLD decreases, which results in late restenosis in some lesions. In-stent restenosis before SES implantation and MLD at 8-month follow-up are independent predictors of late restenosis.

Repeated sirolimus-eluting stent implantation to treat sirolimus-eluting stent and bare-metal stent restenosis

BACKGROUND

In-stent restenosis (ISR) remains a persistent, unresolved issue even in the era of percutaneous coronary intervention (PCI) using drug-eluting stents. The present study compares the clinical and angiographic outcomes of using sirolimus-eluting stents (SES) for re-intervention against ISR that was originally treated with sirolimus-eluting or bare-metal (BMS) stents.

METHODS AND RESULTS

This prospective single-center registry investigated 179 ISR lesions in 158 consecutive patients (53 lesions in 49, and 126 in 109 patients originally treated with SES and BMS, respectively), who had undergone re-intervention with SES. The patients were clinically and angiographically followed up at 8 months after re-PCI. The incidence of re-restenosis (29 vs 12%, P<0.01), ischemia-driven target lesion revascularization (TLR; 21 vs 8%, P<0.05) and major adverse cardiac events (MACE; 21 vs 9%, P<0.05) were significantly greater in ISR lesions originally treated with SES than in those originally treated with BMS at 8 months after re-PCI. Moreover, late luminal loss was significantly greater in the group with post-SES restenosis (P<0.05). Even after adjustment, post-SES restenosis was the only independent predictor of re-restenosis and MACE (P<0.05, each).

CONCLUSIONS

Although the re-restenosis rate is acceptable, the incidence rates of late restenosis, ischemia-driven TLR and MACE are higher after repeated SES implantation to treat SES, than BMS restenosis. These results might affect the mid-term clinical outcomes of re-intervention with SES.

Phase separations in mixtures of a liquid crystal and a nanocolloidal particle

We present a mean field theory to describe phase separations in mixtures of a liquid crystal and a nanocolloidal particle. By taking into account a nematic, a smectic A ordering of the liquid crystal, and a crystalline ordering of the nanoparticle, we calculate the phase diagrams on the temperature-concentration plane. We predict various phase separations, such as a smectic A-crystal phase separation and a smectic A-isotropic-crystal triple point, etc., depending on the interactions between the liquid crystal and the colloidal surface. Inside binodal curves, we find new unstable and metastable regions, which are important in the phase ordering dynamics. We also find a crystalline ordering of the nanoparticles dispersed in a smectic A phase and a nematic phase. The cooperative phenomena between liquid-crystalline ordering and crystalline ordering induce a variety of phase diagrams.

Disentangling the dynamical origin of P11 nucleon resonances

We show that two almost degenerate poles near the piDelta threshold and the next higher mass pole in the P11 partial wave of piN scattering evolve from a single bare state through its coupling with piN, etaN, and pipiN reaction channels. This finding provides new information on understanding the dynamical origins of the Roper N{*}(1440) and N{*}(1710) resonances listed by Particle Data Group. Our results for the resonance poles in other piN partial waves are also presented.

Volume phase transitions of smectic gels

We present a mean-field theory to describe volume phase transitions of side-chain liquid crystalline (LC) gels, accompanied by isotropic-nematic-smectic- A phase transitions. Three different uniaxial nematic phases ( N1 , N2 , and N3 ) and smectic- A phases ( S1 , S2 , and S3 ) are defined by using orientational order parameter S_{m} of side-chain liquid crystals (mesogens), S_{b} of semiflexible backbone chains, and a translational order parameter sigma for a smectic- A phase. We derive the free energy for smectic- A phases of side-chain LC gels dissolved in an isotropic solvent and examine the swelling curve of the LC gel, the orientational order parameters, and the deformation of the LC gel as a function of temperature. We find that the LC gel discontinuously changes the volume at an isotropic-nematic, an isotropic-smectic- A , and a nematic-smectic- A phase transition.

Relationships between leaching of methylmercury from the soil and the basic characteristics of alkali soil polluted by mercury in Guizhou China

To determine the relationship between soluble methylmercury and soil characteristics which was contaminated by mercury, several experiments were conducted. As a result, a good correlation was founding between the leached methylmercury level from soil and the EC (electronic conductivity) level of soil. Moreover, to grasp the relationship between soluble methylmercury and soluble anions from soil, several anions (Cl(-), NO(3-), SO(4) (2-)) were measured using the ion chromatography method. Although the correlation coefficient was small (r = 0.40), only a correlation between the level of SO(4) (2-) and leached methylmercury was recognized.

Theory of volume phase transitions of side-chain liquid crystalline gels

We present a mean field theory to describe volume phase transitions of side-chain liquid crystalline gels. Three different uniaxial nematic phases (N(1), N(2), and N(3)) are defined by using orientational order parameter S(m) of side-chain liquid crystals (mesogens) and S(b) of backbone chains. We derive the free energy for the three nematic phases of side-chain liquid crystalline gels dissolved in isotropic solvents and calculate the swelling curve of the gel, the order parameters of a backbone chain and of side-chain liquid crystals, and the deformation of the gel as a function of temperature and an electric field. We find isotropic-nematic (N(1), N(2), and N(3)) and N(1)N(2) phase transitions of the gels, depending on the interaction between a backbone chain and a side-chain liquid crystal.

Translocation and insertion of an amphiphilic polymer

Translocation of amphiphilic polymers (random and block copolymers), consisting of hydrophilic and hydrophobic monomers, threading a pore is studied by using a three-dimensional dynamic Monte Carlo simulation. We find that there is a "translocation-insertion" threshold in the fraction of hydrophobic monomers on an amphiphilic polymer. The translocation time is given by simple scaling laws and increases with increasing the fraction of hydrophobic monomers.