Search

This study aimed to investigate the feasibility of estimating functional ischemia information from coronary artery computed tomography (CACT) data (i.e., morphological information). Fifty-five suspected ischemic heart disease patients were included in this study. To calculate the ischemic myocardium percentage (LV myocardial territories volume of distal portion the stenotic lesion/total LV myocardial volume) from CACT data with "coronary territories analysis, Ziostation2", and compared with the ischemic LV myocardium percentage and the functional flow reserve (FFR). The results showed that ischemic LV myocardium percentage was correlated with the FFR (r=-0.57). The median ischemic LV myocardium percentage of the FFR-positive group (n=33) was 37.1% (interquartile range [IQR] 33, 41.4%) and that of the FFR-negative group (n=22) was 24.8% (IQR 19.6, 30.6%). The ischemic LV myocardium percentage was significantly higher in the FFR-positive group (p0.01) than in the FFR-negative group. The receiver operating characteristic (ROC) curve showed that the cutoff value for the ischemic LV myocardium percentage was 30%, with the sensitivity of 90.9% and the specificity of 77.3%. In conclusion, myocardial ischemia to diagnosis of FFR may occur when ischemic LV myocardium percentage is over than 30% and is unlikely to occur when it is less than 30%. This study suggests that the analysis of CACT data may contribute to the diagnosis of functional ischemia.

The sequence effects on the conformations and intra-molecular hydrogen bonds (NH···OC: H-bond) of collagen-like co-peptides (single chains) were analyzed using co-glycine (G)/L-proline (P) oligopeptides (6- and 9-mer, G/P = 1/2 mol), by QCC [B3LYP/6-31G(d,p)], with homo-oligopeptides. Each sequence was specified using three kinds of basic triplets of GPP, PGP, and PPG. The conformations (dihedral angles: φn/ψn) varied depending on the sequences. The conformation types of each unit were classified in the following three groups: φ/ψ of g−/g + (shorter polyproline II helical structure: P-like) with H-bond, g−/t + (polyproline II helical structure: PPII) with no H-bond, and φ/ψ of t−/g + with no H-bond. All H-bonds that have seven-membered ring were formed between units separated by one peptide. The positions and number (Nh) of H-bonds varied depending on the sequences. The H-bonds between CO of proline and NH of glycine unit were newly formed. The co-peptides that have no GPP triplet in N-end side (CH3CO-GPP) were found to be more stable than the corresponding blend models due to the formations of newly formed H-bonds. From the comparison with the structures observed for triple helix of collagen in other works and the findings (the existence of the CO group that have no H-bond), it was inferred that collagen may be formed by conformational rearrangement from P-like (single chain) to PPII (triple helix) and may be stabilized by inter-molecular hydrogen bonding between the residual CO groups and water molecules.

The purpose of this study was to educate operators regarding cardiac catheterization using radiation protection slides prepared for this study and to consider whether or not this radiation protection education contributes to reducing the exposure of the operator's ocular lens. Thermoluminescent dosimeter (TLD) was installed at the outside left, inside left, outside right, and inside right of the X-ray protective eyewear of the operators performing the cardiac catheterization. The exposure dose rate before and after radiation protection education for 3 operators performing cardiac catheterization was compared. The exposure dose ratio was defined by dividing the TLD measurement value, which is the air kerma calculated by the X-ray diagnosis apparatus for the angiography. In other words, this can calculate the ratio of how much the operators are exposed to radiation from the dose of the patient per examination. When comparing the radiation dose ratio obtained from the dosimeter installed on the right outer side before and after education, p-value was

We conducted a nationwide survey of multiple institutions and collected data of various interventional procedures in the field of cardiology. Included in the analysis were 126 institutions, 381 X-ray systems, and 805 protocols. The dose values were compared with the Japanese diagnostic reference levels (DRLs) 2015. Fluoroscopy time, air kerma at the patient entrance reference point (Ka, r), and air kerma-area product (PKA ) were analyzed for various interventional procedures in 5,734 cardiology patients. The fluoroscopic dose rate (FDR) for pulmonary vein isolation (PVI) was less than half that of the 75th percentile of the Japanese DRLs 2015. The 75th percentiles of fluoroscopy time, Ka, r, and PKA for the respective interventional procedures were as follows: 11.0 min, 735 mGy, and 64 Gy･cm2 for diagnostic coronary angiography (CA); 13.2 min, 839 mGy, and 75 Gy･cm2 for CA + left ventriculography; 34.4 min, 1,810 mGy, and 148 Gy･cm2 for percutaneous coronary intervention (PCI) excluding chronic total occlusion; 80.1 min, 4,338 mGy, and 312 Gy･cm2 for PCI for chronic total occlusion; 74.4 min, 833 mGy, and 90 Gy･cm2 for PVI; and 34.0 min, 795 mGy, and 94 Gy･cm2 for transcatheter aortic valve implantation, respectively. In assessing dose values in interventional radiology, the difficulty of the technique needs to be considered, and the DRL values for FDR, fluoroscopic time, Ka, r, and PKA for each interventional procedure are considered necessary when reassessing or updating DRLs.

The visibility of moving images during cardiac catheterization and treatment may be reduced by a number of factors. First, it involves multiple movements that occur simultaneously, such as the movements due to the heart beat and movement of the guide wire used during the treatment. There is also the influence of the X-ray dose on the image quality in the X-ray output. If X-rays are irradiated onto moving objects such as a guide wire moving during treatment of the heart, cardiac catheterization may be displaced to the next image recorded even when an insufficient X-ray dose has been irradiated because the imaged object is moving during the time the X-rays are emitted (pulse width). If the X-ray dose planned to be irradiated to the target is low, there is also the possibility that noise will appear in the image, and the imaged object may be lost in noise and visibility be reduced. For this reason, we conducted basic research into how changes in the speed of rotation of guide wires affect visibility when wires are positioned horizontally and vertically, using a dynamic phantom and recorded X-ray moving images. The purpose of this study is to elucidate whether the deterioration in the visibility is affected by the X-ray dose, the orientation or movement of a guide wire, or caused by other conditions, in order to contribute to improving the visibility in the X-ray moving images. The results showed a lower visual evaluation only in the vertical direction at the more rapid movement here, but this did not result in significant changes in the physical evaluation. This suggests that the structure and characteristics of the human eyes would be involved, as human vision is stronger with lateral movements and weaker with vertical movements due to the arrangement of the human eyes, side by side. Findings from this basic study can be utilized to improve the visibility in the X-ray moving images by paying attention to the observation environment of the observer of the X-ray moving images. In addition, the findings of this study can also be used to determine protocols for improving visibility in X-ray moving images, such as adjusting the X-ray dose in an X-ray device when further improvement is required. Therefore, this study was able to provide suggestions to contribute to the development of improved visibility of X-ray moving images.

The quality of the present day fluoroscopic images is sufficiently high for use as exposure images depending on the environment where the fluoroscopic images are recorded. In some facilities which use fluoroscopic images as exposure images they are recorded with a radiological x‐ray diagnostic device equipped with a fluoroscopic storage function. There are, however, cases where fluoroscopic images cannot be used as exposure images because the quality of the fluoroscopic image cannot be assured in the environment where the fluoroscopic images are recorded. This poses problems when stored fluoroscopic images are used in place of exposure images without any clearly established standard. In the present study, we establish that stored fluoroscopic images can be used as exposure images by using gray values obtained from profile curves. This study finds that replacement of stored fluoroscopic images with exposure images requires 20.1 or higher gray scale value differences between the background and signal, using a 20 cm thick acrylic phantom (here an adult abdomen as representing the human body) as the specific geometry. This suggests the conclusion that the gray value can be considered a useful index when using stored fluoroscopic images as exposure images.

Background: Fractional flow reserve (FFR) is used to evaluate the need for percutaneous coronary intervention (PCI) in cases of moderate stenosis of the coronary artery. Recently, diagnostic imaging support with computational fluid dynamics (CFD) analysis has been garnering attention. This study defines the relationship between FFR conducted for cardiac catheterization and CFD analyses conducted using coronary computed tomography (CT) for moderate stenosis, in addition to considering whether wall pressure (WP) and wall shear stress (WSS) can be used to evaluate ischemia. Methods and Results: Cases in which FFR was measured via coronary CT and cardiac catheterization was performed within 3 months were collected retrospectively. In the CFD analysis, WP and WSS were calculated and compared with FFR. Three groups were created to compare results of CFD analysis and FFR values according to the location of the stenosis: the right coronary artery, the left anterior descending artery, and the left circumflex artery. There was a correlation between FFR and WSS according to CFD analysis for moderate stenosis of the coronary artery, with a cut-off value for treatment able to be calculated. Conclusions: The results of this study suggest that ischemia can be evaluated by conducting CFD analysis (WSS) using coronary CT.

It is important to optimize the exposure dose when conducting interventional radiology, but optimization is difficult for medical centers to achieve independently. In 2005, we administered a questionnaire on the measurement of dose rates and awareness of exposure reduction when performing percutaneous coronary intervention. Ten years later, we conducted a follow-up survey of the same 31 centers to determine the current situation and identify trends. The results of the survey showed that the mean fluoroscopy dose rate decreased to 55% of the 2005 value, from 28.2 to 15.6 mGy/min, and the mean radiography dose rate decreased to 71% of the 2005 value, from 4.2 to 3.0 mGy/s. Dose rates for both fluoroscopy and radiography decreased by 84% of facilities. The results also indicated greater cooperation by physicians compared to 10 years ago. In particular, there was a considerable increase in the exchange of ideas with physicians regarding exposure, suggesting a stronger level of interest in exposure. The overall score for questionnaire items was 33% higher than that in the previous survey. These results show that in the past 10 years, awareness of exposure reduction has improved, and dose optimization has been a major factor in the downward trend in dose rates in radiography and fluoroscopy.

Purpose We conducted a multicenter study to investigate the current status of difference between the actual values at the patient entrance reference point (PERP) and display air kerma. Methods We exposure dose and fluoroscopy dose were measured by 32 apparatuses at 32 member institutions of the Japanese Society of Circulation Imaging Technology (CITEC) under unified conditions, and the actual measured values and display air kerma were compared. We entrance doses during fluoroscopy and imaging were measured at the PERP, with focus detector distance (FDD) 110 cm, a copper plate of 3.5 mm in thickness adhered to the front face of flat panel detector (FPD) as absorber, field-of-view (FOV) 18 cm, and the frame rate of 15 f/s, excluding the bed. Display air kerma were recorded at the same time. JIS (Z 4751-2-43: 2012) specify "The reference air kerma rate and the cumulative reference air kerma shall not deviate from their respective display air kerma by more than ±35% over the range of 6 mGy/min and 100 mGy to the maximum value." The number of apparatuses display air kerma deviated from this condition and its percentage were obtained. Results The mean difference percentage between actual measured values and display air kerma in 32 apparatuses was approximately 15.6%, with some apparatuses showing substantially different display air kerma. Conclusion In order to estimate patients' skin exposure dose from display air kerma more accurately, it is necessary to perform calibration of the apparatus by regular dose measurement or convert values.

The structures and energies of anhydrate and hydrate (hydrate rate: h of 1) states of l-alanine (LA), glycine (G), l-proline (LP), and N-methyl glycine (MG) pentamers were calculated by quantum chemical calculation using B3LYP/6-31G(d,p), for four kinds of conformers (β-extended: φ/ψ = t−/t+, PPII: g−/t+, PPII-like: g−/g+, and α-helix: g−/g−). In LA and G, which have imino proton (NH), three conformation types of β-extended, PPII-like, and α-helix were obtained, and water molecules were mainly inserted between intra-molecular hydrogen bond of CO···HN in PPII-like and α-helix and attached to CO group in β-extended. In LA and G, PPII-like conformers were the most stable in the anhydrate and hydrate states, and the result for LA was different from some experimental and theoretical results reported by other works reporting that the main stable conformation of alanine oligopeptide was PPII. On the other hand, in LP and MG, which have no imino proton, two conformers (PPII and PPII-like) and three conformers (PPII, PPII-like, and α-helix) were obtained, respectively. PPII conformers were the most stable in the anhydrate and hydrate states, and the result for LP supported the reported experimental results that the main conformation of proline oligomer was PPII. It was found that the formation pattern and stability of conformation of oligopeptide were strongly dominated by the presence/absence of intra-molecular hydrogen bonding of CO···HN or the presence/absence of NH2 group in the starting amino acid.

The structure and association energy of hydrated l-alanine pentamers at the hydration rate (h) of 0–1 were calculated by quantum chemical calculation (QCC) using the density functional theory [B3LYP/6-31G(d, p)] method for three kinds of stable conformers (β-extended: t−/t+, PPII-like: g−/g+, α-helix: g−/g−) converged by convergent calculations from l-alanine pentamers in gas phase. Water molecules are mainly inserted between intramolecular hydrogen bond of CO–HN in PPII-like and α-helix conformers and attached to the CO group in β-extended conformer. α-Helix conformer turns to PPII-like conformer at higher hydration rate. The association energy decreased with the increase of the hydration rate, indicating that the conformers were stabilized by the hydration. It was found that PPII-like conformer, which was the most stable in the anhydrate state, was also the most stable in the hydrate state. This structure corresponds to a middle structure of PPII (g−/t+) and β-extended (t−/t+) structures. These results obtained by energy calculation using QCC support the experimental results by Eker et al. and Graf et al., who reported that alanine oligomer exhibited a mixture of PPII and β-extended structure in aqueous solution.

In recent years, reports have been made that predict the state of aneurysm by performing computational fluid dynamics (CFD) analysis using cerebral aneurysm blood flow analysis software. However, analysis results are not constant and there are various opinions, and it is conceivable that the image quality and analysis conditions of medical images used for CFD analysis are not standardized. In this study, CFD analysis of cerebral aneurysm phantom was performed, and image quality and analysis conditions were standardized. Then, we investigated whether increase of cerebral aneurysm and prediction of rupture are possible. From this study, stable results of wall shear stress analysis were obtained under slice thickness 1.0 mm or less, CT value 400 HU or more, reconstruction function as soft part function, image SD under 10 HU. In addition, as the size of the cerebral aneurysm became larger, wall shear stress tended to be lower, and the same tendency was shown also in clinical cases. Although CFD analysis using software dedicated to blood flow analysis did not reach the prediction of rupture, it can be evaluated based on the quantitative values for the aneurysm increase at the preceding stage and plays an important role in prediction there is a possibility.

The conformational convergent calculations of alanine oligomer (2- to 7-mer) were performed by QCC in the order starting from 2-mer (4 × 164 kinds). The ϕ/ψ of 4- to 7-mer was converged to three types; α-helix (g+/g+ or g−/g−), PPII-like (g+/g− or g−/g+) and β-extended (t+/t− or t−/t+), in lower energy order. PPII-like was different from the PPII (g−/t+) reported, and considered to be 2.27 ribbon . The energy differences in left- and right-handed ‘methyl type’ of end group were found.

Following recent rapid advances in devices and treatment technology, indications for percutaneous peripheral intervention (PPI) have been expanded to include complex lesions (long-segment lesions, completely obstructed chronic lesions, etc.) and even lesions of the superficial femoral artery and arteries distal to the popliteal artery. However, when PPI is used for treatment of complete obstruction, treatment can take a long time or its outcome can be less satisfactory for reasons such as difficulty in assessing the vascular distribution/arrangement or the direction of calcification in the obstructed area or excessively long lesions. In the present study, we conducted three-dimensional image processing of CT data from leg arteries conventionally used for preoperative diagnosis. Using this processing technique, we created virtual images of the blood vessels of the completely obstructed area and mapped these virtual vessel images onto the fluoroscopic monitor image during catheter treatment. The usefulness of this technique for PPI was then evaluated. We succeeded in creating virtual vessel images of the completely obstructed parts of leg arteries with the use of preoperative CT images of leg arteries that we then mapped onto the fluoroscopic monitor images during treatment. We were successful in mapping virtual images onto the abdominal aorta in 96.8% of cases and in 95.7% with the common iliac artery. This technique is thus able to supply reliable information on vascular distribution/arrangement, suggesting that it can enable the surgeon to advance the treatment device precisely along the vessels, making it useful for treatment with PPI. The study additionally showed that differences in the angle of imaging affect the manual mapping of the CT images onto angiograms.

The reproducibility of lateral radiography of the knee joint in the lateral position is low because patient positioning can be easily affected by passive rotation of the knee joint. We calculated the correction angle of the femoral external rotation and the lower leg elevation and developed our own auxiliary tool for obtaining a lateral view image. We were able to obtain, in a single attempt, an image with misalignment of the condyle limited to less than 7 mm. Our tool also contributed to the reduction of the re-imaging rate, suggesting its usefulness in contributing to a lower re-imaging rate for lateral radiography of the knee joint.

Three types of fullerene (C60)-end-capped poly(4-diphenylaminostyrene) (C60–PDAS) and poly(4-diphenylaminostyrene) (PDAS) blends were prepared to investigate their potential as bipolar polymer semiconductors. The concentration of C60 in the C60–PDAS/PDAS blends strongly affected the hole and electron drift mobility values; the hole drift mobility decreased with an increase in the C60 concentration. However, the electron drift mobility increased with an increase in the C60 concentration. The hole and electron drift mobility values were almost the same for the 1/2 C60–PDAS/PDAS blend; therefore, this polymer blend was thought to be a bipolar polymer semiconductor. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Semiconducting polymers, poly(1,4-phenylene) (PPP) and poly(4-diphenylaminostyrene) (PDAS), which are soluble to organic solvents, were synthesized and were deposited by means of electrospray deposition (ESD). The ESD generated spherical shells of diameters ranging from a few to several tens of microns. The shells consisted of coagulation of nanometric particles of the semiconducting polymers. Formation of the shells was largely influenced by the concentration of spray solution. It was also found that the formation of shells can be achieved with various types of soluble polymers.

ポリエチレンイミン(PEI)の 5 量体水和モデルを用いた量子化学計算により，水和過程における配座の会合エネルギー(Ec)に及ぼす配座効果(torsion facter: ft の影響)の見積もりを行った．非水モデルとして構造最適化された 4 種の配座モデル [(ttt)5, (ttg+)5, (g+g+g+)5 および(tg+t)5, ft=1.00～1.35] を準備し，水和モデルは水和率(h)を 0～1 とし水分子をイミノ基に対し非連続または連続的に配置した．Ec は ft の増加とともに水の配置形式の影響を強く受けた．(tgt)5 配座では，水和率の増加(h>0.5)とともにキンク(trans→gauche)を伴う大きい構造ゆらぎが認められ Ec は増加傾向を示した．Ec の計算結果は PEI 結晶の水和過程での構造転移(tgt→ttt)に関する観測結果にほぼ対応し，構造転移の推進力の一つとしてらせん構造の構造ゆらぎが関係することが推察された．

Block copolymerization of plural types of monomers offers a new opportunity for the preparation of a variety of multifunctional polymers. Poly(4-diphenylaminostyrene) (PDAS)-poly(9-vinylanthracene) (PVAN) binary block copolymer (PDAS-PVAN) was synthesized by (living) anionic polymerization using the benzyllithium/N,N,N′,N′-tetramethylethylenediamine system. The photoluminescence emission of PDAS-PVAN was enhanced by the fluorescence resonance energy transfer from PDAS block to PVAN block in PDAS-PVAN. The hole drift mobility of the copolymer was controllable by the amount of triphenylamino groups in the polymer chain. The optical and electrical properties of PDAS-PVAN were adjustable through the polymer chain structure. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

The effect of polymer chain structure on the optical and electrical properties are reported for poly(4-diphenylaminostyrene) (PDAS), which was prepared by the living anionic polymerization of 4-diphenylaminostyrene (DAS) with the benzyllithium (BzLi)/ N , N , N ′, N ′-tetramethylethylenediamine (TMEDA) system. The optical properties of PDAS are strongly affected by the stereoregularity of the PDAS polymer chain; intramolecular excimer-forming fluorescence was observed from PDAS with a syndiotactic-rich configuration. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of PDAS were approximately −5.4 and −2.0 eV, respectively, regardless of the polymer chain structure. The hole and electron drift mobilities for PDAS were in the order of 10 −4 to 10 −5 (cm 2 /V s) and 10 −5 (cm 2 /V s), respectively, with negative slopes. The distance of each triphenylamino (TPA) group in the polymer chain was a major factor influencing the drift mobility of PDAS. The current–voltage ( I – V ) characteristics of PDAS were controllable according to the polymer chain structure of PDAS.

Structure analyses for hydrate models of ethyleneimine oligomer (5-mer as model of PEI) were investigated by quantum chemical calculations. Conformation energies and structures optimized for hydrate models of (ttt)5 and (tgt)5 conformers were examined. Hydrate ratio, h [h = H2O/N (mol)], was set from 0.5 to 2. In anhydrates, (tg+t)5 conformer was more stable (?1.8 kcal/m.u.) than (ttt)5. In hydrates, (ttt)5 conformers were more stable (?0.7 - ?4.3) than (tg+t)5. These results corresponded to experimental results that anhydrous linear PEI crystal changes from double helical to single planar chain in hydration process. Structures calculated for (ttt)5 agreed in those observed for hydrates of PEI. In all (tg+t)5 conformers, O???H bonds between waters were found with the decreases of N???H bonds between imino group and water. The O???H bonds in (tg+t)5 conformer resulted in its high chain torsion, and strongly related with instability and structure change (large swelling).

Physical vapor deposition polymerization was achieved by evaporating vinyl monomers followed by heat treatment. This technique was utilized for preparing a hole-transport layer (HTL) and emissive layers (EMLs) of organic light emitting diodes (OLEDs). Adivinyl derivative of tetraphenyldiaminobiphenyl, DvTPD, was used both for the HTL and for the host material of red phosphorescent EML. A vinyl derivative of bis(N-carbazolyl)benzene, vmCP, was used for the host material of blue phosphorescent EML. The ELMs were doped with red or blue-emitting phosphorescent iridium complexes modified with styril units. After characterizing the devices that have single EML of red or blue emission, an OLED having multilayered ELM was prepared by stacking these layers to achieve quasi-white emission. It was found that the deposition polymerization was effective to improve the emission efficiency. The improvement appeared to be related to the proper carrier balance in the EML.

Hole transport copolymers consisting of 3,4-ethylenedioxythiophene (EDOT) and N-4-butylphenyl-N,Ndiphenylamine (BTPA) were synthesized by oxidative coupling reaction using FeCl3 as an oxidant. These copolymers showed good solubility and their thin films showed sufficient morphological stability. The copolymers showed an absorption maximum around 320 nm. Copolymers had an oxidation peak at approximately 1.03∼1.14 V versus the Ag/AgCl electrode. The hole mobility increased with increasing portion of the EDOT unit. The hole mobility of the copolymer containing 57% of the EDOT unit showed the highest mobility of 3×10-5 cm2/V·s.

Hydrate effects on the conformations of ethylene oxide oligomers (EO-x, x = 1–8 mers) were examined using quantum chemical calculations (QCC). Conformational analyses were carried out by RHF/6-31G. The models were constructed by locating a water molecule to each ether–oxygen in the structures optimized for non-hydrate oligomers. Hydrate ratio, h (h = H2Omol/Omol in oligomer), was set from 0 to 1.0. The six type conformations with repeated units of O–C, C–C and C–O bonds were examined. Conformational energy, E c (HF), was calculated as difference between the energy of oligomer with water molecules and that of non-hydrogen and/or hydrogen bonding water molecules. Hydrate energies for each conformer, ∆μ h (kcal/m.u., based on E c in non-hydrate state), were negative and linearly decreased with the increase of h values, and such effects with the increase of h values were weaken with increasing x values. These results were consistent with our previous results calculated using the permittivity, e (e = 0–80.1), by QCC. In non-hydrate (h = 0), the (ttt) x conformers were the most stable independent of x. However, in hydrate states (h = 0.44–0.67), the (tg+t) x conformers were the most stable independent of x values, and in h = 1, the (tg+t)8 conformer (8-mer) was most stable [∆E c(g) = −1.3 kcal/m.u., ∆E c(g): energy difference between a given oligomer and the (ttt) x oligomer]. These results supported the experimental those based on NMR analyses using dimethoxyethane and triglyme solutions. Molecular lengths (l) of (tg+t) x , (tg+g−) x and (g+g+g+) x conformers having higher x values significantly decreased with increasing h values. Such contraction with hydration, however, was independent of ΔE c(g) values of each conformer.

Hydrate effects on the conformations of ethylene oxide oligomers (EO-x, x = 1–8 mers) were examined using quantum chemical calculations (QCC). Conformational analyses were carried out by RHF/6-31G. The models were constructed by locating a water molecule to each ether–oxygen in the structures optimized for non-hydrate oligomers. Hydrate ratio, h (h = H2Omol/Omol in oligomer), was set from 0 to 1.0. The six type conformations with repeated units of O–C, C–C and C–O bonds were examined. Conformational energy, Ec (HF), was calculated as difference between the energy of oligomer with water molecules and that of non-hydrogen and/or hydrogen bonding water molecules. Hydrate energies for each conformer, ∆μh (kcal/m.u., based on Ec in non-hydrate state), were negative and linearly decreased with the increase of h values, and such effects with the increase of h values were weaken with increasing x values. These results were consistent with our previous results calculated using the permittivity, e (e = 0–80.1), by QCC. In non-hydrate (h = 0), the (ttt)x conformers were the most stable independent of x. However, in hydrate states (h = 0.44–0.67), the (tg+t)x conformers were the most stable independent of x values, and in h = 1, the (tg+t)8 conformer (8-mer) was most stable [∆Ec(g) = −1.3 kcal/m.u., ∆Ec(g): energy difference between a given oligomer and the (ttt)x oligomer]. These results supported the experimental those based on NMR analyses using dimethoxyethane and triglyme solutions. Molecular lengths (l) of (tg+t)x, (tg+g−)x and (g+g+g+)x conformers having higher x values significantly decreased with increasing h values. Such contraction with hydration, however, was independent of ΔEc(g) values of each conformer.

The grafting reaction of poly( N -vinylcarbazolyl)lithium (PNVCLi) with tert -butyllithium onto fullerene-C 60 (C 60 ) was examined to explore the possibility of preparing new materials for effective photovoltaic cells. When the molar ratio of C 60 /Li was over four, the grafting reaction products obtained were completely soluble in tetrahydrofuran. The number-average molecular weight of the grafting reaction products obtained was greater than that of the respective parent PNVCs, indicating the formation of PNVC with a C 60 end-group. Gel permeation chromatography and 13 C NMR analyses showed that the product of the grafting reaction was C 60 bonded to PNVC and t -butyl groups. UV/vis and PL spectra suggested that this PNVC may be useful for preparing effective photovoltaic cells.

Soluble poly(para-phenylene) having a long polymer chain (more than six repeat units) was synthesized with a tert-butyl end-group (t-PPP) and was found to have improved solubility and excellent optical properties. Poly(1,3-cyclohexadiene) (PCHD) consisting of only 1,4-cyclohexadiene (1,4-CHD) units was synthesized with a tert-butyl end-group (t-PCHD), and completely dehydrogenated to obtain t-PPP. This end-group effectively prevented the crystallization of t-PPP, and polymers containing up to 16 repeat units were soluble in tetrahydrofuran. Soluble t-PPP obtained had an ability to form a tough thin film prepared by spin-coating method. Optical analyses of t-PPP provided strong evidence for a linear polymer chain structure. A block copolymer of t-PPP and a soluble polyphenylene (PPH) was then synthesized, and the excellent optical properties were retained by this block copolymer along with its solubility.

Conformational analyses using quantum chemical calculations were carried out for 1- to 4-mers of ethylene oxide (EO) and ethylene imine (EI) oligomer models (EO-x and EI-x, x = 1 - 4) in the liquid phase using four solvents (permittivity: e = 2.0 ~80.1). The results were compared against those obtained in the gaseous phase. The calculations involved either RHF/6-31+G(d,p) or B3LYP/6-31G(d) // SCRF/IPCM, based on the observed and calculated results for the energy difference between trans- and cis-dichloroethane. The conformations repeated for a unit of X-C, C-C and C-X bonds (X: O or N) were examined. For both oligomers, the energies of every conformer decreased with increasing e values, and were linear against the Kirkwood function (Kf = (e-1)/(2e+1)). For the EO oligomers, the (ttt)x conformer was most stable in the gaseous phase. In liquid phases, however, the preference for the gauche-conformation (gauche preference) of the C-C bonds increased with higher values of e. In the case of EO-3, the (tg+t)x conformer was most stable above an e value of 8.9, which were in good agreement with those observed for triglyme solutions using NMR analysis. For the EI oligomers, the (tg+t)x conformer was most stable in either gaseous or liquid phase, and the gauche preference of the C-C bonds in both phases were comparable. These results were in good agreement with those observed for di-MEDA solutions using NMR analysis. It was estimated that such small solvent effects on gauche preferences of the EI oligomers result in weakening for hydrogen bonds (NH-N) of neighboring imino groups by solvents.

N-butyl-N,N-diphenylamine (BDPA) and N-4-butylphenyl-N,N-diphenylamine (BTPA) were polymerized by oxidation polymerization using iron (III) chloride as oxidant. BDPA showed higher polymerizability. Poly(BDPA) and poly(BTPA) showed UV absorption maximum at 362 and 373 nm. Oxidation potential of poly(BDPA) was 1.02 V versus Ag/AgCl, while that of poly(BTPA) was 1.12 V. Hole mobility of poly(BDPA) was 4.93 × 10−5 cm2/Vs and that of poly(BTPA) was 2.89 × 10−5 cm2/Vs at the electric field of 35 V/μm. The differences of the properties were explained by the higher electron donating power of alkyl group than phenyl group and conjugation of phenyl ring. It was found that both poly(BDPA) and poly(BTPA) can be used as hole transporting material for electroluminescent device.

A well-controlled anionic polymerization of 4-diphenylaminostyrene (DAS) with alkyllithium (RLi) has been achieved for the first time. The nucleophilicity and solubility of RLi, 4-diphenylaminostyryllithium (DASLi), and poly(4-diphenylaminostyryl)lithium (PDASLi) were very important controlling factors. An initiator system of tert-butyllithium (t-BuLi)/N,N,N′,N′-tetramethylethylenediamine (TMEDA) in toluene was found to be very effective. In this system, the t-BuLi/TMEDA complex reacts with toluene to form the benzyllithium (BzLi)/TMEDA complex, and this complex initiates the anionic polymerization of DAS. The DASLi/TMEDA and PDASLi/TMEDA complexes have sufficient nucleophilicity and stability as propagating species, without the metalation of toluene, and as a result, living anionic polymerization was achieved. The high molecular weight poly(4-diphenylaminostyrene) (PDAS), synthesized using the RLi/TMEDA system, had a syndiotactic-rich configuration, independent of the polymerization solvent.

Conformational analyses have been carried out for ethylene oxide (EO) and ethylene imine (EI) oligomer models (single chain) by quantum chemical calculations (RHF/6-31+G(d,p)). The conformations repeated for a unit of X-C, C-C and C-X bonds (X: O or N) were examined. For optimizations of the EI oligomers, some designation systems with trans values were used, taking account of pseudoasymmetry. For the EO oligomers (EO-x, x = 2- to 8-mers), (ttt)x and (tg+t)x conformers were first and second stable (ΔE = 1.17–1.26 kcal/m.u.), respectively. On the contrary, for the EI oligomers (EI-x, x = 2- to 11-mers), (tg+t)x and (ttt)x were first and second stable (ΔE = 1.32–1.42 kcal/m.u.), respectively. Therefore, the gauche preference of C-C bond in EI-x is stronger than that in EO-x. The calculated structures of (ttt)x and (tg+t)x in EO-x agreed with those observed by XRD analysis for PEO crystals in stretched (planar zigzag) and original (7/2 helix) states, respectively. The calculated structures of (tg+t)x and (ttt)x in EI-x also agreed with those observed for PEI crystals in dehydrate (7/2 helix) and hydrate (planar zigzag) states, respectively. However, the dihedral angles (EO-8) and the 5 mol length (EI-11) in both helices did not agree with each of the observed values for the polymers. Each difference between the oligomers (single chain) and polymers was estimated by the effect of intermolecular interactions in PEO or PEI. For (tg+t)x of EI-11, the existence of metastable skewed helical structures (reversed and/or kinked) were estimated in addition to the helix.

Organic light-emitting diodes were prepared by coevaporating 4,4'-N,N'-dicarbazolylbiphenyl (CBP) host material, tris(2-phenylpyridinate) iridium(III) [Ir(ppy)3] dopant material, and their vinyl derivatives for the emissive layer. It was found that the emission spectrum changes with time during device operation when both the host and the dopant molecules have vinyl groups. This spectral change corresponded to the transition of emission from vinyl-modified Ir(ppy)3 to nonmodified Ir(ppy)3. The spectral transition was more prominent when an acrylate derivative was used in place of a vinyl derivative of CBP. A similar change in luminescence spectrum was observed when the film was polymerized by thermal annealing or electron-assisted deposition. It is speculated that the spectral transition is caused by the copolymerization of host and dopant molecules during device operation. Such a current-induced polymerization can be a novel and convenient method of preparing polymeric thin films by the physical vapor deposition of functional monomers.

Organic light-emitting diodes (OLEDs) were prepared by a deposition polymerization method, in which vinyl monomers were evaporated and then annealed after deposition. N,N'-diphenyl-N,N'-bis(4-vinylphenyl)benzidine (DvTPD) was used both for a hole transport layer (HTL) and for the host material of an emissive layer (EML). bis(1-phenylisoquinoline)acetylacetonate iridium(III) [Ir(piq)2acac] and its styryl derivative bis(1-phenylisoquinolinate)-6-(4-vinylphenyl)acetylacetonate iridium(III) [Ir(piq)2acac-vb] were used as dopants. Ir(piq)2acac and Ir(piq)2acac-vb showed comparable emission characteristics. The device lifetime was improved by the thermal polymerization of DvTPD, and it was further improved by polymerizing both the host and dopant molecules to form a copolymer instead of a molecularly dispersed EML. In addition, the device with a codeposition-polymerized EML showed a small tendency of luminescence efficiency to decrease with increasing luminance. Deposition polymerization, achieved by evaporating vinyl monomers followed by thermal annealing, can be a promising method for constructing OLED structures.

Cytochrome P450 isoforms from male rat liver microsomes were comprehensively identified using nano liquid chromatography tandem mass spectrometry (nanoLC-MS/MS). The enrichment of P450, an endomembrane-anchored heme protein, was achieved by solubility-based protein fractionation, and greatly improved the total number of identified P450 isoforms. LC-MS/MS analysis of fractions resulted in the identification of total 36 P450 isoforms. The combination of proteomic analysis and the solubility-based fractionation would provide powerful tool for the expression analysis of the superfamily proteins having great similarities between the amino acids sequences.

Photoconductive poly(4-butyltriphenylamine) particles were prepared by a chemical oxidative dispersion polymerization. The utilization of statistical copolymer of methyl methacrylate with 2-hydroxyethyl methacrylate (30:70) as a dispersant afforded particles with the narrowest distribution when the other experimental conditions such as the rate of monomer feed, and the dispersant concentration were appropriately selected. Porous particles were obtained at 40 °C using poly(vinyl pyrrolidone) as a dispersant.

A new electroluminescent polymer was prepared by oxidative coupling copolymerization of N -(4- n -butylphenyl)phenoxazine (PPX) and 9,9-di- n -butylfluorene (DBF) using iron(III) chloride. The obtained polymers were soluble in common organic solvents and had number-average molecular weight as high as 10,000. The UV–vis absorption maximum and photoluminescence peak shifted to longer wavelengths with the increase of PPX content. The increase of PPX content also caused increase of hole mobility and decrease of electron mobility. A simple single-layer light-emitting-diode device having a structure of indium tin oxide/polymer/Ca/Al was fabricated. The polymer containing 30% of PPX unit showed highest electroluminescent properties with a maximum luminance of 1084 cd/m 2 at 15.5 V operating voltage.

Hole transport polymers consisting of 4-methoxytriphenylamine (P-MOTPA) and 4- n -butyltriphenylamine (P-BTPA) were synthesized by oxidative coupling reaction using FeCl 3 as an oxidant. These polymers had good solubility and their thin films showed sufficient morphological stability. 1 H NMR and 13 C NMR revealed that the monomers were exclusively connected at the p -positions of unsubstituted phenyl groups. Polymers had UV absorption maximum around 370 nm. Cyclic voltammograms of polymers showed well-defined pairs of reduction and oxidation peaks at 1.1 V versus Ag/AgCl, indicating that the polymers are electrochemically active. P-MOTPA and P-BTPA had hole drift mobility of being 4.04 × 10 −5 and 2.98 × 10 −5 cm 2 /V s at the electric field of 50 V/μm, respectively.

Polystyrene (PSt)/poly (4-butyltriphenylamine; PBTPA) composite particles was prepared by a chemical oxidative seeded dispersion polymerization of (4-butyltriphenylamine) with PSt seed particles that were prepared by nonaqueous dispersion polymerization of styrene. Monodisperse composite particles were obtained when the ratio of monomer to seed, the rate of monomer feed, and poly(N-vinyl pyrrolidone; PVP) concentration was appropriately selected. The introduction of PBTPA was confirmed by the presence of the characteristic absorption band attributed to PBTPA from a Fourier transform infrared spectra. The solvent extraction with ethyl acetate revealed that composite particles consisted of PSt core and PBTPA shell. Then two-dimensional arrays of composite particles were also fabricated.

Polymers having 2,5-diphenyl-1,3,4-oxadiazole (BCO) or anthracene (BCA) as an electron transport unit and N,N′-diphenyl-N,N′-bis(4-butylphenyl)-benzidine (BTPD) as a hole transport unit were prepared by condensation polymerization using Friedel–Crafts reaction. It was found that BCO was less reactive than BCA. The low reactivity of the BCO monomer can be explained by the oxygen atom in the oxadiazole unit, which acts as a Lewis base and reduces the activity of the catalyst. The redox behavior measured by cyclic voltammetry showed for both BTPD-BCO and BTPD-BCA almost the same oxidation potential. In addition, the BTPD-BCO also exhibited a reduction peak. Hole and electron drifts mobility of the polymers were measured by the time-of-flight method. The hole drift mobility of both BTPD-BCO and BTPD-BCA was 7.4 × 10−5 cm2 V−1 s−1. The electron drift mobilities of BTPD-BCO and BTPD-BCA were 6.5 × 10−5 cm2 V−1 s−1 and 5.2 × 10−6 cm2 V−1 s−1, respectively. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3083–3089, 2007

The new type of coronary angiography(CAG)that uses 40 mm volumetric computed tomography(VCT)has great potential for cardiac disease. However, it is still necessary to be cognizant of exposure dose. We measured doses of CAG by both VCT and cardiovascular X-ray using a body phantom within 170 glass dosimeters. VCT protocols were 120 kV, 570 mA, and 0.35 sec/rot with and without the dose-reduction features(small cardiac X-ray beam filter and ECG mA modulation). The cardiovascular X-ray protocol was Auto(65 - 77 kV)kV, Auto(41 - 46 mA)mA, 5 secx11 shots+11 min fluoroscopy(minimum protocol for screening). VCT with and without the dose-reduction features has the same dose distribution, however, the dose-reduction features reduced the amount of dose by about 40-50%. For VCT with those features, measured dose was about 70 mGy in the cardiac area and 60 mGy at the skin of the back, whereas those of cardiovascular X-ray were 10 mGy and 30 mGy. We measured detailed dose distributions and variations in the phantom, and we also demonstrated the possibility of VCT's dose-reduction features. The CT dose was still higher than that of cardiovascular X-ray, however, there were advantages of CT scanning, for instance, information about calcification, soft plaque, and 3D visualization. We think it is important to use both systems with an understanding of their advantages and limitations.

The reactivity of three types of quinones (3,4,5,6-tetrachloro-1,2-(o-)-benzoquinone (TOQ), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), and 2,3,5,6,-tetrachloro-1,4-(p-)-benzoquinone (TCQ)) was examined for the dehydrogenation of poly(1,3-cycohexadiene) (PCHD) composed of 1,2-cyclohexadiene and 1,4-cyclohexadiene units. The order of reactivity was TOQ > DDQ > TCQ. The steric hindrance of CO groups in the quinones appeared to be an important factor in determining their reactivity. DDQ was found to be an appropriate dehydrogenation reagent for PCHD. The reactivity of TCQ was considerably low for PCHD containing 1,2-cyclohexadiene units. The reactivity of TOQ was too high and side reactions occurred, causing the formation of structural defects. Copyright © 2007 Society of Chemical Industry

We report fluorescence lifetime studies of a charge-transfer dye, dimethyl-amino-N-acetyl-3-aminobenzanthrone, embedded in a series of polymer matrices. In all polymers studied, the fluorescence lifetime has two components, indicating the existence of two classes of molecular environments. Microscopic studies on sub-ensembles of the dye molecules carried out in PMMA and PVAc matrices reveal that the polymer films are spatially heterogeneous with respect to their physical properties on scales of more than few hundreds of nm. The heterogeneity further increases on molecular scale, as observed by fluorescence lifetime distribution of the dye in the PMMA matrix.

BACKGROUND: Poly(1,3-cyclohexadiene) (PCHD) is of interest as a precursor for the synthesis of a new class of high-performance hydrocarbon polymers. ω-Functionalization of PCHD offers a new opportunity for the preparation of a variety of multifunctional PCHD derivatives. RESULTS: ω-Functionalized PCHD containing a fluorenyl (or anthracenyl) group at the polymer chain end was successfully synthesized by post-polymerization reaction of poly(1,3-cyclohexadienyl)lithium (PCHDLi) with alkyl halides containing a fluorescent functional group. The degree of nucleophilicity of PCHDLi and the control of side reactions were very important factors to achieve a high conversion for the post-polymerization reactions of PCHDLi. The ω-functionalized PCHDs obtained exhibited strong photoluminescence and the wavelength of the fluorescence was adjustable by changing the structure of the ω-functional group. CONCLUSION: ω-Functionalized PCHD is a preferable precursor that can be utilized to obtain a new class of multifunctional hydrocarbon polymers containing six-membered rings in the main chain. Copyright © 2007 Society of Chemical Industry