Search

A microstructure film has been developed to improve drastically LCD viewing angle characteristics (grayscale inversion, color shift, contrast ratio, etc.). By simply attaching it to the surface of commercially available LCD, the LCD has realized the excellent visibility without the blur of the frontal image and the reduction of the contrast ratio under bright ambient light conditions. This technology can be applied to various LCD modes including TN and MVA modes.

A microstructure film with many micro cavities positioned behind small black dots has been developed for improving LCD viewing-angle characteristics. The micro cavities are fabricated by the self-alignment photolithography of the transparent photoresist using the black dots as photo masks. The cavity shapes are optimized by controlling the photolithography conditions.

Venous thromboembolism is a serious complication after surgery for malignant musculoskeletal tumors in the lower extremity. However, the incidence of postoperative venous thromboembolism in patients with benign musculoskeletal tumors and musculoskeletal tumors in the upper extremity or trunk remains unclear. Identifying risk factors may provide useful information for selecting patients who should receive chemoprophylaxis.A retrospective study of 833 patients with musculoskeletal tumors who underwent surgery was conducted. Patients were divided into four groups: 364 patients with benign tumors in the upper extremity or trunk (group 1); 315 patients with benign tumors in the lower extremity or pelvis (group 2); 50 patients with malignant tumors in the upper extremity or trunk (group 3); and 104 patients with malignant tumors in the lower extremity or pelvis (group 4). The incidence of venous thromboembolism was investigated, and risk factors were examined for group 4.The incidence of postoperative venous thromboembolism was 0, 0.95, 0, and 4.8 % in groups 1, 2, 3, and 4, respectively. The incidence of venous thromboembolism in the malignant tumor group (groups 3 + group 4) was significantly higher than that in the benign tumor group (group 1 + group 2). The incidence of postoperative venous thromboembolism in the upper extremity or trunk group (group 1 + group 3) was significantly lower than that in the lower extremity or pelvis group (group 2 + group 4). In group 4, a higher incidence of postoperative venous thromboembolism was significantly correlated with a history of cerebrovascular disease and surgery in the prone position.Patients with malignant tumors in the lower extremity or pelvis, particularly those with a history of cerebrovascular disease and surgery in a prone position, were at high risk of venous thromboembolism. Patients with benign tumors in the lower extremity or pelvis were at intermediate risk. This is important information for predicting the incidence of postoperative venous thromboembolism and determining who should receive chemoprophylaxis after surgery for musculoskeletal tumors.

Pyomyositis in immunocompromised patients may present only minimal inflammatory changes and thus clinically mimic soft tissue tumour. We report two patients with pyomyositis which was initially suspected to be a soft tissue tumour. Patient 1 was a 64–year–old woman who had pyomyositis at the distal part of the left thigh. She had uncontrolled diabetes mellitus. Causative organism was gram positive rods. Patient 2 was a 54–year–old man who had pyomyositis at the medial head of the gastrocnemius. He had ill–controlled diabetes mellitus. Causative organism was Staphylococcus aureus. Both of them were immunocompromised hosts. They showed minimal inflammatory findings and the swelling of the muscles took the appearance of a soft tissue tumour rather than pyomyositis. The inflammation prevailed beyond the muscle compartment and fluid collection representing abscess were seen on MR images. Patient 1 was treated conservatively and Patient 2 was treated surgically. When needle biopsy is performed for soft tissue tumour–like lesions even with minimal inflammatory changes, not only histological examination but also bacteriological examination should be performed.

炭素数 12 の長鎖アルキル基を 3 個有する芳香族ジアミンモノマーである 12G1 と脂肪族骨格のテトラカルボン酸二無水物である Cyclo-DA，もしくは芳香族骨格のテトラカルボン酸二無水物である DSDA，また，共重合用のジアミンとして DDE を用いて，溶解性に優れ，耐熱性も十分な可溶性ポリイミドを合成した．得られたポリイミドの薄膜に紫外線(λmax; 254 nm)を照射すると，水に対する接触角は照射した紫外線エネルギーに応じ，100°付近から最少 20°付近まで大きく低下し，疎水性から親水性に制御可能であることが判明した．接触角測定の結果および ATR 解析の結果より，紫外線照射によってポリイミド表面の疎水基である長鎖アルキル基が減少しヒドロキシル基などの親水基が生成していることが考えられる．本技術は，紫外線照射により，ポリイミド表面を容易に疎水部と親水部にパターニングする手法として，プリンタブルエレクトロニクスの分野での応用が期待される．

Ligand efficiency is frequently used to evaluate fragment compounds in fragment-based drug discovery. We applied ligand efficiency indices in a conventional virtual screening-initiated lead generation study of soluble epoxide hydrolase inhibitors. From a considerable number of screening hits, we carefully selected a compound exhibiting relatively weak inhibitory activity but high ligand efficiency. This ligand efficiency-guided selection could reveal compounds possessing preferable lead-like characteristics in terms of molecular size and lipophilicity. The following hit-to-lead medicinal chemistry campaign successfully led to a more potent, ADMET-clean, lead-like compound preserving high ligand efficiency. Retrospective analyses, including consideration of the more recently proposed indices of ligand efficiency, shed light on the validity of our hit triage and hit-to-lead studies. The present work proposes a practical methodology for lead generation using the concept of ligand efficiency.

Polyimides having dendritic side chains were investigated. The terphenylene diamine monomer having a first-generation monodendron, 3,4,5-tris(n-dodecyloxy)-benzoate and the monomer having a second-generation monodendron, 3,4,5-tris[-3’,4’,5’-tri(n-dodecyloxy)benzyloxy]benzoate were successfully synthesized and the corresponding soluble dendritic polyimides were obtained by polycondensation with conventional tetracarboxylic dianhydride monomers such as benzophenone tertracarboxylic dianhydride (BTDA). The two-step polymerizations in NMP that is a general method for the synthesis of soluble polyimides is difficult; however, the expected dendritic polyimides can be obtained in aromatic polar solvents such as m-cresol and pyridine. The solubility of these dendoronized polyimides is characteristic; soluble in common organic solvents such as dichloromethane, chloroform, toluene and THF. These dendronized polyimides exhibited high glass transition temperatures and good thermal stability in both air and under nitrogen. Their application as alignment layers for LCDs was investigated, and it was found that these polyimides having dendritic side chains were applicable for the vertically aligned nematic liquid crystal displays (VAN-LCDs).

The synthesis, and structural and retrostructural analysis of a library of second-generation conical dendrons that self-assemble into spherical supramolecular dendrimers is reported. This library consists of amphiphilic dendrons with n-alkyl groups containing from 4 to 16 carbon atoms. The dendrons containing 6 to 16 carbon atoms in their n-alkyl groups self-assemble into spherical supramolecular dendrimers that self-organize in a Pm3n cubic lattice. The structural and retrostructural analysis of the Pm3n lattices generated from the supramolecular dendrimers demonstrated that the volume of the aromatic core of the spherical dendrimers is not dependent on the number of carbon atoms from their alkyl groups. This result facilitated the calculation of the average values of the absolute electron density of the aliphatic and aromatic domains of the spherical supramolecular dendrimers. The relative intensity of the higher order diffraction peaks of the Pm3n lattice increases as the volume of the aliphatic part of the sphere mediated by the number of carbon atoms in the n-alkyl groups decreases. This study demonstrates the maximum increase of the relative intensity of the higher order diffraction peaks of the Pm3n lattice generated from non-hollow supramolecular dendrimers.

The synthesis and characterization of a novel series of soluble polyimides bearing long-chain alkyl groups on their side chains using aromatic diamine monomers such as N-alkyl-3,5-diaminobenzamide (ADBA-X, X = carbon numbers of alkyl chain, 9~14) and N-(3,5-diaminophenyl)-3,4,5-tris(alkoxy)benzamide (DPABA-X, X = 6,12) are described. Polyimides obtained from 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) and ADBA-9~14 were insoluble, however, copolyimides based on BTDA, ADBA-9~14, and 4,4′-diaminodiphenylether (DDE) were soluble. The solubility of these copolyimides may be improved by the entropy effect of long-chain linear alkyl groups as well as the randomizing effect based on copolymerization. The effect of ADBA for the enhancement of solubility was compared with a series of functional diamines bearing long-chain alkyl groups via various linkage groups reported from our laboratory such as alkoxydiaminobenzene (AODB, ether linkage), alkyldiaminobenzophenone (ADBP, benzoyl linkage) and diaminobenzoic acid alkylester (DBAE, ester linkage), and it is concluded that the effect of functional diamines are increased as AODB (ether linkage) > ADBP (benzoyl linkage) > ADBA (amide linkage) > DBAE (ester linkage). The polyimides and copolyimides based on BTDA, DPABA-6 or DPABA-12, and DDE containing 50 mol % or more DPABA were soluble, showing that the effect of DPABA for the enhancement of solubility was larger than ADBA. It is speculated that the three long-chain alkyl groups in DPABA enhance the solubility of polyimides. Above polyimides and copolyimides were soluble in various polar solvents and exhibited good heat-resistance.

The vital roles of peptide/protein thioesters in protein chemistry, including chemical or semi-synthesis of proteins, have encouraged studies on the development of methods for the preparation of such chemical units. Biochemical protocols using intein or sortase have proved to be useful in protein chemistry as methods suitable for naturally occurring sequences, including recombinant proteins. Although chemical protocols are potential options for thioester preparation, only a few are applicable to naturally occurring sequences, because standard chemical protocols require an artificial chemical device for producing thioesters. In this context, the chemical preparation of thioesters based on a reaction sequence consisting of regioselective S-cyanylation and hydrazinolysis was investigated. Regioselective S-cyanylation, which is required for cysteine-containing thioesters, was achieved with the aid of a zinc-complex formation of a CCHH-type zinc-finger sequence. Free cysteine residues that are not involved in complex formation were selectively protected with a 6-nitroveratryl group followed by S-cyanylation of the zinc-binding cysteine. Hydrazinolysis of the resulting S-cyanopeptide and subsequent photo-removal of the 6-nitroveratryl group yielded the desired peptide hydrazide, which was then converted to the corresponding thioester. The generated thioester was successfully used in N-to-C-directed one-pot/sequential native chemical ligation using an N-sulfanylethylanilide peptide to give a 64-residue peptide toxin. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 531-546, 2016.

The synthesis and characterization of a novel series of soluble polyimides, that are based on diaminobenzoic acid alkylester (DBAE) having long-chain alkyl groups with 8–14 carbon atoms, are described. Polyimides obtained from 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) and DBAE-8–14, and copolyimides based on BTDA, DBAE-8–14, and 4,4′-diaminodiphenylether (DDE) were insoluble in polar solvents such as N-methyl-2-pyrrolidone (NMP) and the effect of long-chain linear alkyl groups for the enhancement of solubility was not recognized. However, it was found that two methods improve the solubility. One is the use of branched alkyl groups such as nonan-5-yl and 2,6-dimethylheptane-4-yl, and the other is the use of relatively flexible diamine co-monomer, 4,4′-diaminodiphenylmethane (DDM). These polyimides and copolyimides based on DBAE were soluble in various polar solvents and exhibited good thermal stability in air and under nitrogen. The effect of DBAE for the enhancement of solubility was lower than the effects of alkyloxydiaminobenzene (AODB) and alkyldiaminobenzophenone (ADBP), probably due to the rigid ester linkage group in DBAE.

Soluble Polyimides and Copolyimides Based on Alicyclic Dianhydride Having Cyclohexene and Tetralin Moieties

To find a more efficient phytoremediation, the accumulation mechanism of elucidating heavy metals of a hyperaccumulator is important. We measured the behavior and glutathione quantity of the heavy metal accumulation level in calli using Brassica juncea, which is a hyperaccumulator of Pb and Cd. Brassica juncea from a seed was used to grow callus, which was for three months. Then, for two weeks, we conducted long-term exposure to a culture in heavy-metal component culture media (Cr, Cu, Zn, Cd, Pb, Co, Ni). Furthermore, we used a liquid culture medium; for Pb, we conducted a short-term exposure for five days. As for Cd and Pb, the absorbed dose was high, and the Cd, in particular, showed the absorbed dose to be high at a low concentration (10∼100 μM), compared with other heavy-metal classes. There were many things that necrotized, in other heavy metals, the fastness was not found to influence the heavy metal. In the short-term exposure of Pb, the absorption level increased during the early phase. However, 96 hours later, according to the cell cycle, that absorption appeared to be promoted. In addition, in GSH, while a large difference was not recognized, a high concentration level was much contained it.

One of the useful methods for exploration of the function of proteins is utilization of the synthesized proteins which include artificial units such as fluorescence dye. For the synthesis of such proteins, a peptide thioester and an N-terminal cysteinyl peptide prepared by Solid Phase Peptide Synthesis (SPPS) are coupled to each other using Native Chemical Ligation (NCL) [1]. However, due to the limitation of the number of amino acid residues applicable to SPPS, multistep NCLs are required for chemical synthesis of large proteins. On the other hand, in semi-synthesis of proteins, only single NCL of protein thioester prepared from expressed protein with chemically synthesized N-terminal cysteinyl peptide enables to incorporate functional moieties to large proteins. However, there are only a few methods for preparation of protein thioesters applicable to naturally occurring sequences [2]. Therefore, new protocols for preparation of protein thioesters has been required.

The synthesis and characterization of a novel series of soluble polyimides, which are based on alkyloxydiaminobenzene (AODB) and have long-chain linear alkyl groups with 10—14 carbon atoms, are described. Polyimides obtained from 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) and AODB-10—14 were soluble in polar solvents such as N-methyl-2-pyrrolidone (NMP) and the effect of long-chain linear alkyl groups for the enhancement of solubility was confirmed. Soluble copolyimides based on AODB and the conventional aromatic diamine diaminodiphenylether (DDE) may also be obtained. The incorporation of DDE resulted in an increase of the molecular weight and improved the thermal stability. These polyimides and copolyimides based on AODB were soluble in various polar solvents and exhibited high thermal stability in air and nitrogen. The copolymerization experiments and the solubility tests demonstrated that the most effective alkyl chain length for improving the solubility is twelve.

The synthesis and characterization of a novel series of soluble polyimides based on alkyldiaminobenzophenone (ADBP) having long chain linear alkyl groups with 9—14 carbon atoms are described. Polyimides containing tetracarboxylic dianhydrides such as 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) and ADBP with even number carbon atoms were soluble in polar solvents such as N-methyl-2-pyrrolidone (NMP), while polyimides containing BTDA and ADBP with odd number carbon atoms (ADBP-9, 11, 13) were insoluble in NMP. These unique odd-even effects of solubility were assumed due to the conformational effects of long chain linear alkyl groups. Soluble copolyimides based on ADBP with conventional aromatic diamine, diaminodiphenylether (DDE) can be obtained. The incorporation of DDE resulted in increment of molecular weight and improve the thermal stability. Soluble polyimides and copolyimides based on ADBP were soluble in various polar solvents and exhibited high thermal stability in air and nitrogen.

Soluble Copolyimides Based on 2,3,5-Tricarboxycyclopentyl Acetic Dianhydride and Conventional Aromatic Tetracarboxylic Dianhydrides

Soluble polyimides with polyalicyclic structure were prepared by reactions of 2,3,5-tricarboxycyclopentyl acetic dianhydride (TCA-AH) with aromatic diamines. The two-step polymerization systems including poly(amic acids) synthesis and solution imidization using pyridine and acetic anhydride were performed and soluble polyimides with high inherent viscosities and high imidization ratios were obtained. TCA-AH polyimides exhibited high thermal stability in air and nitrogen, and good solubility in common polar solvents such as NMP (N-methyl-2-pyrrolidone). In comparison with soluble aromatic polyimides based on fluorine containing monomers, TCA-AH polyimides showed slightly less thermal stability and lower solubility in a few solvents.

Peptidyl prolyl thioesters, which have been regarded as too unreactive for practical use in native chemical ligations (NCLs), were proven to be versatile reagents in peptide coupling. Tuning the reactivity of prolyl thioesters enabled a one-pot/sequential NCL reaction based on kinetically controlled ligation.

In this paper, we propose a novel method for storing high dynamic range (HDR) spectral images compactly and displaying them quickly taking into account the properties of the human visual system (HVS). It is important to display images quickly to various kinds of display monitors with different resolutions. To accelerate the display process, we store the 2D spatial components and 1D spectral components separately in a discrete wavelet transform process. When displaying the image, we first convert the 1D spectral components into RGB tristimulus color components. In the RGB conversion, we make use of the property of orthonormal-basis functions. Then, we retrieve a RGB color image using a part of the spatial components (converted RGB coefficients) depending on the resolution of a display device. Our method makes it possible to efficiently convert and quickly display HDR spectral images to RGB display monitors.

Improving the photon to electron conversion efficiency of photodetecting devices including photo sensors and solar cells having an ultrathin-film photoelectric-conversion layer (PECL) is important for several reasons: enhanced carrier extraction, reduced material usage and simplified fabrication processing. In order to achieve this target, an effective method to trap and ultimately absorb photons within the ultrathin PECL is necessary. Over the years, various methods to precisely manipulate the properties of photons have been demonstrated with photonic crystals1–5 (PCs) among which are the band-edge modes of two-dimensional (2D) PC used to couple in-plane optical resonances with large area to external radiation as applied to lasers2, 6–9 and light-emitting diodes10. Here, we focus instead on the process opposite to emission: optical absorption at the band edge. If the incident light couples to a resonant mode of the PC, enhanced optical absorption and ultimately improved photoelectric conversion efficiency may potentially be realized even in an ultrathin PECL. The underlying mechanism is the resonant Q matching condition11 which should play an important role in designing an optimal lattice structure. Recently, a number of photonic-crystal designs have been proposed to improve light-trapping efficiency by exploiting the wave-nature of incident radiation12–18. However there have been no investigations of devices having an ultrathin PECL (thickness less than 100 nm) and no corresponding demonstrations of photocurrent enhancement at the photonic band edge related to the Q matching. In this paper, we demonstrate the enhancement of the photocurrent in ultrathin (50 nm) Si photodetecting devices by the photonic band-edge effect via measurement of the photocurrent spectra.

Polyimides exhibit excellent thermal and mechanical properties, and have extensive engineering and microelectronics applications. Aromatic polyimides such as polyimides based on pyromellitic dianhydride are prepared from aromatic diamines and aromatic tetracarboxylic dianhydrides via poly(amic acid)s. Since conventional aromatic polyimides are insoluble, these polymers are usually processed as the corresponding soluble poly(amic acid) precursors, and then either thermally or chemically imidized. However, owing to the instability of poly(amic acid)s and the liberation of water in the imidization process, problems can arise (Fig. 1). Extensive research has been carried out to improve the solubility of polyimides and successful recent examples involve the incorporation of fluorine moieties, isomeric moieties, methylene units, triaryl imidazole pendant groups, spiro linkage groups, and sulfonated structure. Soluble polyimides bearing long-chain alkyl groups have also been reported, and their applications mainly involve their use as alignment layers for liquid crystal displays (LCDs). Our research group has systematically investigated the synthesis and characterization of soluble polyimides based on aromatic diamines bearing long-chain alkyl groups such as alkyldiaminobenzophenone (ADBP-X, X = carbon numbers of alkyl chain) (Tsuda et al., 2000a) alkoxydiaminobenzene (AODB-X) (Tsuda et al., 2000b), diaminobenzoic acid alkylester (DBAE-X) (Tsuda et al., 2006), and alkyldiaminobenzamide (ADBA-X) (Tsuda et al., 2008), and the results from these research are described in the original papers and the review paper (Tsuda, 2009). Our recent paper has described soluble polyimides having dendritic moieties on their side chain, and it was found that these polyimides having dendritic side chains were applicable for the vertically aligned nematic liquid crystal displays (VAN-LCDs) (Tsuda et al., 2009). These dendronized polyimides were synthesized using the novel diamine monomer having a first-generation monodendron, 3,4,5-tris(ndodecyloxy)benzoate and the monomer having a second-generation monodendron, 3,4,5tris[-3’,4’,5’-tri(n-dodecyloxy)benzyloxy]benzoate. Some soluble polyimides were synthesized from the diamine monomer having three longchain alkyl groups; aliphatic tetracarboxylic dianhydride; 5-(2,5-dioxotetrahydrofuryl)-3methyl-3-cyclohexene-1,2-dicarboxylic anhydride (Cyclohexene-DA) or aromatic tetracarboxylic dianhydride; 3,3’,4,4’-diphenylsulfone tetracarboxylic dianhydride (DSDA)

Good local control of high-grade non-small round cell soft tissue sarcomas (NSRCSTSs) has been achieved with significant advances in surgical techniques and radiotherapy. However, the role of chemotherapy remains controversial. Our aim was to investigate the efficacy, feasibility and adverse effects of neoadjuvant and adjuvant chemotherapy with modified mesna, adriamycin, ifosfamide and dacarbazine (MAID) regimen for NSRCSTSs.We conducted a retrospective review of 40 consecutive patients (29 men, 11 women; median age 47 years) with high-grade NSRCSTSs treated in two referral centers between 2004 and 2009 (median follow-up 38.5 months). Patients with distant or nodal metastases at diagnosis were excluded. The regimen consisted of ifosfamide 2,500 mg/m(2)/6 h (days 1-3), mesna 2,500 mg/m(2)/6 h (days 1-3), tetrahydropyranyl adriamycin 20 mg/m(2)/0.5 h (days 1-3), and dacarbazine 300 mg/m(2)/1 h (days 1-3).Among the 26 evaluable patients, there were 8 with a partial response, 15 with stable disease, and 3 with progressive disease. Two- and 5-year overall survival rates were 92 and 86%, respectively, and corresponding disease-free survival rates were 80 and 77%. All relapses were metastases without local recurrence. Grade 3-4 neutropenia, anemia and thrombocytopenia were observed in 38, 18, and 21 patients, respectively. No serious infectious complications occurred due to the administration of granulocyte colony-stimulating factor and prophylactic antibiotics. No other life-threatening serious adverse events were observed.The modified MAID regimen achieved a better outcome with less serious adverse events than previously reported and is a potential option in the management of NSRCSTSs. Further evaluation with long-term follow-up is required.

It has been reported that osteoid osteoma may heal spontaneously. To elucidate the efficacy of conservative treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) for osteoid osteoma, clinical courses of the 15 patients with osteoid osteoma conservatively treated with NSAIDs were observed. Twelve out of the 15 patients took a usual dose of NSAIDs regularly (regular group). Except for one patient, all the patients of the regular group maintained pain-free state. Eight out of the 12 patients of the regular group were free of pain even after discontinuing NSAIDs in the average of 18.3 months (range 2–36 months). Because one patient of the regular group required twice the usual dose to maintain pain-free state, we performed surgical excision. The remaining three patients of the regular group were asymptomatic and still taking NSAIDs. The healing rate of the osteoid osteoma with regular dose of NSAIDs was 8/12 (67%) at the time of this study, which may be improved up to 11/12 (92%). On the other hand, mean period of time until spontaneous diminution of pain in the 14 patients conservatively observed without NSAIDs so far reported in the literature was 75 months (range 24–180 months). Thus, osteoid osteoma is highly likely to heal spontaneously and administration of NSAIDs accelerates spontaneous healing. Therefore, conservative treatment with NSAIDs can be an important option other than surgical excision in treating osteoid osteoma.

This paper describes the synthesis and characterization of copolyethers based on 1-(4-hydroxyphenyl)-2-(2-methyl-4-hydroxyphenyl)ethane (MBPE) and various combinations of from three to eight α,ω-dibromoalkanes. Copolymers containing spacers with an odd number of methylene units display a uniaxial nematic mesophase and a second unidentified mesophase. Copolymers containing spacers with odd and even or only even numbers of methylene units display a uniaxial nematic mesophase. The parameters of the mesomorphic phase transitions of all copolymers represent weight-averaged values of the corresponding parameters of the parent homopolymers. This proves that the structural units of these copolymers are isomorphic within their mesophase. These results also demonstrate that the parameters of the mesomorphic phases can be engineered by copolymerization. All MBPE copolymers are crystallizable. Their crystallizability decreases by increasing the number of flexible spacers and decreasing their length, and by using an odd rather than an even number of methylenic units in the spacer.

The isomorphism of polyether chains based on 1-(4-hydroxyphenyl)-2-(2-methyl-4-hydroxyphenyl)ethane (MBPE) and α,ω-dibromoalkanes (MBPE-X, MBPE-X/Y(A/B) and MBPE-X/Y/Z(A/B/C), where X, Y, Z are the number of methylene units in the spacer and A/B/C the molar ratio between each spacer), most of which display virtual mesophases, was investigated in their crystalline and liquid-crystalline phases. Binary mixtures of polyethers with even-even, even-odd and odd-odd spacers, binary copolyethers and polyethers, binary copolyethers and copolyethers, ternary copolyethers and polyethers, and ternary mixtures of polyethers were all investigated. Out of 20 mixtures studied, only eight were isomorphic either within both their crystalline and liquid-crystalline phases or within only their liquid-crystalline or crystalline phases. The mixtures displaying isomorphism are: MBPE-7/MBPE-9, MBPE-8/MBPE-10, MBPE-5/13(50/50)/MBPE-9/11(50/50), MBPE-5(33)/MBPE-7(33)/MBPE-9(33), MBPE-5/7/9(33/33/33)/MBPE-5, MBPE-5/7/9(33/33/33)/MBPE-7, BPE-8/10(50/50)/MBPE-8/16(50/50) and MBPE-5/7/9(33/33/33)/MBPE-9. In the case of mixtures of homopolymers, the tendency towards isomorphism increases with the decrease of the difference between the spacer length and parity. In the case of mixtures of copolymers with copolymers and of copolymers with homopolymers the tendency towards isomorphism increases by increasing the number of flexible spacers from the copolymer. By analogy with copolymers containing structural units that are isomorphous within mesomorphic phases, mixtures of polymer chains that display virtual mesophases and are isomorphic in their mesophase can be used to determine virtual mesomorphic phase transition temperatures and thermodynamic parameters of the parent homopolymers.

Les polyethers prepares presentent une mesophase nematique virtuelle; les temperatures de transition virtuelle isotrope-nematique et les parametres thermodynamiques associes des polyethers contenant de 4 a 20 groupes methylene dans le motif flexible varient selon que le nombre de methylene est pair ou impair. Discussion de la contribution entropique des motifs flexibles a la transition

Etude par DSC de polyethers prepares a partir du MBPE et du dibromo-1,15 pentadecane (MBPE-15) et du dibromo-1,16 hexadecane (MBPE-16) et de copolyethers bases sur le MBPE, le dibromo-1,8 octane et le dibromo-1,15 pentadecane (MBPE-8/15) ou le dibromo-1,16 hexadecane (MBPE-8/16). Le MBPE-15 et MBPE-16 sont cristallins alors que les MBPE-8/15 et MBPE-8/16 montrent une mesophase monotrope ou meme enantiotrope nematique

Ternary copolyethers [MBPE-5/7/9(A/B/C)] were synthesized, and their mesomorphic phase behavior was characterized by DSC and optical polarized microscopy. Three-dimensional representations of experimental data demonstrated that isomorphic-mesomorphic phase transition temperatures and enthalpy changes of all copolymers are situated on planar surfaces that represent the weight-averaged values of the corresponding thermal transitions and enthalpy changes of the MBPE-5, MBPE-7, and MBPE-9 homopolymers

The first total synthesis and structural determination of YCM1008A, a Ca 2+ signaling inhibitor, have been achieved. The N -methoxy pyrano-pyridone moiety was synthesized by successive O- and N-conjugate additions with diketoamide 15 . The absolute structure was determined to be (2 R ,3 R ,4 S ,8′ R )-configuration.

The estimation of time delay between the two spatially separated noisy signals by modelling the problem as system identification with input and output corrupted by additive white Gaussian noise is addressed. The time delay estimation problem is equivalent to that of system delay optimization. The proposed method is based on the adaptive Butler-Cantoni (ABC) equalizer. The ABC approach decouples the noise power estimation from channel estimation. The separation noise variance estimation and the channel estimation open the way for a variety of noise variance estimation techniques. We propose an IIR filter based whitening approach using the Burg algorithm to eliminate the noise effects before updating the equalizer coefficients. Matching the system delay to the time delay results in a noise robust estimator. Simulation results confirm the superiority of this approach at low signal-to-noise ratios (SNRs).

An efficient adaptation technique of the delay is introduced for accomplishing more accurate adaptive equalization. It is focused on the adaptive Butler-Cantoni (ABC) equalizer, which can deal easily with a variable delay for each iteration and the adaptation is conducted with channel estimation. The delay is adapted by checking the first and last elements of the coefficient vector for the ABC equalizer and it results in a linear transversal equalizer (LTE) providing a lower mean square error (MSE) than the other LTEs with the same order. The performance of the ABC equalizer with the delay adaptation is confirmed by computer simulations.

We demonstrate an enhancement of the photoelectric-conversion efficiency of an ultrathin (50 nm) silicon active-layer photodetecting device using a two-dimensional photonic crystal positioned nearby to boost the optical absorption. We show both experimentally and with simulations that the incident-light absorption within the active layer is enhanced by optical-resonance effects at the photonic band edge. We also find that a photonic crystal with deeper holes can lead to an even larger absorption enhancement due to better quality (Q)-factor matching between the photonic band-edge modes and the intrinsic material absorption. The experimentally observed photocurrent of the fabricated photonic-crystal sample is increased by a factor of ∼20 at the photonic band-edge wavelength relative to that of a control sample without the photonic crystal which is attributed to the improved Q matching.