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Microphysiological systems (MPS), also known as Organ(s)-on-Chip (OoC), are in vitro cell culture platforms that reproduce the function of cells/tissues/organs in a microenvironment. To closely mimic in vivo physiological functions, MPS must allow the cells to attain three-dimensional arrangements and be supplied with adequate oxygen and growth factors (via microfluidic channels). Furthermore, as MPS are mostly used in cell-based drug development assays, they must ensure easy analysis and high usability. To make MPS which conform to these various requirements, it is crucial to select appropriate materials; oftentimes, MPS-appropriate materials have been developed. Here, we review the functions and properties of materials used to make MPSs and summarize the specifications, considerations, and selection methods employed in choosing appropriate materials and technologies to fabricate MPS that meet standard requirements. Where possible, we give specific examples to explain several important functions. The functions of the chosen material for MPS depend on the context of use (COU) in the drug development process. Because of the diverse COUs, the material selection strategies and the processes used to fabricate required material functionalities are complex. We also discuss the importance of standardizing MPS material and recent international efforts made in this direction.

Longwave Infrared Camera (LIR) on board Akatsuki first revealed the global structure of the thermal tides in the upper cloud layer of Venus. The data were acquired over three Venusian years, and the analysis was done over the areas from the equator to the midlatitudes in both hemispheres and over the whole local time. Thermal tides at two vertical levels were analyzed by comparing data at two different emission angles. Dynamical wave modes consisting of tides were identified; the diurnal tide consisted mainly of Rossby‐wave and gravity‐wave modes, while the semidiurnal tide predominantly consisted of a gravity‐wave mode. The revealed vertical structures were roughly consistent with the above wave modes, but some discrepancy remained if the waves were supposed to be monochromatic. In turn, the heating profile that excites the tidal waves can be constrained to match this discrepancy, which would greatly advance the understanding of the Venusian atmosphere. On Venus, the atmosphere circulates 60 times faster than the solid body of Venus; this phenomenon is called “superrotation,” and it is one of the mysteries of the Venusian atmosphere. To maintain the fast circulation, thermal tides, which are global‐scale atmospheric waves excited by solar heating, have been considered a very important candidate because they have the ability of accelerating the atmosphere through propagating. A midinfrared camera onboard the Japanese Venus orbiter, Akatsuki, can capture temperature perturbations due to the thermal tides in the upper cloud level (60‐ to 70‐km altitude), and it revealed their global and vertical structures with a long‐term observation (more than three Venusian years) for the first time. Interestingly, we found that the location of the maximum temperature at the cloud top level was different from noon where solar energy input is at a maximum. In addition, the location was shifted toward the morning side as the sensing altitude increased. This finding is an evidence of the vertical traveling of the thermal tides, indicating the wave's atmospheric acceleration. Akatsuki/LIR revealed the global structures of thermal tides across the equator in the upper cloud layer of Venus for the first timeUsing the emission angle dependence of LIR's sensing altitude, upward propagation of the semidiurnal tide was confirmedWave types consisting of the thermal tides were identified

A class of perovskite manganese oxides undergo photoinduced and current-driven insulator-to-metal transition. The conductance near the transition is quite "noisy" indicating macroscopic fluctuations. The spatial and temporal magnitude of the fluctuations is too large to be accounted for by simple first- order phase transition. An alternative view is proposed that the material is in the two-phase coexistence regime with extremely large fluctuations, reminiscent of the critical phenomena.

The differences and similarities in morphologies acquired across various wavelengths in simultaneously obtained Venus' dayside images may provide clues on cloud/atmospheric physics and chemistry. Here, we focus on spatial scales smaller than ∼600 km, where cell‐like or streaky features seem to dominate in ultraviolet images. Using images acquired at ultraviolet wavelengths of 283 nm, 365 nm, and infrared wavelengths of 0.90, 2.02, and 10 μm by the Venus orbiter Akatsuki, correlation coefficient maps between pairs of wavelengths, such as 2.02 μm/10 μm, 2.02 μm/283 nm, 2.02 μm/365 nm, 283 nm/365 nm, and 0.90 μm/2.02 μm were created. Our results show a clear negative correlation between images obtained at 2.02 μm (CO2absorption) and 10 μm (cloud top temperature), meaning that elevated clouds are cooled by adiabatic expansion or the ambient air. A clear negative correlation was found between 2.02 μm and 283 nm (SO2absorption), suggesting that SO2is transported to the cloud top region during cloud ascent. We observed a clear positive correlation between images obtained at 283 and 365 nm (unknown absorber), implying a close relationship between the unknown absorber and SO2or a non‐negligible contribution of the unknown absorber at 283 nm. We found a low correlation between images obtained at 0.90 μm (middle/lower cloud) and 2.02 μm, suggesting a weak vertical coupling in the clouds. Sulfuric acid clouds cover the whole globe of Venus at altitudes of 50–70 km. These clouds show various patterns at ultraviolet and infrared wavelengths. The physical/chemical processes that create the cloud patterns are not fully known. Atmospheric variables such as cloud height and temperature can be mapped at various wavelengths. The relationship between the spatial patterns at these wavelengths provides crucial information on the processes that create such cloud features. We used image data obtained at multiple wavelengths by the Venus orbiter Akatsuki to investigate the correlation of small‐scale (<600 km) cloud patterns acquired at various wavelengths, namely 283 nm (SO2abundance), 365 nm (the unknown absorber), 0.9 μm (middle/lower cloud), 2.02 μm (cloud top altitude), and 10 μm (cloud top temperature). The correlations among these wavelengths place new constraints on the processes responsible for the cloud production. For example, a negative correlation was found between 2.02 μm and 283 nm, suggesting that SO2is transported to the cloud top region during cloud ascent. We performed a statistical analysis on the correlation of small‐scale patterns on the Venus dayside acquired at various wavelengthsSignificant correlation was found between the ultraviolet absorption, the cloud top altitude and the cloud top temperatureWe propose that vertical motions in the upper cloud region play an important role in creating small‐scale patterns We performed a statistical analysis on the correlation of small‐scale patterns on the Venus dayside acquired at various wavelengths Significant correlation was found between the ultraviolet absorption, the cloud top altitude and the cloud top temperature We propose that vertical motions in the upper cloud region play an important role in creating small‐scale patterns

The Akatsuki spacecraft of Japan was launched on May 21, 2010. The spacecraft planned to enter a Venus-encircling near-equatorial orbit in December 7, 2010; however, the Venus orbit insertion maneuver has failed, and at present the spacecraft is orbiting the Sun. There is a possibility of conducting an orbit insertion maneuver again several years later. The main goal of the mission is to understand the Venusian atmospheric dynamics and cloud physics, with the explorations of the ground surface and the interplanetary dust also being the themes. The angular motion of the spacecraft is roughly synchronized with the zonal flow near the cloud base for roughly 20 hours centered at the apoapsis. Seen from this portion of the orbit, cloud features below the spacecraft continue to be observed over 20 hours, and thus the precise determination of atmospheric motions is possible. The onboard science instruments sense multiple height levels of the atmosphere to model the three-dimensional structure and dynamics. The lower clouds, the lower atmosphere and the surface are imaged by utilizing near-infrared windows. The cloud top structure is mapped by using scattered ultraviolet radiation and thermal infrared radiation. Lightning discharge is searched for by high speed sampling of lightning flashes. Night airglow is observed at visible wavelengths. Radio occultation complements the imaging observations principally by determining the vertical temperature structure.

To prevent and control diseases caused by exposure to various agents, it is necessary to determine the harmful level for intervention and to establish a method for measuring that level. In-air microparticle-induced X-ray emission (in-air micro-PIXE) analysis is based on irradiation of specimens with a proton ion microbeam, and has been modified for biological application. Two-dimensional analysis and quantitative analysis using the system confirmed that asbestos induced apoptosis by upregulating Fas expression and also revealed the accumulation of CD163-expressing macrophages in the lungs of patients with asbestosis. By quantitative comparison of the area of Fas or CD163 expression and the Fas- or CD163-negative area in asbestos lung tissue, the harmful levels which caused the expression of Fas or CD163 could be estimated on Silica, Ferrous iron, and Magnesium (the components of asbestos) deposition. These results indicate that the system could be useful for investigating the pathogenesis of inhaled particle-induced immune reactions and for determining harmful levels of exogenous agents.

Inhalation of asbestos increases the risk of lung cancer and pulmonary fibrosis. It is difficult to directly assess the distribution and content of inhaled particles in lung tissue sections. The purpose of this study is to employ an in-air micro particle induced X-ray emission (in-air micro-PIXE) system for assessment of the spatial distribution and content of asbestos and other metals in lung tissue. A proton ion-microbeam from this system was applied to irradiate lung tissue of patients with or without asbestosis, tumor tissue from both groups, and asbestos fibers (in vitro). The content of each element composing asbestos and those of other metals were calculated and their distribution was assessed from the characteristic X-ray pattern for each element obtained after irradiation. This in-air micro-PIXE system could identify the location of asbestos bodies composed of Si, Mg, and Fe in lung tissue sections. Macrophage and lymphocytes accumulated in that area. This new system also revealed deposits of titanium, nickel, and cobalt in the lung tissues, in addition to asbestos bodies. The Si and Fe content were higher in lungs with asbestosis than in lungs without asbestosis or in tumor tissue. Analysis of asbestos fibers composed of chrysotile, crocidolite, and amosite showed that the ratios of Si, Fe, and Mg corresponded with those for the chemical structures. In-air micro-PIXE analysis is useful for assessing the distribution and quantities of asbestos bodies and also other metals in lung tissue comparing to immune-related cell localizations, and is also useful for analysis of standard asbestos fibers.

Abstract: Background: Recently, some studies have suggested that sentinel node biopsy also can be applied to gastric cancer. The authors apply sentinel lymph node biopsy in laparoscopy assisted distal gastrectomy to perform it as safe limited surgery. Limited surgery is a procedure in which the extent of lesion resection and lymph node dissection is reduced. The authors demonstrate that intraoperative diagnosis of lymph node metastasis is useful in this respect. Methods: The study was conducted with 38 patients (29 men and 9 women) who had a preoperative diagnosis of T1 tumor invasion. The patients had a mean age of 66.2 years. Patent blue (1%) was injected submucosally into four or five different sites around the primary tumor at 1 ml per site. Blue-stained lymphatics and lymph nodes could be seen by turning over the greater omentum and the lesser omentum extraperitoneally. If blue nodes were found, biopsy was performed. Results: The mean number of blue nodes dissected was 2.5 1.9. Intraoperative identification and biopsy of blue nodes could be performed for 35 (92.1%) of the 38 patients. Of the 35 patients in whom blue nodes were identified, 4 (9.7%) had metastases in blue nodes confirmed by intraoperative frozen-section diagnosis. Intraoperative frozen-section diagnosis was negative for blue node metastasis in 31 patients. Postoperative permanent section diagnosis also showed no evidence of lymph node metastasis in these 31 patients (100% accuracy, 0% false-negative rates). Conclusions: The reported method allows observation of blue-stained lymphatics up to 2 h after patent blue injection. Sentinel node biopsy was performed in laparoscopy assisted distal gastrectomy, making it technically equivalent to open gastrectomy. Sentinel node biopsy can serve as a method to determine the appropriate use of laparoscopy assisted distal gastrectomy for management of T1 gastric cancer.

Designs and test results for a single-flux-quantum(SFQ) eight-bit shift register circuit operating at frequencies above 100GHz are described. Thehigh-speed performance was realized by introducing a planarized 10kAcm−2 Nb fabrication process as an advanced process and by adopting middle-damped junctions with McCumber parameters βc of 1.8–2.9 in the circuit. The middle-damped junctions were used to reduce the repulsion between SFQ pulses and to adjust the timing. The circuit was designed using a cell-based design method and was tested by constructing an on-chip test system with a ladder-type four-bit high-frequency clock generator. We confirmed its correct operations up to 120 GHz.

Designs and test results for a single-flux-quantum (SFQ) eight-bit shift register circuit operating at frequencies above 100 GHz are described. The high-speed performance was realized by introducing a planarized 10 kA cm?2Nb fabrication process as an advanced process and by adopting middle-damped junctions with McCumber parameters ?cof 1.8-2.9 in the circuit. The middle-damped junctions were used to reduce the repulsion between SFQ pulses and to adjust the timing. The circuit was designed using a cell-based design method and was tested by constructing an on-chip test system with a ladder-type four-bit high-frequency clock generator. We confirmed its correct operations up to 120 GHz.

The Superconductivity Research Laboratory has successfully fabricated large quantities of single flux quantum (SFQ) large scale integrated circuits, including several thousands of Josephson junctions (JJs). Using a Jc= 2.5 kA cm?2process in which the number of Nb layers was four and the minimum JJ size was 2 µm square. We developed a new advanced fabrication process that produced a Jc= 10 kA cm?2, nine Nb layers and a minimum JJ size of 1 µm square. The increase in the number of Nb layers was achieved by using a planarization technique. The target of our next generation process is a Jc= 40 kA cm?2with a 0.5 µm square for the minimum junction size. This specification will be achieved by using advanced semiconductor technologies. This process will enable SFQ circuits to be produced with one million JJs on a chip and achieve a clock frequency greater than 100 GHz.

The stereocontrolled total synthesis of (−)-spirofungin A (1) and (+)-spirofungin B (2a), polyketide-type antibiotics having various antifungal activities, has been achieved employing the Weinreb amide 8, the alkyne 9, and the vinyl boronate 5 readily available from the common intermediate 10. The first synthesis proceeded with a longest linear sequence of 31 steps, affording (−)-1 and (+)-2a in 7.9% and 5.2% overall yields, respectively.

The cyclopolymerizations of α,ω-diacetylene monomers, 1,14-bis(4‘-ethynylphenoxy)-3,6,9,12-tetraoxatetradecane (1) and 1,17-bis(4‘-ethynylphenoxy)-3,6,9,12,15-pentaoxaheptadecane (2), were carried out in chloroform at a monomer concentration of 0.02 mol L^-1 using Rh(nbd)BPh4 as the catalyst to afford organic-solvent-soluble and gel-free polymers. The obtained polymers were assignable to poly(phenylacetylene) derivatives with crown ether on the main chain (poly-1 and poly-2, respectively). In addition, the laser Raman spectra showed that both polymers possessed a highly cis−transoidal stereoregularity. The CD spectra of poly-1 and poly-2 in the presence of the perchloric acid salts of l-phenylglycine (l-Pgly·HClO4) showed a characteristic induced CD (ICD) in the UV−vis absorption region of the polymer backbone from 290 to 530 nm, and the CD patterns of both polymers in the presence of d- and l-Pgly·HClO4 were mirror images. Like other dynamic helical polymers, the amount of a guest, temperature, and solvent had significant influences on the induced helical structure.

The ring-opening multibranching polymerizations of 1,6-anhydro-β-d-glucopyranose (1) and 1,6-anhydro-β-d-galactopyranose (2) have been studied in order to synthesize hyperbranched polysaccharides. The solution polymerization in propylene carbonate and the bulk polymerization of 1 and 2 using a thermally induced cationic initiator proceeded through a ring-opening reaction and a proton transfer reaction to afford highly water-soluble polysaccharides, i.e., poly-1 and poly-2, respectively. For the polymers from 1 and 2 with the same polymerization conditions, the Mw,SLS and yield of poly-1 were higher than those of poly-2. Here, poly-1 and poly-2 were characterized as hyperbranched polysaccharides consisting of α- and β-linked d-hexopyranosyl and d-hexofuranosyl repeating units, hyperbranched d-glucan and d-galactan, respectively. In addition, poly-1 and poly-2 had ca. 30−40 mol % nonreducing d-hexopyranosyl and d-hexofuranosyl terminal units, and the degree of branching was ca. 0.38 for poly-1 and 0.44−0.60 for poly-2. The respective viscosities of poly-1 and poly-2 in aqueous NaNO3(0.2 mol·L^-1) solution were very low with the intrinsic viscosity values of 0.023−0.042 dL·g^-1. The steady shear flow of poly-1 in aqueous solution exhibited a Newtonian behavior with steady shear viscosities independent of the shear rate, even at high concentrations. The results indicated that the characteristics of the viscosities were attributed to the spherical structure of the hyperbranched polysaccharide in aqueous solution.

2,3-Anhydroerythritol (1a) and 2,3-anhydro-dl-threitol (1b) were polymerized using boron trifluoride diethyl etherate (BF3·OEt2) as a cationic initiator. The polymerizations of 1a and 1b proceeded through a ring-opening reaction with a proton-transfer reaction to produce hyperbranched carbohydrate polymers (2a and 2b) consisting of dl-threitol and erythritol units, respectively. The degrees of branching (DBs) estimated by the ¹³C NMR spectra of 2a and 2b were 0.47 and 0.45, respectively. The weight-average molecular weight (Mw,SLS) values (2.67 × 10⁵−3.20 × 10⁶) estimated using static light scattering (SLS) of the resulting hyperbranched carbohydrate polymers were significantly higher than the weight-average molecular weight (Mw,SEC) values (1.04 × 10³−2.77 × 10³) estimated using size exclusion chromatography (SEC). The viscosities of 2a and 2b in aqueous sodium nitrate (NaNO3) solution were very low, and the intrinsic viscosities ([η]) of 2a and 2b were in the range from 0.0190 to 0.0250 dL g^-1. The three-dimensional properties characterized by the SLS and viscosity measurements indicated that 2a and 2b should be spherical molecules.

Objectives. To examine whether autoantibodies against bone morphogenetic protein receptor-II (BMPR-II) or activin receptor-like kinase 1 (ALK-1) are associated with pulmonary arterial hypertension (PAH) in patients with mixed connective tissue disease (MCTD).Methods. We studied sera from 37 MCTD patients with or without PAH, six patients with idiopathic PAH, and 30 healthy controls. Circulating anti-BMPR-II and anti-ALK-1 antibodies were detected using immunoprecipitation of recombinant antigens generated by in vitro transcription/translation and indirect immunofluorescence of cultured cells that were induced to express these antigens by gene transfer. Anti-BMPR-II antibodies were further examined by immunoprecipitation and immunoblotting using a recombinant fragment of the extracellular domain of BMPR-II.Results. Serum anti-BMPR-II and anti-ALK-1 autoantibodies were not detected in MCTD patients irrespective of the presence or absence of PAH, or in patients with idiopathic PAH.Conclusions. Our finding does not support the hypothesis that autoantibody-mediated dysregulation of signals through BMPR-II or ALK-1 contributes to the development of PAH in patients with connective tissue diseases.

No Heading We study the behavior of the interface between the 3He-concentrated and 3He-dilute phases of a phase-separated 3He-4He liquid mixture in the presence of superflow in the d-phase. The superflow can produce a Kelvin-Helmholtz instability in the system. Here we consider two types of the instability: (i) quantized vortex in the superfluid liquid near the superfluid-normal interface; (ii) tangential flow of the superfluid component with respect to the normal fluid in the direction parallel to the interface. In these cases the Kelvin-Helmholtz instability has a threshold due to the surface tension and acceleration of the liquid in the direction normal to the interface. The acceleration is of centrifugal origin in (i) and gravitational one in (ii). The presence of the threshold results in quite different scales of characteristics distances. The centrifugal acceleration induces a scale of the order of the core radius b of several angstroms. The acceleration of gravity yields a scale of the capillary length ? 1.3 mm. In case (i) we obtain an instability of the vortex at a critical distance Rcr = b?d/(?d - ?c). The vortex should disappear at distances smaller than Rcr. In case (ii) the interface becomes unstable provided the superfluid component flows in the direction tangential to the interface with a velocity exceeding its critical value ~6.3 cm/s. There appear ripples with the wavelength of the order of the capillary constant. The instability threshold is found to be lower than in the absence of dissipation and independent of the magnitude of dissipation.

Summary. Founding queens of the arboreal ant Polyrhachis moesta aggregate independently of kinship and cooperate in caring for their brood. In field studies, the number of queens in a founding nest varied from 1 to 8. The number of queens in the nests with multiple queens decreased significantly with time after the nuptial flight, resulting in monogynous or oligogynous nests. Single- and multiple-founding queens did not differ in characteristics representing nutritional states or body size immediately after the nuptial flight. Wet body weight decreased as days passed, whereas head width of founding queens who overwintered successfully were relatively larger. In laboratory studies, founding queens performed liquid food exchanges more frequently with queens from other founding nests or immature colonies than with those from the same nests. Queens in founding nests and immature colonies were observed to show no aggression against non-nestmate queens, whereas queens in established colonies showed aggressive behaviours against non-nestmates. This indicates that founding queens change drastically in their aggression levels before and after colony establishment. Multiple-founding queens started laying eggs earlier than single-founding queens under laboratory conditions. Higher brood productivity and lower brood mortality were observed in multiple-queen nests. These potential advantages in multiple-queen founding may support the cooperative association among unrelated founding queens.

Polymerization of a novel α,ω-diisocyanate monomer, 1,14-bis(4-isocyanatophenoxy)-3,6,9,12-tetraoxatetradecane (1), was carried out in DMF using MeLi to afford a gel-free linear polymer according to a cyclopolymerization mechanism. The resulting polymer was assignable to poly(phenyl isocyanate) with a C2 symmetrical crown cavity on the main chain (2). The circular dichroism (CD) spectrum of 2 in the presence of the perchloric acid salt of l-phenylglycine (l-Pgly·HClO4) showed a negative Cotton effect with a high intensity of −3.2 × 10⁴ deg cm² dmol^-1 in the range from 245 to 330 nm, corresponding to the absorption of the polymer backbone, while a positive Cotton effect was observed for d-Pgly·HClO4, and the CD spectrum pattern was a mirror image of that of 2 with l-Pgly·HClO4. Thus, this suggested that the novel type of poly(phenyl isocyanate) with the crown cavity on the main chain (2) formed a one-handed helical structure driven by the host−guest complexation with the chiral guest molecules. Although the solvent significantly influenced the CD intensities of 2, the CD intensities hardly changed at any temperature.

1,4-Anhydroerythritol (1a) and 1,4-anhydro-l-threitol (1b) were polymerized using trifluoromethanesulfonic acid (CF3SO3H) or fluorosulfonic acid (FSO3H) as a cationic initiator. The polymerizations of 1a and 1b proceeded through a ring-opening reaction with a proton-transfer reaction to produce hyperbranched carbohydrate polymers (2a and 2b) mainly consisting of erythritol and l-threitol units, respectively. The degrees of branching (DB) estimated by the ¹³C NMR spectra of 2a and 2b were ca. 0.28−0.47. The weight-average molecular weight (Mw,SLS) values (3.2 × 10⁴−5.1 × 10⁵) estimated using static laser light scattering (SLS) of the resulting hyperbranched carbohydrate polymers were significantly higher than the weight-average molecular weight (Mw,SEC) values (1.5 × 10³−1.4 × 10⁴) estimated using size exclusion chromatography (SEC). The solution viscosities of 2a and 2b were very low, and the intrinsic viscosities ([η]) of 2a and 2b were in the range from 3.26 × 10^-2 to 7.30 × 10^-2 dL·g^-1. The three-dimensional properties characterized by the SLS and viscosity measurements indicated that 2a and 2b should be nanoscale particles.

Among the various synthetic gene carriers based on biomaterials, cationic polymers with polysaccharide backbones have long been studied as nonviral vectors due to their low immunogenicity and high water solubility. Schizophyllan, a β-(1,3)-glucan, is one of the various polysaccharides that are clinically administered. Furthermore, its safety in the human body has already been confirmed. Various functional groups can be selectively introduced into the side chain, not into the main chain of schizophyllan. Therefore, we have synthesized various oligoamine conjugates from schizophyllan. It was confirmed that their in vitro transfection efficiencies are superior to that of polyethylenimine by adjusting the molecular weight and the degree of amination of cationic schizophyllan. While it was possible to reduce cytotoxicity by adjusting the amount of DNA complex per cell, as seen with poly-l-lysine, polyethylenimine, and chitosan, PEGylation was the most effective means of reducing toxicity. Furthermore, using cationic schizophyllan carriers, it was also possible to express a reporter protein for a long period of time due to a long residence time of plasmid DNA in cells.

We developed a method to measure the transmission coefficient of sound for the interface between the c- and d-phases of a phase-separated 3He-4He liquid mixture at various temperatures and sound frequencies. From the data the kinetic growth coefficient of the interface ξω(T), describing phase-conversion processes at the interface, can be determined.We have extended the experiment down to 6 mK with sound of 9, 14, and 32 MHz. The main specific features observed are as follows: (i) ξω(T) showsa maximum at Tmax(ω), (ii) above Tmax(ω), ξω(T) decreases with the increase of temperature as ξω(T)=Aω5/2/T3, and (iii) below Tmax(ω), ξω(T)decreases with the decrease of temperature and the frequency-dependence seems to disappear. That is, Tmax(ω) corresponds to the crossover temperature between the hydrodynamic and ballistic regimes for ξω(T).

The thermally induced cationic polymerization of 1,6-anhydro-β-d-mannopyranose (1) as a latent cyclic AB4-type monomer was carried out using 2-butenyltetramethylenesulfonium hexafluoroantimonate (2) as the initiator. The solution polymerization in propylene carbonate proceeded without gelation to produce the water-soluble hyperbranched polysaccharides (3) with controlled molecular weights and narrow polydispersities. The weight-average molecular weight (Mw,SLS) values of 3 measured by static laser light scattering (SLS) varied in the range 6.5 × 10³ to 6.4 × 10⁵, which were significantly higher than the weight-average molecular weight (Mw,SEC) values by size exclusion chromatography (SEC). The viscosity of the solution of 3 was very low, and the intrinsic viscosities were from 0.032 to 0.047 dL·g^-1. Polymer 3 was composed of α- and β-linked hyperbranched polysaccharides consisting of 19 kinds of d-mannopyranosyl and d-mannofuranosyl repeating units, which had numerous nonreducing d-mannopyranosyl terminal units. The degree of branching (DB), estimated by the methylation analysis of 3, was in the range of 0.38−0.44. The thermally induced cationic polymerization of 1 using 2 is a facile method leading to the hyperbranched polysaccharide with a high DB value.

The cyclopolymerization of 1,2:5,6-dianhydro-d-mannitol (1) was carried out using BF3·OEt2 and t-BuOK. Although the anionic polymerization tended to form gels, the cationic polymerization proceeded through the proton-transfer reaction mechanism to produce hyperbranched carbohydrate polymers (2) mainly consisting of 2,5-anhydro-d-glucitol units. The weight-average molecular weight (Mw,SLS) values of 2 measured by static light scattering (SLS) varied in the range of 2.08 × 10⁵−26.9 × 10⁵, which were significantly higher than the weight-average molecular weight (Mw,SEC) values by size exclusion chromatography (SEC). The degree of branching (DB), estimated by the ¹³C NMR measurements, was ca. 0.44−0.46. The α value of the Mark−Houwink equation, which was determined by the viscosity measurements, was ca. 0.3. The hyperbranched polymers 2 were nanoscale particle with the radii of gyration (Rg) of 67.4−132.0 nm.

β-Cyclodextrin (β-CyD) was modified into a seven-functional initiator (1) for 2,2,6,6-tetramethylpiperidinyloxy- (TEMPO-) mediated living radical polymerization. Styrene (St) was polymerized with 1 under several conditions to afford original products I−IV. Size exclusion chromatography (SEC) traces of I−IV exhibited trimodal molecular weight distributions; hence, they were fractionated into the respective three species, i.e., main products 2, byproducts 3 with lower molecular weights, and byproducts 4 with higher molecular weights. The weight-average molecular weights determined by SEC and static laser light scattering measurement (Mw,SEC and Mw,SLS, respectively) were 1.34 × 10⁴ and 2.98 × 10⁴ for 2-I, 4.52 × 10⁴ and 6.77 × 10⁴ for 2-II, 1.35 × 10⁵ and 1.87 × 10⁵ for 2-III, and 9.67 × 10⁵ and 1.89 × 10⁶ for 2-IV. The Mw,SLS's were larger than the respective Mw,SEC's. In the ¹H NMR spectra of 2, the signals due to polystyrene (PSt) appeared along with the characteristic signals due to the 1 unit. Therefore, those of 2 were assignable to a star PSt with an acetylated β-CyD core. Polymer 2 was treated with sulfuric acid to give core-cleaved polymer 2‘. The Mw,SEC's were 2.80 × 10³, 9.60 × 10³, 2.70 × 10⁴, and 2.61 × 10⁵ for 2‘-I, 2‘-II, 2‘-III, and 2‘-IV, indicating that the arm number of 2, NPSt, was seven. The byproducts 3 and 4 were characterized and found to be a TEMPO-terminated linear PSt and a star−star coupled polymer, respectively. The seven-arm star PSt with a β-CyD core, 5, was obtained through deacetylation of 2 using sodium methoxide in dry THF. The Mw,SLS values were 3.96 × 10⁵, 3.78 × 10⁵, 2.40 × 10⁵, and 1.94 × 10⁶ for 5-I, 5-II, 5-III, and 5-IV. Hence, 5-I and 5-II showed aggregation in a good solvent for PSt with aggregation-numbers (NA) of 13 and 6, respectively.

2,2,6,6-Tetramethylpiperidinyloxy (TEMPO)-substituted β-cyclodextrin (β-CyD), 1, was synthesized as the initiator for the nitroxide-mediated living radical polymerization. Styrene (St) was polymerized with 1 using a molar ratio of St and 1 in a feed ([St]/[1]) of 200 at 120 °C for 6 h. The size exclusion chromatography (SEC) trace of the product exhibited a symmetrical peak with a weight-average molecular weight (Mw,SEC) of 11 400 and a polydispersity (Mw/Mn) of 1.13. In the ¹H NMR spectrum of the product, the signals due to polystyrene (PSt) appeared along with the characteristic signals due to the 1 unit. Thus, the product was assignable to the end-functionalized PSt with acetylated β-CyD, 2. The introduction of acetylated β-CyD into 2 was found to occur in a quantitative fashion, which was confirmed by thin-layer chromatography equipped with a flame ionization detector (TLC-FID). For the [St]/[1] of 600 at 120 °C, the St/1 system proceeded in a controlled manner to afford 2 with polymerization times of 1.5−9 h with yields of 5−40% and Mw,SEC's of 7500−26 000. On the other hand, the St/1 system for 15 and 20 h afforded polymers with 54 and 75% though an unexpected side reaction occurred. Polymer 2 with Mw,SEC's of 7500−26 000 was modified by deacetylation using sodium methoxide in dry THF into end-functionalized PSt with β-CyD, 3. Particle formation was observed during dynamic laser light scattering measurements of 3 in benzene, indicating that 3 was stably suspended in a good solvent for PSt by forming aggregates with β-CyD as a core. The average aggregation numbers (NA) of the aggregates were found to range from 42 to 125, which were determined by static laser light scattering measurement.