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A bis-tert-alcohol-functionalized crown-6-calix[4]arene (BACCA) was designed and prepared as a multifunctional organic promoter for nucleophilic fluorinations with CsF. By formation of a CsF/BACCA complex, BACCA could release a significantly active and selective fluoride source for SN2 fluorination reactions. The origin of the promoting effects of BACCA was studied by quantum chemical methods. The role of BACCA was revealed to be separation of the metal fluoride to a large distance (>8 A), thereby producing an essentially "free" F(-). The synergistic actions of the crown-6-calix[4]arene subunit (whose O atoms coordinate the counter-cation Cs(+)) and the terminal tert-alcohol OH groups (forming controlled hydrogen bonds with F(-)) of BACCA led to tremendous efficiency in SN2 fluorination of base-sensitive substrates.

We apply the quantum renormalization group to construct a holographic dual for the U(N) vector model for complex bosons defined on a lattice. The bulk geometry becomes dynamical as the hopping amplitudes which determine connectivity of space are promoted to quantum variables. In the large N limit, the full bulk equations of motion for the dynamical hopping fields are numerically solved for finite systems. From finite size scaling, we show that different phases exhibit distinct geometric features in the bulk. In the insulating phase, the space gets fragmented into isolated islands deep inside the bulk, exhibiting ultra-locality. In the superfluid phase, the bulk exhibits a horizon beyond which the geometry becomes non-local. Right at the horizon, the hopping fields decay with a universal power-law in coordinate distance between sites, while they decay in slower power-laws with continuously varying exponents inside the horizon. At the critical point, the bulk exhibits a local geometry whose characteristic length scale diverges asymptotically in the IR limit., 44+11 pages, many figures, added how to extract critical exponent from bulk (Fig. 13), other minor changes

We study a system of weakly interacting electrons described by the energy dispersion $��(\mathbf{k}) = k_x^2 - k_y^2 - ��$ in two dimensions within a renormalization group approach. This energy dispersion exhibits a neck-narrowing Lifshitz transition at the critical chemical potential $��_c=0$ where a van Hove singularity develops. Implementing a systematic renormalization group analysis of this system has long been hampered by the appearance of nonlocal terms in the Wilsonian effective action. We demonstrate that non-locality at the critical point is intrinsic, and the locality of the effective action can be maintained only away from the critical point. We also point out that it is crucial to introduce a large momentum cutoff to keep locality even away from the critical point. Based on a local renormalization group scheme employed near the critical point, we show that, as the energy scale $E$ is lowered, an attractive four-fermion interaction grows as $\log^2 E$ for $E > ��$, whereas it retains the usual BCS growth, $-\log E$, for $E < ��$. Starting away from the critical point, this fast growth of the pairing interaction suggests that the system becomes unstable toward a superconducting state well before the critical point is reached., 9 pages, 11 figures; Minor revision

Commonly, the flocculant is dissolved in process or recycle water in industrial plant which has many ionic materials. Therefore, the polymer degradation in aqueous solution by chemical, mechanical or bacteriological may occur, sometimes rapidly. Even if the same flocculant is dissolved, the flocculation characteristics and the properties of dissolving polymer varied with the kind of dissolving water. In this study, we try to estimate the interaction between flocculants and ionic materials in dissolving water using self inversing emulsion polymer; polyacrylamide-co-trimethyl ammonium ethyl acrylate chloride flocculants which have varying molecular weights and structures at a several conditions. The polymeric flocculant is dissolved in artificial dissolving water with Potassium Chloride (PC), Calcium Chloride anhydrous (CC), Potassium Hydroxide (PH), Sodium Chloride (SC), Sodium Bromate (SB) and Iron (II) Sulfate Heptahydrate (IS) as ionic sources. Experimental results indicate that the cationic and anionic ions in dissolving water induce the hydrolysis, degradation of cationic functional group and uncoiling of polymeric flocculants, therefore, the flocculation efficiency decreased by undesired polymer. According that result, it is important to estimate not only its structures and physical properties but also the qualities of dissolving water to optimize the efficiency.

In order to create a single flocculant/dual flocculation system, polyacrylamide-co-trimethyl ammonium ethyl acrylate chloride (TAEAC) polymers with varying molecular weights and structures were prepared for use of flocculants. The higher the cationic density of the polymer is higher, the higher was the conversion rate and the ratio of monomer. An acrylamide as nonionic monomer was less reactive than a TAEAC as cationic monomer. The branched polymer which was polymerized with a cross-linking agent, N, N-methylene bis-acrylamide had a higher stability and higher viscosity than a linear polymer but its dewatering efficiency was poor in a single flocculation system. In the case of single flocculant/dual flocculation, the branched polymer has better flocculation efficiency and the water content of the dewatered cakes was lower than the others, as the result of a re-flocculation effect. The optimum conditions for dual flocculation are a sequence in which the and dosage are 75% and 25%/total dosage of a single flocculation system. The dewatering efficiency of a dual flocculation system is improved considerably from 10 to 25% under the experimental conditions used herein.

The characteristics of plantlets redifferentiated from calli of F1 hybrid between Panax ginseng and Panax quinquefolius were investigated. Growth of plantlets redifferentiated from F1 hybrid was superior to the plants redifferentiated from Korean ginseng. Stem color of plantlets redifferentiated from F1 hybrid was more purple than that from Korean ginseng and leaf color of the former was also greener than that of the latter. Chunpoong, Yunpoong and Seonweon which are belonged to Korean ginseng showed same PCR band(A), while American ginseng showed different PCR band (B) in Internal Transcribed Spacer (ITS) region. F1 hybrid exhibited both A and B PCR band which belonged to Korean ginseng and American ginseng, respectively. F1 hybrid calli and plantlets redifferentiated from F1 hybrid calli showed same PCR band with that of F1 hybrid plant in ITS region. Therefore it was confirmed that piantlets redifferentiated from F1 hybrid exhibited genetic stability in ITS region.

We consider the D2-brane probe action in the gravity background dual to N coincident D p -branes by treating the separation between the D2- and D p -branes as a non-dynamical parameter for p = 2 , 4 , 6 . The gauge coupling, the core size of a non-BPS instanton and the mass gap of the compact U ( 1 ) gauge theory in the D2-brane are determined as a function of the separation in the type IIA gravity region. The results are interpreted in terms of the ( 2 + 1 ) D U ( 1 ) gauge theory coupled with the matter fields which are also strongly coupled with the ( p + 1 ) D SU ( N ) gauge field. It is shown that strong coupling of the matter fields to the SU ( N ) gauge field can drastically modify their screening of the U ( 1 ) gauge field. The non-perturbative dependence of the U ( 1 ) gauge coupling on the energy scale is obtained.

The interfacial transport processes of proteins from a reverse micellar phase to an aqueous phase have been investigated focusing on micellar-micellar interaction. The proteins solubilized into reverse micelles were back-extracted to the aqueous phase depending on the concentration of reverse micelles in organic phase. This fact seems to suggest the importance of micellar-micellar interactions in back-extraction processes. The interactions induced by various alcohol addition and temperature change could be evaluated easily and quantitatively by the percolation phenomena in reverse micellar systems (RVMS). The interactions were influenced considerably by the presence of small amount of alcohol and temperature in the RVMS. The addition of alcohols promotes the back-extraction of proteins depending on their species and concentrations. In particular, the alcohols that suppress the cluster formation of reverse micelles, remarkably improve the back-extraction processes. With a small amount of alcohol (20 mM OctOH), Bovine carbonic anhydrase (CAB) can be back-extracted completely from reverse micelles to aqueous solution at the optimal temperature, in which the so high concentration of salt is not necessary.

The effects of the addition of alcohol and carboxylic acid on the back-extraction of several small globular proteins such as β-lactoglobulin (β-LG), bovine carbonic anhydrase (CAB), and lipase have been studied using reverse micellar systems (RVMS). The protein back-extraction induced by the addition of alcohol and carboxylic acid was markedly influenced by the structural changes of reverse micelles (βt) and protein (m). The alcohols and carboxylic acids suppressing the formation of reverse micelle clusters (positive value of βt) remarkably enhanced the back-extraction of proteins. On the other hand, the alcohols and carboxylic acids enhancing the formation of reverse micelle clusters (negative value of βt) suppressed the back-extraction of proteins. The markedly effective alcohol and carboxylic acid molecules on the denaturation of proteins (high values of m) suppressed the back-extraction of proteins. The m values were estimated by measuring the dependence of the free energy change of denaturation on the concentration of alcohol or carboxylic acid, and were correlated well with the solvent-accessible surface area (ASA) of alcohol and carboxylic acid molecules. We have constructed a simple equation on the basis of these factors for explaining the effect of alcohols and carboxylic acids in back-extraction processes of proteins of RVMS. These results suggested that the back-extraction processes were controlled by the formation of reverse micelle clusters as well as the denaturation of proteins.

The effects of the addition of various carboxylic acids on the formation of AOT-reverse micelle clusters have been studied by quantitative analysis of their percolation phenomena. The results were compared with those of various alcohols based on the functional groups, namely, the hydrocarbon group, hydroxyl group, halogen substituents, and carboxyl group. Among these groups, the hydrophobic hydrocarbon group and halogen substituents suppressed the formation of micellar clusters, depending on their chain number or species. However, the hydrophilic carboxyl and hydroxyl groups enhanced the formation of micellar clusters. Furthermore, the effect of a hydroxyl groups on the formation of micellar clusters was stronger than that of carboxyl groups. These results can be explained by the additive contribution of each carboxylic acid and alcohol molecule, and they can be interpreted as a simple correlation based on the accessible surface area (ASA). These results suggest that the formation of AOT-reverse micelle clusters by the addition of carboxylic acids and alcohols can be explained by the hydrophobicity of the molecule, as well as by the formation of micelle-like structures with both carboxylic acid and alcohol molecules.

The relationship between the behaviors of c.c.lipase back-extraction and their percolation phenomena by using AOT reverse micellar systems (RVMS) has been studied by the addition of a small amount of additives to organic phase such as thiols and nonionic-surfactants focusing on micelle-micelle interactions. The values of β t defined by the variation of percolation processes and back-extraction behaviors of c.c.lipase have a good linear correlation. The hydrophobicity of additive molecules suppressing the cluster formation of reverse micelles (high values of β t ) improved the back-extraction behavior of c.c.lipase. The back-extraction fraction and its rate of c.c.clipase are increased with decreasing of the value of hydrophilic lipophilic balance (HLB) and increasing of the hydrophobicity per additive molecules added to reverse micellar systems (RVSM) in the same additives concentration.

Recently, we have reported hydrolysis reactions of three N-acylimidazoles compounds having one phenyl substituent in the imidazole leaving group. 1 In the hydrolysis reaction of N-furoyl- and N-thenoyl-2-phenylimidazole of these three compounds observed a change in rate determining step in acidic region, whereas, that of N-benzoyl-2-phenylimidazole found to be related with the diprotonated species in acidic region. Even though, the change in the structure of Nacylimidazoles, sometimes, give rise to an abnormal reactivity in hydrolysis reaction, 2 the feature of the hydrolysis of the above three N-acyl-2-phenylimidazoles compounds was very unique in comparison with the previous obtained results from hydrolysis of N-acylimidazole derivatives. 3-9 In this study, our interest is to examine how the substituent effect of the acyl group in the hydrolysis of N-acylimidazoles exhibits when the leaving group imidazole has two phenyl group. So, we have performed the hydrolyses reactions of N-benzoyl-4,5-diphenylimidazole, N-toluoyl4,5-diphenylimidaozole and N-anisoyl-4,5-diphenylimidazole. Materials. Materials of synthesis of the substrates were purchased from Aldrich or Tokyo Kasei. Acetonitrile was dried with CaH2 stored over molecular sieves. Deionized water was distilled using a Streem III Glass Still and ketp under a nitrogen atomosphere. Buffer materials for kinetic studies were analytical grade. N-benzoyl-4,5-diphenylimidazole (1-a) was prepared by mixing benzoyl chloride and 10 mmol of 4,5-dephenylimidazole in 100 mL of dichloromethane in the presence of triethylamine a catalyst. The reaction mixture was refluxed for 48 hr and filterd. The filtrate was evaproated under vaccum. The product was recrystallized from ether-hexane (pale yellow), m.p. 186-187 o C, FT-IR (KBr), 1340 (C-N), 1718 (C=O), 3109 (C-H); 1 H NMR (CDCl3, 200 MHz), 7.24-7.52 (m, 10H), 7.54 (d, J = 5.6 Hz, 2H), 7.64 (m, 1H)

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By using a low energy effective Lagrangian of the U(1) slave boson mean field theory we examine the vortex binding-unbinding transition (KT transition) from a doped Mott insulator at low temperatures in a d-wave superconductor. It is shown that the interaction potential between vortices is modified by a "Doppler energy shift" resulting in additional attractive interaction, as a consequence of supercurrent fluctuations coupled to the particle-hole excitations of the massless Dirac fermions.

One of the key factors that determine the fates of quantum many-body systems in the zero temperature limit is the competition between kinetic energy that delocalizes particles in space and interaction that promotes localization. While one dominates over the other in conventional metals and insulators, exotic states can arise at quantum critical points where none of them clearly wins. Here we present a novel metallic state that is realized at the antiferromagnetic (AF) quantum critical point in space dimensions three and below. At the critical point, interactions between particles are screened to zero in the low energy limit at the same time the kinetic energy is suppressed in certain spatial directions to the leading order in a perturbative expansion that becomes asymptotically exact in three dimensions. The resulting dispersionless and interactionless state exhibits distinct quasi-local strange metallic behaviors due to the subtle dynamical balance between screening and infrared singularity caused by the spontaneous reduction of effective dimensionality., Comment: v2) minor revision; appendix A added

Transient versus sustained ERK MAP kinase (MAPK) activation dynamics induce proliferation versus differentiation in response to epidermal (EGF) or nerve (NGF) growth factors in PC‐12 cells. Duration of ERK activation has therefore been proposed to specify cell fate decisions. Using a biosensor to measure ERK activation dynamics in single living cells reveals that sustained EGF/NGF application leads to a heterogeneous mix of transient and sustained ERK activation dynamics in distinct cells of the population, different than the population average. EGF biases toward transient, while NGF biases toward sustained ERK activation responses. In contrast, pulsed growth factor application can repeatedly and homogeneously trigger ERK activity transients across the cell population. These datasets enable mathematical modeling to reveal salient features inherent to the MAPK network. Ultimately, this predicts pulsed growth factor stimulation regimes that can bypass the typical feedback activation to rewire the system toward cell differentiation irrespective of growth factor identity., Molecular Systems Biology, 11 (11), ISSN:1744-4292

Tight regulation of the MAP kinase Hog1 is crucial for survival under changing osmotic conditions. Interestingly, we found that Hog1 phosphorylates multiple upstream components, implying feedback regulation within the signaling cascade. Taking advantage of an unexpected link between glucose availability and Hog1 activity, we used quantitative single cell measurements and computational modeling to unravel feedback regulation operating in addition to the well-known adaptation feedback triggered by glycerol accumulation. Indeed, we found that Hog1 phosphorylates its activating kinase Ssk2 on several sites, and cells expressing a non-phosphorylatable Ssk2 mutant are partially defective for feedback regulation and proper control of basal Hog1 activity. Together, our data suggest that Hog1 activity is controlled by intertwined regulatory mechanisms operating with varying kinetics, which together tune the Hog1 response to balance basal Hog1 activity and its steady-state level after adaptation to high osmolarity., Integrative Biology, 7 (4), ISSN:1757-9694, ISSN:1757-9708

We examined by quantum chemical methods the mechanism of SN2 reaction using metal bromide MBr (M = Na, K, Cs) and KX (X= F, Cl) in CH3CN promoted by crown ether (18-crown-6). We focus on whether the metal salts react as a contact ion pair (CIP; M+ and X– in close contact) or as a solvent-separated ion pair (SSIP; M+ and X– at large distance). In SSIP mechanism, X– is removed far enough from M+ for the metal salt to be considered as “separated” by the effects of the crown ether and the solvent. In the CIP picture, conversely, the coordination of 18-crown-6 to M+ is not sufficient to overcome the powerful Coulombic interactions between M+ and X–. We find that the CIP route is favored for SN2 bromination processes using MBr (M = Na, K, Cs). For SN2 reaction using KF, the feasibility of the two pathways is essentially equal, whereas for SN2 chlorination by KCl the SSIP route is predicted to be favored.

We examine the dependency of optical conductivity on antiferromagnetic Heisenberg coupling J , hole doping concentration δ and temperature T . The computed results are shown to predict the general feature of the peak–dip–hump structure, the trend of which is in reasonable agreement with observation.

Focusing on the hole-doped two-dimensional systems of strongly correlated electrons, we examine the geometric phases which arise as a result of polaron transport around closed loops. It is of interest to see differences in the geometric phases between the two different systems of antiferromagnets, the Ising antiferromagnets and the Heisenberg antiferromagnets. For this study we apply the Lanczos exact diagonalization method to the Holstein–Hubbard, Holstein- tJ , and Holstein- tJ z models. It is shown from this study that the transverse spin interactions (fluctuations) are responsible for the generation of non-trivial geometric phases for the Heisenberg antiferromagnets, unlike the case of the Ising antiferromagnets.

Linear theory for phonon scattering by discrete breathers in the discrete nonlinear Schrödinger equation using the transfer matrix approach is presented. Transmission and reflection coefficients are obtained as a function of the wave vector of the input phonon. The occurrence of a nonzero transmission, which in fact becomes perfect for a symmetric breather, is shown to be connected with localized eigenmodes thresholds. In the weak-coupling limit, the perfect reflection is shown to exist, which requires two scattering channels. A necessary condition for a system to have a perfect reflection is also considered in a general context.

Based on the t–J Hamiltonian of U(1) slave-boson symmetry it is shown from our derived free energy that symmetry breaking can occur to allow holon-pair bose condensation. Supersymmetry conditions are proposed based on our derived quasiparticle Hamiltonian involving both spinons and holons.

Using an exact diagonalization treatment of Ising and Heisenberg model Hamiltonians, we study field-induced phase transition for two-dimensional antiferromagnets. For the system of Ising antiferromagnet the predicted field-induced phase transition is of first order, while for the system of Heisenberg antiferromagnet it is the second-order transition. We find from the exact diagonalization calculations that the second-order phase transition (metamagnetism) occurs through a spin-flop process as an intermediate step., Comment: 4 pages, 4 figures

A possibility of holon (boson) pair condensation is explored for hole doped high T_c cuprates, by using the U(1) slave-boson representation of the t-J Hamiltonian with the inclusion of hole-hole repulsion. A phase diagram of the hole doped high T_c cuprates is deduced by allowing both the holon pairing and spinon pairing. It is shown that the spin gap size remains nearly unchanged below the holon pair condensation temperature. We find that the s-wave holon pairing under the condition of d-wave singlet pairing is preferred, thus allowing d-wave hole pairing.

Based on the U(1) and SU(2) slave-boson approaches to the t-J Hamil-tonian, we evaluate the one electron spectral functions for the hole doped high Tccuprates for comparison with the angle resolved photoemission spectroscopy(ARPES) data. We find that the observed quasiparticle peak in the superconducting state is correlated with the hump which exists in the normal state. We find that the spectral weight of the quasiparticle peak increases as doping rate increases, which is consistent with observation. As a conse-quence of the phase fluctuation effects of the spinon and holon pairing order parameters the spectral weight of the predicted peak obtained from the SU(2) theory is found to be smaller than the one predicted from U(1) mean field theory.

The oxidation reactions of dichloromethane, dichloroethane and n-hexane were carried out over honey-comb type platinum basic VOC catalyst (BVC) containing vanadium, chromium, manganese, cobalt, copper or barium. In dichloromethane and dichloroethane catalytic oxidation up to 450 °C, chromium was found as the most active component. Although vanadium was also effective initially, it was deactivated after treatment in the furnace at 800 °C for 120 hours. Chromium, cobalt, vanadium and barium promoted catalysts showed higher activities than BVC in the reaction of n-hexane.

It is important to develop a noninvasive label-free detection method to monitor dynamic phenomena in biology and medicine. Here, we utilize nanoplasmonic optical imaging as the noninvasive and label-free method in order to monitor in vitro amyloid fibrogenesis in real-time, which is considered as the primary pathological mechanism of Alzheimer's disease. Using Rayleigh scattering of gold nanoplasmonic probes (GNPs), which have an enhanced scattering optical cross-section due to the surface plasmon resonance, we accomplished efficient tracking of the random movements of the GNPs in Aβ solution, and quantified the kinetics of the fibrogenesis. We expect that this noninvasive and label-free in vitro method can be utilized in monitoring in a wide range of other research fields as well. As future applications, we can envision long-term monitoring in neuronal cells to elucidate the mechanism of amyloid growth and NIR-based in vivo imaging with nanoplasmonic optical antennas for gene delivery, photonic gene circuits, and monitoring toward the theranostics of neurodegenerative diseases.

We study low-energy effective field theories for non-Fermi liquids with Fermi surfaces of general dimensions and co-dimensions. When the dimension of Fermi surface is greater than one, low-energy particle-hole excitations remain strongly coupled with each other across the entire Fermi surface. In this case, even the observables that are local in the momentum space (such as the Green's functions) become dependent on the size of the Fermi surface in singular ways, resulting in an ultraviolet/infrared (UV/IR) mixing. By tuning the dimension and co-dimension of the Fermi surface independently, we find perturbative non-Fermi liquid fixed points controlled by both UV/IR mixing and interactions., Comment: minor typos corrected

We demonstrate the use of a simple microfluidic setup, in which single budding yeast cells can be tracked throughout their entire lifespan. The microfluidic chip exploits the size difference between mother and daughter cells using an array of micropads. Upon loading, cells are trapped underneath these micropads, because the distance between the micropad and cover glass is similar to the diameter of a yeast cell (3-4 mu m). After the loading procedure, culture medium is continuously flushed through the chip, which not only creates a constant and defined environment throughout the entire experiment, but also flushes out the emerging daughter cells, which are not retained underneath the pads due to their smaller size. The setup retains mother cells so efficiently that in a single experiment up to 50 individual cells can be monitored in a fully automated manner for 5 days or, if necessary, longer. In addition, the excellent optical properties of the chip allow high-resolution imaging of cells during the entire aging process.

In this paper, we investigate uniformly dispersed size-selected Pd(n) clusters (n = 4, 10, and 17) on alumina supports. We study the changes of clustered Pd atoms under oxidizing and reducing (O2 and CO, respectively) conditions in situ using ambient pressure XPS. The behavior of Pd in the clusters is quite different from that of Pd foil under the same conditions. For all Pd clusters, we observe only one Pd peak. The binding energy of this Pd 3d peak is ~1-1.4 eV higher than that of metallic Pd species and changes slightly in CO and O2 environments. On the Pd foil however many different Pd species co-exist on the surface and change their oxidation states under different conditions. We find that the Pd atoms in direct contact with Al2O3 differ in oxidation state from the surface Pd atoms in a foil under reaction conditions. Compared to previous literature, we find that Pd 3d peak positions are greatly influenced by the different types of Al2O3 supports due to the combination of both initial and final state effects.

Experimental uptake curves wore collected by a shallow bed technique at 298.2 K. Adsorbent particles employed were macroreticular (MR) resins and adsorbates were phenol and its derivatives. From the uptake curves and equilibrium data obtained by the so-called, batch bottle technique, equilibrium and kinetic parameters were determined and the effects of functional groups within both adsorbate molecules and adsorbent particles on those parameters are discussed. From the results, it became clear that physical and chemical properties, surface area of adsorbent functional group, and solubility of adsorbates affected adsorption equilibria. Also, nitro-functional groups seemed to hinder adsorption equilibria and kinetics. Results can be explained by the resonance effects of functional groups.

found a change of the rate dertermining step in acidic regions. These results are very unique even though the feature of hydrolysis reactivity of N-acylimidazole derivatives depends on the structure of N-acylimidazole. But, when one changes the acyl group with the heteroaryl group to the benzoyl group having same leaving group, the pH rate profile for the hydrolysis reaction of N-benzoyl-2-phenylimidazole observed to be related with the diprotonated species of the substrate in acidic region. 3 If N-heteroarylimidazole having the strong electron withdrawing group in the leaving group is hydrolyzed, how does the feature of the hydrolysis reaction appear? This is our concerns in this study. And so, we have performed the hydrolysis reactions of N-furoyl-4(5)-nitroimidazole ( 1) and N-thenoyl-4(5)-nitroimidazole (2) in order to compare with the previous results of the hydrolysis of N-heteroarylimidazoles having the phenyl group in the leaving group. Materials. All materials used for synthesis of the substrates were purchased from Aldrich or Tokyo Kasei. All organic solvents were purified by the known method. Deionized water were distilled using a Streem III Glass Still and kept under a nitrogen atmosphere. Buffer materials for kinetic studies were analytical reagent grade.

A non-Fermi liquid state without time-reversal and parity symmetries arises when a chiral Fermi surface is coupled with a soft collective mode in two space dimensions. The full Fermi surface is described by a direct sum of chiral patch theories, which are decoupled from each other in the low energy limit. Each patch includes low energy excitations near a set of points on the Fermi surface with a common tangent vector. General patch theories are classified by the local shape of the Fermi surface, the dispersion of the critical boson, and the symmetry group, which form the data for distinct universality classes. We prove that a large class of chiral non-Fermi liquid states exist as stable critical states of matter. For this, we use a renormalization group scheme where low energy excitations of the Fermi surface are interpreted as a collection of (1+1)-dimensional chiral fermions with a continuous flavor labelling the momentum along the Fermi surface. Due to chirality, the Wilsonian effective action is strictly UV finite. This allows one to extract the exact scaling exponents although the theories flow to strongly interacting field theories at low energies. In general, the low energy effective theory of the full Fermi surface includes patch theories of more than one universality classes. As a result, physical responses include multiple universal components at low temperatures. We also point out that, in quantum field theories with extended Fermi surface, a non-commutative structure naturally emerges between a coordinate and a momentum which are orthogonal to each other. We show that the invalidity of patch description for Fermi liquid states is tied with the presence of UV/IR mixing associated with the emergent non-commutativity. On the other hand, UV/IR mixing is suppressed in non-Fermi liquid states due to UV insensitivity, and the patch description is valid., Comment: 37 pages, 25 figures; v3) Typos fixed

We devise a dimensional regularization scheme for quantum field theories with Fermi surface to study scaling behaviour of non-Fermi liquid states in a controlled approximation. Starting from a Fermi surface in two space dimensions, the co-dimension of Fermi surface is extended to a general value while the dimension of Fermi surface is fixed. When Fermi surface is coupled with a critical boson centered at zero momentum, the interaction becomes marginal at a critical space dimension d_c=5/2. A deviation from the critical dimension is used as a small parameter for a systematic expansion. We apply this method to the theory where two patches of Fermi surface is coupled with a critical boson, and show that the Ising-nematic critical point is described by a stable non-Fermi liquid state slightly below the critical dimension. Critical exponents are computed upto the two-loop order., Comment: 46 pages, 10 figures; v3) typos corrected

Quantum renormalization group scheme provides a microscopic understanding of holography through a general mapping between the beta functions of underlying quantum field theories and the holographic actions in the bulk. We show that the Einstein gravity emerges as a long wavelength holographic description for a matrix field theory which has no other operator with finite scaling dimension except for the energy-momentum tensor. We also point out that holographic actions for general large N matrix field theories respect the inversion symmetry along the radial direction in the bulk if the beta functions of single-trace operators are gradient flows with respect to the target space metric set by the beta functions of double-trace operators., Comment: 5 pages; 1 figure; v2) references added

We present an efficient method for measuring cell stretching based on three-dimensional viscoelastic particle focusing. We suspended cells in a biocompatible viscoelastic medium [poly(vinylpyrrolidone) solution in phosphate-buffered saline]. The medium viscoelasticity significantly homogenized the trajectories of cells along the centerline of a simple straight channel, which could not be achieved in conventional Newtonian media. More than 95% of red blood cells (RBCs) were successfully delivered to the stagnation point of a cross-slot microchannel and stretched by extensional flow. By computational simulations, we proved that this method prevents inaccuracies due to random lateral distributions of cells and, further, guarantees rotational-free cell stretching along the shear-free channel centerline. As a demonstration, we characterized the differences in RBC deformabilities among various heat treatments. Furthermore, we monitored the decrease of deformability due to nutrient starvation in human mesenchymal stem cells. We envisage that our novel method can be extended to versatile applications such as the detection of pathophysiological evolution in impaired RBCs due to malaria or diabetes and the monitoring of cell quality in stem cell therapeutics.

We investigate the scaling of the bipartite entanglement entropy across Lifshitz quantum phase transitions, where the topology of the Fermi surface changes without any changes in symmetry. We present both numerical and analytical results which show that Lifshitz transitions are characterized by a well-defined set of critical exponents for the entanglement entropy near the phase transition. In one dimension, we show that the entanglement entropy exhibits a length scale that diverges as the system approaches a Lifshitz critical point. In two dimensions, the leading and sub-leading coefficients of the scaling of entanglement entropy show distinct power-law singularities at critical points. The effect of weak interactions is investigated using the density matrix renormalization group algorithm., 11 pages, 11 figures; v2) references added

We propose a local renormalization group procedure where length scale is changed in spacetime dependent way. Combining this scheme with an earlier observation that high energy modes in renormalization group play the role of dynamical sources for low energy modes at each scale, we provide a prescription to derive background independent holographic duals for field theories. From a first principle construction, it is shown that the holographic theory dual to a D-dimensional matrix field theory is a (D+1)-dimensional quantum theory of gravity coupled with matter fields of various spins. The gravitational theory has (D+1) first-class constraints which generate local spacetime transformations in the bulk. The (D+1)-dimensional diffeomorphism invariance is a consequence of the freedom to choose different local RG schemes., Comment: 34 pages, 4 figures; v2) sections VIII and IX added; v3) typos corrected (to appear in JHEP)

Much difficulty has been encountered in manipulating small-scale materials, such as submicron colloidal particles and macromolecules (e.g., DNA and proteins), in microfluidic devices since diffusion processes due to thermal (Brownian) motion become more pronounced with decreasing particle size. Here, we present a novel approach for the continuous focusing of such small-scale materials. First, we successfully focused fluorescent submicron polystyrene (PS) beads along equilibrium positions in microchannels through the addition of a small amount water-soluble polymer [500 ppm poly(ethylene oxide) (PEO)]. Lateral migration velocity significantly depends upon the viscoelastic effect (Weissenberg number: Wi) and the aspect ratio of particle size to channel height (a/h). Interestingly, focusing using viscoelastic flows was also observed for flexible DNA molecules (λ-DNA and T4-DNA), which have radii of gyration (R(g)) of approximately 0.69 μm and 1.5 μm, respectively. This small-scale material manipulation using medium viscoelasticity will contribute to the design of nanoparticle separation and genomic mapping devices.

We propose two possible experimental realizations of a 2+1 dimensional spacetime supersymmetry at a quantum critical point on the surface of three dimensional topological insulators. The quantum critical point between the semi-metallic state with one Dirac fermion and the s-wave superconducting state on the surface is described by a supersymmetric conformal field theory within $\epsilon$-expansion. We predict the exact voltage dependence of the differential conductance at the supersymmetric critical point., Comment: 8 pages, 2 figures; published version

The two-dimensional layers of cuprate oxides are known to be the systems of strongly repulsive (correlated) electrons as the Mott insulators which have revealed various novel physical properties uniquely different from the conventional low temperature superconductors. They show the antiferromagnetic (AF) infinite-range or long-range order (AFLRO) at and near half-filling. As hole doping increases, the AFLRO diminishes and the short-range (finite-range) AF order takes over with the emergence of d-wave superconductivity. The two-dimensional systems of strongly correlated electrons involved with strong repulsive interactions may favor the spin singlet pairing order (or correlations) of d-wave symmetry over that of s-wave symmetry. Here the spin singlet paring correlations are concerned with the AF spin fluctuations of the shortest possible correlation length among the AF spin fluctuations of all possible correlation lengths which appear in the region of hole doping away from half-filling. In this region of hole doping the cuprate oxides exhibit the novel structure of the high TC phase diagram characterized by the dome-shaped superconducting transition temperature, TC and the monotonously decreasing pseudogap temperature, T∗.

Important insights into aging have been generated with the genetically tractable and short-lived budding yeast. However, it is still impossible today to continuously track cells by high-resolution microscopic imaging (e.g., fluorescent imaging) throughout their entire lifespan. Instead, the field still needs to rely on a 50-y-old laborious and time-consuming method to assess the lifespan of yeast cells and to isolate differentially aged cells for microscopic snapshots via manual dissection of daughter cells from the larger mother cell. Here, we are unique in achieving continuous and high-resolution microscopic imaging of the entire replicative lifespan of single yeast cells. Our microfluidic dissection platform features an optically prealigned single focal plane and an integrated array of soft elastomer-based micropads, used together to allow for trapping of mother cells, removal of daughter cells, monitoring gradual changes in aging, and unprecedented microscopic imaging of the whole aging process. Using the platform, we found remarkable age-associated changes in phenotypes (e.g., that cells can show strikingly differential cell and vacuole morphologies at the moment of their deaths), indicating substantial heterogeneity in cell aging and death. We envision the microfluidic dissection platform to become a major tool in aging research.

We present a theory of three dimensional fractionalized topological insulators in the form of U(1) spin liquids with gapped fermionic spinons in the bulk and topologically protected gapless spinon surface states. Starting from a spin-1/2 model on a pyrochlore lattice, with frustrated antiferromagnetic and ferromagnetic exchange interactions, we show that decomposition of the latter interactions, within slave-fermion representation of the spins, can naturally give rise to an emergent spin-orbit coupling for the spinons. This stabilizes a fractionalized topological insulators which also have bulk bond spin-nematic order. Finally, we describe the low energy properties of these states., 10 pages

We have developed a single-cell assay platform that allows quantitative analysis of single cell chemotaxis by dynamic morphogenetic gradients, subcellular microscopic imaging and automated image analysis, and have applied these to measure cellular polarization of budding yeast. The computer-controlled microfluidic device regulates the gradient profile at any given time, and allows quantitative monitoring of cell morphology and the localization and expression of specific marker proteins during the dynamic polarization process. With this integrated experimental system, we compare the polarized signaling response of wild-type and far1-H7 mutant cells, which express a truncated Far1 protein unable to interact with Cdc24. Our results confirm that Far1 functions as an adaptor that recruits polarity establishment proteins to the site of extracellular signaling. Moreover, by changing the gradient profile and estimating the number of bound surface receptors, we quantitatively address why surprisingly small differences in pheromone concentration across yeast cells can be amplified into a robust polarity axis. This integrated single cell experimental platform thus opens the possibility to quantitatively investigate the molecular regulatory mechanism of chemotaxis in yeast, which serves as a paradigm to understand the fundamental processes involved in cancer metastasis, angiogenesis and axon generation.

The pH-rate profiles for the hydrolysis of these two compounds exhibited three distingtive regions corresponding to hydronium ion catalyzed reaction, pH independent reaction and hydroxide ion catalyzed reaction above pH 8. Surprisingly, a character of hydrolysis reaction of these two compounds is a change in rate determining step (RDS) in acidic region. These results were very interesting in comparison with hydrolyses 3-9 of N-acylimidazoles having an aromatic or aliphatic acyl group, even though the change in the structure of N-acylimidazole, sometimes, gives rise to an abnormal reactivity in hydrolysis reactions. 10,11 In this study, our aim is to examine how the reaction mechanism changes in acidic region when the acyl group varies from a heteroaryl group to a benzoyl group. We have performed hydrolysis of N-benzoyl-2-phenylimidazole in order to compare with our previous results obtained from hydrolyses of N-furoyl-2-phenylimidazole and N-thenoyl-2phenylimidazole.

The stability of model catalysts based on size-selected Pd clusters supported on graphite surfaces has been explored under realistic conditions for catalytic oxidation of methane at mild temperatures. The experimental results show that aggregated films of nanoparticles are highly unstable, but clusters pinned to the surface in the submonolayer coverage regime are much more stable against sintering. The degree of sintering of the pinned clusters, which does occur, proceeds by the release of clusters from their pinning sites. The suppression of sintering depends on the cluster deposition energy with respect to the pinning threshold.

Transitions among quantum Hall plateaux share a suite of remarkable experimental features, such as semi-circle laws and duality relations, whose accuracy and robustness are difficult to explain directly in terms of the detailed dynamics of the microscopic electrons. They would naturally follow if the low-energy transport properties were governed by an emergent discrete duality group relating the different plateaux, but no explicit examples of interacting systems having such a group are known. Recent progress using the AdS/CFT correspondence has identified examples with similar duality groups, but without the DC ohmic conductivity characteristic of quantum Hall experiments. We use this to propose a simple holographic model for low-energy quantum Hall systems, with a nonzero DC conductivity that automatically exhibits all of the observed consequences of duality, including the existence of the plateaux and the semi-circle transitions between them. The model can be regarded as a strongly coupled analog of the old `composite boson' picture of quantum Hall systems. Non-universal features of the model can be used to test whether it describes actual materials, and we comment on some of these in our proposed model., LaTex 52 pages 11 figures. Repost improves the discussion of the probe approximation; corrects minor errors; adds references. Second repost generalizes charged solution and improves scaling discussion