A homozygous variant in growth and differentiation factor 2 (GDF2) may cause lymphatic dysplasia with hydrothorax and nonimmune hydrops fetalis.

The etiology of nonimmune hydrops fetalis is extensive and includes genetic disorders. We describe a term-born female neonate with late onset extensive nonimmune hydrops, that is, polyhydramnios, edema, and congenital bilateral chylothorax. This newborn was successfully treated with repetitive thoracocentesis, total parenteral feeding, octreotide intravenously and finally surgical pleurodesis and corticosteroids.

Hierarchical Self-Assembly of Supramolecular Double-Comb Triblock Terpolymers.

Involving supramolecular chemistry in self-assembling block copolymer systems enables design of macromolecular architectures that are challenging to obtain through conventional all-covalent routes. In this work we present supramolecular double-comb triblock terpolymers in which both outer blocks are able to interact with a surfactant via hydrogen bonding and thereby form a comb-shaped architecture upon complexation. While the neat triblock terpolymer only formed a triple lamellar morphology, multiple hierarchical structures were observed in these supramolecular comb-coil-comb triblock terpolymers by simply adjusting the surfactant concentration.

The Origin of Hierarchical Structure Formation in Highly Grafted Symmetric Supramolecular Double-Comb Diblock Copolymers.

Involving supramolecular chemistry in self-assembling block copolymer systems enables design of complex macromolecular architectures that, in turn, could lead to complex phase behavior. It is an elegant route, as complicated and sensitive synthesis techniques can be avoided. Highly grafted double-comb diblock copolymers based on symmetric double hydrogen bond accepting poly(4-vinylpyridine)-block-poly(N-acryloylpiperidine) diblock copolymers and donating 3-nonadecylphenol amphiphiles are realized and studied systematically by changing the molecular weight of the copolymer.

Hierarchical Layer Engineering Using Supramolecular Double-Comb Diblock Copolymers.

The formation of unusual multilayered parallel lamellae-in-lamellae in symmetric supramolecular double-comb diblock copolymers is presented. While keeping the concentration of surfactant fixed, the number of internal layers was found to increase with molecular weight M up to 34 for the largest block copolymer. The number of internal structures n was established to scale as M and therefore enables easy design of such structures with great precision.

Highly Ordered Structure Formation in RAFT-Synthesized PtBOS-b-P4VP Diblock Copolymers.

Linear poly(4-tert-butoxystyrene)-b-poly(4-vinylpyridine) (PtBOS-b-P4VP) diblock copolymers are synthesized using reversible addition-fragmentation chain transfer polymerization. The self-assembly of four different PtBOS-b-P4VP diblock copolymers is studied using small-angle X-ray scattering and transmission electron microscopy and a number of interesting observations are made. A tBOS62 -b-4VP28 diblock copolymer with a weight fraction P4VP of 0.

Bioinspired Synthesis of Well-Ordered Layered Organic-Inorganic Nanohybrids: Mimicking the Natural Processing of Nacre by Mineralization of Block Copolymer Templates.

The unique mechanical performance of nacre, the pearly internal layer of shells, is highly dependent on its complex morphology. Inspired by the structure of nacre, the fabrication of well-ordered layered inorganic-organic nanohybrids is presented herein. This biomimetic approach includes the use of a block copolymer template, consisting of hydrophobic poly(vinylidene fluoride) (PVDF) lamellae covered with hydrophilic poly(methacrylic acid) (PMAA), to direct silica (SiO2 ) mineralization.

Gyroid nickel nanostructures from diblock copolymer supramolecules.

Nanoporous metal foams possess a unique combination of properties - they are catalytically active, thermally and electrically conductive, and furthermore, have high porosity, high surface-to-volume and strength-to-weight ratio. Unfortunately, common approaches for preparation of metallic nanostructures render materials with highly disordered architecture, which might have an adverse effect on their mechanical properties. Block copolymers have the ability to self-assemble into ordered nanostructures and can be applied as templates for the preparation of well-ordered metal nanofoams.

Perpendicular lamellar-in-lamellar and other planar morphologies in A-b-(B-b-A)2-b-C and (B-b-A)2-b-C ternary multiblock copolymer melts.

Ordered planar morphologies in A-b-(B-b-A)2-b-C and (B-b-A)2-b-C terpolymer melts are studied within the framework of the self-consistent field theory for volume fractions of components A, B, and C in the ratio 1:1:2 and the Flory-Huggins interaction parameters satisfying χ(AB) = 2χ(AC). The stable phases turn out to be the disordered, hexagonal, parallel lamellar-in-lamellar L∥ (including the simple lamellar) as well as non-shifted and shifted (L⊥ and SL⊥) perpendicular lamellar-in-lamellar morphologies. Depending on the value of the ratio r = Θ(AB)/Θ(BC), where Θ is a characteristic temperature of the units involved, different sequences of phase transitions are shown to occur.

Shear-induced orientation of gyroid PS-b-P4VP(PDP) supramolecules.

The phase behavior of block copolymer based supramolecular complexes polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) and amphiphilic pentadecylphenol (PDP) molecules resembles the phase behavior of conventional block copolymers. Several PS-b-P4VP(PDP) complexes are found to self-assemble into gyroid nanostructures. Typically, the grains are randomly oriented with a maximal size of several micrometers.

Poly(vinylidene fluoride)/nickel nanocomposites from semicrystalline block copolymer precursors.

The fabrication of nanoporous poly(vinylidene fluoride) (PVDF) and PVDF/nickel nanocomposites from semicrystalline block copolymer precursors is reported. Polystyrene-block-poly(vinylidene fluoride)-block-polystyrene (PS-b-PVDF-b-PS) is prepared through functional benzoyl peroxide initiated polymerization of VDF, followed by atom transfer radical polymerization (ATRP) of styrene. The crystallization of PVDF plays a dominant role in the formation of the block copolymer structure, resulting in a spherulitic superstructure with an internal crystalline-amorphous lamellar nanostructure.

Automated TIMI frame counting using 3-d modeling.

Three dimensional coronary modeling and reconstruction can assist in the quantitative analysis of coronary flow velocity from 2-d coronary images. In this paper a novel method to assess coronary flow velocity is proposed. First, 3-d models of the coronary arteries are estimated from bi-plane X-ray images using epipolar constraint energy minimization for the selected fiducial points like bifurcations, and subsequently 3-d B-spline energy minimization for the arterial segments.

Self-assembly of (A-comb-C)-b-(B-comb-C) diblock copolymer-based comb copolymers.

The phase behavior of (A-comb-C)-b-(B-comb-C) diblock copolymer melts is investigated using the strong segregation theory approach. Three different regimes are distinguished. In regime 1 both disordered comb blocks are microphase separated from each other, in regime 2 the side chains C are microphase separated from the disordered A-b-B diblock backbones, and, finally, in regime 3 all species A, B, and C are microphase separated.

Supramolecular route to well-ordered metal nanofoams.

Metal nanofoams with a porosity above 50% v/v have recently attracted great interest in materials science due to their interesting properties. We demonstrate a new straightforward route to prepare such nanofoams using diblock copolymer-based PS-block-P4VP(PDP) supramolecules that self-assemble into a bicontinuous gyroid morphology, consisting of PS network channels in a P4VP(PDP) matrix. After dissolving the PDP, the P4VP collapses onto the PS struts and a free-standing bicontinuous gyroid template of 50-100 μm thickness and interconnected, uniformly sized pores is formed.

Hierarchical self-assembly of two-length-scale multiblock copolymers.

The self-assembly in diblock copolymer-based supramolecules, obtained by hydrogen bonding short side chains to one of the blocks, as well as in two-length-scale linear terpolymers results in hierarchical structure formation. The orientation of the different domains, e.g.

Nanoporous network channels from self-assembled triblock copolymer supramolecules.

Supramolecular complexes of a poly(tert-butoxystyrene)-block-polystyrene-block-poly(4-vinylpyridine) triblock copolymers and less than stoichiometric amounts of pentadecylphenol (PDP) are shown to self-assemble into a core-shell gyroid morphology with the core channels formed by the hydrogen-bonded P4VP(PDP)complexes. After structure formation, PDP was removed using a simple washing procedure, resulting in well-ordered nanoporous films that were used as templates for nickel plating.

Annealing-induced changes in double-brush Langmuir-Blodgett films of alpha-helical diblock copolypeptides.

The effect of annealing on the structure and the helix orientation in Langmuir-Blodgett (LB) monolayers of diblock copolymers (PLGA-b-PMLGSLGs) of poly(alpha-L-glutamic acid) (PLGA) and poly(gamma-methyl-L-glutamate-ran-gamma-stearyl-L-glutamate) with 30 mol % of stearyl substituents (PMLGSLG) with unidirectional helix orientation deposited on hydrophilic silicon substrates was characterized by means of small-angle X-ray reflectivity, transmission Fourier transform infrared spectroscopy, and atomic force microscopy. Upon annealing at 100 degrees C for 24 h, the alpha-helices became less tilted toward the substrate surface normal. Surface area shrinkage accompanied the change in tilt, indicated by an increase in both film thickness and electron density, resulting in more compact and uniform films.

Dipping-induced azimuthal helix orientation in Langmuir-Blodgett monolayers of alpha-helical amphiphilic diblock copolypeptides.

The azimuthal helix orientation of the rigid-rod amphiphilic diblock copolypeptides (PLGA-b-PMLGSLGs) of poly(alpha-L-glutamic acid) (PLGA) and poly(gamma-methyl-L-glutamate-ran-gamma-stearyl-L-glutamate) with 30 mol % of stearyl substituents (PMLGSLG) in Langmuir-Blodgett (LB) monolayers was investigated using polarized transmission Fourier transform infrared spectroscopy. The relative position of dipping with respect to the previous transfer position can be used to manipulate the azimuthal orientation of the helices parallel to or tilted by an angle of 45 degrees with respect to the dipping direction in the transferred films. The study of the azimuthal order for the LB monolayers of PLGA-b-PMLGSLGs of various block lengths revealed that the observed effect arises mainly from the deformation of the PMLGSLG top brush layer, induced by the flow orientation around the transfer region.

Parallel versus perpendicular lamellar-within-lamellar self-assembly of A-b-(B-b-A)(n)-b-C ternary multiblock copolymer melts.

Different types of lamellar-within-lamellar structure formations in A-b-(B-b-A)(n)-b-C terpolymer melts, with a volume fraction of components A, B, and C in the ratio of 1:1:2, are analyzed in the strong segregation limit using a simple theoretical approach. We consider the lamellar, parallel lamellar-within-lamellar, and perpendicular lamellar-within-lamellar self-assembled states. The influence of the copolymer chain length N, the value of the Flory-Huggins interaction parameters chi(AB), chi(AC), and chi(BC), and the number of blocks n in the AB multiblock chain on the phase behavior is discussed.

Surface potentials in Langmuir monolayers of unidirectionally oriented alpha-helical diblock copolypeptides.

The surface potentials and effective dipole moments of alpha-helical amphiphilic diblock copolypeptides during monolayer compression at the air-water interface are reported. Amphiphilic diblock copolypeptides (PLGA-b-PMLGSLGs) of poly(alpha-L-glutamic acid) (PLGA) and poly(gamma-methyl-L-glutamate-ran-gamma-stearyl-L-glutamate) with 30 mol % of stearyl substituents (PMLGSLG) of various block lengths were studied during the double-brush formation process at the water surface. Upon monolayer spreading of PLGA-b-PMLGSLGs, surface potentials of hundreds of millivolts were recorded, attributed to the dipole moments of water molecules reorienting due to interactions with the monolayers.

Nonmonotonic incommensurability effects in lamellar-in-lamellar self-assembled multiblock copolymers.

Using the self-consistent-field theory numerical procedure we find that the period D of the lamellar-in-lamellar morphology formed in symmetric multiblock copolymer melts A(mN/2)(B(N/2)A(N/2))(n)B(mN/2) at intermediate segregations changes nonmonotonically with an increase in the relative tail length m. Therewith D reveals, as a function of the Flory chi-parameter, a drastic change in the vicinity of the internal structure formation, which can be both a drop and a rise, depending on the value of m. It is argued that the unusual behavior found is a particular case of a rather general effect of the incommensurability between the two length scales that characterize the system under consideration.

Lamellar-in-lamellar structure of binary linear multiblock copolymers.

A theoretical description of the lamellar-in-lamellar self-assembly of binary A-b-(B-b-A)(m)-b-B-b-A multiblock copolymers in the strong segregation limit is presented. The essential difference between this binary multiblock system and the previously considered C-b-(B-b-A)(m)-b-B-b-C ternary multiblock copolymer system is discussed. Considering the situation with long end blocks, the free energy of the lamellar-in-lamellar self-assembled state is analyzed as a function of the number k of "thin" internal lamellar domains for different numbers m of repeating (B-b-A) units and different values of the Flory-Huggins chi(AB) interaction parameter.

Nonconventional morphologies in two-length scale block copolymer systems beyond the weak segregation theory.

The order-disorder and order-order transitions (ODT and OOT) in the linear multiblock copolymers with two-length scale architecture A(fmN)(B(N2)A(N2))(n)B((1-f)mN) are studied under intermediate cooling below the ODT critical point where a nonconventional sequence of the OOTs was predicted previously [Smirnova et al., J. Chem.

4-(4-Ethyl-phenyl-diazen-yl)phenol.

The crystal structure of the title compound, C(14)H(14)N(2)O, determined at 100 K, shows that the mol-ecules are not planar in the solid state, in contrast to other diazene (azobenzene) derivatives. The dihedral angle between the planes of the two aromatic rings is 42.32 (7)°.

Tailoring of the hierarchical structure within electrospun fibers due to supramolecular comb-coil block copolymers: polystyrene-block-poly(4-vinyl pyridine) plasticized by hydrogen bonded pentadecylphenol.

Previously we demonstrated hierarchical self-assembly and mesoporosity in electrospun fibers using selected polystyrene--poly(4-vinylpyridine) (PS--P4VP) diblock copolymers with hydrogen-bonded 3--pentadecylphenol (PDP), which rendered distorted spherical P4VP(PDP) domains within the PS matrix, internal lamellar order within the P4VP(PDP) domains, and allowed distorted spherical pores by removing PDP (. 2005, , 1048). Here we study whether the internal structure of electrospun fibers can be systematically tailored by varying the compositions of PS--P4VP(PDP).