Chain Precursor Research Articles

Nanoscale Inhomogeneities and Thermodynamics of Unfilled Polymer Gels

The description of the structure of swollen polymer networks and its relationship with mechanical and thermodynamic properties has been an unresolved problem for a long time. In spite of a number of theoretical approaches, no simple formalism has been found that captures the structural variety of real gels. Here we report a new approach to describe inhomogeneities in the nanometer size range that develop in the course of the cross‐linking process, and their relationship with the macroscopic elastic properties. Experimental data from small angle neutron scattering (SANS), osmotic swelling pressure, and elastic modulus measurements were obtained on polyfluorosilicone (PFSi) gels prepared by different cross‐linking processes from precursor chains of monomodal and bimodal distributions. The neutron scattering response of these gels reveals two types of concentration fluctuations, namely, those originating from nanoscale frozen‐in constraints generated by the cross‐links and the time‐dependent thermodynamic fluctuations associated with the osmotic properties of the network chains. The amplitude of the frozen‐in concentration fluctuations deduced from small angle neutron scattering measurements is found to be proportional to the ratio of the macroscopic elastic shear modulus to the osmotic compression modulus. The thermodynamic concentration fluctuations are in agreement with the results of dynamic light scattering and macroscopic osmotic pressure measurements. The present approach describes the effect of the nanoscale features on the macroscopic properties of the gel. Dedicated to Professor John L. Stanford on the occasion of his 60th birthday.

Dansylation of tryptic peptides for increased sequence coverage in protein identification by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometric peptide mass fingerprinting

A database search using peptide mass fingerprints obtained by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry leads to protein identification with incomplete sequence coverage, because certain peptides are preferentially desorbed/ionized and some are not detected at all. We show that certain tryptic peptides mainly with C-terminal arginine not detected before derivatization become detectable upon dansylation. Others, mainly with C-terminal lysine, are suppressed. An increase in protein sequence coverage and protein identification score by combined data from underivatized and dansylated peptides in database search is demonstrated using human amnion proteins (human serum albumin precursor, calmodulin, collagen alpha 2(VI) chain precursor, galectin-3) separated by two-dimensional gel electrophoresis as well as femtomole amounts of BSA in solution.

Precursor chemistry for ULK CVD

Deposited thin silicon-based films used for electronic devices as insulators in interconnections should have low and ultra low permittivity (ULK) to be acceptable to the future integration requirements, especially for the advanced technology (45 nm and below). Diffusion dielectric barrier should have also low permittivity to limit the increase of the effective global constant and should be also acceptable for etch selectivity. After an explanation of the different factors that can increase the dielectric permittivity as a function of the working frequency and the chemical bonds and atoms present in silicon-based materials, examples of plasma-polymerised materials a-SiOC:H obtained by plasma enhanced chemical vapour deposition are presented, starting with different single precursor vapours and mixed vapours. A way to get a low dielectric constant is to decrease the weight density of the bulk material, keeping the same material family, by choosing complex precursors. Voids inside the bulk material could be obtained with macropores or larger (air gap), mesopores (xerogels, SOD) or micropores up to free volume. In that case, cyclic chain precursors and/or a porogen approach can be selected in agreement with plasma experimental conditions to synthesise low density plasma-polymers with intrinsic free volume or with microporosity revealed by a post treatment.

Novel Role of the Lipopolysaccharide O1 Side Chain in Ferric Siderophore Transport and Virulence of Vibrio anguillarum

From a library of approximately 20,000 transposon mutants, we have identified mutants affected in chromosomal genes involved in synthesis of the siderophore anguibactin, as well as in ferric anguibactin utilization. Genetic and sequence analyses of one such transport-defective mutant revealed that the transposon insertion occurred in an open reading frame (ORF) with homology to rmlC, a dTDP-rhamnose biosynthetic gene. This ORF resides within a cluster of four ORFs, all of which are predicted to function in the biosynthesis of this O side chain precursor. The same phenotype was seen in a mutant obtained by allelic exchange in rmlD, another ORF in this dTDP-rhamnose biosynthetic cluster. This mutation could be complemented with the wild-type rmlD gene, restoring both production of the O1 antigen side chain and ferric anguibactin transport. Presence of the O1 side chain was crucial for the resistance of Vibrio anguillarum to the bactericidal action of nonimmune serum from the fish host. Surprisingly, further analysis demonstrated that these mutations were pleiotropic, leading to a dramatic decrease in the levels of FatA, the outer membrane protein receptor for ferric anguibactin transport, and a concomitant reduction in iron transport. Thus, our results in this work demonstrate that the lipopolysaccharide O1 side chain is required for the operation of two critical virulence factors in V. anguillarum: serum resistance and anguibactin-mediated iron transport. These factors allow V. anguillarum to survive in serum and multiply in the iron-limiting milieu of the host vertebrate.

Synthesis of CdS nanoparticles dispersed within amphiphilic poly(urethane acrylate‐co‐styrene) films

AbstractCdS nanoparticles were prepared using amphiphilic urethane acrylate nonionomer (UAN) precursor chains having a poly(propylene oxide)‐based hydrophobic segment and a hydrophilic poly(ethylene oxide) segment. Cadmium salts were first dissolved in UAN/styrene solutions, and then the solutions were copolymerized to obtain poly(urethane acrylate‐co‐styrene) films containing dissolved cadmium salts. After reduction with H2S gas, freestanding films containing CdS nanoparticles were obtained. Transmission electron microscopy images of the films showed that 9.67‐nm CdS nanoparticles were dispersed within the poly(urethane acrylate‐co‐styrene) matrix. The formation of CdS nanoparticles was also confirmed with UV absorption spectra and photoluminescence emission spectra of the films. Transmission electron microscopy and dynamic mechanical analysis measurements confirmed that hydrophilic/hydrophobic microphase separation in UAN/styrene solutions occurred during the dissociation of the cadmium salts, and the microphase‐separated structures were locked in by crosslinking copolymerization. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2357–2363, 2005

Synthesis of Monoalkyl End-Capped Poly(2-methyl-2-oxazoline) and Its Micelle Formation in Aqueous Solution

Novel monoalkyl end-capped poly(2-methyl-2-oxazoline) (POXZ-C12 and POXZ-C18), with molecular weights varying from 5500 to 8500, were synthesized by the use of the “initiator method”. The micellar behavior of these polymers in water was investigated by the fluorescence technique. Critical micelle concentrations are in the range of 0.007−0.4 g L-1 and are dependent on the hydrophilic/lipophilic balance. An aggregation number of 11 was determined for POXZ-C12. The structural properties of the aggregates have also been investigated by viscometry. Intrinsic viscosities of these polymers have been compared to the ones of poly(2-methyl-2-oxazoline) (POXZ). The POXZ-C12 aggregates show similar compactness as POXZ precursor chains, whereas POXZ-C18 aggregates are more expanded. Addition of β-cyclodextrin (CD) has dissociated the aggregates, and the intrinsic viscosities of the CD end-capped chains have become comparable to the ones of POXZ precursor chains.

Fatty acid metabolism pathway play an important role in carcinogenesis of human colorectal cancers by Microarray-Bioinformatics analysis

The present study systematically explored metabolic pathways and altered expressions of genes speculatively participating in colorectal carcinogenesis by using a Microarray-Bioinformatic analysis methods. The results revealed that 157 genes were up-regulated and 281 genes were down-regulated in colorectal cancer (CRC). Gene Ontology (GO) and relevant bioinformatics tools indicated that the functional category to which 438 genes (12%; 438/3800) of the most frequent alteration belonged was metabolism. The analysis of 10 colorectal cancer tissue specimens demonstrated that genes involved in fatty acid metabolic pathways had high rates of overexpression. In addition, we stimulated CRL-1790 cell line with linoleic acid (a polyunsaturated fatty acid) for 12, 24, 48 and 72 h. Cell proliferation was elevated by 5, 25, 28 and 31% ( P<0.05), respectively. Further analyses revealed that the genes increasingly expressed in the cell line included enoyl-Coenzyme A, hydratase/3-hydroxyacyl Coenzyme A dehydrogenase (EHHADH), enoyl Coenzyme A hydratase, short chain, 1, mitochondrial (ECHS1); glutaryl-Coenzyme A dehydrogenase (GCDH), acyl-Coenzyme A oxidase 2, branched chain (ACOX2); acyl-Coenzyme A dehydrogenase, C-2 to C-3 short chain precursor (ACADS); carnitine palmitoyltransferase 1B (CPT1B), acyl-CoA synthetase long-chain family member 5 (ACSL5), and cytochrome P450, family 4, subfamily A, and polypeptide 11 (CYP4A11) genes. This indicated that the stimulating effect of linoleic acid on cell proliferation was due to interference with the metabolic pathway of fatty acid metabolism. In conclusion, genes with altered expression levels in CRC were mainly associated with fatty acid metabolic pathways speculated to have an important role linked to carcinogenesis.

Disorder effects on the strain response of model polymer networks

Molecular dynamics simulations are used to investigate polymer networks made by either end-linking or randomly crosslinking a melt of linear precursor chains. The resulting network structures are very different, since end-linking leads to nearly ideal monodisperse networks, while random crosslinking leads to polydisperse networks, characterized by an exponential strand length distribution. Networks with average strand length 20 and 100 were generated. These networks were used to study the effects of disorder in the network connectivity on observables averaged either over the entire network or selected sub-structures. Heterogeneities in the randomly crosslinked networks cause significant differences in the localization of monomers, however, neither the localization of crosslinks nor the microscopic strain response are significantly affected. Compared to end-linked networks, randomly crosslinked networks have a slightly increased tube diameter, and as a result a slightly decreased shear modulus, but otherwise identical stress–strain behavior. For the investigated systems, we conclude that the microscopic strain response, tube diameter, and stress–strain relation are all insensitive to the heterogeneities due to the linking process by which the network were made.

Identification of Amadori-Modified Plasma Proteins in Type 2 Diabetes and the Effect of Short-Term Intensive Insulin Treatment

Growing evidence supports that nonenzymatic glycation products may cause hyperglycemia-induced diabetes complications. Amadori-modified proteins are the intermediate products of nonenzymatic glycation and constitute the forms of glycated proteins in diabetes. The objective of the current study was to utilize two-dimensional gel electrophoresis, Western blot, and mass spectrometry to identify Amadori-modified plasma proteins in type 2 diabetic patients with poor glycemic control and assess the impact of short-term insulin treatment on the glycation of these proteins. We compared eight type 2 diabetic subjects (aged 56 +/- 3 years and BMI 29.7 +/- 0.9 kg/m(2)) with an average diabetes duration of 8.5 years (range 3-19) with equal numbers of weight-matched (aged 56 +/- 2 years and BMI 30.1 +/- 10.0 kg/m(2)) and lean (aged 58 +/- 2 years and BMI 25 +/- 00.5 kg/m(2)) nondiabetic subjects who have no first-degree relatives with diabetes. Two separate blood samples were collected from the type 2 diabetic subjects, one following 2 weeks of withdrawal of all antidiabetic medications (T(2)D-; plasma glucose 12.6 +/- 1.0 mmol/l) and another following 10 days of intensive insulin treatment (T(2)D+; plasma glucose 5.5 +/- 0.2 mmol/l). Plasma proteins were separated using single and two-dimensional gel electrophoresis. Western blot analysis was performed, and several proteins, which reacted with the Amadori-antibody (1-deoxyfructosyl lysine), were identified by tandem mass spectrometry. No significant differences in the glycation of proteins between the obese and lean groups were noted, but type 2 diabetic patients had several proteins with higher glycation than the control groups. We identified 12 plasma proteins with reduced reaction to the anti-Amadori antibody upon intensive insulin treatment. A significant (P < 0.03) difference in Amadori modification was observed between the T(2)D- and control subjects for all these proteins except the Ig light chain. Insulin treatment reduced Amadori modification of albumin (23.2%, P < 0.02), fibrin (34.6%, P < 0.001), Ig heavy chain constant region (20.7%, P < 0.05), transferrin (25.4%, P < 0.04), and Ig light chain (13%, P < 0.02). In addition, Western blot analysis of two-dimensional gel electrophoresis identified alpha-fibrinogen precursor, beta-fibrinogen precursor, fibrinogen gamma-B chain precursor, hemopexin, vitamin D binding protein, and serine protease inhibitor as proteins with a reduced reaction to anti-Amadori antibody upon intensive insulin treatment. The current approach offers the opportunity to identify Amadori modification of many proteins that may cause functional alterations and offers the potential for monitoring short-term glycemic control in diabetic patients.

The Synthesis of (−)-Isodomoic Acid C

The neuroactive algal metabolite (-)-isodomoic acid C, a kainoid amino acid, has been synthesized for the first time. Asymmetric dearomatizing cyclization of an aromatic amide using a chiral lithium amide base generates a bicyclic enone containing a pyrrolidinone ring with the relative and absolute stereochemistry of the target. A further 15 synthetic steps, including conjugate cuprate addition to the enone of a side chain precursor, a Ru-promoted oxidation of the phenyl ring to the C2-carboxylic acid substituent, a regioselective Baeyer-Villiger reaction, and an E-selective Horner-Wadsworth-Emmons reaction, elaborate the cyclization product into the target molecule.

Lysosomal Acid α-Glucosidase Consists of Four Different Peptides Processed from a Single Chain Precursor

Pompe's disease is caused by a deficiency of the lysosomal enzyme acid alpha-glucosidase (GAA). GAA is synthesized as a 110-kDa precursor containing N-linked carbohydrates modified with mannose 6-phosphate groups. Following trafficking to the lysosome, presumably via the mannose 6-phosphate receptor, the 110-kDa precursor undergoes a series of complex proteolytic and N-glycan processing events, yielding major species of 76 and 70 kDa. During a detailed characterization of human placental and recombinant human GAA, we found that the peptides released during proteolytic processing remained tightly associated with the major species. The 76-kDa form (amino acids (aa) 122-782) of GAA is associated with peptides of 3.9 kDa (aa 78-113) and 19.4 kDa (aa 792-952). The 70-kDa form (aa 204-782) contains the 3.9- and 19.4-kDa peptide species as well as a 10.3-kDa species (aa 122-199). A similar set of proteolytic fragments has been identified in hamster GAA, suggesting that the multicomponent character is a general phenomenon. Rabbit anti-peptide antibodies have been generated against sequences in the proteolytic fragments and used to demonstrate the time course of uptake and processing of the recombinant GAA precursor in Pompe's disease fibroblasts. The results indicate that the observed fragments are produced intracellularly in the lysosome and not as a result of nonspecific proteolysis during purification. These data demonstrate that the mature forms of GAA characterized by polypeptides of 76 or 70 kDa are in fact larger molecular mass multicomponent enzyme complexes.

Structural ordering of self-assembled alkylene-bridged silsesquioxanes probed by X-ray diffraction experiments

Powder X-ray diffraction experiments have been performed to analyse the structural order in alkylene bridged silsesquioxanes. These organic–inorganic hybrids were obtained by the hydrolysis–condensation of a series of six α,ω-bis[triethoxysilyl(propyl)ureido]alkylenes associating hydrophobic alkylene units with various chain length and H-bonding urea groups. The sol–gel hydrolysis in ethanol with a stoichiometric amount of water and using fluoride anion as catalyst only afforded amorphous bridged silsesquioxanes. Conversely, the hydrolysis with a large excess of water under acidic catalysis produced materials as layered sheets. A lamellar periodicity on the molecular scale level was observed for longer alkylene chain (Cn C8–C12). Under similar reaction conditions, the hydrolysis of the short alkylene chain precursor (C6) led to an amorphous solid. The medium to long range arrangement of the organic fragment in the solids is attributable to a combination of the hydrogen bonding interactions between the urea groups and of the van der Waals interactions between the long alkylene chains. In excess water, the hydrophobic nature of the long alkylene chains prevails and favours the formation of the intermolecular H-bonds between the urea groups leading to ordered assemblies of the organic substructures in the silsesquioxane network.

Engineered Polymeric Nanoparticles for Bioremediation of Hydrophobic Contaminants

Sorption of hydrophobic organic contaminants, such as polycyclic aromatic hydrocarbons (PAHs), to soil has been shown to limit their solubilization rate and mobility. In addition, sequestration of contaminants by sorption to soil and by partitioning in nonaqueous phase liquids (NAPLs) reduces their bioavailability. Polymeric nano-network particles have been demonstrated to increase the "effective" solubility of a representative hydrophobic organic contaminant, phenanthrene (PHEN) and to enhance the release of PHEN from contaminated aquifer material. In this study, we investigate the usefulness of nanoparticles made from a poly(ethylene) glycol modified urethane acrylate (PMUA) precursor chain, in enhancing the bioavailability of PHEN. PMUA nanoparticles are shown to increase the mineralization rate of PHEN crystal in water, PHEN sorbed on aquifer material, and PHEN dissolved in a model NAPL (hexadecane) in the presence of aquifer media. These results show that PMUA particles not only enhance the release of sorbed and NAPL-sequestered PHEN but also increase its mineralization rate. The accessibility of contaminants in PMUA particles to bacteria also suggests that particle application may be an effective means to enhance the in-situ biodegradation rate in remediation through natural attenuation of contaminants. In pump-and-treat or soil washing remediation schemes, bioreactors could be used to recycle extracted nanoparticles. The properties of PMUA nanoparticles are shown to be stable in the presence of a heterogeneous active bacterial population, enabling them to be reused after PHEN bound to the particles has been degraded by bacteria.

Characteristics of the binding features of Nelin with F-actin and screening Nelin interactive proteins

The interaction of nelin, a cardiac-specific expressed protein of human novel genenelin, with F-actin was studied by both F-actin cosedimentationin vitro and colocalization assays. The results showed that nelin is a new F-actin binding protein and is colocolized with F-actin in cytoplasm of cells. Three new nelin binding proteins, filamin C subtype, titin N2B subtype and inter-alpha trypsin inhibitor heavy chain precursor (ITIH), were identified from human heart cDNA library using yeast two-hybrid screening. The binding activity of filamin C with nelin was confirmed by coimmunoprecipitation. Filamin C binds to nelin through its C-terminal region. It is indicated that nelin is a cytoskeleton associated protein and acts as a membrane-cytoskeleton associated protein involved in the formation of focal adhesions.

Influence of Alkylene Chain Length on the Morphology of Chiral Bridged Silsesquioxanes

Four chiral diureido derivatives of trans-(1R,2R)- and trans-(1S,2S)-diaminocyclohexane with different carbon chain lengths (n = 3, 4, 5, 10) were synthesized and were hydrolyzed in aqueous acidic conditions in order to examine the role of the carbon chain spacer on the resulting hybrid bridged silsesquioxanes. Solid state NMR (29Si and 13C) studies demonstrated the presence of covalently bonded organo-bridged silica networks in these materials. Scanning electron microscopy (SEM) showed the materials obtained from the short chain derivatives to consist of fibers (n = 3 and 4). In contrast, plate-like shapes were formed from the longer chain precursors (n = 5 and 10). A lamellar structure was observed via transmission electron microscopy (TEM) for the hybrid obtained from the precursor with the longest chain (n = 10). This lamellar form was confirmed by powder X-ray diffraction (PXRD) measurement of the hybrid.

Synthesis and Anti-Tubulin Activity of a 3‘-(4-Azidophenyl)-3‘-dephenylpaclitaxel Photoaffinity Probe

The synthesis and biological evaluation of a novel paclitaxel photoaffinity probe is described. The synthesis involved the preparation of an azide-containing C13 side chain through a Staudinger cycloaddition followed by a lipase-mediated kinetic resolution to obtain the azetidinone in 99% ee. Coupling of the enantiopure side chain precursor to 7-TES-baccatin III and subsequent silyl ether deprotection afforded 3'-(4-azidophenyl)-3'-dephenylpaclitaxel, which was shown to be as active as paclitaxel in tubulin assembly and cytotoxicity assays.

Increased type I collagen content and DNA binding activity of a single-stranded, cytosine-rich sequence in the high-salt buffer protein extract of the copper-deficient rat heart

Dietary copper (Cu) deficiency not only causes a hypertrophic cardiomyopathy but also increases cancer risk in rodent models. However, a possible alteration in gene expression has not been fully examined. The present study was undertaken to determine the effect of Cu deficiency on protein profiles in rat heart tissue. Male Sprague-Dawley rats were fed diets that were either a Cu-adequate diet (6.0 μg Cu/g diet, n = 6) or a Cu-deficient diet (0.3 μg Cu/g diet, n = 6) for 5 weeks. The high-salt buffer (HSB) protein extract from heart tissue of Cu-deficient, but not Cu-adequate rats showed a 132 kDa protein band by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) analysis. This protein band stained pink with Coomassie Blue, suggesting the presence of collagens or other proline-rich proteins. Dot immunoblotting demonstrated that total type I collagen was increased by 110% in HSB protein extract from Cu-deficient, relative to Cu-adequate, rats. Liquid chromatography with mass spectrometry analysis indicated that the 132 kDa protein band contained a collagen α (I) chain precursor as well as a leucine-rich protein 130 (LRP130) in HSB protein extract from Cu-deficient but not Cu-adequate rats. A gel shift assay showed that HSB protein extract from Cu-deficient rats bound to a single-stranded cytosine-rich DNA with higher affinity than the extract of Cu-adequate rats, similar to reports of an increase in LRP130 single-stranded DNA binding activity in several types of tumor cells. Collectively, these results not only suggest an additional feature of altered collagen metabolism with Cu deficiency but also demonstrate for the first time an increase in single-stranded cytosine-rich DNA binding in Cu-deficient rat heart.

Protein biomarkers in the plasma of workers occupationally exposed to polycyclic aromatic hydrocarbons.

Polycyclic aromatic hydrocarbons (PAHs) form a chemical family containing several hundred compounds, including benzo[a]pyrene and pyrene. They are usually produced by the incomplete burning of coal, oil, gas, garbage, or other organic substances like tobacco or charbroiled meat. Exposure to PAH causes tumors, primarily in the lung, the bladder, and the skin. To investigate the differentially expressed proteins resultant from PAH exposure, the protein expression in human plasma was analyzed using two-dimensional electrophoresis (2-DE). The plasma exposed to PAH was obtained from 48 waste gas pollution measurers working at an automobile emission inspection center. The 1-hydroxypryene (1-OHP) level, which is the urinary PAH metabolite used for evaluation of PAH exposure, was 0.28 micromol/mol creatinine in PAH exposure groups, and 0.078 micromol/mol creatinine in unexposed groups (control, n = 33). A protein upregulated by PAH (putative capacitative calcium entry channel) and five overexpressed proteins (two fibrinogen gamma-A chain precursors, a hemopexin precursor, an albumin precursor, and T-cell receptor beta chain C region) were identified with matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) and confirmed with tandem MS (MS/MS) and Western blotting. The putative capacitative calcium entry channel was partially validated with a laboratory made antibody of a representative peptide fragment in PAH-exposed human plasma samples.

Proteomic identification of collagens and related proteins in human fibroblasts.

Fibroblasts are used for diagnosis of a series of metabolic diseases and are particularly suitable for the diagnosis of collagen disorders. We aimed to generate a skin fibroblast map that would be suitable for the concomitant determination of collagen and collagen-related proteins.A human skin fibroblast cell line was cultivated, homogenised, proteins extracted and subject to two-dimensional gel electrophoresis with subsequent in-gel-digestion of protein spots and mass spectrometrical identification (MALDI-TOF). Collagen alpha1 (I) chain precursor, collagen alpha1 (III) chain precursor, collagen alpha2 (VI) precursor and collagen modifying enzymes prolyl 4-hydroxylase alpha-2-subunit precursor, procollagen-lysine 2-oxoglutarate 5-dioxygenase 1 and 2, protein disulfide isomerase ER-60 precursor and peptidyl-prolyl cis-trans isomerase were among the abundant proteins. The finding of collagen and collagen-related structures as well as the identification of other metabolic enzyme systems on one 2D gel may propose the use of this proteomic method for further characterization of collagen and collagen-related proteins or for preliminary screening of metabolic disorders.

Structure of Trifunctional End-Link Polymer Gels Studied by SANS

We investigate, using small-angle neutron scattering (SANS), the polymer concentration fluctuations in a particular type of end-linked polystyrene gels, in the swollen state. These gels are obtained from the cross-linking of well-defined end-capped low-polydispersity chains end-linked through a trifunctional cross-linking agent. Polystyrene precursor chains of three different molecular weights, namely 5.5K, 10K, and 15.2K, were used. The scattering at low scattering vectors is expected to come from static concentration fluctuations. Here the intensity displays a dominant scattering characterized either at low q by a unique correlation length or on a wider q range by a set of two correlation lengths, one of which has been locked to the correlation length in the semidilute solution of same polymer concentration. We note ξhet as a characterization of swelling heterogeneity, the unique low q correlation length, or the larger one in the double length fit. For both fits, the variation of ξhet with the polymer volume fraction φ is almost the same for all precursor molecular masses; it scales close to ξhet ∼ φ-5/3. Such a variation is surprisingly identical to that observed in “statistical gels” randomly cross-linked from semidilute solutions of very large polymer chains. Results of this paper are thus different from the observations on other end-linking gels, the scattering of which seems to belong to other “classes”, displaying two distinct correlation lengths or a maximum corresponding to soft order between nodule-like junctions.