Degradation Behavior of Polymer Gels Caused by Nonspecific Cleavages of Network Strands

We report a systematical study of degradation behavior of hydrogels that suffer from the nonspecific cleavage on the network strands. The volume of the gel specimens increased with the degradation progress, and denoted the temperature dependence and the network strand length dependence. Our new model based on the pseudo-first-order cleavage kinetics of the chemical bonds on the network strands well agreed with the degradation behavior. The estimated apparent degradation rate constants of the network strands were linear function of their length, corresponding to the network strand length dependence on the macroscopic volume change of the gel specimens. The estimated degradation rate constants of the chemical bonds on the network stand, which were ether and amide bond, obeyed the transition state theory. The calculated activation enthalpy of each bond was in the range of the values in previous studies, indicating the validity of our modeling

Fabrication and Structural Characterization of Module-Assembled Amphiphilic Conetwork Gels

Structural analysis of inhomogeneity-free poly­(ethylene glycol)–poly­(dimethyl­siloxane) (PEG–PDMS) amphiphilic conetwork gels has been performed by the complementary use of small-angle X-ray and neutron scattering. Because of the hydrophobicity of PDMS units, the PEG–PDMS gels exhibit a microphase-separated structure in water. Depending on the volume fraction of PDMS, the microphase-separated structure varies from core–shell to lamellar. The obtained X-ray and neutron scattering profiles are reproduced well using a core–shell model together with a Percus–Yevick structure factor when the volume fraction of PDMS is small. The domain size is much larger than the size of individual PEG and PDMS unit, and this is explained using the theory of block copolymers. Reflecting the homogeneous dispersion conditions in the as-prepared state, scattering peaks are observed even at a very low PDMS volume fraction (0.2%). When the volume fraction of PDMS is large, the microphase-separated structure is lamellar and is demonstrated to be kinetically controlled by nonequilibrium and topological effects

Base-pairing probability in the microRNA stem region affects the binding and editing specificity of human A-to-I editing enzymes ADAR1-p110 and ADAR2

<p>Adenosine deaminases acting on RNA (ADARs) catalyze the deamination of adenosine (A) to inosine (I). A-to-I RNA editing targets double-stranded RNA (dsRNA), and increases the complexity of gene regulation by modulating base pairing-dependent processes such as splicing, translation, and microRNA (miRNA)-mediated gene silencing. This study investigates the genome-wide binding preferences of the nuclear constitutive isoforms ADAR1-p110 and ADAR2 on human miRNA species by RNA immunoprecipitation of ADAR-bound small RNAs (RIP-seq). Our results suggest that secondary structure predicted by base-pairing probability in the mainly double-stranded region of a pre-miRNA or mature miRNA duplex may determine ADAR isoform preference for binding distinct subpopulations of miRNAs. Furthermore, we identify 31 unique editing sites with statistical significance, 19 sites of which are novel editing sites. Editing sites are enriched in the seed region responsible for target recognition by miRNAs, and isoform-specific nucleotide motifs in the immediate vicinity and opposite of editing sites are consistent with previous studies, and further reveal that ADAR2 may edit A/C bulges more frequently than ADAR1-p110 in the context of miRNA.</p

Survival in Patients with Appendiceal Carcinoma by the Log-Rank Test (n = 108).

a<p>pap, papillary adenocarcinoma; well, well differentiated adenocarcinoma; mod, moderately differentiated adenocarcinoma; por, poorly differentiated adenocarcinoma; sig, signet-ring cell carcinoma; muc, mucinous carcinoma.</p>b<p>m, mucosa; sm, submucosa; mp, muscularis propria; ss, subserosa, se, serosa; si, invasion to other organ.</p>c<p>27 cases without lymph node dissection were excluded.</p>d<p>3 cases with unknown details regarding curative or non-curative resection were excluded.</p><p>Survival in Patients with Appendiceal Carcinoma by the Log-Rank Test (n = 108).</p

In appendiceal carcinoma cells (A, D, G, J, M, P and S), MUC1 showed membrane expression (B and C); MUC2 showed supranuclear expression (E and F); MUC4 (H and I), MUC5AC (K and L) and MUC6 (N and O) showed cytoplasmic expression; MUC16 showed membrane expression (Q and R); and MUC17 (T and U) showed supranuclear expression. HE, hematoxylin and eosin stain; IHC, immunohistochemical stain.

<p>In appendiceal carcinoma cells (A, D, G, J, M, P and S), MUC1 showed membrane expression (B and C); MUC2 showed supranuclear expression (E and F); MUC4 (H and I), MUC5AC (K and L) and MUC6 (N and O) showed cytoplasmic expression; MUC16 showed membrane expression (Q and R); and MUC17 (T and U) showed supranuclear expression. HE, hematoxylin and eosin stain; IHC, immunohistochemical stain.</p

Correlation between mucin expression and the cumulative survival rate.

<p>In the study of the correlation between mucin expression and the cumulative survival rate in patients with appendiceal carcinoma using the Kaplan-Meier method, the survival rate of patients with a positive expression of MUC3 were poorer than those of patients with negative expression of MUC3 (p = 0.004).</p

Multivariate Analysis of Prognostic Factors.

<p>Multivariate Analysis of Prognostic Factors.</p