Search

The ectopic thyroid gland is a rare condition. In most cases, ectopic thyroid tissue is the only functioning thyroid tissue, but it may rarely be associated with a normal thyroid gland. Ectopic thyroid carcinoma within a thyroglossal duct cyst is a very rare entity, with controversial individual approaches. This encouraged us to present the case of a 31-year- old woman, with papillary thyroid carcinoma in the thyroid gland and in the thyroid ectopic tissue within the thyroglossal duct. After suspicion of thyroid malignancy in the ultrasonography of the neck, FNA-biopsy was performed on the thyroid nodule and the thyroglossal duct cyst. Since the pathological exam revealed a papillary carcinoma in the eutopic and ectopic thyroid tissues, the Sistrunk procedure and total thyroidectomy were done, followed by radioiodine ablation.

We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring Z1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring Z1.6±0.3) and the simulations (η0,linear/η0,ring Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem.

We have demonstrated directed self-assembly of poly(styrene-b-dimethylsiloxiane) (PS-b-PDMS) down to sub- 10-nm half-pitch by using grating Si substrate coated with PDMS. The strong segregation between PS and PDMS enables us to direct the self-assembly in wide grooves of the grating substrate up to 500 nm in width. This process can be applied to form various type of sub-10-nm stripe pattern along variety of grating shape. V C 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 2297-2301, 2010

The equilibrium properties of polymer brushes formed by starlike polymers with varying number of arms attached to a surface by their center were studied experimentally with neutron reflectrometry (NR). Polystyrene (PS) stars in a good solvent (toluene) were centrally adsorbed onto a quartz substrate via a zwitterionic anchor group. Increasing the number of arms resulted in significantly lower equilibrium adsorbance, while replacement experiments of a 3-armed star brush by linear chains revealed interesting equilibrium and kinetic features related to the special architecture of star polymers. These results are compared with scaling theoretical calculations and Monte Carlo simulations of centrally adsorbed star polymers that were performed under the bond fluctuation simulation scheme. Several features of the experimental results are reproduced in our simulation study.

The complexation between narrow molecular weight distribution poly(2-vinylpyridine) (P2VP) and polystyrene (suPS) or polyisoprene (suPI) end-functionalized with one sulfonic acid group was examined in tetrahydrofuran dilute solutions by a combination of static and dynamic laser light scattering. Both apparent weight-average molecular weight (M w,app ) and hydrodynamic radius (R h ) of the complexes exhibited a maximum at a certain molar ratio of suPS chains to P2VP monomeric units. This indicated that the P2VP backbone may be saturated by the grafted end-functionalized chains because of repulsion between the grafted chains. By changing the molar mass of P2VP from 100,000 to 30,000 g/mol, the values of M w,app and R h decreased. When suPI was used instead of suPS, similar trends were observed. In the latter case, it was possible to prepare block copolymer-like micelles by transferring the P2VP/suPI blend solutions in decane, which is a selective solvent for PI. The non-covalent-bonded polymeric micelle characteristics were investigated as a function of sulfonic acid/2-vinylpyridine units ratio as well as temperature.

Six poly(2,2-diphenylethyl methacrylate) samples, with relatively low polydispersity index ( M w / M n :1.2-1.4) and M w ranging from 14.4 2 10 4 to 184.4 2 10 4 , were prepared by free-radical polymerization and fractionation. The dilute solution properties of the samples were studied by low-angle laser-light scattering in THF at 25°C and viscometry in a thermodynamically good solvent (toluene at 25°C) and in a ‹ -solvent (p-xylene at 22°C). Differential scanning calorimetry was used for the T g determination. The results are compared with those reported for poly(2-phenylethyl methacrylate) and poly(diphenylmethyl methacrylate).

The formation of homopolymer and block copolymer brushes grafted from Au and Si (SiOx) surfaces via living anionic surface-initiated polymerization (LASIP) is described. The initiator precursor 1,1-diphenylethylene (DPE) was functionalized with alkylsilane or alkylthiol and grafted onto planar Si wafer and Au surfaces, respectively, by self-assembled monolayer techniques. n-BuLi was used to activate the DPE initiator for anionic polymerization of monomers at the interface. A high-vacuum reactor was used for polymerization at surfaces under anhydrous solution conditions. By a careful sequence of monomer introduction, reaction, and termination, homopolymer and block copolymer tethered polymer brushes were obtained. The grafted polymer chains were investigated using surface sensitive techniques such as ellipsometry, contact angle measurements, atomic force microscopy, Fourier transform infrared spectroscopy, surface plasmon spectroscopy, and X-ray photoelectron spectroscopy. The importance of activation of t...

This study aimed to clarify the role of peritoneal T-lymphocytes in peritoneal immune defense mechanisms. This study was designed to examine the changes in T-cell subpopulations during peritonitis in patients treated with continuous ambulatory peritoneal dialysis (CAPD). Our observations were correlated to responses to treatment and with outcomes. The present study was carried out in 20 patients (8 males, 12 females) under CAPD. Peritonitis was diagnosed according to the criteria defined by the Ad Hoc Advisory Committee on Peritonitis Management. Peritoneal dialysate effluent (PDE) samples were collected from our patients, and lymphocyte subsets (CD2+, CD3+, CD3+/4+, CD3+/8+, CD3-/16+56+, CD4/CD8 ratio) were quantitated by using monoclonal antibodies. CD4/CD8 ratio was measured every day during peritonitis until the patients had completely recovered. The serial measurements of the CD4/CD8 ratio made in the PDE during peritonitis followed two patterns: the first pattern was characterized by a progressive increase in the CD4/CD8 ratio. The CD4/CD8 ratios on days 5, 6, and 7 were significantly higher than those on day 1 (P0.05). Overall, the patients who exhibited pattern 1 had favorable clinical courses. The second pattern was characterized by high initial CD4/CD8 ratios, which progressively decreased significantly (P0.05). This second pattern was associated with a delayed clinical response to treatment. Symptoms and signs of peritonitis persisted beyond 72 h. The pattern of the CD4/CD8 ratio in PDE may determine the outcome of peritonitis in CAPD patients.

Homopolymer and block copolymer brushes grafted from Au and Si (SiOx) surfaces via living anionic surface initiated polymerization (LASIP) has been reported. 1,1-diphenylethylene (DPE) derivative, an initiator for anionic polymerization, was grafted onto planar Si-wafer and Au surfaces by self-assembled monolayer (SAM) techniques. n-BuLi was used to activate the DPE for anionic polymerization of monomers at the interface under high vacuum. By a careful sequence of monomer introduction, reaction, and termination, homopolymer and block copolymer tethered polymer brushes were obtained. The importance of initiator activation, control of polymerization conditions, and removal of excess BuLi is emphasized. Interesting differences in morphology, thickness, grafting density, and polymerization conditions contrasts LASIP from solution and other surface initiated polymerization (SIP) mechanisms. The formation of block copolymer sequences highlights the unique utility of a living anionic polymerization technique on surfaces.