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The complications of concurrent chemoradiotherapy for nasopharyngeal carcinoma include dryness of mouth, sensorineural hearing loss, dental caries, trismus, pituitary dysfunction, myelitis, paralysis of cranial nerves IX–XII, massive neck fibrosis and pharyngeal wall necrosis. Tornwaldt's cyst formation after concurrent chemoradiotherapy for nasopharyngeal carcinoma has not been reported previously in the world literature. Tornwaldt's cyst, a persistent pharyngeal bursa, is found in about 3 per cent of the adult population, although the majority of these are asymptomatic. We describe the previously unreported complication of Tornwaldt's cyst formation after concurrent chemoradiotherapy for nasopharyngeal carcinoma. [ABSTRACT FROM AUTHOR]

To provide coherent x-ray sources for probing the dynamic structures of solid or liquid biological substances on the picosecond timescale, a high-aspect-ratio x-ray resonator cavity etched from a single crystal substrate with a nearly vertical sidewall structure is required. Although high-aspect-ratio resonator cavities have been produced in silicon, they suffer from unwanted multiple beam effects. However, this problem can be avoided by using the reduced symmetry of single-crystal sapphire in which x-ray cavities may produce a highly monochromatic transmitted x-ray beam. In this study, we performed nominal 100 µm deep etching and vertical sidewall profiles in single crystal sapphire using inductively coupled plasma (ICP) etching. The large depth is required to intercept a useful fraction of a stopped-down x-ray beam, as well as for beam clearance. An electroplated Ni hard mask was patterned using KMPR 1050 photoresist and contact lithography. The quality and performance of the x-ray cavity depended upon the uniformity of the cavity gap and therefore verticality of the fabricated vertical sidewall. To our knowledge, this is the first report of such deep, vertical etching of single-crystal sapphire. A gas mixture of Cl2/BCl3/Ar was used to etch the sapphire with process variables including BCl3 flow ratio and bias power. By etching for 540 min under optimal conditions, we obtained an x-ray resonant cavity with a depth of 95 µm, width of ~30 µm, gap of ~115 µm and sidewall profile internal angle of 89.5°. The results show that the etching parameters affected the quality of the vertical sidewall, which is essential for good x-ray resonant cavities. [ABSTRACT FROM AUTHOR]

Short-range-order and long-range-order structures in Ge1 − xSnx/Ge thin films grown by molecular beam epitaxy (MBE) were investigated by using extended x-ray absorption fine structure (EXAFS) and x-ray diffraction (XRD) techniques, respectively. These materials are of great potential for constructing efficient optoelectronic devices. The EXAFS analysis demonstrates that Sn atoms occupy Ge sites in these thin-film samples with Sn concentration up to 20 at.%. The Ge-Sn bonds expected in the substitutional model were also observed in Raman spectra of these samples. The XRD results show that, in the out-of-plane direction, the lattice constants of the films are distinctly larger than that of the Ge substrates. However, such increased lattice parameters were not observed in the in-plane direction. Our x-ray and Raman results have clearly revealed substitutional incorporation of Sn with high concentration in dislocation-free MBE-grown Ge films of practical-device thickness. [ABSTRACT FROM AUTHOR]

A continuum model of piezoelectric potential generated in a bent ZnO nanorod cantilever is presented by means of the first piezoelectric effect approximation. The analytical solution of the model shows that the piezoelectric potential in the nanorod is proportional to the lateral force but is independent along the longitudinal direction. The electric potential in the tensile area and that in the compressive area are antisymmetric in the cross section of the nanorod, which makes the nanorod a 'parallel plate capacitor' for piezoelectric nanodevices, such as a nanogenerator. The magnitude of piezoelectric potential for a ZnO nanorod of 50 nm diameter and 600 nm length bent by a 80 nN lateral force is about 0.27 V, which is in good agreement with the finite element method calculation. [ABSTRACT FROM AUTHOR]

Selective bradykinin (BK) B 1receptor antagonists could be novel therapeutic agents for the treatment of pain and inflammation. Elucidation of the structure activity relationships of the structurally novel HTS lead compound 1provided potent hBK B 1receptor antagonists with excellent receptor occupancy in the CNS of hBK B 1transgenic rats. [ABSTRACT FROM AUTHOR]

The protein Merlin is involved in the regulation of cell proliferation and differentiation in the eyes and wings of Drosophila and is a homolog of the human protein encoded by the Neurofibromatosis 2 (NF2) gene whose mutations cause auricular nerve tumors. Recent studies show that Merlin and Expanded cooperatively regulate the recycling of membrane receptors, such as the epidermal growth factor receptor (EGFR). By performing a search for potential genetic interactions between Merlin (Mer) and the genes important for vesicular trafficking, we found that ectopic expression in the wing pouch of the clathrin adapter protein Lap involved in clathrin-mediated receptor endocytosis resulted in the formation of extra vein materials. On the one hand, coexpression of wild-type Merlin and lap in the wing pouch restored normal venation, while overexpression of a dominant-negative mutant Mer(DBB) together with lap enhanced ectopic vein formation. Using various constructs with Merlin truncated copies, we showed the C-terminal portion of the Merlin protein to be responsible for the Merlin-lap genetic interaction. Furthermore, we showed that the Merlin and Lap proteins colocalized at the cortex of the wing imaginal disc cells.

Co-ordination of proliferation and differentiation in cells committed to muscle fate requires the interaction of the retinoblastoma gene product (pRb) with transcription factors of the E2F family. pRb has different affinities for distinct E2Fs, however, the mechanism involved in pRb-E2Fs interaction has not been completely investigated. We have found that pRb carrying a small deletion at the end of the T antigen binding region (deltaS/N), and unable to interact with large T antigen, could induce acute cell cycle block, stable prolongation of the cell cycle in G0/G1 and G2/M phases and suppression of the growth of tumor cells. The deltaS/N showed increased affinity for E2F4, bound hyperphosphorylated forms of E2F4 and induced its nuclear compartmentalization. The ability of deltaS/N to form complexes with E2F4 on DNA was associated with an increase in formation of "free" E2F4 and transsuppression of the specific reporter through preferential binding to E2F4 but not t o E2F1. Stable expression of deltaS/N in multi-potent fibroblasts promoted early muscle commitment. The results obtained suggest that a mutation in the T antigen binding region may increase in affinity of the pRb for E2F4 combined with activation of muscle differentiation.

A search for the genes interacting with the Merlin tumor suppressor gene revealed a Merlin-porcupine interaction during wing morphogenesis. Ectopic expression of the porcupine gene in the wing imaginal disk reduced the adult wing, while addition of an UAS construct with a full-length or truncated copy of the Merlin gene partly restored the wing phenotype. The highest restoration level was observed upon adding the fragments coding for the C end of the Merlin protein. In addition, the porcupine gene was shown to mediate the wingless gene autoregulation, which occurs at two ontogenetic stages, segmentation during embryo development and determination of the wg expression band at the boundary between the dorsal and ventral compartments of the wing imaginal disk.