Plasmon-plasmon interaction: controlling light at nanoscale

This paper investigates the effect of the locally induced bulk plasmon resonance on light guiding of a plasma-like medium. It is demonstrated that, by inducing or suppressing the bulk plasmon resonance, one can manipulate the light propagation. This concept is then employed for a hybrid dielectric-loaded plasmonic waveguide with the aim to efficiently control the surface plasmon polaritons with a highly doped silicon as an active material. The proposed approach is shown to have a high potential for nanoscale light manipulation and development of a fully CMOS-compatible electro-optical plasmonic modulator.

Open-type congenital cholesteatoma: differential diagnosis for conductive hearing loss with a normal tympanic membrane

CONCLUSION

In patients with progressive conductive hearing loss and a normal tympanic membrane (TM), and with soft tissue density in the middle ear cavity (MEC) on temporal bone computed tomography (TBCT) scan, open-type congenital cholesteatoma (OCC) should be highly suspected and a proper surgical plan that includes mastoid exploration and second-stage operation is required.

OBJECTIVE

The clinical presentation of OCC is very similar to congenital ossicular anomaly (COA) presenting with a conductive hearing loss with intact TM. Therefore, it is challenging to make a correct preoperative diagnosis in patients with OCC. We evaluated the clinical characteristics of OCC compared with those of COA to find diagnostic clues useful in diagnosis of OCC.

METHODS

The medical records of 12 patients with surgically proven OCC and 14 patients with surgically proven COA were reviewed for demographic data, otologic history, preoperative TBCT findings, intraoperative findings, and pre- and postoperative audiologic data.

RESULTS

There was no difference between OCC and COA based on demographic data, preoperative hearing, and ossicular status on TBCT. However, the presence of progressive hearing loss, soft tissue density in the MEC on TBCT scan, and the need for mastoid surgery and second-stage operation were significantly more frequent in OCC patients.

Highly sensitive graphene biosensors based on surface plasmon resonance

A surface plasmon resonance (SPR) based graphene biosensor is presented. It consists of a graphene sheet coated above a gold thin film, which has been proposed and experimentally fabricated recently [ChemPhysChem 11, 585 (2010)]. The biosensor uses attenuated total reflection (ATR) method to detect the refractive index change near the sensor surface, which is due to the adsorption of biomolecules. Our calculations show that the proposed graphene-on-gold SPR biosensor (with L graphene layers) is (1 + 0.025 L) x gamma (where gamma > 1) times more sensitive than the conventional gold thin film SPR biosensor. The improved sensitivity is due to increased adsorption of biomolecules on graphene (represented by the factor gamma) and the optical property of graphene.

Up-regulation of MUC5AC and MUC5B mucin genes in chronic rhinosinusitis

BACKGROUND

Excess mucus production and hypersecretion characterize upper airway diseases. The primary mechanisms leading to mucus hypersecretion in chronic rhinosinus inflammation are not well understood. Mucus hypersecretion is commonly accompanied by goblet cell and submucosal gland cell hyperplasia. It is important to identify which mucin gene messenger RNAs (mRNAs) are expressed in the sinus mucosa.

OBJECTIVES

To investigate the expression of MUC5AC and MUC5B mRNAs and localization of these proteins in human sinus mucosa and to compare the expression of MUC5AC and MUC5B mRNAs in normal and in chronic sinus mucosa.

DESIGN

Twenty chronic maxillary sinusitis mucosa samples and 20 normal maxillary sinus mucosa samples were obtained; RNAs were extracted from sinus mucosa, and semiquantitative reverse transcription-polymerase chain reaction was performed for MUC5AC and MUC5B. Localization of these proteins was sought by using immunohistochemical analysis.

RESULTS

The levels of MUC5AC and MUC5B mRNA in chronic rhinosinusitis were significantly increased compared with those in normal sinus mucosa (P =.02). In inflammed sinus mucosa, MUC5AC protein was expressed in the cytoplasm of the goblet cell in the surface epithelium, and MUC5B expression was restricted to mucous cells of the submucosal glands and to the epithelium of sinus mucosa. However, in the normal sinus mucosa, MUC5AC and MUC5B proteins were expressed at low levels in the sinus epithelium and submucosal glands, respectively.

CONCLUSION

These results suggest that up-regulation of MUC5AC and MUC5B, which are major components of respiratory secretion in chronic rhinosinusitis, may play important roles in the pathogenesis of sinus hypersecretion in chronic rhinosinusitis.

Tumor implantation along abdominal trocar site after pelviscopic removal of malignant ovarian tumor--a case report

The application of pelviscopic surgery for the management of ovarian tumors has increased dramatically in the last few years. Of particular concern is the pelviscopic excision of malignant ovarian tumors. One of the important potential problems with this approach is disseminating malignant cells to peritoneal surface. The aim of this report is to draw attention to the possibility of the occurrence of a tumor implantation at the pelviscopic port site in patients with malignant ovarian tumors. A case is presented here in which a localized tumor implant occurred in the abdominal trocar site after pelviscopic removal of ovarian mass subsequently found to be squamous cell carcinoma arising in mature cystic teratoma with brief review of literatures.

Inhibition of nucleoside transport in murine lymphoma L5178Y cells and human erythrocytes by the uridine phosphorylase inhibitors 5-benzylacyclouridine and 5-benzyloxybenzylacyclouridine

The uridine phosphorylase inhibitors, 5-benzylacyclouridine (BAU) and 5-benzyloxybenzylacyclouridine (BBAU) (Biochem. Pharmacol., 31: 1857, 1982), inhibited uptake of uridine in L5178Y cells. By a rapid sampling technique, BAU and BBAU were shown to inhibit the transport (zero-trans influx) of uridine, thymidine, and adenosine in human erythrocytes as well as in murine L5178Y cells. In all cases, competitive inhibitions were observed. Km values for the transport of adenosine, uridine, and thymidine in erythrocytes were 2.2, 195, and 199 microM, while Vmax were 2.9, 118, and 96.5 pmol/min/10(6) cells, respectively. In L5178Y cells, Km values of 14.8 and 23.1 microM and Vmax of 389 and 176 pmol/min/10(6) cells were obtained for adenosine and uridine, respectively. For erythrocytes, the Ki values of BAU were 127, 124, and 198 microM using adenosine, uridine, and thymidine as the substrate; and those of BBAU, 14.1 and 19.2 microM for adenosine and uridine, respectively. In L5178Y, the Ki values of BAU were 202 and 234 microM, and those of BBAU, 39.8 and 27.9 microM for adenosine and uridine, respectively. These data indicate that, in two cell types, Ki values for BAU and BBAU did not vary regardless of the substrate used; that the values of Ki are different for the erythrocytes and L5178Y cells; and that BBAU is at least 5-fold more potent than BAU as an inhibitor of nucleoside transport. The inhibitory effects on the efflux of preloaded uridine indicate that BAU and BBAU are inhibitors, rather than permeants, of the nucleoside transport system.