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AbstractLet be the field of Laurent series over the finite field complete with respect to the degree valuation |·| and let Idenote the ring . It is known that there is a probability measure Pwith respect to the Haar measure on normalized by P(I) = 1. The aim of this work is to study some metric properties involving the sets of digits appeared in the Oppenheim continued fraction expansions of the Laurent series, using the measure P.

A child with Down syndrome, who had undergone uneventful ventricular septal defect repair one year earlier with a normal heart rate during routine follow-up, presented with recurrent seizure-like episodes that did not respond to antiepileptics. She was subsequently found to have complete heart block with significant bradycardia requiring permanent pacemaker insertion. This late and unusual presentation of complete heart block after ventricular septal defect repair is discussed. Prudence must be applied in the evaluation of children who have undergone surgical correction of congenital heart defects and presented with recurrent seizure-like episodes.

Gold based bulk metallic glass was synthesized at with different quenching rates. Au54Ag5Pd2Cu24.3Si14.7 alloy ingots were cast into wedge shape and cone shape samples. The critical casting thickness of this alloy composition was found to be 4 mm when cast in copper mold. Completely amorphous structure as found in sections thinner than 4 mm when considering a infinite copper plate geometry. In locations with slower cooling rates, there are small fractions of transformed nanocrystals. The transmission electron microscope (TEM) study of Au54Ag5Pd2Cu24.3Si14.7 solidified microstructure could offer snap shots of nucleation and growth of crystals from nanometer to micrometer length-scale as evolved with different cooling rates. The phase evolution was recorded by transmission electron microscope study, electron diffraction and metallography using scanning electron microscope. The specimens comprised of both fully amorphous solid and nanocomposites which were the combination of nano-crystals of controlled sizes in amorphous matrix. Vickers hardness values increased to 350-450 Hv, when compared to sub 100-150 Hv level of conventional 18-k gold alloys as cast. The study offers a revolutionary way to create ultrahigh strength bulk metals that comprise of large percentage of nano-crystals in amorphous matrix.

OBJECTIVE To explore the effect of Ki-67 and vascular endothelial growth factor A (VEGF-A) expression on the risks of advanced T category (T3,4) and positive lymph node involvement (N+) in oral and pharyngeal squamous cell carcinoma (SCC) compared with laryngeal SCC. DESIGN Immunohistochemical analysis of prospectively recruited patients. SETTING University-affiliated hospital. PATIENTS A total of 147 previously untreated patients with different stages of SCC in the oral cavity, pharynx, and larynx. MAIN OUTCOME MEASURES Relative risks of T3,4 tumor and N+, a risk ratio comparing risks under high vs low marker expression. RESULTS A significant association of Ki-67 and VEGF-A expression with tumor T category was observed for oral and pharyngeal SCC and for laryngeal SCC (P ≤ .006). Regarding nodal status, Ki-67 expression was a significant risk factor for N+ in all tumors (P ≤ .009), whereas VEGF-A expression was related to N+ in oral and pharyngeal SCC only (P < .03). Analytically, Ki-67 expression alone in oral and pharyngeal SCC was associated with a relative risk of N+ of 3.83 (95% confidence interval, 1.22-11.99; P = .009), and additional expression of VEGF-A raised the value to 6.12 (2.09-17.93; P < .001). Moreover, the combined expression of both markers was 3.25 times more effective in predicting N+ for T1,2 tumor compared with T3,4 tumor. CONCLUSIONS Proliferative status was a common risk factor for N+ in all of the tumors in this series. Exploitation of VEGF-A in lymph node metastasis in addition to proliferation by oral and pharyngeal SCC but not by laryngeal SCC explains the clinical aggressiveness of oral and pharyngeal SCC, especially the early lymphatic invasion. In the management of cervical lymph nodes, combined expression of Ki-67 and VEGF-A may help identify patients at risk for occult metastases. This study suggests anti–VEGF-A therapy, an additional intervention to the classic antiproliferative regimen, for preventing lymphatic progression of oral and pharyngeal SCC.Arch Otolaryngol Head Neck Surg. 2008;134(12):1305-0--

Subglottic tracheal stenosis is a common clinical entity. Management in severe cases is often problematic. Various techniques for tracheal replacement have been used with varying degrees of success. In this study we used cryopreserved, irradiated tracheal homografts, the use of which in human beings has not been reported previously. In a sterile setup, the tracheas were harvested from donor cadavers within 24 hours of death. The grafts were initially kept at 57°C for 20 minutes; they were then placed in a −70°C chamber for another 2 to 3 days or more and were irradiated to 25 kGy (2.5 million rad). Finally, the grafts were stored at −70°C until usage. Seven patients underwent the surgery, but only 4 are presented here. In the remaining 3 patients, the follow-up time was too short to be evaluated. Four patients, 2 male and 2 female (aged 2-40 years, mean 16 years), with severe subglottic tracheal stenosis underwent segmental tracheal graft reconstruction. Immunosuppressant medications were not given to any patient. Follow-up ranged from 18 to 20 months. Three patients successfully underwent decannulation, and 1 patient had local infection and dislodgment of the intraluminal stent with subsequent restenosis. The postoperative tracheal lumen appeared to be near normal, with histologic evidence of normal respiratory epithelium at the grafted site. In conclusion, cryopreserved, irradiated tracheal homograft transplantation is a valuable alternative for subglottic tracheal reconstruction.

This study was conducted to determine the effectiveness of fluorescence-guided biopsy in diagnosis of unknown primary cancers in the head and neck. Thirteen patients with biopsy-proven cervical node metastases were evaluated prospectively with laser-induced fluorescence (LIF) endoscopy in parallel to panendoscopy. Among the 13 positive sites suggested by LIF imaging, 5 were confirmed by histopathology as squamous cell carcinoma, 4 as dysplasia, 2 as inflammation, and 2 as normal. Panendoscopy with random biopsies located 2. The 2 cases of squamous cell carcinomas discovered conventionally were identified by histologic sections from ipsilateral tonsillectomy. In this series, the unknown primary cancers were localized by LIF imaging and conventional means at rates of 38.5% and 15.4%, respectively. The LIF imaging not only aided in revealing a greater proportion of occult primary cancers, but also helped in reducing the number of unnecessary biopsies. Fluorescence-guided biopsy diagnosis provides useful information for therapeutic planning with curative aim or for adequate palliation.

Laser-induced fluorescence tumor imaging exploits the difference in tissue autofluorescence properties between normal and cancerous tissues. The effectiveness and reliability of fluorescence imaging with a lung imaging fluorescence endoscopy (LIFE) system for cancers in the head and neck were compared to those of white light endoscopy (WLE). Examinations by WLE and LIFE were conducted on 25 patients suspected for malignancy. Histologic diagnosis was confirmed by biopsy. Posttreatment evaluations were performed on 6 cancer patients identified by this study. By LIFE, all 16 cancerous lesions, including 2 occult cancers, were identified (100%), while WLE achieved only an 87.5% detection rate. LIFE (specificity 87.5%) was greatly helpful to WLE (specificity 50%) in differentiating inflammation from malignancy, though it failed to exclude granuloma. The results of this study suggest potential roles of LIFE in early detection, correct staging, and treatment evaluation of cancers in the head and neck.