Electron-lattice energy relaxation in laser-excited thin-film Au-insulator heterostructures studied by ultrafast MeV electron diffraction.

We apply time-resolved MeV electron diffraction to study the electron-lattice energy relaxation in thin film Au-insulator heterostructures. Through precise measurements of the transient Debye-Waller-factor, the mean-square atomic displacement is directly determined, which allows to quantitatively follow the temporal evolution of the lattice temperature after short pulse laser excitation. Data obtained over an extended range of laser fluences reveal an increased relaxation rate when the film thickness is reduced or the Au-film is capped with an additional insulator top-layer. This behavior is attributed to a cross-interfacial coupling of excited electrons in the Au film to phonons in the adjacent insulator layer(s). Analysis of the data using the two-temperature-model taking explicitly into account the additional energy loss at the interface(s) allows to deduce the relative strength of the two relaxation channels.

The prevalence of pterygium in Alkhobar: A hospital-based study.

OBJECTIVE: To analyze the epidemiology of pterygium in a hospital-based population in Alkhobar, which is located in the eastern province of Saudi Arabia. MATERIALS AND METHODS: This was a retrospective, non-randomized, and consecutive case study. Out of 88,666 patients who were seen in the ophthalmology clinic between January 1995 through the end of December 2010, 116 patients were diagnosed with advanced pterygium. The medical records of these patients were evaluated. RESULTS: The overall prevalence of pterygium was found to be 0.074%. There was no significant difference by either gender, side, or by laterality (P > 0.05). A significant increase was noticed in the prevalence of pterygium with increasing age and nasal location (P < 0.05). CONCLUSION: The overall prevalence rate of pterygium in Alkhobar is low when compared with results reported from other areas of the world.

Myxomas and angiomyxomas of the orbit: a clinicopathologic study of 6 cases.

PURPOSE: To report clinical and histopathologic features and biologic behavior of orbital myxomas and angiomyxomas. DESIGN: Noncomparative retrospective case series. PARTICIPANTS: Patients with histopathologic diagnoses of orbital myxoma or angiomyxoma. METHODS: Clinical metadata and features were obtained from the medical record. Neoplasms were studied by routine histopathology, special stains, and immunohistochemistry. MAIN OUTCOME MEASURES: Final diagnosis, based on histopathology, special stains, and immunohistochemistry, and clinical course from analysis of metadata and clinical features. RESULTS: Three myxomas and 3 angiomyxomas were identified in 5 males and 1 female. Median age at presentation was 56 years (range, 4-69), with a follow-up ranging from 6 months to 8 years. Two angiomyxomas occurred in children ages 4 and 7 years whose tumors were locally aggressive and recurred. Recurrence also complicated one case of myxoma after incomplete excision. Pathologically, the tumors were poorly circumscribed. Histopathology showed them to be hypocellular, containing stellate and spindled cells in an abundant, loose, myxoid stroma rich in hyaluronic acid. Small blood vessels were rare in myxomas but abundant in angiomyxomas. Tumor cells were frequently immunoreactive for vimentin, CD34, and factor XIIIa. CONCLUSIONS: Myxomas rarely involve orbital tissue, and no angiomyxomas of the region have been previously reported. Angiomyxomas in children may be aggressive. Vascularity and bone involvement appear to be important prognostic features for recurrence. Complete resection with a margin of healthy tissue appears to be the treatment of choice. Tumor cell immunopositivity for vimentin, CD34, and factor XIIIa may assist in the histopathologic diagnosis.

Does metal coating improve the durability of silicone voice prostheses?

Voice prostheses, which are used for voice rehabilitation in cancer patients after laryngectomy, usually become colonized with a mixed biofilm of bacteria and Candida after 2-4 months and lose their efficiency. It is essential to ensure the stability and biocompatibility of these implants. With the aid of surface frame analysis we have shown that local antifungal treatment is inadequate for eliminating the deep infiltration and encapsulation of Candida colonies in silicone. A surface that prevents the adhesion of microorganisms is required. Because of its special properties there are few methods available for coating silicone. We employed, for the first time, a new method of surface modification using anodic vacuum arc coating. Using this method it was possible to obtain a solid film of gold or titanium metal with a layer thickness < 100 nm. Resistance against Candida colonization and destruction of coated prostheses were tested both in vitro and in vivo. A titanium coating seemed to provide the optimal solution to the problem, because surface adhesion and the smoothness of the material appeared to be superior to those of a gold coating.

Inadvertent Swan-Ganz catheter placement in the left pericardiophrenic vein.

Placement of flow-directed Swan-Ganz catheters without fluoroscopic guidance occasionally results in placement in positions other than the pulmonary artery. In the case presented, the inadvertent placement of such a catheter into the left pericardiophrenic vein was probably facilitated by distortion of the right heart and systemic venous anatomy.

Nonbacterial thrombotic endocarditis associated with bone marrow transplantation.

Two patients were treated with bone marrow transplantation and subsequently developed nonbacterial thrombotic endocarditis (NBTE). Both patients died of embolic sequellae and in neither was NBTE suspected antefinem. It is clear that NBTE occurs with increased frequency in bone marrow transplant (BMT) recipients and through arterial embolization contributes significantly to the morbidity and mortality of this procedure. In those at greatest risk, including BMT recipients, detection of disseminated intravascular coagulation; soft, changing systolic cardiac murmurs; hematuria; and signs of central embolic events suggest the diagnosis of NBTE. Awareness of the diagnosis of NBTE is essential for those who must interpret neurologic, myocardial and renal abnormalities in BMT recipients.