An in vitro comparison of apical microleakage after obturation with JS Quick-Fill or lateral condensation

In order to investigate the blood supply of osteo-periosteal flap of lateral inferior part of tibia, 40 lower limbs of adult cadavers were observed. The result showed that the superior malleolar branch was the biggest branch on the lateral inferior part of tibia and served as the main blood supply to the above area. It originated from the anterior tibial artery, 3.1 +/- 0.8 cm above the intermalleolar line. During its way to the anterior border of the tibia, it gave out the ascending and descending branches. The ascending branch was along the anterior border upward and anastomosed with the musculo-periosteol branch of the anterior tibial artery at the level of 6.3 +/- 1.3 cm above the intermalleolar line. The decending branch was anastomosed with the anterior medial malleolar artery. For the anastomosis between the superior malleolar branch with the peripheral vessels, the osteo-periosteol flap could be designed at the lateral side of the lower part of tibia in size of 8-10 cm x 4-6 cm. This was a new donor area of osteo-periosteol flap for repair of non-union of bone in lower end of tibia or arthrodesis of the ankle joint.     

A novel mechanism-based mammalian cell assay for the identification of SH2-domain-specific protein-protein inhibitors

BACKGROUND: Many intracellular signal-transduction pathways are regulated by specific protein-protein interactions. These interactions are mediated by structural domains within signaling proteins that modulate a protein's cellular location, stability or activity. For example, Src-homology 2 (SH2) domains mediate protein-protein interactions through short contiguous amino acid motifs containing phosphotyrosine. As SH2 domains have been recognized as key regulatory molecules in a variety of cellular processes, they have become attractive drug targets. RESULTS: We have developed a novel mechanism-based cellular assay to monitor specific SH2-domain-dependent protein-protein interactions. The assay is based on a two-hybrid system adapted to function in mammalian cells where the SH2 domain ligand is phosphorylated, and binding to a specific SH2 domain can be induced and easily monitored. As examples, we have generated a series of mammalian cell lines that can be used to monitor SH2-domain-dependent activity of the signaling proteins ZAP-70 and Src. We are utilizing these cell lines to screen for immunosuppressive and anti-osteoclastic compounds, respectively, and demonstrate here the utility of this system for the identification of small-molecule, cell-permeant SH2 domain inhibitors. CONCLUSIONS: A mechanism-based mammalian cell assay has been developed to identify inhibitors of SH2-domain-dependent protein-protein interactions. Mechanism-based assays similar to that described here might have general use as screens for cell-permeant, nontoxic inhibitors of protein-protein interactions.     

MEMS integrated submount alignment for optoelectronics

One of the most expensive and time-consuming production processes for single-mode fiber-optic components is the alignment of the photonic chip or waveguide to the fiber. The alignment equipment is capital intensive and usually requires trained technicians to achieve desired results. Current technology requires active alignment since tolerances are only /spl sim/0.2/spl mu/m or less for a typical laser diode. This is accomplished using piezoelectric actuated stages and active optical feedback. Joining technologies such as soldering, epoxy bonding, or laser welding may contribute significant postbond shift, and final coupling efficiencies are often less than 80%. This paper presents a method of adaptive optical alignment to freeze in place directly on an optical submount using a microelectromechanical system (MEMS) shape memory alloy (SMA) actuation technology. Postbond shift is eliminated since the phase change is the alignment actuation. This technology is not limited to optical alignment but can be applied to a variety of MEMS actuations, including nano-actuation and nano-alignment for biomedical applications. Experimental proof-of-concept results are discussed, and a simple analytical model is proposed to predict the stress strain behavior of the optical submount. Optical coupling efficiencies and alignment times are compared with traditional processes. The feasibility of this technique in high-volume production is discussed.     

Trapezoid dislocation with a Galeazzi fracture

Significant airway stenosis occurs in 7% to 14% of lung transplant recipients. The use of permanent, nonadjustable, wire mesh stents can be of concern in the transplant recipient with nonmalignant stricture. We report the replacement and repositioning of an expandable wire mesh stent in a double lung transplantation with distal bronchial stenosis.     

A fluorescent extension to the Kubelka–Munk model

Traditionally, single constant Kubelka–Munk‐type colorant formulation algorithms have been used for color control in the paper industry. One of the limitations of the Kubelka–Munk approaches is that they neglect fluorescence phenomena and the interdependence of absorption and scattering. In this article, an extended phenomenologic model is derived, incorporating fluorescence and interdependence of absorption and scattering. This model predicts illuminator‐independent radiance transfer factors based on dye‐on‐fiber, from which the total radiance factor responses under arbitrary illumination can be computed. Illuminator‐independent responses to changes in colorant concentration can also be modeled, allowing control of illuminator metamerism in coloring processes with fluorescent colorants. This method requires spectrofluorimetric (two‐monochromator method) measurements to characterize the coloring process. © 2002 Wiley Periodicals, Inc. Col Res Appl, 28, 4–14, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.     

Surface ultrastructure of human dermis and wounds

BACKGROUND: Intermediate uveitis is characterized by vitreal inflammation with associated inflammation of the vitreous base and peripheral anterior retina and choroid. It may be found as an isolated and idiopathic condition or in association with systemic disorders such as multiple sclerosis and sarcoidosis. OBJECTIVE: To identify the clinical features of intermediate uveitis and assess its association with systemic diseases. METHODS: Retrospective study of 83 patients presenting with intermediate uveitis between 1970 and 1991. RESULTS: Evidence of systemic disorders was found in 26 of 83 patients (31.3%). Of these 26 patients, 10 had presumed sarcoidosis, 6 had multiple sclerosis, 2 had isolated optic neuritis, 2 had inflammatory bowel disease, 4 had isolated thyroid abnormalities, and 2 had histories suggestive of Epstein-Barr virus infection. Associated ocular findings included cystoid macular edema, peripheral retinal perivascular sheathing, cataracts, posterior vitreous detachment, fine keratic precipitates, preretinal macular fibrosis, retinal tears, retinal detachment, and optic disc edema. CONCLUSIONS: Patients with intermediate uveitis may have associated systemic diseases and should have careful follow-up with regular systemic evaluation.     

Low insertion loss and low dispersion penalty InGaAsP quantum-well high-speed electroabsorption modulator for 40-Gb/s very-short-reach, long-reach, and long-haul applications

We present a metal-organic-chemical-vapor-deposition-grown low-optical-insertion-loss InGaAsP/InP multiple-quantum-well electroabsorption modulator (EAM), suitable for both nonreturn-to-zero (NRZ) and return-to-zero (RZ) applications. The EAM exhibits a dynamic (RF) extinction ratio of 11.5 dB at 1550 nm for 3 Vp-p drive under 40-Gb/s modulation. The optical insertion loss of the modulator in the on-state is -5.2 dB at 1550 nm. In addition, the EAM also exhibits a 3-dB small-signal response (S21) of greater than 38 GHz, allowing it to be used in both 40-Gb/s NRZ and 10-Gb/s RZ applications. The dispersion penalty at 40 Gb/s is measured to be 1.2 dB over /spl plusmn/40 ps/nm of chromatic dispersion. Finally, we demonstrate 40-Gb/s transmission performance over 85 km and 700 km.     

Effect of flecainide on atrial and ventricular refractoriness and conduction in patients with normal left ventricle. Implications for possible antiarrhythmic and proarrhythmic mechanisms

We studied the effects of intravenous flecainide (2 mg.kg-1) on atrial and ventricular refractoriness and conduction during sinus rhythm, induced atrial fibrillation and atrial pacing at rates of 100, 120 and 150 ppm, in 14 patients with normal left ventricle. Flecainide caused a significant increase in QRS duration during sinus rhythm (mean +/- SD: 87.2 +/- 8.4 ms vs 102.8 +/- 9.1 ms, P < 0.001), atrial fibrillation (87.8 +/- 10.0 ms vs 108.8 +/- 13.7 ms, P < 0.001) and at all paced rates. The duration of the atrial electrogram was significantly increased during sinus rhythm (54.9 +/- 13.2 ms vs 64.8 +/- 16.6 ms, P = 0.003) and at all pacing rates. The PA interval was also significantly prolonged, as was the pacing stimulus-to-atrial-electrogram interval at all pacing rates. There was increased QRS duration and atrial electrogram prolongation at higher pacing rates. Atrial refractoriness was prolonged during sinus rhythm (216.4 +/- 28.2 vs 228.6 +/- 36.1, P = 0.02), but not during atrial pacing at any rate. The QT interval, but not the JT interval or ventricular refractoriness, was significantly prolonged during sinus rhythm and at all pacing rates. Flecainide slows atrial conduction in a use dependent manner and increases atrial refractoriness during sinus rhythm but not during faster atrial pacing, thus not displaying a use-dependent effect. QRS duration is prolonged in a use-dependent manner without a commensurate increase in ventricular refractoriness. In the presence of rapidly conducted atrial fibrillation, which was not found to be slowed by flecainide, this effect may constitute a proarrhythmic mechanism even in patients with no apparent myocardial abnormality.