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Abstract: Compact layers are used in dye-sensitized solar cells (DSSCs) to passivate transparent conducting oxides (TCOs). TCO passivation increases DSSC performance by reducing electrical loss from recombination at the TCO-electrolyte interface and by improving electrical contact between the TCO and TiO2 photoelectrode. A novel process for synthesis of 4.5nm colloidal TiO2 compact layer particles via acid hydrolysis of titanium isopropoxide was developed. DSSCs fabricated with the colloidal TiO2 compact layer, with no compact layer, and those with an RF-sputtered compact layer were evaluated. Relative to a DSSC with no compact layer, the colloidal compact layer improved the short-circuit current density, fill factor, and solar energy conversion efficiency by 17.6%, 4.4%, and 25.3%, respectively. Relative to the sputtered compact layer, the colloidal compact layer improved the short-circuit current density and solar energy conversion efficiency by 5.5% and 5.3%, respectively, with no significant change in the fill factor. The improved DSSC characteristics were attributed to increased shunt resistance due to decreased electrolyte reduction at the TCO-electrolyte interface and decreased series resistance due to improved electrical contact between the TCO and the TiO2 photoelectrode. [Copyright &y& Elsevier]

We examined the morphosyntax of eight left hemispherectomized children at two different stages and compared it to MLU-matched normals. We found that the language of the hemispherectomies paralleled that of their MLU matches with respect to the specific morphosyntactic characteristics of each stage. Our findings provide strong evidence for the presence of functional categories in all early grammars and demonstrate that grammatical development, regardless of its neural substrate, is highly constrained by UG and follows a narrowly determined course. We discuss our findings within a neurobiological framework in which etiology defines the integrity of the remaining hemisphere, which in turn, determines its potential for linguistic reorganization and/or acquisition. [ABSTRACT FROM AUTHOR]

Abstract: Objective: In developing countries, tibial shaft fractures are frequently stabilised using Surgical Implant Generation Network (SIGN) nails. Despite widespread use throughout the world, little is known regarding their biomechanical properties. This study aimed to compare the mechanical stiffness of the SIGN tibial nail with a standard hollow tibial nail. Methods: A fracture gap model was created to simulate a comminuted mid-shaft tibia fracture (AO/OTA42-C3) using synthetic composite bones. The constructs were stabilised with either a 9mm solid SIGN nail or a 10mm hollow Russell–Taylor nail. Both nail systems were interlocked proximally and distally. Following fixation, the specimens were loaded in axial, torsional, and cyclical axial modes to calculate construct stiffness and irreversible (plastic) deformation. Results: The mean axial stiffness for the SIGN nail constructs was 47% higher than mean stiffness for the RT nail constructs (p <0.001). The difference in torsional stiffness was not statistically significant. However, the SIGN group demonstrated 159% more irreversible deformation than the Russell–Taylor group (p =0.006) for the loading parameters studied. Conclusion: The SIGN tibial nail, despite its slightly smaller diameter, can provide similar construct stiffness and stability, when compared to a larger hollow nail for stabilisation of tibial shaft fractures. [Copyright &y& Elsevier]

STUDY DESIGN: Quantitative gene expression analysis and immunohistochemistry were used to investigate the temporal and spatial expression of bone morphogenic proteins (BMPs) and BMP antagonists in a posterolateral spine fusion model in rabbits. OBJECTIVE: To identify the expression pattern of BMPs and BMP antagonists and to determine the molecular and histologic changes of the graft and surrounding tissue during fusion. SUMMARY OF BACKGROUND DATA: There are no studies on BMP antagonists during spinal fusion. Furthermore, the reciprocal interaction between bone grafts and surrounding tissue is still unknown in fusion. METHODS: Eighteen New Zealand White rabbits underwent bilateral posterolateral spine fusion with autogenous bone graft. Rabbits were killed at 1, 2, 4, or 6 weeks after arthrodesis. The spinal fusions were analyzed by radiography. On the right side, specimens were collected from the outer zone over the transverse processes, the inner zone between the transverse processes, muscle surrounding bone grafts, and the transverse process. Gene expression of BMP-2, BMP-4, and BMP-7, noggin, chordin, Sox9, and Runx2 were measured by real-time polymerase chain reaction at each time point of each sample. On the left side, molecules of interest were evaluated by immunohistochemistry on tissue sections. RESULTS: BMP-2, BMP-4, and BMP-7, noggin, and chordin were colocalized in rimming osteoblasts, osteoclasts, and chondrocytes. The outer zone demonstrated earlier bone maturation and faster increase in BMP gene expression than the inner zone. Muscle surrounding bone grafts showed significantly higher BMP expression and Runx2 activity at the early phase. BMP-positive cells were also noted around blood vessels. CONCLUSION: The colocalization and temporal relationship of BMPs and BMP antagonists suggests that BMP activity is tightly regulated by the antagonists during fusion. In addition, not only the decorticated transverse process, but also muscle surrounding bone grafts, is actively involved in osteogenesis during fusion. [ABSTRACT FROM AUTHOR]