Background
Craniopharyngiomas are benign sellar lesions. Surgical excision of craniopharyngiomas is difficult because of the surrounding important neurovascular structures. The choice of surgery ...depends on the histological type, location, hormonal status, and size of the craniopharyngioma, surrounding neurovascular structures, and invasion of the brain parenchyma.
Methods
We describe the resection of an adamantinomatous craniopharyngioma using an extended endoscopic endonasal approach and discuss the relevant surgical anatomy, indications, limitations, and possible complications.
Conclusions
The extended endoscopic endonasal approach allows successful removal of the craniopharyngioma and poses little risk to surrounding neurovascular structures.
Decreasing transistor feature size has led to an increase in the number of transistors in integrated circuits (IC), allowing for the implementation of more complex logic. However, such logic also ...requires more complex clock tree synthesis (CTS) to avoid timing violations as the clock must reach many more gates over larger areas. Thus, timing analysis requires significantly more computing power and designer involvement than in the past. For these reasons, IC designers have been pushed to nix conventional synchronous (SYNC) architecture and explore novel methodologies such as asynchronous, self-timed architecture.This dissertation evaluates the nominal active energy, voltage-scaled active energy, and leakage power dissipation across two cores of a stream processor: Smoothing Filter (SF) and Histogram Equalization (HEQ). Both cores were implemented in Multi-Threshold NULL Convention Logic (MTNCL) and clock-gated synchronous methodologies using a gate-level netlist to avoid any architectural discrepancies while guaranteeing impartial comparisons.MTNCL designs consumed more active energy than their synchronous counterparts due to the dual-rail encoding system; however, high-threshold-voltage (High-Vt) transistors used in MTNCL threshold gates reduced leakage power dissipation by up to 227%. During voltage-scaling simulations, MTNCL circuits showed a high level of robustness as the output results were logically valid across all voltage sweeps without any additional circuitry. SYNC circuits, however, needed extra logic, such as a DVS controller, to adjust the circuit’s speed when VDD changed. Although SYNC circuits still consumed less average energy, MTNCL circuit power gains accelerated when switching to lower voltage domains.
Abstract
Chordomas are rare tumors of the axial skeleton that are refractory to conventional therapy. Few studies have compared the morphological and molecular characteristics of chordomas according ...to the skull base and sacral locations. Histopathological data and changes revealed by array comparative genomic hybridization (CGH) and next-generation sequencing (NGS) of cell cycle regulation genes were analyzed for 28 skull base (SBCs) and 15 sacral (SC) chordomas. All cases were conventional chordomas. SBCs were significantly more frequent in patients aged <40 years and SCs predominated in patients aged >60 years. Mitotic indices ≥2 mitoses/10 high-power fields were correlated with high degrees of nuclear atypia and Ki67 labeling indices ≥6%. We identified 321 genomic positions, and copy number variation losses were more frequent than gain. Moreover, we report a panel of 85 genetic variants of cell cycle genes and the presence of molecular clusters for chordoma as well in CGH as in NGS. These new data strengthen the view that the chordoma should not be considered as a single molecular entity.
Asynchronous circuits in general offer better voltage scalability compared to their synchronous counterparts due to the lack of clock and flexible timing requirement. NULL Convention Logic (NCL), a ...quasi-delay-insensitive asynchronous paradigm, is comprised of threshold gates as fundamental logic building components. The structure of these gates directly impacts performance and power aspects of the entire circuit. This paper introduces an alternative design methodology for NCL gates called logic transformation (LT) for supporting low operating voltages. Representative NCL gates and NCL components are implemented and presented to compare their performance. The results and analysis can be used by designers for selecting the most appropriate design for their specific applications.
