The pseudoknot structure of a viral RNA reveals a conserved mechanism for programmed exoribonuclease resistance.

Exoribonuclease-resistant RNAs (xrRNAs) are viral RNA structures that block degradation by cellular 5'-3' exoribonucleases to produce subgenomic viral RNAs during infection. Initially discovered in flaviviruses, xrRNAs have since been identified in wide range of RNA viruses, including those that infect plants. High sequence variability among viral xrRNAs raises questions about the shared molecular features that characterize this functional RNA class.

Adaptive Significance of Non-coding RNAs: Insights from Cancer Biology.

The molecular basis of adaptive evolution and cancer progression are both complex processes that share many striking similarities. The potential adaptive significance of environmentally-induced epigenetic changes is currently an area of great interest in both evolutionary and cancer biology. In the field of cancer biology intense effort has been focused on the contribution of stress-induced non-coding RNAs (ncRNAs) in the activation of epigenetic changes associated with elevated mutation rates and the acquisition of environmentally adaptive traits.

Improved visualization of the inferior tympanic and mastoid canaliculi with photon counting detector CT.

Purpose: To compare the performance of the photon-counting detector (PCD)-CT versus a state-of-the-art energy-integrating detector (EID)-CT to identify segments of the inferior tympanic canaliculus (Jacobsons nerve) and the mastoid canaliculus (Arnolds nerve).

Materials & Methods: Patients were prospectively recruited to undergo temporal bone CT on both EID-CT (Siemens Somatom Force) and PCD-CT (Siemens NAEOTOM Alpha) scanners under an IRB-approved protocol. Three neuroradiologists reviewed cases by consensus comparing the ability to identify the proximal, mid, and distal segments of the inferior tympanic canaliculus/Jacobsons nerve and mastoid canaliculus/Arnolds nerve on each scanner using 5-point Likert scales (with 1 indicating EID is far superior to PCD, 3 indicating they are equivalent, and 5 indicating PCD is far superior to EID).

Sacroiliac Joint: Function, Pathology, Treatment, and Contribution to Outcomes in Spine and Hip Surgery.

➢ Low back pain has a lifetime incidence of up to 84% and represents the leading cause of disability in the United States; 10% to 38% of cases can be attributed to sacroiliac joint (SIJ) dysfunction as an important pain generator.➢ Physical examination of the SIJ, including >1 provocation test (due to their moderate sensitivity and specificity) and examination of adjacent joints (hip and lumbar spine) should be routinely performed in all patients presenting with low back, gluteal, and posterior hip pain.➢ Radiographic investigations including radiographs, computed tomography, and magnetic resonance imaging with protocols optimized for the visualization of the SIJs may facilitate the diagnosis of common pathologies.