Systematic Studies into the Area Selectivity of Chemical Vapor Deposition Polymerization.

As the current top-down microchip manufacturing processes approach their resolution limits, there is a need for alternative patterning technologies that offer high feature densities and edge fidelity with single-digit nanometer resolution. To address this challenge, bottom-up processes have been considered, but they typically require sophisticated masking and alignment schemes and/or face materials' compatibility issues. In this work, we report a systematic study into the impact of thermodynamic processes on the area selectivity of chemical vapor deposition (CVD) polymerization of functional [2.2]paracyclophanes (PCP). Adhesion mapping of preclosure CVD films by atomic force microscopy (AFM) provided a detailed understanding of the geometric features of the polymer islands that form under different deposition conditions. Our results suggest a correlation between interfacial transport processes, including adsorption, diffusion, and desorption, and thermodynamic control parameters, such as substrate temperature and working pressure. This work culminates in a kinetic model that predictes both area-selective and nonselective CVD parameters for the same polymer/substrate ensemble (PPX-C + Cu). While limited to a focused subset of CVD polymers and substrates, this work provides an improved mechanistic understanding of area-selective CVD polymerization and highlights the potential for thermodynamic control in tuning area selectivity.

Pre-medication with Gabapentin is associated with significant reductions in nausea and vomiting after shoulder arthroscopy: A meta-analysis.

INTRODUCTION: Arthroscopic shoulder surgery is increasingly performed as a day case procedure. Nausea, vomiting and inadequate pain control are the most frequent reasons for reattendance or failed discharge. Gabapentin is advocated as an adjunct to mitigate these symptoms and its use in shoulder arthroscopy may provide improved post-operative symptom control. The aim of this study was to perform a meta-analysis of studies evaluating the role of gabapentin in the peri-operative management of shoulder arthroscopy. HYPOTHESIS: Gabapentin is associated with significant improvements in post-operative nausea, vomiting and pain control after shoulder arthroscopy. MATERIAL AND METHODS: A systematic review using Medline was conducted in accordance with the PRISMA guidelines. Randomised controlled trials studies reporting on patients >15 years old receiving either preoperative gabapentin or placebo before any shoulder arthroscopic surgery were considered for eligibility. Studies were appraised against the Consolidated Standards of Reporting Trials (CONSORT) checklist. A meta-analysis was performed using Review Manager 5.3. RESULTS: Four randomized controlled trials were identified for inclusion (n=227). Meta-analysis demonstrated a beneficial effect of gabapentin in preventing nausea and vomiting in the postoperative period (Odds Ratio 0.30, p=0.04). However, pooled data analysis did not show significant advantage in using gabapentin for postoperative pain control (p=0.11), although one study demonstrated a significant reduction in opioid consumption after gabapentin. No significant difference was reported in post-operative dizziness or sedation between the groups. DISCUSSION: Gabapentin did not show any significant benefit in postoperative pain control but is associated with significant reductions in post-operative nausea and vomiting after shoulder arthroscopy. LEVEL OF EVIDENCE: I, meta-analysis.