Carbon molecular sieve (CMS) membranes are able to efficiently separate gases that have a small difference in molecular sizes. To withstand the large transmembrane pressures required to attain high gas flux, it is preferred to prepare CMS membranes as composite configurations using inorganic supports. This paper reports on the synthesis and properties of novel CMS membranes on mesoporous γ-alumina supports. Such supports allow coating of thin, high-quality polymer films and subsequent CMS membranes. Thin CMS membranes were obtained by pyrolysis of defect-free polymer/ceramic composite membranes in an oxygen-free inert gas environment. Compared to macroporous α-alumina supported membranes, both polymer and CMS membranes prepared on γ-alumina show better gas permeation and separation characteristics. A 1.6 μm thick CMS membrane on γ-alumina support offers a pure-gas ideal separation factor of 45 for He/N2 and 5.1 for O2/N2 . When tested with a 50/50 C3H6/C3H8 mixture, the CMS membrane shows a mixed-gas C3H6/C3H8 selectivity up to 36 with a C3H6 permeance of around 3 × 10–9 mol/Pa·s·m2 (9 gpu).
Objective: To evaluate the overall survival of patients with operable stage IA non-small-cell lung cancer (NSCLC) who undergo “early” SBRT (within 0–30 days after diagnosis) versus “delayed” surgery (90–120 days after diagnosis). Summary of Background Data: During the COVID-19 pandemic, national guidelines have recommended patients with operable stage IA NSCLC to consider delaying surgery by at least 3 months or, alternatively, to undergo SBRT without delay. It is unknown which strategy is associated with better short- and long-term outcomes. Methods: Multivariable Cox proportional hazards modeling and propensity score-matched analysis was used to compare the overall survival of patients with stage IA NSCLC in the National Cancer Data Base from 2004 to 2015 who underwent “early” SBRT (0–30 days after diagnosis) versus that of patients who underwent “delayed” wedge resection (90–120 days after diagnosis). Results: During the study period, 570 (55%) patients underwent early SBRT and 475 (45%) underwent delayed wedge resection. In multivariable analysis, delayed resection was associated with improved survival [adjusted hazard ratio 0.61; (95% confidence interval (CI): 0.50–0.76)]. Propensity-score matching was used to create 2 groups of 279 patients each who received early SBRT or delayed resection that were well-matched with regard to baseline characteristics. The 5-year survival associated with delayed resection was 53% (95% CI: 45%–61%) which was better than the 5-year survival associated with early SBRT (31% [95% CI: 24%–37%]). Conclusion: In this national analysis, for patients with stage IA NSCLC, extended delay of surgery was associated with improved survival when compared to early treatment with SBRT.
Background. A right-sided pneumonectomy after induction therapy for non-small cell lung cancer (NSCLC) has been shown to be associated with significant perioperative risk. We examined the effect of laterality on long-term survival after induction therapy and pneumonectomy using the National Cancer Data Base. Methods. Perioperative and long-term outcomes of patients who underwent pneumonectomy after induction chemotherapy, with or without radiotherapy, from 2004 to 2014 in the National Cancer Data Base were evaluated using multivariable Cox proportional hazards modeling and propensity score-matched analysis. Results. During the study period, 1,465 patients (right, 693 [47.3%]; left, 772 [52.7%]) met inclusion criteria. Right-sided pneumonectomy was associated with significantly higher 30-day (8.2% [57 of 693] vs 4.2% [32 of 772], p < 0.01) and 90-day mortality (13.6% [94 of 693] vs 7.9% [61 of 772], p < 0.01), and right-sided pneumonectomy was a predictor of higher 90-day mortality (odds ratio, 2.23; p < 0.01). However, overall 5-year survival between right and left pneumonectomy was not significantly different in unadjusted (37.6% [95% confidence interval {CI}, 0.34 to 0.42] vs 35% [95% CI, 0.32 to 0.39], log-rank p [ 0.94) or multivariable analysis (hazard ratio, 1.07; 95% CI, 0.92 to 1.25; p [ 0.40). A propensity score-matched analysis of 810 patients found no significant differences in 5-year survival between the right-sided versus left-sided groups (34.7% [95% CI, 0.30 to 0.40] vs 34.1%, [95% CI, 0.29 to 0.39], log-rank p [ 0.86). Conclusions. In this national analysis, right-sided pneumonectomy after induction therapy was associated with a significantly higher perioperative but not worse long-term mortality compared to a left-sided procedure.
The coronavirus disease 2019 (COVID-19) pandemic has led to a significant shortage of personal protective equipment in multiple health care facilities around the world, with the highest impact on N95 respirator masks. The N95 respirator is a mask that blocks at least 95% of very small (0.3 μm) particles and is considered a standard for enhanced respiratory precautions. The N95 mask shortage has created a need for other options for nasal and oral respiratory protection with similar filtration efficiency and “medical-grade” clearance, which can be used in health care settings. However, the literature around various filter types, their filtration capabilities, and the organizations certifying their use is dense, confusing, and not easily accessible to the public. Here, we synthesize relevant literature to analyze and disseminate information on (1) alternative viable filter options to N95s, (2) the National Institute for Occupational Safety and Health certification process, (3) the relationship of National Institute for Occupational Safety and Health certification to Food and Drug Administration certification of filtration devices and surgical masks, and (4) how this relationship may affect future filtration usage in the medical community during a pandemic. Analysis of these standards is meant to inform regarding evidence of respirator efficacy but does not imply any official endorsement of these alternatives. With this article, we illuminate viable alternative respirator options during the COVID-19 pandemic to help alleviate the dependency on N95 face masks.
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