Nine flex-fuel vehicles meeting Tier 1, light duty vehicle-low emission vehicle (LDV-LEV), light duty truck 2-LEV (LDT2-LEV), and Tier 2 emission standards were tested over hot-start and cold-start three-phase LA92 cycles for nonmethane organic gases, ethanol, acetaldehyde, formaldehyde, acetone, nitrous oxide, nitrogen oxides (NO(x)), carbon monoxide (CO), and carbon dioxide (CO(2)), as well as fuel economy. Emissions were measured immediately after refueling with E40. The vehicles had previously been adapted to either E10 or E76. An overall comparison of emissions and fuel economy behavior of vehicles running on E40 showed results generally consistent with adaptation to the blend after the length of the three-phase hot-start LA92 test procedure (1735 s, 11 miles). However, the single LDT2-LEV vehicle, a Dodge Caravan, continued to exhibit statistically significant differences in emissions for most pollutants when tested on E40 depending on whether the vehicle had been previously adapted to E10 or E76. The results were consistent with an overestimate of the amount of ethanol in the fuel when E40 was added immediately after the use of E76. Increasing ethanol concentration in fuel led to reductions in fuel economy, NO(x), CO, CO(2), and acetone emissions as well as increases in emissions of ethanol, acetaldehyde, and formaldehyde.

C oronavirus disease 2019 (COVID-19) has a 3.1% fatality rate and is spread primarily through droplets and contact. Anesthetists working in hospitals may perform procedures and provide care involving the respiratory system [eg, cardiopulmonary resuscitation (CPR), airway management, intubation, chest compression, and face mask ventilation], which increases their risk of viral infection and death. To help mitigate these adverse outcomes, the European Resuscitation Council has prioritized staff safety and recommends that personal protective equipment (PPE) is worn by rescuers performing CPR. The minimum PPE recommendation includes a respirator mask (FFP2 or N95 respirator mask if FFP3 is not available).While the N95 mask has met safety guidelines in the past, there are downsides to the N95 mask design: it is only 95% effective against aerosol particle penetration compared with the 99% of FFP3 masks, it does not have a face-tight seal, and the shape and movement may compromise its efficacy (a study found 61% of those wearing N95 masks failed at least one third of chest compression sessions, and 18% experienced mask failures). Value and cup-type N95 mask efficacy was especially low.Powered air-purifying respirators, while not being perfectly protective and though they are more cumbersome and time consuming to put on, are shown to be more protective than N95 masks while providing CPR.Health care workers should consider the risk and benefits of available PPE when approaching situations involving CPR for optimal safety.

Questions continue to be raised regarding the benefit of genetic assessment of embryos prior to transfer in IVF, specifically with regards to preimplantation genetic testing for aneuploidy (PGT-A). To evaluate and quantify these concerns, we appraised the most recent (2012–2019) randomized controlled trials on the topic. Only two of these six studies listed cumulative live birth rates per started cycle, with both eliciting a statistically non-significant result. This article describes the concern that a focus on results from the first embryo transfer compared to cumulative outcomes falsely construes PGT-A as having superior outcomes, whilst its true benefit is not confirmed, and it cannot actually improve the true pregnancy outcome of an embryo pool.

Highlights Low-grade blastocysts have traditionally received less focus.  Low-grade blastocysts have similar euploidy and pregnancy success rates.  Further research is required to stratify low-grade blastocysts.  We should quantify the low-grade blastocyst threshold and reassess their use.