An Environmental Dilemma for China During the COVID-19 Pandemic: The Explosion of Disposable Plastic Wastes

Plastic pollution control has been on top of the political agenda in China. In January 2020, China announced a phased ban on the production and usage of various types of single-use plastics as a solution to environmental pollution problems. However, the outbreak of COVID-19 seems to be a new obstacle to the ban on single-use plastic products. To basically satisfied the daily necessities and contain the spread of SARS-CoV-2 under the background of the regular epidemic prevention and control in China, online ordering, contactless delivery and wearing mask have become an important and feasible way of daily life. However, the unrestrained use of disposable plastic bags, lunch boxes and masks within the nationwide quarantine leads to hundreds of millions of plastics wastes every day. The potential environmental pollution caused by the use of disposable plastic products during the pandemic should arouse social concern. The Chinese government should manage environmental protection in parallel with anti-pandemic endeavors as the situation of the pandemic evolves.

     

A universally applicable mask attachment for fiberoptic intubation. The Mainz Universal Adapter

The problems associated with "difficult airways" have almost subsided since the introduction of flexible fiberoptic bronchoscopes for tracheal intubation. Limitations of this technique persist with uncooperative patients, children and infants. We describe an universally applicable connector for fiberoptic intubation during mask ventilation, which fits all masks with a 22-mm connector, including the Rendell-Baker-Soucek type. This technique is of utmost value when a "difficult airway" is encountered only subsequent to induction of anesthesia, especially if nondepolarizing muscle relaxants have been administered. The device makes intubation possible with all sizes of fiberoptic bronchoscopes. The prerequisites for application of this technique include an airway that will be maintained by mask ventilation.     

"Could it be asthma?": the impact of a mass media campaign aimed at raising awareness about asthma in Australia

Asthma is a very common chronic illness in Australia; however,unrecognized and undertreated asthma is responsible for muchpreventable morbidity in the community. In 1988, a coalitionof private and public sector agencies was formed to conducta national mass communications program aimed at increasing awarenessabout asthma. This pilot campaign comprised a mailout to allprimary care physicians and a mass media campaign, entitled"Could it be asthma?". The impact of this media-based strategywas assessed using population surveys of 1300 adults beforeand after the campaign. Following the campaign, recall of recentasthma media messages increased from 24 to 49% (P < 0.001)and the proportion who recognized possible asthma symptoms intheir household increased from 3.4 to 5.5% following the campaign.Of those with symptoms, twice as many reported that they visiteda doctor to have their symptoms assessed after the campaign.Knowledge of asthma symptoms was significantly higher followingthe campaign (P < 0.001), after adjustment for age, sex andthe presence of asthma in the respondents family. The campaignappeared to have some success in raising awareness about asthma,and has been followed by the development of a National AsthmaCampaign in Australia focusing on reducing asthma morbidityand improving its management.     

Acute systemic and antiischemic effects of epanolol in patients with coronary artery disease

Summary Antiischemic effects of ₁-blocking agents are based on intrinsic negative inotropic and chronotropic properties. Partial ₁-agonistic activity, although useful in preserving cardiac function, may counteract such antischemic properties by modulating the intrinsic negative cardiac effects of beta-blockade. To investigate the acute hemodynamic and antiischemic profile of epanolol, a cardioselective ₁-antagonist and partial agonist, 20 patients with left coronary artery disease underwent two incremental atrial pacing tests, 45 minutes before (APST I) and 15 minutes after (APST II) 4 mg intravenous epanolol, administered over 5 minutes. Additional measurements were carried out at 1, 3, 5, 10, and 15 minutes after epanolol, at basal and fixed heart rates. Epanolol immediately reduced heart rate with a maximum of 10% at 15 minutes and decreased contractility (Vmax) by 7% (both p<.05), whereas cardiac output fell temporarily by 9% (p<.05). Other hemodynamic parameters did not change, except for a significant 11% reduction in myocardial oxygen demand. Despite comparable pacing conditions, both the double product and contractility decreased significantly less during APST II, resulting in a 17% lower myocardial oxygen consumption (p<.05). Myocardial ischemia was markedly reduced, indicated by normalization of lactate metabolism [lactate extraction 16±7% vs. –7±8% (APST I)], less ST depression (21%), and modulation of LV end-diastolic pressure postpacing (all p<.05 vs. APST I), whereas angina was absent or less in 14 patients. None of the patients reported an adverse effect. Thus, under resting conditions intravenous epanolol induces moderate, short-lasting negative chronotropic and inotropic effects, but does not alter cardiac pump function or vascular resistance, reflecting its additional ₁-agonistic properties. Alternatively, during pacing it still reduces ischemia through negative inotropic effects and diminishes myocardial oxygen demand, reflecting its ₁-antagonistic profile.     

Left-ventricular pressure gradients: a computer-model simulation

Both invasive left-ventricular pressure measurements and non-invasive colour M-mode echographic measurements have shown the existence of intraventricular pressure gradients (IVPGs) during early filling. The mechanisms responsible for these IVPG cannot be completely explained by the experiments. Therefore a one-dimensional numerical model is developed and validated. The model describes filling (both velocities and pressures) along a left ventricular (LV) base-apex axis. Blood-wall interaction in the left ventricle with moving boundaries is taken into account. The computational results for a canine heart indicate that the observed IVPGs during filling are the consequence of a complex interaction between, on the one hand, pressure waves travelling in the LV and, on the other hand, LV geometry, relaxation and compliance. The computational results indicate the pressure dependency of wavespeed (0.77-1.90 m-1 s) for different mean intraventricular pressures (0.88-5.00 mmHg) and IVPGs up to 2 mmHg, independent of the ratio of end systolic volume and equilibrium volume. Increasing relaxation rate not only decreases minimum basal pressure (2.8 instead of 3.6 mmHg) but also has a strong influence on the time delay between the minimum basal and apical pressures (14 ms instead of 49 ms). The results sustain the hypothesis that pressure-wave propagation determines IVPGs and that IVPGs are no proof of elastic recoil.