An unusual cause of intraoperative high airway pressure and ventilator failure: message to be learned

Failure of ventilation of an anesthetised patient due to problems in mechanical ventilator is not uncommon. The proper functioning of machine should be ensured before anesthetising a patient by the automated checking system or manually by the attending anaesthesiologist. However, sudden malfunction of some system of the machine during operation may cause the ventilator to stop risking the patient’s life. About one third of the equipment problems are due to anesthesia machine and one quarter of the problems are due to human error. We present a case of malfunction of anesthesia ventilator due to an unusual cause of blockage of anesthesia gas scavenging system.

Functions of Nano-Materials in Food Packaging

Food packaging has been changing from bulky and rigid form in the past to different variation of lights and plastic packagings. Regardless of the changes, the packaging must be able to uphold its original function which is to serve as food containment as well as to protect the food from the external environment. Coupled with the increasing consumer’s awareness on food waste, higher standard of living, technological developments are underway to enhance the shelf-life of packed food as well as methods to provide indications of food packaging environment. There are many different indicators for food spoilage, but two commonly found gases in food packaging are oxygen and carbon dioxide. Oxygen is the main mechanism for food spoilage, while carbon dioxide is often used in modified-atmosphere-packaging. There are also different methods of gas scavenging and/or sensing techniques based on different concepts in the literature. In this review, the focus will be on nano-materials, namely titanium dioxide, silica, zeolites and metal organic frameworks. This review is structured in a manner to highlight how each material can be used in both gas scavenging and/or indicators applications. The last part of the review focuses on the approach and some key considerations when integrating nano-materials into the plastic film.

Metal–Organic Framework for Selective Gas Scavenging

Selective gas adsorption plays an important role in adsorptive separation of gases and scavenging unfavorable or hazardous gases. The use of cost-effective and environmentally friendly materials for selective gas adsorption has become one of the most pressing needs today. The development of new adsorbents is essential but difficult due to the selectivity and efficiency requirements for practical application. As potential scavengers, metal–organic frameworks (MOFs) have drawn great attention. In this review, the current progress of science and technology development of MOFs on selective gas scavenging will be highlighted. Future perspectives for exploring MOFs for practical application will also be put forward.

Persistence of the dominant soil phylumAcidobacteriaby trace gas scavenging

The majority of microbial cells in global soils exist in a spectrum of dormant states. However, the metabolic processes that enable them to survive environmental challenges, such as nutrient-limitation, remain to be elucidated. In this work, we demonstrate that energy-starved cultures ofPyrinomonas methylaliphatogenes, an aerobic heterotrophic acidobacterium isolated from New Zealand volcanic soils, persist by scavenging the picomolar concentrations of H2distributed throughout the atmosphere. Following the transition from exponential to stationary phase due to glucose limitation, the bacterium up-regulates by fourfold the expression of an eight-gene operon encoding an actinobacteria-type H2-uptake [NiFe]-hydrogenase. Whole-cells of the organism consume atmospheric H2in a first-order kinetic process. Hydrogen oxidation occurred most rapidly under oxic conditions and was weakly associated with the cell membrane. We propose that atmospheric H2scavenging serves as a mechanism to sustain the respiratory chain ofP. methylaliphatogeneswhen organic electron donors are scarce. As the first observation of H2oxidation to our knowledge in theAcidobacteria, the second most dominant soil phylum, this work identifies new sinks in the biogeochemical H2cycle and suggests that trace gas oxidation may be a general mechanism for microbial persistence.