The review paper presents a systematic understanding of different synthesis routes to obtain holey graphene, its properties, and key applications in different fields. The article also evaluates the current progress and future opportunities of HG.

Currently, a wide range of materials are being used as barrier coatings for different applications. Among them, polymers and graphene have been the focus of many studies. Polymers are used in numerous industries due to their remarkable properties, including resistance to thermal degradation, resistance to chemical permeation, and good mechanical properties. On the other hand, graphene, a one-atom-thick and two-dimensional material, does not allow the permeation of gases or liquid molecules through its plane; thus, it has been considered one of the promising nanomaterials used in gas and liquid barrier applications and corrosion inhibition coatings.

The geometrical dependence of humidity sensors on sensing performance has not been quantitatively outlined. Furthermore, the etching effect on humidity sensors is still elusive due to the difficulty in separating the effects of the geometrical change and etching-induced porosity on the overall performance. Here, we use COMSOL Multiphysics to perform a numerical study of a capacitive graphene oxide (GO) humidity sensor, with emphasis on the dimensions and etching effect on their sensing performance. GO is a useful and promising material in detecting humidity because of its selective superpermeability to water molecules. The mechanism of improved sensing performance of the etched humidity sensors is discussed in terms of the morphological profile and the effective permittivity including the etching-induced porosity effect. Our study shows that as compared to the unetched sensors, isotropic etching achieves the lowest response time of 1.011 s at 15.75% porosity, while vertical etching achieves the highest capacitance sensitivity of 0.106 fF/RH %.

clinical case of the rare ROHHAD syndrome which represents a condition related to central sleep apnea. Objective To review the literature data on sleep-related breathing disorders and present our own clinical case of the rare ROHHAD syndrome. Methods More than 100 literature sources were reviewed. Presented the case of a 6-year-old child with sleep apnea hospitalized to the Mordovian Republic Clinical Hospital. Results ROHHAD syndrome is a very rare disease (about 100 cases are described worldwide). In most cases it presented as rapid obesity development since 3-5 years of age as well as hypoventilation, endocrine dysfunction, electrolyte disturbances. Autonomic nervous system dysfunction reveled in ROH-HAD pediatric patients rarely. Own observation demonstrated a typical clinical presentation of ROHHAD syndrome. Boy D., 6 years 11 months was admitted to the pediatric department of the Children's republican clinical hospital with severe weakness, fatigue during physical exertion, obesity, shortness of breath at rest, orthopnea, inability to sleep on the back (sleeps with an elevated head end or on the right side); lower extremities weakness during walking and climbing upstairs during the last year, changes in walking and in behavioral reactions. Cyanotic attacks and tachycardia have appeared during sleep in previous six months before admission. Firstly, the condition manifested with sudden and rapidly progressive obesity. Ventilation disorders became clinically evident after carried over pneumonia. Episodes of sleep apnea lasted up to 20 seconds, were accompanied by cyanotic attacks and tachycardia. Multiple investigations were performed to exclude systemic connective tissue diseases, neurological disturbances and brain pathology, muscular tissue pathology and metabolic diseases. Finally, the diagnosis was confirmed by the polysomnography and genetic tests. The ventilation support during sleep was prescribed. Conclusion The rarity of the disease leads to a decreased awareness of pediatricians. The diagnosis is made by clinical picture and polysomnography, and timely diagnostics can increase the duration and improve the quality of life of patients.