China 
Africa 
Explore chapters and articles related to this topic
Techniques for Chest Radiography, Fluoroscopy, Tomography (including CT and MR) and Ultrasound
Published in Fred W Wright, Radiology of the Chest and Related Conditions, 2022
These gases may be inhaled or given IV. They allow much higher MR signals to be obtained as up to 60% hyperpolarisation can be obtained. This with helium compensates for grossly lower density (2,500 times) compared with hydrogen concentrates in tissue, Reduced aeration of areas of lung have been shown in relation to tumours, areas of emphysema, bronchiolitis, etc. The pulmonary vessels are demonstrated as areas without signal. The problem is cost as the gases are very expensive.
Plastic Bag Asphyxia
Published in Burkhard Madea, Asphyxiation, Suffocation,and Neck Pressure Deaths, 2020
Lisa B.E. Shields, John C. Hunsaker
Toxicological analysis does not include testing for helium gas in cases of plastic bag asphyxia with helium. In addition, while petechial haemorrhages are often observed in classic asphyxial deaths [29], they are seldom encountered in plastic bag asphyxia [2,19,32]. In Bollock and Diniz's study [4], only 7 victims (7.5%) had conjunctival or facial petechiae. The most common observations were pulmonary oedema and congestion (6.2%) and visceral petechiae (18.7%). The study by Haddix et al. [19] also described a paucity of petechiae observed upon postmortem external examination. Only six victims had petechiae, and they were few in number (usually less than three in total) and located on the conjunctivae.
Non-Radiographic Imaging
Published in Eric Ford, Primer on Radiation Oncology Physics, 2020
The forces and torques described above are the result of magnetic fields interacting with each other. One of these fields is from the nucleus itself. The nucleus has a magnetic dipole moment denoted as μ. This can be thought of as analogous to a bar magnet which has a dipole moment (“north” and “south” poles). The gyromagnetic ratio and the magnetic dipole moment are related through the equation , where μ is the magnetic dipole moment, and I is a quantum mechanical property of the nucleus called spin. Note that some nuclei have a spin that is non-zero but in some others the spin is zero. The hydrogen nucleus, for example, has a spin of ½ but the helium nucleus has a spin of zero. MRI imaging is therefore not possible with helium because the magnetic dipole moment, γIℏ, is zero.
Helium inhalation injuries managed at emergency departments
Published in Clinical Toxicology, 2021
This study describes helium inhalation-related injuries managed at US EDs. Previous literature reports inhalation of helium can result in adverse effects such as dizziness, loss of consciousness, headache, nausea, seizures, coma, and even death [1–3,6–18]. The estimated number of helium inhalation-related injuries rose during the twenty-year study period. Previous studies have reported an increase in suicides by helium inhalation in the US and other parts of the world over the last several decades [11–18]. Although the current study could not ascertain the intent of the helium inhalation, the majority of injuries resulted from inhalation from a balloon, and no deaths were reported. This might suggest that, at least in the majority of cases, the patients were not trying to commit suicide but were either playing with the helium or attempting to become intoxicated. Thus, helium inhalation for purposes other than suicide also may be increasing. Alternately, the observed increase may be a product of the data (e.g., NEISS coders may have become more precise in their coding and including more details in the description in later years). Examination of helium inhalation injuries in other datasets, such as poison center data, that document the intent of the inhalation may be useful to verify whether this trend is true.
Pharmacotherapeutic strategies for critical asthma syndrome: a look at the state of the art
Published in Expert Opinion on Pharmacotherapy, 2020
Alessandro Vatrella, Angelantonio Maglio, Corrado Pelaia, Girolamo Pelaia, Carolina Vitale
In order to reduce respiratory work and improve ventilation, a mixture of oxygen and helium (heliox) has been introduced in clinical practice, since the lower density of helium reduces the resistance to airflow in turbulent flow conditions [92,94]. A systematic review with meta-analysis of randomized trials designed to evaluate the efficacy of heliox versus oxygen in driving b2-agonist nebulization in patients with acute asthma suggests that heliox benefits in airflow limitation and hospital admissions could be considered clinically significant [95]. Furthermore, heliox has proven to be quite useful in pairs with bronchodilator therapy, as it appears to be able to make superior functional improvements compared to bronchodilator therapy alone [96,97]. Despite these encouraging data, at the moment, GINA guidelines suggest there is no role for this intervention in routine care, but it may be considered for patients who do not respond to standard therapy [1].
Antimicrobial activities of Trichoderma atroviride against common bean seed-borne Macrophomina phaseolina and Rhizoctonia solani
Published in Egyptian Journal of Basic and Applied Sciences, 2020
Naglaa M. El-Benawy, Gamal M. Abdel-Fattah, Khalid M. Ghoneem, Yasser M. Shabana
Helium was used as a carrier gas at approximately 1 ml/min., pulsed split less mode. The solvent delay and the injection size were 3 min and 1.0 ml, respectively. The mass spectrophotometric detector was operated in electron impact ionization mode in ion energy of 70 e.v. scanning from m/z 50 to 500. The ion source temperature was 230°C and quadrupole temperature was 150°C. The electron multiplier voltage was maintained 1250 v above autotune. The instrument was manually tuned using perfluorotributylamine. The GC temperature program was started at 60°C for 2 min then elevated to 280°C at a rate of 5°C/min, and 10 min hold at 280°C the injector temperature was set at 280°C. Separated peaks were identified using Wiley and Nist 05 mass spectral database.