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Fixation and Tissue Pretreatment
Published in Lars-Inge Larsson, Immunocytochemistry: Theory and Practice, 2020
Thus, an intermedium that does not boil at as low a temperature as liquid nitrogen is desirable to use. Freon-22® is freely available in pressure bottles from several refrigeration firms and is preferred. When cooled by liquid nitrogen, the Freon® solidifies. It is convenient to use a metallic cup suspended in a liquid nitrogen bath to collect the Freon.® The cup is filled and then taken up from the nitrogen bath (Figure 10). Upon melting of the Freon® ice, specimens embedded in O.C.T. compound and supported on stiff paper are immersed and frozen in the Freon.® The frozen specimens (after 10 to 20 sec of freezing) are then quickly transferred to liquid nitrogen. They can be stored in this or in a − 80 to − 70°C freezer until required for sectioning. Intermedia other than Freon® may be used (propane-propylene or isopentane). Due care should be excercised when employing such intermedia, as propane-propylene mixtures in particular may be explosive when mixed with nitrogen!
Clove leaf oil compound in combination with standard drugs for effective liver cancer therapy
Published in Ade Gafar Abdullah, Isma Widiaty, Cep Ubad Abdullah, Medical Technology and Environmental Health, 2020
S.A.D. Trusda, T. Respati, E. Hendryanny, L. Yuniarti, M. Tejasari
The test material was in the form of compound 1,2-epoxy-3(3-(3,4-dimethoxyphenyl)-4H-1benzopyran-4on. The propane was synthesized at the Organic Chemistry Laboratory MIPA Faculty, Universitas Gajah Mada, Yogyakarta. Doxorubicin was used as a positive control (Sigma Chem. Co., St. Louis, USA). The concentrations used were obtained from preliminary research in the form of IC50 Epoxy 50.62 μg/mL and IC50 Dox 20.25 μg/mL.
Short-Lived Positron Emitting Radionuclides
Published in Frank Helus, Lelio G. Colombetti, Radionuclides Production, 2019
From hot atom investigations in the earlier 1960s emerged11,12 that when cyclopropane is bombarded with protons, 11C-acetylene is formed through the same nuclear reaction. Because of the chemical difference between target and product, very high specific activities can be obtained.91 Alternatively methane, ethane, or propane can be used as target. Because of the low radiation stability of the alkanes resulting in polymerization, only low beam currents can be used. For routine production of useful amounts of 11C-acetylene this method is not very suitable.92 Recently Crouzel93 prepared 11C-acetylene by pyrolysis of 11CH4 in an inductive argon plasma. The 11CH4 is produced by bombarding a mixture of N2 and 5% H2 with protons. The conditions are the same as described for the production of H11CN. The 11CH4 produced is trapped and introduced batch-wise together with some carrier methane into the base of an argon plasma. The plasma is generated with a high frequency generator using a flow of argon as the plasmagenic gas. Under these circumstances 60% of the 11CH4 can be converted momentarily into 11C-acetylene while 40% remains unconverted. After separation, H11C≡CH with a purity of 98% and a specific activity of 150 Ci/mmol can be obtained. Of course the specific activity which can be achieved depends upon the available proton beam current.
Characteristics and circumstances of volatile solvent misuse-related death in Australia, 2000–2021
Published in Clinical Toxicology, 2023
Shane Darke, Emma Zahra, Johan Duflou, Amy Peacock, Michael Farrell, Julia Lappin
Gas fuels predominated, but liquid fuels (e.g. gasoline) and adhesives/paints were common, and together constituted 74.4% of cases. The toxicology was consistent with these patterns, with butane, toluene, and propane being the solvents most commonly detected. Solvents such as butane, petroleum, and glue are all readily available, and these findings may reflect use patterns among people who misuse volatile solvents. While there has been legitimate concern about nitrous oxide [4], such cases constituted a relatively small proportion of this series. Why this is the case is unclear, but could be due to wider use of substances such as butane, or the relative recency of widespread nitrous oxide use. Similarly, nitrite inhalation, although capable of causing methaemoglobinaemia, was not identified as a cause of death. Other substances were present in just over half of the cases, mainly cannabis and alcohol.
Human error identification and risk prioritization in LPG unloading operations
Published in International Journal of Occupational Safety and Ergonomics, 2023
Prabhjot Singh Virdi, Gulab Pamnani
Gautam and Saxena [15] surveyed four LPG installation units in north India to determine the criticality of risk involved in the entire operation. On the basis of this survey, the authors drafted a few recommendations for reducing the risk involved in such installation units. Gallab et al. [16] presented a case study in which a new systematic modeling approach is used in order to analyze the risk associated with different tasks performed during transfer of LPG and for simulating different failure scenarios. Salamonowicz and Majder-Łopatka [17] in their research described the probable and potential worst-case emergency scenarios during accidents concerning LPG. The authors summarized the accidents involving LPG and propane from all over the world in tabular form, thereby providing a database which includes the cause, effect and observations of all accidents, which involves incidents such as vapor cloud explosion (VCE), boiling liquid expanding vapor explosion (BLEVE), fireball (FB), JF, FF and gas emissions without ignition. The research also lays out the guidelines related to rescue operations for tackling LPG incidents and recognition signs to identify the approaching BLEVE.
Spray freeze-drying for inhalation application: process and formulation variables
Published in Pharmaceutical Development and Technology, 2022
Mostafa Rostamnezhad, Hossein Jafari, Farzad Moradikhah, Sara Bahrainian, Homa Faghihi, Reza Khalvati, Reza Bafkary, Alireza Vatanara
Unlike the SFV/L, the nozzle in the SFL is located in the lower parts, directly in contact with the liquid (Figure 1). This liquid can be cryogenic. SFL can be conducted at atmospheric pressure with liquid nitrogen, hydrofluoroether, pentane, and argon. Also, it is applicable in the pressurized systems of liquid carbon dioxide, propane, and/or ethane. Droplets are frozen immediately after formation. The cryogenic agents may be stirred to prevent particle aggregation. Then, the frozen droplets are freeze-dried to produce a dry powder with an elegant flow. In the SFL, a liquid–liquid collision occurs between the atomized droplets ejected from the nozzle and the cryogenic liquid. The higher density and viscosity of liquids compared to gases cause the necessity for more vigorous atomization leading to create smaller droplets accordingly (Hu et al. 2002). The smaller droplets increase the specific surface area of the resultant particles and the heat transfer (Engstrom et al. 2007). Furthermore, supersaturation generates a high rate of nucleation from the dissolved components. Rapid nucleation, followed by a limited core growth, results in very small particles (Hu et al. 2002). The high surface area and minimum drug destruction have made this method suitable for preparing the dosage forms (Yu et al. 2004).