Sir, In the challenging paper by Wang et al. (2008), the authors have reported about an effective method of vitrification of human ovarian tissue with direct contact of cells in liquid nitrogen, named needle immersed vitrification. Childbirth after cryopreservation of ovarian tissue is now a reality (Donnez et al., 2004; Demeestere et al., 2007; Meirow et al., 2007; Andersen et al., 2008) and t...

The vitrification of a liquid occurs when ice crystal formation is prevented in the cryogenic environment through ultrarapid cooling. In general, vitrification entails a large temperature difference between the liquid and its surrounding medium. In our droplet vitrification experiments, we observed that such vitrification events are accompanied by a Leidenfrost phenomenon, which impedes the hea...

The main and upper stages of heavy lift launchers for space applications are often fuelled by cryogenic liquids. In order to enable the re-ignition of a cryogenic upper stage for orbital changes, it is crucial to study the behaviour of these fluids in microgravity. As gaseous bubbles entering the fuel lines of the engine can cause the destruction of the engine, these bubbles are a risk for the ...

Feasibility will take into account whether it is possible to operate the freezer in tile plant location. A liquid nitrogen freezer (LNF), for instance, may be suitable in every respect for freezing the product and the high costs of using this method of freezing may be justified. However, if the location of the plant is such that there can be no guaranteed supply of liquid nitrogen, the freezer ...

The electrical conductivity of beryllium at radio frequency (800 MHz) and liquid nitrogen temperature were investigated and measured. This summary addresses a collection of beryllium properties in the literature, an analysis of the anomalous skin effect, the test model, the experimental setup and improvements, MAFIA simulations, the measurement results and data analyses. The final results show ...

The glandular odontogenic cyst (GOC) is a rare lesion with odontogenic origin. It shows a propensity for recurrence revealed in 30% of all case. This investigation reports a case of recurrent GOC in a 35-year-old female in the anterior region of the maxilla, which is uncommon and discusses about IHC finding, surgical methods, and differential diagnosis. Under general anesthesia, peripheral bone...

Ten resistance thermometers were tested as point sensors for detecting the liquid-vapor interface in liquid nitrogen and liquid hydrogen. Test results showed that most could be made to detect the liquid surface and lead orientation can be important. A silicon resistive sensor had the fastest response and produced the greatest signal change.

Mars’ total atmospheric nitrogen content is 0.2 mbar. One-dimensional (1D) photochemical simulations of Mars’ atmosphere show that nitric acid (HNO3(g)), the most soluble nitrogen oxide, is the principal reservoir species for nitrogen in its lower atmosphere, which amounts to a steady-state value of 6×10−2 kg or 4 moles, conditions of severe nitrogen deficiency. Mars could, however, support *10...