Blue Midevil Ballet
- Sigel A, Sigel H, Sigel RK (2011). Metal ions in toxicology: effects, interactions, interdependencies. Metal Ions in Life Sciences. 8. pp. vii–viii. doi:10.1039/9781849732512. ISBN 978-1-84973-094-5. PMID 21473373.
- Bal W, Protas AM, Kasprzak KS (2011). "Chapter 13. Genotoxicity of metal ions: chemical insights". In Sigel R, Sigel, Sigel H (eds.). Metal Ions in Toxicology: Effects, Interactions, Interdependencies (Metal Ions in Life Sciences). Metal Ions in Life Sciences. 8. Cambridge, Eng: Royal Society of Chemistry. pp. 319–373. doi:10.1039/9781849732116-00319. ISBN 978-1-84973-091-4.
- Smith MT (December 1996). "The mechanism of benzene-induced leukemia: a hypothesis and speculations on the causes of leukemia". Environmental Health Perspectives. 104 Suppl 6: 1219–25. doi:10.1289/ehp.961041219. PMC 1469721. PMID 9118896.
- raising the risk of secondary cancers, such as leukemia.[12]
In order to use off-the-shelf materials, it needs to be crystallized sequentially, using controlled temperature, in order to extract KCl, which is the subject of ongoing research.[citation needed] It also emits a relatively low level of 511 keV gamma rays from positron annihilation, which can be used to calibrate medical scanners.[citation needed]
Potassium chloride is used in some de-icing products designed to be safer for pets and plants, though these are inferior in melting quality to calcium chloride [lowest usable temperature 12 °F (−11 °C) v. −25 °F (−32 °C)]. It is also used in various brands of bottled water.[citation needed]
Potassium chloride was once used as a fire extinguishing agent, used in portable and wheeled fire extinguishers. Known as Super-K dry chemical, it was more effective than sodium bicarbonate-based dry chemicals and was compatible with protein foam. This agent fell out of favor with the introduction of potassium bicarbonate (Purple-K) dry chemical in the late 1960s, which was much less corrosive, as well as more effective. It is rated for B and C fires.[citation needed]
Along with sodium chloride and lithium chloride, potassium chloride is used as a flux for the gas weldingof aluminium.
While cheap, KCl crystals are hygroscopic. This limits its application to protected environments or short-term uses such as prototyping. Exposed to free air, KCl optics will "rot". Whereas KCl components were formerly used for infrared optics, it has been entirely replaced by much tougher crystals such as zinc selenide.[citation needed]
Potassium chloride is used as a scotophor with designation P10 in dark-trace CRTs, e.g. in the Skiatron.
Redox and the conversion to potassium metal[edit]
Although potassium is more electropositive than sodium, KCl can be reduced to the metal by reaction with metallic sodium at 850 °C because the more volatile potassium can be removed by distillation (see Le Chatelier's principle):
- KCl(l) + Na(l) ⇌ NaCl(l) + K(g)
This method is the main method for producing metallic potassium. Electrolysis (used for sodium) fails because of the high solubility of potassium in molten KCl.[9]
Physical properties[edit]
The crystal structure of potassium chloride is like that of NaCl. It adopts a face-centered cubic structure. Its lattice constant is roughly 6.3 Ã…. Crystals cleave easily in three directions.
Some other properties are
- Transmission range: 210 nm to 20 µm
- Transmittivity = 92% at 450 nm and rises linearly to 94% at 16 µm
- Refractive index = 1.456 at 10 µm
- Reflection loss = 6.8% at 10 µm (two surfaces)
- dN/dT (expansion coefficient)= −33.2×10−6/°C
- dL/dT (refractive index gradient)= 40×10−6/°C
- Thermal conductivity = 0.036 W/(cm·K)
- Damage threshold (Newman and Novak): 4 GW/cm2 or 2 J/cm2 (0.5 or 1 ns pulse rate); 4.2 J/cm2 (1.7 ns pulse rate Kovalev and Faizullov)
As with other compounds containing potassium, KCl in powdered form gives a lilac flame.
https://en.wikipedia.org/wiki/Potassium_chloride
The trihydrogen cation or protonated molecular hydrogen is a cation (positive ion) with formula H+
3, consisting of three hydrogen nuclei (protons) sharing two electrons.
The trihydrogen cation is one of the most abundant ions in the universe. It is stable in the interstellar medium (ISM) due to the low temperature and low density of interstellar space. The role that H+
3 plays in the gas-phase chemistry of the ISM is unparalleled by any other molecular ion.
The trihydrogen cation is the simplest triatomic molecule, because its two electrons are the only valence electrons in the system. It is also the simplest example of a three-center two-electron bond system.
H+
3 was first discovered by J. J. Thomson in 1911.[1] While studying the resultant species of plasmadischarges, he discovered something very odd. Using an early form of mass spectrometry, he discovered a large abundance of a molecular ion with a mass-to-charge ratio of 3. He stated that the only two possibilities were C4+ or H+
3. Since C4+ would be very unlikely and the signal grew stronger in pure hydrogen gas, he correctly assigned the species as H+
3.
The formation pathway was discovered by Hogness & Lunn in 1925.[2] They also used an early form of mass spectrometry to study hydrogen discharges. They found that as the pressure of hydrogen increased, the amount of H+
3 increased linearly and the amount of H+
2 decreased linearly. In addition, there was little H+ at any pressure. These data suggested the proton exchange formation pathway discussed below.
In 1961, Martin et al. first suggested that H+
3 may be present in interstellar space given the large amount of hydrogen in interstellar space and its reaction pathway was exothermic (~1.5 eV).[3] This led to the suggestion of Watson and Herbst & Klemperer in 1973 that H+
3 is responsible for the formation of many observed molecular ions.[4][5]
It was not until 1980 that the first spectrum of H+
3 was discovered by Takeshi Oka,[6] which was of the ν2 fundamental band using a technique called frequency modulation detection. This started the search for extraterrestrial H+
3. Emission lines were detected in the late 1980s and early 1990s in the ionospheres of Jupiter, Saturn, and Uranus.[7][8][9] In the textbook by Bunker and Jensen.[10] Figure 1.1 of this book reproduces part of the ν2 emission band from a region of auroral activity in the upper atmosphere of Jupiter, [11] and its Table 12.3 lists the transition wavenumbers of the lines in the band observed by Oka[6] with their assignments.
Structure[edit]
The three hydrogen atoms in the molecule form an equilateral triangle, with a bond length of 0.90 Ã… on each side. The bonding among the atoms is a three-center two-electron bond, a delocalized resonance hybrid type of structure. The strength of the bond has been calculated to be around 4.5 eV (104 kcal/mol).[15]
Isotopologues[edit]
In theory, the cation has 10 isotopologues, resulting from the replacement of one or more protons by nuclei of the other hydrogen isotopes; namely, deuterium nuclei (deuterons, 2
H+) or tritium nuclei (tritons, 3
H+). Some of them have been detected in interstellar clouds.[16] They differ in the atomic mass number A and the number of neutrons N:
- H+
3 = 1
H+
3 (A=3, N=0) (the common one).[17][16] - [DH
2]+ = [2
H1
H
2]+ (A=4, N=1) (deuterium dihydrogen cation).[17][16] - [D
2H]+ = [2
H
21
H]+ (A=5, N=2) (dideuterium hydrogen cation).[17][16] - D+
3 = 2
H+
3 (A=6, N=3) (trideuterium cation).[17][16] - [TH
2]+ = [3
H1
H
2]+ (A=5, N=2) (tritium dihydrogen cation). - [TDH]+ = [3
H2
H1
H]+ (A=6, N=3) (tritium deuterium hydrogen cation). - [TD
2]+ = [3
H2
H
2]+ (A=7, N=4) (tritium dideuterium cation). - [T
2H]+ = [3
H
21
H]+ (A=7, N=4) (ditritium hydrogen cation). - [T
2D]+ = [3
H
22
H]+ (A=8, N=5) (ditritium deuterium cation). - T+
3 = 3
H+
2 (A=9, N=6) (tritritium cation).
The deuterium isotopologues have been implicated in the fractionation of deuterium in dense interstellar cloud cores.[17]
Formation[edit]
The main pathway for the production of H+
3 is by the reaction of H+
2 and H2.[18]
- H+
2 + H2 → H+
3 + H
The concentration of H+
2 is what limits the rate of this reaction in nature - the only known natural source of it is via ionization of H2 by a cosmic ray in interstellar space:
- H2 + cosmic ray → H+
2 + e− + cosmic ray
The cosmic ray has so much energy, it is almost unaffected by the relatively small energy transferred to the hydrogen when ionizing an H2 molecule. In interstellar clouds, cosmic rays leave behind a trail of H+
2, and therefore H+
3. In laboratories, H+
3 is produced by the same mechanism in plasma discharge cells, with the discharge potential providing the energy to ionize the H2.
Destruction[edit]
The information for this section was also from a paper by Eric Herbst.[18] There are many destruction reactions for H+
3. The dominant destruction pathway in dense interstellar clouds is by proton transfer with a neutral collision partner. The most likely candidate for a destructive collision partner is the second most abundant molecule in space, CO.
- H+
3 + CO → HCO+ + H2
The significant product of this reaction is HCO+, an important molecule for interstellar chemistry. Its strong dipole and high abundance make it easily detectable by radioastronomy. H+
3 can also react with atomic oxygen to form OH+ and H2.
- H+
3 + O → OH+ + H2
OH+ then usually reacts with more H2 to create further hydrogenated molecules.
- OH+ + H2 → OH+
2 + H - OH+
2 + H2 → OH+
3 + H
At this point, the reaction between OH+
3 and H2 is no longer exothermic in interstellar clouds. The most common destruction pathway for OH+
3 is dissociative recombination, yielding four possible sets of products: H2O + H, OH + H2, OH + 2H, and O + H2 + H. While water is a possible product of this reaction, it is not a very efficient product. Different experiments have suggested that water is created anywhere from 5–33% of the time. Water formation on grains is still considered the primary source of water in the interstellar medium.
The most common destruction pathway of H+
3 in diffuse interstellar clouds is dissociative recombination. This reaction has multiple products. The major product is dissociation into three hydrogen atoms, which occurs roughly 75% of the time. The minor product is H2 and H, which occurs roughly 25% of the time.
Or
tho/Para-H3+[edit]
The protons of [1
H
3]+ can be in two different spin configurations, called ortho and para. Ortho-H+
3 has all three proton spins parallel, yielding a total nuclear spin of 3/2. Para-H+
3has two proton spins parallel while the other is anti-parallel, yielding a total nuclear spin of 1/2.
The most abundant molecule in dense interstellar clouds is 1
H
2 which also has ortho and para states, with total nuclear spins 1 and 0, respectively. When a H+
3 molecule collides with a H2 molecule, a proton transfer can take place. The transfer still yields a H+
3molecule and a H2 molecule, but can potentially change the total nuclear spin of the two molecules depending on the nuclear spins of the protons. When an ortho-H+
3 and a para-H2 collide, the result may be a para-H+
3 and an ortho-H2.[18]
Spectroscopy[edit]
The spectroscopy of H+
3 is challenging. The pure rotational spectrum is exceedingly weak.[19] Ultraviolet light is too energetic and would dissociate the molecule. Rovibronic (infrared) spectroscopy provides the ability to observe H+
3. Rovibronic spectroscopy is possible with H+
3 because one of the vibrational modes of H+
3, the ν2 asymmetric bend mode, has a weak transition dipole moment. Since Oka's initial spectrum,[6] over 900 absorption lineshave been detected in the infrared region. H+
3 emission lines have also been found by observing the atmospheres of the Jovian planets. H+
3 emission lines are found by observing molecular hydrogen and finding a line that cannot be attributed to molecular hydrogen.
Planetary atmospheres[edit]
The detection of the first H+
3 emission lines was reported in 1989 by Drossart et al.,[7] found in the ionosphere of Jupiter. Drossart found a total of 23 H+
3lines with a column density of 1.39×109/cm2. Using these lines, they were able to assign a temperature to the H+
3 of around 1,100 K (830 °C), which is comparable to temperatures determined from emission lines of other species like H2. In 1993, H+
3 was found in Saturn by Geballe et al.[8] and in Uranus by Trafton et al.[9]
Molecular interstellar clouds[edit]
H+
3 was not detected in the interstellar medium until 1996, when Geballe & Oka reported the detection of H+
3 in two molecular cloud sightlines, GL2136 and W33A.[12] Both sources had temperatures of H+
3 of about 35 K (−238 °C) and column densities of about 1014/cm2. Since then, H+
3 has been detected in numerous other molecular cloud sightlines, such as AFGL 2136,[20] Mon R2 IRS 3,[20] GCS 3-2,[21] GC IRS 3,[21] and LkHα 101.[22]
Diffuse interstellar clouds[edit]
Unexpectedly, three H+
3 lines were detected in 1998 by McCall et al. in the diffuse cloud sightline of Cyg OB2 No. 12.[13] Before 1998, the density of H2was thought to be too low to produce a detectable amount of H+
3. McCall detected a temperature of ~27 K (−246 °C) and a column density of ~1014/cm2, the same column density as Geballe & Oka. Since then, H+
3 has been detected in many other diffuse cloud sightlines, such as GCS 3-2,[21]GC IRS 3,[21] and ζ Persei.[23]
Steady-state model predictions[edit]
To approximate the path length of H+
3 in these clouds, Oka[24] used the steady-state model to determine the predicted number densities in diffuse and dense clouds. As explained above, both diffuse and dense clouds have the same formation mechanism for H+
3, but different dominating destruction mechanisms. In dense clouds, proton transfer with CO is the dominating destruction mechanism. This corresponds to a predicted number density of 10−4 cm−3 in dense clouds.
- n(H+
3) = (ζ / kCO)[n(H2) / n(CO)] ≈ 10−4/cm3 - n(H+
3) = (ζ / ke)[n(H2) / n(C+)] ≈ 10−6/cm3
In diffuse clouds, the dominating destruction mechanism is dissociative recombination. This corresponds to a predicted number density of 10−6/cm3 in diffuse clouds. Therefore, since column densities for diffuse and dense clouds are roughly the same order of magnitude, diffuse clouds must have a path length 100 times greater than that for dense clouds. Therefore, by using H+
3 as a probe of these clouds, their relative sizes can be determined.
See also[edit]
- Dihydrogen cation, H+
2 - Helium hydride ion, [HeH]+
https://en.wikipedia.org/wiki/Trihydrogen_cation
The facility built in 1911 over 8 hectares started to produce nitrogenous fertilizers two years later. This included mainly a mixture of potassium chloride and ammonium nitrate in equal proportions. The raw material ammonia was produced using the new Haber-Bosch process that uses atmospheric nitrogen. There were 8,000 people working on the site.
During war times, ammonia salts were produced for military use such as constituents for explosives. However after 1918, ammonium salts continued to be produced for civil purposes.
Since 1919, the potassium chloride/ammonium nitrate mixture was gradually replaced by a 50/50 mixture of ammonium sulphate and ammonium nitrate called "mischsaltz". This highly hygroscopic mixture had the disadvantage of clogging together under the pressure of its own weight during storage. It was common practice to loosen the "aggregated” product by firing explosives in holes drilled using a jumper bar in the hardened mass. Until the day of the accident over 20,000 firings were carried out in the "mischsaltz" without any sign of accident being observed.
https://www.aria.developpement-durable.gouv.fr/wp-content/files_mf/FD_14373_oppau_1921_ang.pdf
Brainstem Organoids From Human Pluripotent Stem Cells
Nobuyuki Eura1†, 
Takeshi K. Matsui1,2†, Joachim Luginbühl3†, 
Masaya Matsubayashi2, 
Hitoki Nanaura1,2, 
Tomo Shiota1, Kaoru Kinugawa1, 
Naohiko Iguchi1, Takao Kiriyama1, 
Canbin Zheng4, Tsukasa Kouno3, Yan Jun Lan3, Pornparn Kongpracha5, 
Pattama Wiriyasermkul5, Yoshihiko M. Sakaguchi2, Riko Nagata2, Tomoya Komeda2, Naritaka Morikawa2, Fumika Kitayoshi2, Miyong Jong2, Shinko Kobashigawa2, Mari Nakanishi2, Masatoshi Hasegawa6, 
Yasuhiko Saito7, 
Takashi Shiromizu8, 
Yuhei Nishimura8, Takahiko Kasai9, Maiko Takeda9, 
Hiroshi Kobayashi10, Yusuke Inagaki11, 
Yasuhito Tanaka11, 
Manabu Makinodan12, Toshifumi Kishimoto12, Hiroki Kuniyasu13, Shushi Nagamori5, 
Alysson R. Muotri14,15, Jay W. Shin3*, 
Kazuma Sugie1* and 
Eiichiro Mori2*- 1Department of Neurology, Nara Medical University, Kashihara, Japan
- 2Department of Future Basic Medicine, Nara Medical University, Kashihara, Japan
- 3Laboratory for Advanced Genomics Circuit, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
- 4Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, United States
- 5Laboratory of Biomolecular Dynamics, Department of Collaborative Research, Nara Medical University, Kashihara, Japan
- 6Department of Radiation Oncology, Nara Medical University, Kashihara, Japan
- 7Department of Neurophysiology, Nara Medical University, Kashihara, Japan
- 8Department of Integrative Pharmacology, Graduate School of Medicine, Mie University, Tsu, Japan
- 9Department of Laboratory Medicine and Pathology, National Hospital Organization Kinki-Chuo Chest Medical Center, Sakai, Japan
- 10Department of Obstetrics and Gynecology, Nara Medical University, Kashihara, Japan
- 11Department of Orthopaedic Surgery, Nara Medical University, Kashihara, Japan
- 12Department of Psychiatry, Nara Medical University, Kashihara, Japan
- 13Department of Molecular Pathology, Nara Medical University, Kashihara, Japan
- 14Department of Pediatrics, University of California, San Diego, San Diego, CA, United States
- 15Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, CA, United States
The brainstem is a posterior region of the brain, composed of three parts, midbrain, pons, and medulla oblongata. It is critical in controlling heartbeat, blood pressure, and respiration, all of which are life-sustaining functions, and therefore, damages to or disorders of the brainstem can be lethal. Brain organoids derived from human pluripotent stem cells (hPSCs) recapitulate the course of human brain development and are expected to be useful for medical research on central nervous system disorders. However, existing organoid models are limited in the extent hPSCs recapitulate human brain development and hence are not able to fully elucidate the diseases affecting various components of the brain such as brainstem. Here, we developed a method to generate human brainstem organoids (hBSOs), containing midbrain/hindbrain progenitors, noradrenergic and cholinergic neurons, dopaminergic neurons, and neural crest lineage cells. Single-cell RNA sequence (scRNA-seq) analysis, together with evidence from proteomics and electrophysiology, revealed that the cellular population in these organoids was similar to that of the human brainstem, which raises the possibility of making use of hBSOs in investigating central nervous system disorders affecting brainstem and in efficient drug screenings.
https://www.frontiersin.org/articles/10.3389/fnins.2020.00538/full
- Tice RR, Agurell E, Anderson D, Burlinson B, Hartmann A, Kobayashi H, et al. (2000). "Single cell gel/comet assay: guidelines for in vitro and in vivo genetic toxicology testing" (PDF). Environmental and Molecular Mutagenesis. 35 (3): 206–21. doi:10.1002/(SICI)1098-2280(2000)35:3<206::AID-EM8>3.0.CO;2-J. PMID 10737956.
- ^ Bolognesi, Claudia (June 2003). "Genotoxicity of pesticides: A review of human biomonitoring studies". Mutation Research. 543 (3): 251–272. doi:10.1016/S1383-5742(03)00015-2. PMID 12787816.
- ^ Liu SX, Athar M, Lippai I, Waldren C, Hei TK (February 2001). "Induction of oxyradicals by arsenic: implication for mechanism of genotoxicity". Proceedings of the National Academy of Sciences of the United States of America. 98 (4): 1643–8. Bibcode:2001PNAS...98.1643L. doi:10.1073/pnas.98.4.1643. PMC 29310. PMID 11172004.
- ^ Schins RP (January 2002). "Mechanisms of genotoxicity of particles and fibers". Inhalation Toxicology. 14 (1): 57–78. doi:10.1080/089583701753338631. PMID 12122560. S2CID 24802577.
- ^ a b c d Walsh D (2011-11-18). "Genotoxic Drugs". Cancerquest.org. Archived from the original on 2013-03-02. Retrieved 2013-03-16.
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