Energy Medicine
Len Wisneski in The Scientific Basis of Integrative Health, 2017
An important historical note: in early 1950, prior to the invention of the laser, a device that emitted microwave photons (rather than light photons), called MASER for microwave amplification of stimulated emission of radiation, was in use. The maser was developed simultaneously by Charles Townes in the United States and by Alexander Prokhorov and Nikolai Basov in the former Union of Soviet Socialist Republics (USSR); all three investigators shared the 1964 Nobel Prize in Physics for their work (Hecht, 2002). Almost immediately after the development of the maser, speculation arose as to whether or not the same technique could be extended to the optical region of the EM spectrum. In 1958, Townes and Arthur Schawlow set forth the general physical conditions that would have to be met to create a laser (Karu, 2007). In 1960, Theodore Maiman, an electrical engineer at Hughes Aircraft, announced the first successful operation of an optical maser or laser, using a ruby crystal that produce red EM radiation at 694.3 nm from chromium ions. Thus, an understanding of the essential effect of stimulated, coherent emission of radiation from excited atoms, precisely in phase and in the same direction, permitted the development of both the maser and the laser.
The Twentieth Century and Beyond
Scott M. Jackson in Skin Disease and the History of Dermatology, 2023
The next major advancement in twentieth-century dermatologic technology is the laser. “Laser” is an acronym that stands for Light Amplification by Stimulated Emission of Radiation. The scientific history of lasers begins with the work of Max Planck (1858–1947) and Albert Einstein (1879–1955). In 1900, Planck discovered the relationship between energy and frequency in radiation, concluding that energy is emitted or absorbed in discrete chunks called quanta. Einstein applied Planck's idea to light, discovering the photon and formulating the Quantum Theory of Light in 1905. Einstein introduced the concept of stimulated emission about ten years later: a photon of a specific frequency can interact with an excited electron, and new photons are generated that have the same properties (frequency, polarization, direction) as the original photon. Einstein's concept was first applied to microwave radiation, and “masers” were developed in the 1950s. Late in that decade, the same idea was applied to visible light and infrared radiation. Experiments by Charles Townes (1915–2015), Arthur Schawlow (1921–1999), and Gordon Gould (1920–2005) led up to the invention of the laser in 1960.
Hysteroscopy Combined with Laser Vaporesection for Endometrial Polyps
Published in Journal of Investigative Surgery, 2022
Hongyan Ren, Hua Duan, Sha Wang, Yanan Chang
This study was reported according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) [15]. Databases were manually searched, including PubMed, Embase, Ovid, Cochrane Library, the Chinese National Knowledge Infrastructure Database (CNKI), and the Wanfang Database. And relevant literatures were systematically searched. Search words include: "Endometrial polyp", "laser". References to related studies were also searched to avoid missing studies that met the inclusion criteria. The retrieval formula were: (Laser) OR (Q-Switched Lasers) OR (Laser, Q-Switched) OR (Lasers, Q-Switched) OR (Q Switched Lasers) OR (Q-Switched Laser) OR (Pulsed Lasers)) OR (Laser, Pulsed) OR (Lasers, Pulsed) OR (Pulsed Laser) OR (Continuous Wave Lasers) OR (Continuous Wave Laser) OR (Laser, Continuous Wave) OR (Lasers, Continuous Wave) OR (Masers) OR (Maser), (endometrial polyp) OR (endometrial polyps)
Evolving the concept of APD
Published in International Journal of Audiology, 2018
The concept of a spectrum has been used to describe disorders that include a range of linked conditions of similar appearance or resulting from the same underlying mechanism (American Psychiatric Association 2013; Maser and Akiskal 2002). Whereas categorical approaches to disorders seek to provide single diagnostic labels by identifying the presence or absence of specific symptoms in a polythetic manner (Krueger and Bezdjian 2009), spectrum approaches allow for signs and symptoms to be both graded as well as heterogeneous within and overlapping across disorders. Spectrum approaches also allow for greater consideration of temperaments, traits, lifestyle, behavioural patterns and personality as they relate to a disorder (American Psychiatric Association 2013; Maser and Akiskal 2002). Such allowances have been used to link conditions previously thought to be separate (e.g. autism spectrum disorder) and to reconsider a single disorder as a range of subtypes (e.g. bipolar spectrum). The concept of spectrum disorders is not without risk, however, with particular care needed to avoid simple difficulties being reclassified as disorders.
Genotoxicity evaluation of silica nanoparticles in murine: a systematic review and meta-analysis
Published in Toxicology Mechanisms and Methods, 2022
Li Li, Yaxin Deng, XiaoJia Meng, Hongmei Chang, Chunmei Ling, Danni Li, Qian Wang, Tianjiao Lu, Yaqian Yang, Guanling Song, Yunhua Hu
According to the results of treatment time, it was found that short-term exposure (≤12 h) had a higher sensitivity in in vitro MN assay. But it did not mean that a shorter treatment time can induce more MN, only 12 and 24 h treatment times were included in our study. The shortest treatment time in vitro test is 3 h, which meant that the appropriate exposure time may be between 3 and 24 h. When the exposure time is too short, the nanoparticles cannot be absorbed by cells and don’t have enough time to produce toxic reactions. If treatment time is too long, the nanoparticles may aggregate or be diluted by differential growth in the medium or eliminated by apoptosis (OECD 2016), so the genotoxic potential may be underestimated. Similarly, it is speculated that a suitable exposure time is 12–24 h in vitro comet experiment since the DNA damage can be rapidly repaired but not less than 12 h. However, several studies proposed whether the typical culture time, applied to in vitro genotoxicity assays that are usually <24 h, was suitable for more slowly diffusion nanoparticles (Doak et al. 2009; Maser et al. 2015). In summary, we need to explore a suitable time for in vitro genotoxicity tests.
Related Knowledge Centers
- Ammonia
- Hydroxyl Radical
- Methanol
- Laser
- Visible Spectrum
- Hydrogen Maser
- Chemical Polarity
- Pentacene
- Terphenyl
- Hydrogen