X-Ray Free-Electron Lasers for the Structure and Dynamics of Macromolecules.

X-ray free-electron lasers provide femtosecond-duration pulses of hard X-rays with a peak brightness approximately one billion times greater than is available at synchrotron radiation facilities. One motivation for the development of such X-ray sources was the proposal to obtain structures of macromolecules, macromolecular complexes, and virus particles, without the need for crystallization, through diffraction measurements of single noncrystalline objects. Initial explorations of this idea and of outrunning radiation damage with femtosecond pulses led to the development of serial crystallography and the ability to obtain high-resolution structures of small crystals without the need for cryogenic cooling. This technique allows the understanding of conformational dynamics and enzymatics and the resolution of intermediate states in reactions over timescales of 100 fs to minutes. The promise of more photons per atom recorded in a diffraction pattern than electrons per atom contributing to an electron micrograph may enable diffraction measurements of single molecules, although challenges remain.

Biophysical Techniques in Structural Biology.

Over the past six decades, steadily increasing progress in the application of the principles and techniques of the physical sciences to the study of biological systems has led to remarkable insights into the molecular basis of life. Of particular significance has been the way in which the determination of the structures and dynamical properties of proteins and nucleic acids has so often led directly to a profound understanding of the nature and mechanism of their functional roles. The increasing number and power of experimental and theoretical techniques that can be applied successfully to living systems is now ushering in a new era of structural biology that is leading to fundamentally new information about the maintenance of health, the origins of disease, and the development of effective strategies for therapeutic intervention. This article provides a brief overview of some of the most powerful biophysical methods in use today, along with references that provide more detailed information about recent applications of each of them. In addition, this article acts as an introduction to four authoritative reviews in this volume. The first shows the ways that a multiplicity of biophysical methods can be combined with computational techniques to define the architectures of complex biological systems, such as those involving weak interactions within ensembles of molecular components. The second illustrates one aspect of this general approach by describing how recent advances in mass spectrometry, particularly in combination with other techniques, can generate fundamentally new insights into the properties of membrane proteins and their functional interactions with lipid molecules. The third reviewdemonstrates the increasing power of rapidly evolving diffraction techniques, employing the very short bursts of X-rays of extremely high intensity that are now accessible as a result of the construction of free-electron lasers, in particular to carry out time-resolved studies of biochemical reactions. The fourth describes in detail the application of such approaches to probe the mechanism of the light-induced changes associated with bacteriorhodopsin's ability to convert light energy into chemical energy.

History of UV Lamps, Types, and Their Applications.

The use of ultraviolet (UV) light, for the treatment of skin conditions, dates back to the early 1900s. It is well known that sunlight can be of therapeutic value, but it can also lead to deleterious effects such as burning and carcinogenesis. Extensive research has expanded our understanding of UV radiation and its effects in human systems and has led to the development of man-made UV sources that are more precise, safer, and more effective for the treatment of wide variety of dermatologic conditions.

[The Early Years of Military Laser Research and Technology in the Federal Republic of Germany During the Cold War]. / Die Anfänge der Militärischen Laserforschung und Lasertechnik in der Bundesrepublik Deutschland im Zeitalter des Kalten Krieges.

The invention of the laser in 1960 and the innovation process of laser technology during the following years coincided with the dramatic increase of the East-West-conflict during the 1960s - the peak of the so-called Cold War after the erection of the Berlin Wall in 1961. The predictable features of the new device, not only for experimental sciences, but also for technical and military applications, led instantly to a laser hype all over the world. Military funding and research played a major part in this development. Especially in the United States military laser research and development played an important role in the formation of Cold War sciences. The European allies followed this example to a certain degree, but their specific national environments led to quite different solutions and results. This article describes and analyzes the special features and background of this development for the Federal Republic of Germany in the area of conflict between science, politics and industry from 1960 to the early 1970s.

José Morón was the first to introduce the retinal light photocoagulation.

Regarding the early history of laser, it is generally accepted that the technique of retinal light photocoagulation was first pioneered by Gerd Meyer-Schwickerath in 1949. The renowned German ophthalmologist developed the technique to obtain clinically useful results and is worldwide considered the father of retinal photocoagulation. Nevertheless, we believe that the Spanish ophthalmologist José Morón (Seville, 1918-2000) was really the author of the first known experience of therapeutic photocoagulation of the retina, because he had previously used a similar technique in rabbit and human eyes in 1945 and 1946, respectively. These experiences already appeared in his doctoral dissertation, which was defended in Madrid in 1946, almost three years before the pioneering presentation of Meyer-Schwickerath. Despite this, Morón was permanently forgotten in the history of retinal photocoagulation. We would like to highlight his earlier experimental studies and reclaim the figure of this Spanish ophthalmologist, which deserves international recognition. This case is an example of a common phenomenon that inventors of new ideas are often not cited appropriately.

50 years LASERS: in vitro diagnostics, clinical applications and perspectives.

1960 Theodore Maiman built the first Ruby-LASER, starting-point for half a century of R&D on Biomedical LASER continuous improvement. The purpose of this paper is to contribute a review of the often disregarded, however, extremely important Industrial Property documents of LASER-based in vitro Diagnostics devices. It is an attempt to sketch-out the patent-trail leading towards the modern Biomedical Laboratory and to offer an introduction to the employment of "exotic" systems, such as the Free Electron LASER (FEL), that are expected to focus on the fundamental processes of life, following chemical reactions and biological processes as they happen, on unprecedented time and size scales. There are various in vitro LASER applications, however, the most important ones include: Hybrid Coulter Principle-LASER Hematology Analyzers. Flow Cytometry systems. Fluorescent in situ Hybridization (FISH Techniques). Confocal LASER Scanning Microscopy and Cytometry. From the first fluorescence-based flow Cytometry device developed in 1968 by Wolfgang Göhde until nowadays, numerous improvements and new features related to these devices appeared. The relevant industrial property milestone-documents and their overall numeral trends are presented. In 1971, J. Madey invented and developed the Free Electron LASER (FEL), a vacuum-tube that uses a beam of relativistic electrons passing through a periodic, transverse magnetic field (wiggler) to produce coherent radiation, contained in an optical cavity defined by mirrors. A resonance condition that involves the energy of the electron beam, the strength of the magnetic field, and the periodicity of the magnet determines the wavelength of the radiation. The FEL Coherent Light Sources like the Linac Coherent Light Source (LCLS) at Stanford, CA, USA or the Xray Free Electron LASER (XFEL) at Hamburg, Germany, will work much like a high-speed (< 100 femtoseconds) camera, enabling scientists to take stop-motion pictures, on the nanoscale, of atoms and molecules in motion. The curve of FEL-related patents of the last 20 years is much smoother than the corresponding one for in vitro Diagnostics conventional LASERS. If the diodes brought a LASER into almost everyone's pocket, the above-mentioned super-imaging systems are huge facilities of enormous cost--the price to steal a look at the fundamental processes of life.

Masers to magic bullets: an updated history of lasers in dermatology.

Laser therapy is one of the fastest expanding and most exciting fields in dermatology. From its theoretical beginnings in Einstein's imagination, lasers have come to be used in treatments for conditions ranging from skin malignancy and acne to hirsutism and photoaging. We will briefly review the evolution of laser treatment, with a focus on the recent developments surrounding the new millennium.

The relaxed confocal scanning laser ophthalmoscope.

The development of the Scanning Laser Ophthalmoscope is reviewed from a historical perspective. Since a flying-spot scanning principle for an electro-optical ophthalmoscope was first disclosed in 1950, enabling milestones have included the introduction of the laser and inversion of the usual Gullstrand's configuration of optical pupils in 1977, and the application of the optical principle of confocality by means of double or de-scanning in 1983. As a result, high resolution and high contrast confocal infra-red ophthalmoscopy with a 790 nm diode laser, at video rates, is a major novel imaging modality when compared to traditional optical techniques. This imaging mode is ideal to provide the necessary fiducial landmarks for microperimetry, therapeutic laser and SD-OCT based optical sectioning of the retina. DPSS or He-Ne lasers emitting at 532, 543, 561 or 575 nm are used for complimentary red-free fundus imaging. The diode 790 nm and DPSS 490 nm lasers are also used for fluorescence excitation.

Basics of Lasers: History, Physics, and Clinical Applications.

Lasers are increasingly used by plastic surgeons to address issues such as wrinkles and textural changes, skin laxity, hyperpigmentation, vascularity, and excess fat accumulation. A fundamental understanding of the underlying science and physics of laser technology is important for the safe and efficacious use of laser in medical settings. The purpose of this article was to give clinicians with limited exposure to lasers a basic understanding of the underlying science. In that manner, they can confidently make appropriate decisions as to the best device to use on a patient (or the best device to purchase for a practice).

Multiformat video and laser cameras: history, design considerations, acceptance testing, and quality control. Report of AAPM Diagnostic X-Ray Imaging Committee Task Group No. 1.

Acceptance testing and quality control of video and laser cameras is relatively simple, especially with the use of the SMPTE test pattern. Photographic quality control is essential if one wishes to be able to maintain the quality of video and laser cameras. In addition, photographic quality control must be carried out with the film used clinically in the video and laser cameras, and with a sensitometer producing a light spectrum similar to that of the video or laser camera. Before the end of the warranty period a second acceptance test should be carried out. At this time the camera should produce the same results as noted during the initial acceptance test. With the appropriate acceptance and quality control the video and laser cameras should produce quality images throughout the life of the equipment.

The laser in surgery. A 23 year perspective.

Clinically silent malignant tumor recurrence or metastasis can be treated by laser resection or vaporization as well as by a second-look procedure suggested by an increasing level of carcinoembryonic antigen. Laser resection enables surgeons to resect multiple small metastases that would not normally be resectable. The surgical limitations of each laser unit and each wavelength must be identified. The laser is now used by gynecologists, neurosurgeons, otolaryngologists, ophthalmologists, and oncologic surgeons to rapidly and precisely resect or vaporize tissues and, in some cases, to extend tumor-free survival. Twenty-three years after its first experimental use, the laser has established itself as an important surgical tool.

Lasers and the surgeon.

The evolution of laser technology in medicine has progressed rapidly over the past 25 years, and these devices are widely used in surgical treatment today. Three different types of lasers are predominantly used: the carbon dioxide, argon ion, and neodymium-YAG instruments. Each operates on similar principles but because of the different wavelengths of light emitted, their applications differ. However, by and large, all of them utilize thermal energy generated by light and tissue interactions. Recently, the combination of an argon ion and a dye laser used with photosensitizing drugs has shown promise in the treatment of cancers, and this represents a nonthermal application of laser technology. In order to use lasers effectively, a knowledge of the specific laser and tissue properties is essential. In the future, lasers will be used not only as thermal scalpels but also as instruments than can provide a very precise delivery of energy to parts of the body that are otherwise inaccessible without operation. The use of photodynamic therapy will provide a mechanism of selectively destroying tumors while leaving normal tissues intact.

Overview of lasers in plastic surgery.

The laser used today in plastic surgery has gone through many stages of development. This article examines the history of lasers, including the scientific background and the theory of selective photothermolysis in therapy. In addition, current trends and future developments in laser treatment are discussed.