Ions colliding with clusters of fullerenes--decay pathways and covalent bond formations.

We report experimental results for the ionization and fragmentation of weakly bound van der Waals clusters of n C60 molecules following collisions with Ar(2+), He(2+), and Xe(20+) at laboratory kinetic energies of 13 keV, 22.5 keV, and 300 keV, respectively. Intact singly charged C60 monomers are the dominant reaction products in all three cases and this is accounted for by means of Monte Carlo calculations of energy transfer processes and a simple Arrhenius-type [C60]n(+) → C60(+)+(n-1)C60 evaporation model. Excitation energies in the range of only ~0.7 eV per C60 molecule in a [C60]13(+) cluster are sufficient for complete evaporation and such low energies correspond to ion trajectories far outside the clusters. Still we observe singly and even doubly charged intact cluster ions which stem from even more distant collisions. For penetrating collisions the clusters become multiply charged and some of the individual molecules may be promptly fragmented in direct knock-out processes leading to efficient formations of new covalent systems. For Ar(2+) and He(2+) collisions, we observe very efficient C119(+) and C118(+) formation and molecular dynamics simulations suggest that they are covalent dumb-bell systems due to bonding between C59(+) or C58(+) and C60 during cluster fragmentation. In the Ar(2+) case, it is possible to form even smaller C120-2m(+) molecules (m = 2-7), while no molecular fusion reactions are observed for the present Xe(20+) collisions.

Formations of dumbbell C118 and C119 inside clusters of C60 molecules by collision with α particles.

We report highly selective covalent bond modifications in collisions between keV alpha particles and van der Waals clusters of C(60) fullerenes. Surprisingly, C(119)(+) and C(118)(+) are the dominant molecular fusion products. We use molecular dynamics simulations to show that C(59)(+) and C(58)(+) ions--effectively produced in prompt knockout processes with He(2+)--react rapidly with C(60) to form dumbbell C(119)(+) and C(118)(+). Ion impact on molecular clusters in general is expected to lead to efficient secondary reactions of interest for astrophysics. These reactions are different from those induced by photons.

Polycyclic aromatic hydrocarbon-isomer fragmentation pathways: case study for pyrene and fluoranthene molecules and clusters.

We report on measurements of the ionization and fragmentation of polycyclic aromatic hydrocarbon (PAH) targets in Xe(20+) + C(16)H(10) and Xe(20+) + [C(16)H(10)](k) collisions and compare results for the two C(16)H(10) isomers: pyrene and fluoranthene. For both types of targets, i.e., for single PAH molecules isolated in vacuum or for isomerically pure clusters of one of the molecules, the resulting fragment spectra are surprisingly similar. However, we do observe weak but significant isomer effects. Although these are manifested in very different ways for the monomer and cluster targets, they both have at their roots small differences (<2.5 eV) between the total binding energies of neutral, and singly and multiply charged pyrene and fluoranthene monomers. The results will be discussed in view of the density functional theory calculations of ionization and dissociation energies for fluoranthene and pyrene. A simple classical over-the-barrier model is used to estimate cross sections for single- and multiple-electron transfer between PAHs and ions. Calculated single and multiple ionization energies, and the corresponding model PAH ionization cross sections, are given.

The double electrostatic ion ring experiment: a unique cryogenic electrostatic storage ring for merged ion-beams studies.

We describe the design of a novel type of storage device currently under construction at Stockholm University, Sweden, using purely electrostatic focussing and deflection elements, in which ion beams of opposite charges are confined under extreme high vacuum cryogenic conditions in separate "rings" and merged over a common straight section. The construction of this double electrostatic ion ring experiment uniquely allows for studies of interactions between cations and anions at low and well-defined internal temperatures and centre-of-mass collision energies down to about 10 K and 10 meV, respectively. Position sensitive multi-hit detector systems have been extensively tested and proven to work in cryogenic environments and these will be used to measure correlations between reaction products in, for example, electron-transfer processes. The technical advantages of using purely electrostatic ion storage devices over magnetic ones are many, but the most relevant are: electrostatic elements which are more compact and easier to construct; remanent fields, hysteresis, and eddy-currents, which are of concern in magnetic devices, are no longer relevant; and electrical fields required to control the orbit of the ions are not only much easier to create and control than the corresponding magnetic fields, they also set no upper mass limit on the ions that can be stored. These technical differences are a boon to new areas of fundamental experimental research, not only in atomic and molecular physics but also in the boundaries of these fields with chemistry and biology. For examples, studies of interactions with internally cold molecular ions will be particular useful for applications in astrophysics, while studies of solvated ionic clusters will be of relevance to aeronomy and biology.

Ions colliding with cold polycyclic aromatic hydrocarbon clusters.

We report the first experimental study of ions interacting with clusters of polycyclic aromatic hydrocarbon (PAH) molecules. Collisions between 11.25 keV 3He+ or 360 keV 129Xe20+ and weakly bound clusters of one of the smallest PAH molecules, anthracene, show that C14H10 clusters have much higher tendencies to fragment in ion collisions than other weakly bound clusters. The ionization is dominated by peripheral collisions in which the clusters, very surprisingly, are more strongly heated by Xe20+ collisions than by He+ collisions. The appearance size is k=15 for [C 14H10](k)2+.

An inquiry into application of Gokyo (Aikido's Fifth Teaching) on human anatomy.

In this anatomical analysis the authors examined Gokyo, Aikido's Fifth Teaching. Using their cadaver/anatomist-observer model, the authors observed that tissues manipulated by the technique were primarily on the dorsal side of the wrist, proximal to the second metacarpal. The source of the pain was thought to involve the manipulation of the wrist joints and associated carpometacarpal ligaments. Locations of the manipulated tissue and sources of pain associated with that tissue, and their limited practical application were discussed.

What's causing the pain?: a re-examination of the Aikido Nikyo technique.

Recently there have been several investigations into the etiology of the pain produced on the application of Aikido's Nikyo (Second-teaching). This paper analyzes several conclusions as to the discrepancies found in the results of these studies.

An anatomical analysis of Aikido's third teaching: an investigation of Sankyo.

Sankyo, one of Aikido's strongest martial art techniques for peacefully subduing an attacker, produces pain in the hand, wrist, and forearm. Specific target muscles, tendons, and ligaments are identified through an investigation of Sankyo's expert application to two anatomists and a male cadaver.

An anatomical analysis of Aikido's second teaching: an investigation of Nikyo.

One of the strongest subduing techniques of the Martial Art Aikido is classified as Nikyo (Second-teaching). This investigation focused on examining this teaching with the intention of describing the anatomical tissues involved in the etiology of pain experienced with the application of this procedure. Particular focus was placed on the examination of a cadaver's arm musculature affected when this maneuver was applied precisely.

The evaluation and understanding of pain: clinical and legal/forensic perspectives.

The evaluation and proper clinical and legal management of pain clients defy simple remedies. Historically, human pain has challenged the most sophisticated of philosophical, theological, and biomedical explanations. Following an historical overview of pain concepts and treatment, this paper discusses the prevalence in and influence of pain on the modern world. One perspective for viewing multifaceted pain issues is a model developed by John Loeser. This four-level model addresses not only tissue damage (Nociception), but also the patient's perception of such damage (Pain), the negative emotional reactions to such perceptions (Suffering), as well as the pain activity stemming from such damage (Pain Behavior)--all issues critical in medical management as well as in personal injury litigation. Several methods for classifying pain are discussed, including acute vs chronic pain, benign vs cancer pain, "real" vs psychogenic pain, and a multiaxial coding schema for pain which encompasses a number of professional disciplines. Clinical pain assessment is then reframed and translated into a legal format more relevant to forensic discovery and case development.

Myocardial scintigraphy with iodine-123 phenylpentadecanoic acid and thallium-201 in patients with coronary artery disease: a comparative dual-isotope study.

To characterise the clinical usefulness of serial myocardial scintigraphy with iodine-123 phenylpentadecanoic acid (IPPA) in comparison with thallium-201, dual-isotope investigations were performed in 41 patients with angiographically documented coronary artery disease. Both tracers were administered simultaneously during symptom-limited ergometry. Planar scintigrams were acquired immediately after stress, and delayed imaging was performed after 1 h for IPPA and 4 h for 201Tl. Scintigrams were evaluated both qualitatively and quantitatively using a newly developed algorithm for automated image superposition. Initial myocardial uptake of both tracers was closely correlated (r = 0.75, p < 0.001). Both tracers also revealed a similar sensitivity for the identification of individual coronary artery stenoses > or = 75% (IP-PA: 70.0%, 201Tl: 66.3%, P = NS) with identical specificity (69.8%). The number of persistent defects, however, was significantly higher with IPPA (P = 0.021), suggesting that visual analysis of serial IPPA scintigrams may overestimate the presence of myocardial scar tissue. On the other hand, previous Q wave myocardial infarction was associated with a decreased regional IPPA clearance (29% +/- 11% vs 44% +/- 11% in normal myocardium, P < 0.05). The data indicate that serial myocardial scintigraphy with IPPA is essentially as sensitive as scintigraphy with 201Tl for the detection of stress-induced perfusion abnormalities. Quantitative analysis of myocardial IPPA kinetics, however, is required for the evaluation of tissue viability.

A martial arts exploration of elbow anatomy: Ikkyo (Aikido's first teaching).

The Martial Art of Aikido, based on several effective anatomical principles, is used to subdue a training partner. One of these methods is Ikkyo (First Teaching). According to Saotome, the original intent of Ikkyo was to "break the elbow joint" of an enemy. Nowadays the intent is to secure or pin a training partner to the mat. This investigation focused on examining Ikkyo with the purpose of describing the nerves, bones, and muscles involved in receiving this technique. Particular focus was placed on the locations and sources of the reported pain.

An examination of Aikido's Fourth Teaching: an anatomical study of the tissues of the forearm.

One of the basic teachings of Aikido is known as Yonkyo (Fourth Teaching) or Tekubi-Osae (Wrist Securing). According to some Aikido master teachers, Yonkyo is designed to attack the opponent's weak points. This investigation focused on examining this teaching with the purpose of describing the anatomical tissues involved in the etiology of pain when this teaching is applied precisely. Particular focus was placed on the anatomical locations/sources of pain associated with the application of this teaching.

The martial arts and mental health: the challenge of managing energy.

The effective management of energy is an important dimension in the martial arts as well as the mental health professions. The Oriental concept of Ki is described, noting its Indian, Chinese, and Japanese development. Ki and the transfer of energy is studied through the martial encounter, using concepts borrowed from Japanese swordsmanship. Ki is also discussed from a developmental context as youngsters progress in Tae Kwon Do training. In examining the disciplines of Aikido, Tae Kwon Do, and Karate, it becomes clear that more is involved than kicking, punching, and throwing bodies on the floor. These martial arts have some important statements to make in the area of mental health, particularly in terms of energy--within our bodies, psyches, interpersonal relationships, and the universe.