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PubMed2003

Reliability and gender differences of static explosive grip parameters based on force-time curves.

AIM: The purpose of this study was to examine the reliability and gender differences of static explosive grip (SEG) parameters based on force-time curves. METHODS EXPERIMENTAL DESIGN: data were collected from 2 trials of SEG tests on the same day and 2 trials 1 week later. PARTICIPANTS: 50 healthy young males (21.2+/-1.57 yrs) and females (20.1+/-1.18 yrs) participated in this study. MEASURES: 12 variables based on factors such as time-course of force, average force, integrated area, maximal rate of force development, the product of force and inclination and exponential function of force development (EXP-M) were selected as force-time parameters in SEG testing. RESULTS: A significant reliability was obtained for all force-time parameters except the time to 90% of maximal grip strength (MAX), with the reliability of integrated area, average force, maximal rate of force development (DFmax), and the product of force and inclination being particularly high (ICC=0.633-0.930 for the same day, ICC=0.612-0.828 for different days). There were gender differences for all parameters except the time to MAX and EXP-M (p<0.05). In addition, many of the correlation coefficients between parameters were high, particularly for males. The average force, integrated area for 1 sec, and the product of force and inclination during the developmental phase significantly correlated with MAX in both males and females. The ratio between males and females in these force-time parameters was smaller than that of MAX (71.3%). CONCLUSION: It is considered that these parameters are dependent on the speed of muscle contraction. These results suggest that the evaluation parameters, such as average force, integrated area, the product of force and inclination, and maximal rate of force development are useful for evaluating static explosive grip.

Adult↗
PubMed2004

New developments in SPME Part 2: Analysis of ammonium nitrate-based explosives.

Solid-phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) is a simple, reliable technique for the recovery and analysis of many organic explosives. However, this technique is impractical for the analysis of ammonium nitrate-type explosives due to the extreme polarity, low molecular weight, and high volatility of the amine moiety. This article describes an initial investigation of a derivatization process utilizing alkylchloroformates that converts ammonium nitrate and methylammonium nitrate into a form suitable for recovery by SPME and analysis by GC-MS.

Journal Article↗
PubMed2004

Birds in a bush: five genes indicate explosive evolution of avian orders.

All recent studies of bird phylogeny have produced poorly resolved relationships among the orders of Neoaves, the lineage that includes most modern birds. This "bush" result suggests the possibility of an explosive and potentially unresolvable evolutionary radiation. However, simultaneous radiations of multiple lineages are thought to be rare or nonexistent in nature and difficult to corroborate empirically because lack of phylogenetic resolution can also be caused by analytical artifacts. Here we examine the predictions of the explosive radiation hypothesis for five independent genetic datasets for Neoaves. We propose a methodology for testing for polytomies of evolutionary lineages, perform likelihood-ratio tests to compare trees with zero-length branches to more resolved trees, compare topologies between independent gene trees, and propose a power test for the SOWH test. The evidence of (1) extremely short (in some cases zero-length) branches for interordinal relationships across independent gene trees and (2) topological incongruence among gene trees suggests that the bird tree includes essentially simultaneous radiation of multiple lineages. This result explains why a robust phylogeny of birds has not been produced despite much effort on the part of avian systematists.

Animals↗
PubMed2004

Trace analysis of peroxide explosives by high performance liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry (HPLC-APCI-MS/MS) for forensic applications.

An HPLC-APCI-MS(/MS) method for the (trace) analysis of the most commonly encountered peroxide explosives, hexamethylenetriperoxidediamine (HMTD) and triacetonetriperoxide (TATP), has been developed. With this method, HMTD and TATP have been analyzed in the same run. (Pseudo-)molecular ions of these peroxides have been obtained as base peak under the same condition. A series of product ions was produced from these pseudo-molecular ions ([HMTD - 1]+ and [TATP + NH4]+) in the MS/MS analysis. We also pioneered in showing that a TATP molecular ion [TATP + H]+ can be observed with HPLC-MS/MS. The limit of detection for HMTD and TATP was 0.26 and 3.3 ng, respectively, on column by HPLC-MS in the Full Scan mode and 0.08 and 0.8, respectively, by HPLC-APCI-MS/MS in Selected Reaction Monitoring (single mass unit) mode. The method presented has been applied successfully for the identification of peroxides in the bulk solid state (powder sample), as well as in post-blast extracts originating from a forensic case. For the post-blast extracts, the use of tandem MS has been shown clearly to be of crucial importance for the identification and detection of the peroxide explosives.

Journal Article↗
PubMedDate not supplied

Early and explosive development of nodular basal cell carcinoma and multiple keratoacanthomas in psoriasis patients treated with cyclosporine.

The use of cyclosporine to treat psoriasis has been widely adopted since 1997, when the microemulsion form (Neoral) became available. While the causal relationship between cyclosporine and the development of malignant neoplasms has been well described in the transplant literature, it is difficult to apply this relationship to cyclosporine-treated psoriasis, since lower dosages are used (3-5 mg/kg/d vs. 7-15mg/kg/d) for a shorter duration. Current literature suggests that cancer risk is not increased when cyclosporine is used in dermatologic doses for less than 2 years in healthy patients who are not on other immunosuppressants. We report two patients with explosive basal cell carcinoma and keratoacanthoma development, respectively, within 3 months of initiation of cyclosporine. Neither patient had a history of skin cancer, had received PUVA therapy, or was on additional immunosuppressive therapy. To our knowledge, there have been no previous reports of the development of similar lesions in cyclosporine-treated psoriatic patients within such a short timeframe. The results of these patients may herald the need for increased awareness by dermatologists for explosively-growing neoplasms in the setting of cyclosporine-treated psoriasis.

Basal Cell Carcinoma↗
PubMed2004

Enzymatic redox reactions of the explosive 4,6-dinitrobenzofuroxan (DNBF): implications for its toxic action.

With an aim to understand the toxicity mechanisms of the explosive 4,6-dinitro- benzofuroxan (DNBF), we studied its single-electron reduction by NADPH:cytochrome P450 reductase and ferredoxin:NADP(+) reductase, and two- electron reduction by DT-diaphorase and Enterobacter cloacae nitroreductase. The enzymatic reactivities of DNBF and another explosive 2,4,6-trinitrotoluene (TNT) were similar, except for the much lower reactivity of DNBF towards nitroreductase. DNBF was less cytotoxic in FLK cells than TNT. However, their action shared the same mechanisms, oxidative stress and activation by DT-diaphorase. The lower cytotoxicity of DNBF may be explained by the negative electrostatic charge of its adduct with water which may impede cellular membrane penetration, and by the formation of its less reactive adducts with intracellular reduced glutathione.

Animals↗
PubMedDate not supplied

Plant processes important for the transformation and degradation of explosives contaminants.

Environmental contamination by explosives is a worldwide problem. Of the 20 energetic compounds, 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) are the most powerful and commonly used. Nitroamines are toxic and considered as possible carcinogens. The toxicity and persistence of nitroamines requires that their fate in the environment be understood and that contaminated soil and groundwater be remediated. This study, written as a minireview, provides further insights for plant processes important for the transformation and degradation of explosives. Plants metabolize TNT and the distribution of the transformation products, conjugates, and bound residues appears to be consistent with the green liver model concept. Metabolism of TNT in plants occurs by reduction as well as by oxidation. Reduction probably plays an important role in the tolerance of plants towards TNT, and, therefore a high nitroreductase capacity may serve as a biochemical criterion for the selection of plant species to remediate TNT. Because the activities and the inducibilities of the oxidative enzymes are far lower than of nitroreductase, reducing processes may predominate. However, oxidation may initiate the route to conjugation and sequestration leading ultimately to detoxification of TNT, and, therefore, particularly the oxidative pathway deserves more study. It is possible that plants metabolize RDX also according to the green liver concept. In the case of plant metabolism of HMX, a conclusion regarding compliance with the green liver concept was not reached due to the limited number of available data.

Biodegradation, Environmental↗
PubMed2006

Comparison of force-time parameters and EMG in static explosive gripping by various exertion conditions: muscle fatigue state and submaximal exertion.

AIM: The purpose of this study was to compare the exertion and electromyography (EMG) properties during the developmental phase (DFmax) in static explosive grip (SEG), rapid submaximal exertion grip, namely fake SEG exertion (FAKE), and SEG in a muscle fatigue state. METHODS: Thirty healthy males and females performed the SEG and FAKE exertions (50% and 75% of peak value as a target value). Then, they performed sustained repeated rhythmic grip for 6 min (30 times x min(-1)), and SEG after 1-min, 4-min, and 7-min (SEG after the exertion). EMG was measured concurrently to compare with the muscle activation property during each grip exertion. Eight force-time parameters evaluating the DFmax in addition to the peak value were selected. RESULTS: The peak value significantly decreased, and the mean power spectrum density shifted to the low-wave in SEG after the exertion as compared with before. Therefore, SEG after the exertion was judged to be a muscle fatigue state. In addition, because the frequency properties in each exertion differed, the muscle activation properties during their DFmaxs were considered to differ. From the comparison between SEG before and after the exertion and FAKE, it is suggested that the time of reaching the peak value and the relative muscle strength when reaching an inflection point are not useful as parameters to evaluate the explosive muscle function during SEG. CONCLUSIONS: The maximal increasing volume during the DFmax and integrated area until 0.25 and 0.5 s could discriminate a difference of the DFmaxs according to each exertion and they are useful parameters.

Adult↗
PubMed2006

Effects of static stretching volume and intensity on plantar flexor explosive force production and range of motion.

AIM: The aim of the study was to determine the effects of volume and intensity of static stretching in a warm-up on explosive force production and range of motion (ROM) of the plantar flexors. METHODS: Twenty subjects performed 5 warm-ups on different days. The warm-ups contained a 5 min treadmill run and various protocols of 30 s static stretches (SS) of the plantar flexors. Stretching involved dorsi flexion just before the pain threshold, which was considered 100% intensity. The treatments that immediately followed the run were: (i) no other treatment (control); (ii) 1 min SS; (iii) 2 min SS; (iv) 4 min SS; (v) 2 min SS at 90% intensity. Ankle ROM was assessed before and after each warm-up and a concentric calf raise and drop jump (DJ) test was conducted after each warm-up. RESULTS: There were no significant differences (P > 0.05) in peak force or rate of force production in the explosive calf raise between any of the warm-ups. However the run plus 2 min stretch and the run plus 4 min stretch protocols produced significantly lower (P < 0.05) DJ performance (jump height/ground contact time) than the run. The run plus 4 min stretch warm-up also produced a significantly lower DJ score than the run plus 1 min stretch warm-up. There were no significant differences between any of the warm-ups in ankle ROM. CONCLUSIONS: The addition of 2-4 min of SS at 100% intensity to a run caused an impairment to fast stretch shortening cycle muscle performance. The greater impairment from the 4 min stretching condition supported a volume-effect. Two minutes of stretching at 90% intensity had no significant influence on muscle function. The addition of up to 4 min of SS to a run had no appreciable effect on ankle ROM, possibly because of the prior influence of the run.

Adolescent↗
PubMed2006

[Explosion of the subjective world].

PURPOSE: This text was inspired by an article in psycho-oncology: "The influence of psychotherapy on the extension of life in people with advanced cancer". I intend to show that cancer causes disintegration ("explosion") of a person's subjective world. MATERIAL AND METHODS: (philosophical discourse): Categories of the personal world and the subjective world are introduced and the reality of the subjective world is accepted. The following connotations are essential to further discussion: The mind acts on the body. The psychic state (therefore the state of the brain) is reflected in states and processes localized outside the brain. The epistemologist desires to discover the causal mechanism that explains these effects. The body may act on the mind. Overwhelming evidence has accumulated that disorders of the mind may be caused by disturbances of processes in the nervous system. I reject the view that "the brain is the cause of the mind". CONCLUSIONS: Every person lives in his or her own, private, subjective world. It is a relatively stable world of personal memories, observations and imaginations. This world extends in subjective time and space. Its content is composed of conscious psychic experiences, one after another. Experiences create the stream of consciousness. Serious illness leads to the explosion or disintegration of subjective world, destruction of one's sense of personal identity, impossibility of autoreflection, and loss of sense of living. In such cases, individualized psychotherapeutic intervention proves to be irreplaceable.

Body Image↗
PubMedDate not supplied

[Pathophysiologic reactions in sheep to blast waves from detonation of aerosol explosives].

In the controlled field experiments 18 sheep were exposed to the detonation of the aerosol explosive generating the blast wave necessary to produce death in 50% of cases. The time of death and characteristic damages on the predilection sites of some organs are interpreted as blast type injuries. General response of the body to blast wave was similar to the one produced by other etiological factors. A special characteristic of the experiment was the frequency and severity of pathologic changes on the internal organs of the chest and abdomen. According to the authors' opinion the severity and type of pathologic changes could be explained by effects of the complex blast wave generated by detonation of the aerosol explosives.

Animals↗
PubMed1990

[An explosive outbreak of respiratory streptococcal infection with a droplet transmission mechanism].

The data obtained in the study of an explosive outbreak of acute respiratory diseases, tonsillitis and scarlet fever in one of schools in Moscow have made it possible to exclude the alimentary mechanism of its development and to demonstrate the role of the droplet mechanism of transmission in the appearance of its outbreak. The epidemiological analysis of the outbreak has permitted the formulation of the hypothesis on the conditions of the formation and spread of the epidemic variant of the infective agent; this hypothesis corresponds to the available data in literature on the qualitative changes of the infective agent in the course of the epidemic process. The study has shown that the prophylaxis of the explosive outbreaks of respiratory streptococcal infections must be ensured by the system of epidemiological surveillance with timely intervention into the epidemiological process at its early stages.

Adolescent↗
PubMed1989

[Treatment of explosion injury in 30 eyes by keratoplasty].

26 cases (30 eyes) of explosion injury were treated by keratoplasty, with the results that 70% of the grafts were clear, 50% escaped blindness, and a total of 76% had their vision improved. In nine cases of severe injury in the anterior segment with little light perception, reconstructive keratoplasty was performed to keep the eyeballs successfully in seven cases, among whom five cases obtained transparent grafts. The procedure included partial keratectomy, iridectomy, lensectomy, anterior vitrectomy, keratoplasty, and reconstruction of the anterior chamber to restore cosmetic shape of the eyeball. The author deemed keratoplasty valuable in the treatment of ocular explosion injury.

Adolescent↗
PubMed1978

Explosive decompression of subjects up to a 20,000-m altitude using a two-pressure flying suit.

The RSAF two-pressure flying suit system to protect the pilot at high altitude has been tested from different medical safety aspects. To secure adequate alveolar oxygen pressure, the suit admits up to 70 mm Hg (9.3 kPa) positive pressure breathing by counter-pressure against the thorax and by a 3.2 times higher pressure in the anti-G suit. After 1 h of oxygen breathing, subjects were exposed to explosive decompression from an altitude of 9,000 m to 17,500 or 20,000 m in 0.5 s in a hypobaric chamber. No symptoms of decompression sickness or of alveolar rupture with gas embolism to the central nervous system were seen. Pulmonary X-rays after the test did not reveal any signs of lung rupture with extrapulmonary gas leakage. With the precordial Doppler ultrasound technique, intracardial gas bubbles (silent bubbles) could be detected only in one subject after explosive decompression to a 20,000-m altitude in the 10 experiments.

Adult↗
PubMed1987

[Laryngeal lesions caused by explosions (laryngeal blasts)].

Laryngeal lesions due to explosions are termed laryngeal blast injuries when they result exclusively from the shock wave effects on laryngeal structures. Their experimental study is very recent and physical and physiopathologic bases for these lesions are discussed in relation to two cases. It is essential to identify these lesions early in all victims of an explosion since their presence may indicate the existence of pulmonary or abdominal blast injuries, detected at a later stage and affecting vital prognosis.

Blast Injuries↗
PubMed1979

[Microsurgical plastic reconstruction of the explosion-damaged hand].

During the last two years, 16 severe explosion injuries of the hand have been treated with plastic microsurgery in our hospital. The injury had arisen in seven cases from the mixture sugar + sodium chlorate (C12H22O11 + NaClO3). This substance mixture may already be caused to explode by slight vibrations and the warmth of the hands. In explosion injuries, there is mechanical, chemical and thermal tissue damage. The postoperative course is therefore complicated in almost all cases. However, by meticulous removal of the disseminated foreign particles, excision of necrotic tissue and extensive reconstruction of the interrupted vascular and nerve supply, it is possible in a few cases to preserve functionally important parts of the hand. Later plastic procedures are made more difficult by tissue fibrosis and foreign body granulomas.

Adolescent↗
PubMed1993

The explosive Copula of Thomas Willis.

Thomas Willis (1621-1675), arguably the founding father of neurology, devised an interpretation of neurophysiology which involved motor function being mediated by explosions in nerve tissue and muscle, facilitated by the temporary development of an explosive Copula comprising short-lived aggregates of 'nitrous' and 'sulphur' particles i.e. the components of gunpowder. Seen from a modern standpoint, such a concept is manifestly absurd. However, seen from the standpoint of the Paracelsian iatrochemistry to which Willis subscribed, and understood in the spirit of analogy which he probably intended, Willis' interpretation can be regarded as the beginning of the application of bioenergetics to neural function.

England↗
PubMed1993

[Relationship between intracochlear oxygen tension and acoustic trauma following explosion].

Perilymphatic oxygen tension of scala tympani (STPO2) in guinea pigs exposed to explosion was measured with polarographic oxygen microelectrode, the relations between either hearing loss or injuries to hair cells and the change in STPO2 were studied. The results showed: 1. Exposure to 10 shots (1 shot/min) of explosion with 141-171dB average peak pressure levels, caused a sharp decline of STPO2. 2. When the decrease of STPO2 exceeded 20%, hearing loss became definitive. The change of STPO2 correlated with the amount of sound exposure and hearing loss as well as injuries to hair cells. 3. After carbogen inhalation, STPO2 quickly increased by nearly 100%.

Animals↗