RESUMEN
RadiaBeam has developed a 6 MeV accelerator that is compact and light enough to be placed on a robotic arm or light truck. The main drivers of size and weight in conventional accelerators are the power source and the shielding. Small dimensions are enabled by operation at 9.3 GHz frequency (X-band), which allows reducing the size and weight of all accelerator components. Thanks to the robust design of the accelerating structure, the accelerator can be used as a source for novel cargo inspection and radiotherapy techniques. In this paper, we present the linac design and its components, as well the results of the experimental demonstration of beam acceleration.
RESUMEN
PURPOSE: In order to translate the FLASH effect in clinical use and to treat deep tumors, Very High Electron Energy irradiations could represent a valid technique. Here, we address the main issues in the design of a VHEE FLASH machine. We present preliminary results for a compact C-band system aiming to reach a high accelerating gradient and high current necessary to deliver a Ultra High Dose Rate with a beam pulse duration of 3µs. METHODS: The proposed system is composed by low energy high current injector linac followed by a high acceleration gradient structure able to reach 60-160 MeV energy range. To obtain the maximum energy, an energy pulse compressor options is considered. CST code was used to define the specifications RF parameters of the linac. To optimize the accelerated current and therefore the delivered dose, beam dynamics simulations was performed using TSTEP and ASTRA codes. RESULTS: The VHEE parameters Linac suitable to satisfy FLASH criteria were simulated. Preliminary results allow to obtain a maximum energy of 160 MeV, with a peak current of 200 mA, which corresponds to a charge of 600 nC. CONCLUSIONS: A promising preliminary design of VHEE linac for FLASH RT has been performed. Supplementary studies are on going to complete the characterization of the machine and to manufacture and test the RF prototypes.
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Aceleradores de PartículasRESUMEN
We have assessed the effects in normal control volunteers of 2,5-dimethoxy-4-methyl-amphetamine, the chemical present in the hallucinogenic drug STP, in two independent trials. In low doses, this compound produces a mild euphoria. Doses greater than 3 milligrams may cause pronounced hallucinogenic effects lasting about 8 hours and similar to those produced by hallucinogenic doses of lysergic acid diethylamide, mescaline, and psilocybin. 2,5-Dimethoxy-4-methyl-amphetamine, which is chemically related to mescaline and amphetamine, is about 100 times more potent as a hallucinogen than mescaline and only one-thirtieth as potent as lysergic acid diethylamide. Its psychological effects are not accentuated by chlorpromazine.
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Anfetamina/farmacología , Catecolaminas/farmacología , Alucinógenos/farmacología , Adulto , Presión Sanguínea/efectos de los fármacos , Clorpromazina/farmacología , Ensayos Clínicos como Asunto , Euforia/inducido químicamente , Alucinaciones/inducido químicamente , Alucinógenos/administración & dosificación , Humanos , Dietilamida del Ácido Lisérgico/farmacología , Masculino , Mescalina/farmacología , Percepción/efectos de los fármacos , Psilocibina/farmacología , Psicofarmacología , Pupila/efectos de los fármacosRESUMEN
Radio-frequency (RF) photoinjector-based relativistic ultrafast electron diffraction (UED) is a promising new technique that has the potential to probe structural changes at the atomic scale with sub-100 fs temporal resolution in a single shot. We analyze the limitations on the temporal and spatial resolution of this technique considering the operating parameters of a standard 1.6 cell RF gun (which is the RF photoinjector used for the first experimental tests of relativistic UED at Stanford Linear Accelerator Center; University of California, Los Angeles; Brookhaven National Laboratory), and study the possibility of employing novel RF structures to circumvent some of these limits.
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A study of 658 consecutive psychiatric outpatients receiving careful medical and biochemical evaluation, defined an incidence of medical disorders productive of psychiatric symptoms in 9.1% of cases. The most frequent presentations were of depression, confusion, anxiety, and speech or memory disorders. The presence of visual hallucinations was believed to indicate medical etiology until proved otherwise. Major illnesses presenting with psychiatric symptoms in order of frequency were infectious, pulmonary, thyroid, diabetic, hematopoietic, hepatic and CNS diseases. Forty-six percent of these patients suffered from medical illnesses previously unknown to either them or their physician. A plea is made for careful medical evaluation of psychiatric patients.
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Trastornos Neurocognitivos/diagnóstico , Adulto , Enfermedades Cardiovasculares/complicaciones , Enfermedades Cardiovasculares/psicología , Enfermedades Transmisibles/complicaciones , Enfermedades Transmisibles/psicología , Centros Comunitarios de Salud Mental , Enfermedades del Sistema Endocrino/complicaciones , Enfermedades del Sistema Endocrino/psicología , Enfermedades Gastrointestinales/complicaciones , Enfermedades Gastrointestinales/psicología , Enfermedades Hematológicas/complicaciones , Enfermedades Hematológicas/psicología , Humanos , Enfermedades Pulmonares/complicaciones , Enfermedades Pulmonares/psicología , Masculino , Persona de Mediana Edad , Neoplasias/complicaciones , Neoplasias/psicología , Trastornos Neurocognitivos/etiología , Trastornos Neurocognitivos/psicologíaRESUMEN
The authors compared the drug use of 23 patients with 5 or more major surgeries (mean number of surgeries = 9.8) with that of a matched control group (mean number of surgeries = 1). Total drug use of the polysurgical patients was 3.7 times greater than that of the controls and involved narcotics, analgesics, barbiturates, and minor tranquilizers. The authors describe the characteristics of polysurgical patients, one of which is chronic pain, and propose a treatment plan that involves psychological intervention for the patient and his or her family.
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Dolor Intratable/tratamiento farmacológico , Trastornos Psicofisiológicos/tratamiento farmacológico , Trastornos Relacionados con Sustancias/etiología , Procedimientos Quirúrgicos Operativos , Adulto , Anciano , Analgésicos/uso terapéutico , Ansiolíticos/uso terapéutico , Barbitúricos/uso terapéutico , Femenino , Trastorno de Personalidad Histriónica/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Narcóticos/uso terapéutico , Dolor Intratable/terapia , Relaciones Médico-Paciente , Trastornos Psicofisiológicos/terapia , Psicoterapia , Tranquilizantes/uso terapéuticoRESUMEN
The widespread use of synthetic organic fluorides has recently received attention as a potential health hazard. There are a number of organic fluorides which have become important considerations in psychiatry. Therapeutically the organic fluorides include the neuroleptics trifluoperazine, fluphenazine, triflupromazine, and haloperidol, the benzodiazepine flurazepam and the polyfluorinated inhalant convulsant indoklon. On the negative side, deliberate inhalation of fluorocarbon aerosol propellants has become a modern form of drug abuse among the young. A review is presented on the biochemistry and toxicology of organic fluorides with special emphasis on implications to the field of psychiatry.
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Hidrocarburos Fluorados/metabolismo , Aerosoles , Anestesiología , Animales , Ansiolíticos/efectos adversos , Arritmias Cardíacas/inducido químicamente , Benzodiazepinas , Biotransformación , Huesos/efectos de los fármacos , Membrana Celular/efectos de los fármacos , Fenómenos Químicos , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Química , Hipersensibilidad a las Drogas , Exposición a Riesgos Ambientales , Fluoroacetatos/toxicidad , Fluorosis Dental/etiología , Flurotilo/efectos adversos , Humanos , Hidrocarburos Fluorados/efectos adversos , Hígado/efectos de los fármacos , Ratas , Trastornos Relacionados con Sustancias , Tranquilizantes/efectos adversosRESUMEN
Early dropouts from a double-blind comparison of the therapeutic efficacy of alprazolam and imipramine were examined. The dropout rate across the total sample of 99 analyzable outpatients with major depression was 3 times higher in the imipramine treatment group. Although essentially all patients met DSM-III criteria for major depressive episode, only two thirds of the total sample met the restrictive Feighner criteria for primary depressive disorder. Early termination in the imipramine group was concentrated in the group of depressed outpatients who failed to satisfy the Feighner criteria. Implications of these and other recently reported results for choice of drug treatment for depressed psychiatric outpatients are discussed.
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Alprazolam/uso terapéutico , Trastorno Depresivo/tratamiento farmacológico , Imipramina/uso terapéutico , Cooperación del Paciente , Atención Ambulatoria , Ensayos Clínicos como Asunto , Trastorno Depresivo/diagnóstico , Método Doble Ciego , Humanos , Manuales como Asunto , Pacientes Desistentes del Tratamiento , Inventario de Personalidad , Escalas de Valoración Psiquiátrica , Distribución AleatoriaRESUMEN
The effect of the chronic administration of the combination of lithium and haloperidol has been studied in rat brain in vivo. Lithium was administered in food in amounts sufficient to maintain serum lithium levels of 1.0 +/- 0.1 mEq/l; haloperidol (1.5 mg/kg) was given i.p. once daily. Control animals pair-fed with the lithium/haloperidol alone, or neither drug. Fifteen days after the beginning of the experiments the brains were instantaneously frozen with a rapid brain-freezing device and multiple metabolites were measured in the perchloric acid extract of the tissue. Intermediates examined included selected metabolites of the glycolytic pathway and the tricarboxylic acid cycle, N-acetylaspartate and cofactors such as ATP, CoA, and acetyl-CoA. Estimates of the effects of the treatments on cytoplasmic and mitochondrial redox states were also made. The results showed only minor effects of any of the treatments on any of the parameters studied and little or nothing to distinguish the combination of lithium and haloperidol from either treatment alone.
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Encéfalo/metabolismo , Haloperidol/farmacología , Litio/farmacología , Animales , Encéfalo/efectos de los fármacos , Metabolismo de los Hidratos de Carbono , Dieta , Glucólisis/efectos de los fármacos , Masculino , NAD/metabolismo , Oxidación-Reducción , RatasRESUMEN
The goal of the present study was to assess the effects of trans-cranial electrical stimulation on the behavioral signs of the abrupt withdrawal syndrome of rats. However, this goal also necessitated the introduction of an experimental model measuring animal behavior for prolonged periods of time using a computerized animal activity monitoring system to quantify spontaneous motor activities associated with abstinence behavior. Comparable withdrawal severity was obtained by both the activity monitoring system and investigator observation of motor signs of abstinence behavior. Moreover, using this system we demonstrate a time-dependent effect of electrical stimulation in reducing the severity of various indices of motor hyperactivity associated with abrupt morphine withdrawal in rats.
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Estimulación Eléctrica , Dependencia de Morfina/terapia , Síndrome de Abstinencia a Sustancias/terapia , Animales , Conducta Animal , Masculino , Monitoreo Fisiológico/métodos , Actividad Motora , Naloxona/farmacología , Ratas , Ratas Endogámicas , Procesamiento de Señales Asistido por Computador , CráneoRESUMEN
Six Meishan and five Large White hybrid gilts were naturally mated to boars of the same breed during their tenth or third oestrous cycle respectively. Maternal serum progesterone and total oestrone were monitored throughout the pregnancy period. On Day 30 of gestation, all gilts were slaughtered and ovulation rate, embryonic survival, conceptus development and intrauterine steroidogenesis were evaluated. The results of the study confirm previous reports that Meishan pigs have a higher number of live conceptuses (P < 0.03), a higher rate of embryonic survival (92.1% v. 78.6% for Large White hybrids) and a higher ovulation rate (P < 0.02) than Large White hybrid gilts. Embryos from Large White hybrid gilts were heavier (P < 0.001) than Meishan embryos and placental lengths (P < 0.001) and weights (P < 0.001) were greater. The volume of allantoic fluid per conceptus was greater (P < 0.03) in Large White hybrid gilts. The oestradiol concentration in the allantoic fluid was greater in Large White hybrid gilts (P < 0.002), but the progesterone concentration in allantoic fluid did not differ (P > 0.15) between the breeds. More oestradiol was synthesized in vitro on a wet weight basis from placental tissue in Large White hybrid gilts than in Meishan gilts (P < 0.001); however, a positive linear relationship existed in both breeds between oestradiol synthesis and placental length (P < 0.005). Progesterone concentrations in maternal serum tended to be higher overall (P < 0.1) in Meishan gilts than in Large White hybrid gilts throughout the 30-day period of study and were significantly higher (P < 0.02) from Day 13 to Day 30.(ABSTRACT TRUNCATED AT 250 WORDS)
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Desarrollo Embrionario y Fetal/fisiología , Progesterona/análisis , Porcinos/embriología , Porcinos/metabolismo , Útero/química , Alantoides/química , Animales , Cruzamiento , Estradiol/análisis , Estrona/sangre , Femenino , Ovulación/fisiología , Placenta/metabolismo , Embarazo , Progesterona/sangre , Útero/metabolismoRESUMEN
EEG's were carried out on two hundred and one (201) alcoholics admitted to a four week treatment program. The majority were grossly intoxicated on admission and presented the usual differential problems during the first few days of hospitalization. In spite of therapeutic doses of medication before testing, 85% had totally normal EEG's and only 5.5% revealed clearly abnormal tracings. Of those for whom repeat records were later obtained, four of six with an abnormality showed a persistance of abnormality suggesting underlying organic dysfunction and not just "intoxication". EEG has a place in identification of the alcoholic patient at greater risk for neurological complications and may be useful in alerting the psychiatrist to obtain additional personal and family history, neurological examination, and when appropriate, further tests for potential structural abnormality. Routine use of structural tests such as computerized scan will aid in the identification of serious structural abnormalities but will not identify equally serious disorganizing functional abnormalities.
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Alcoholismo/terapia , Electroencefalografía , Alcoholismo/fisiopatología , Clordiazepóxido/uso terapéutico , Humanos , Hiperventilación/fisiopatología , Ritmo TetaRESUMEN
Research on alcohol expectancies among clinical populations has not focused on the extent to which changes in alcohol expectancies correspond to changes in drinking. In this investigation, male and female problem drinkers participating in an outpatient treatment focused on drinking reduction techniques provided data on drinking behavior and alcohol expectancies at pretreatment, posttreatment and at an 18-month follow-up. Results showed a significant relationship between decreases in alcohol expectancies and decreased drinking. Decreases in alcohol expectancies were not found over the course of the 8-week treatment, but instead at the 18-month follow-up. Implications and future research needs are discussed.
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Consumo de Bebidas Alcohólicas/psicología , Alcoholismo/rehabilitación , Disposición en Psicología , Adulto , Cuidados Posteriores/métodos , Consumo de Bebidas Alcohólicas/prevención & control , Alcoholismo/prevención & control , Alcoholismo/psicología , Nivel de Alerta/efectos de los fármacos , Terapia Conductista/métodos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Conducta Sexual/efectos de los fármacos , Conducta SocialRESUMEN
Two experiments were carried out to test the hypothesis that follicles recovered from Meishan animals may provide a more favourable environment for oocyte maturation in vitro than follicles recovered from Large-White hybrid animals. In Experiment 1, all follicles > or = 4 mm were recovered from six Meishan and seven Large-White hybrid gilts in the late follicular phase and healthy oocyte cumulus complexes recovered. Cumulus oocyte complexes were randomly divided into two groups, and each group cultured for 27 or 34 h (62 and 64; 56 and 56 for Meishan and Large-White hybrid, respectively) in defined medium in the presence of either of the two largest follicle shells per animal. Subsequent examination of oocyte nuclear maturation showed that although maturation did not differ significantly between the breeds after 27 h, more (P < 0.01) Meishan oocytes co-cultured with Meishan follicles developed to metaphase II stage than Large-White hybrid oocytes co-cultured with Large-White hybrid follicles after 34 h. The next eight largest follicles per animal were cultured for 34 h to produce conditioned media. In Experiment 2, oocytes recovered from the slaughterhouse were matured for 46 h in the presence of conditioned media from Meishan (612 oocytes) or Large-White hybrid (731 oocytes) follicles, or in fresh medium in the presence of a follicle shell from slaughterhouse ovaries. Oocytes were then inseminated and 12 h later examined for penetration and male pronuclear formation. A higher (P < 0.05) percentage of oocytes cultured in Meishan follicle conditioned medium underwent sperm penetration and male pronuclear formation than oocytes cultured in conditioned media from Large-White hybrid animals. Concentration of oestradiol and progesterone in the conditioned media did not differ between the breeds (P > 0.1). In conclusion, these results suggest that (1) Meishan oocytes have advanced maturational capacity when cultured with Meishan preovulatory follicle shells and (2) differences in follicle maturation in the Meishan compared to the Large-White hybrid pig may result in an improved ability of the follicles, via conditioned media, to support oocyte maturation and fertilization in vitro.