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At least 217 records · Page 12Linked to original sources

Design and structural analysis of highly mobile space suits and gloves.

This paper evaluates the factors that control the flexibility of fabric space-suit elements, in particular gloves, by examining a bending model of a pressurized fabric tube. Results from the model are used to evaluate the design strategies used in space-suit components, to evaluate the current direction in research on highly mobile space-suit gloves and to suggest changes necessary for optimum glove fabric selection. Finally it is shown that the modulus of the fabric used in space-suit joint construction is as important to the flexibility of the joint as the glove size and design.

Astronauts↗

[Abdominal actinomycosis presenting as a malignant tumor--report of a case and review of the literature].

Actinomyces israelii is a normal inhabitant in the gastrointestinal tract of humans, it rarely causes disease. Abdominal involvement occurs in only 20 percent of all cases and can mimic malignant diseases, tuberculosis and inflammatory bowel disease. A case of a 36 years old female patient with abdominal actinomycosis and review of the literature is reported. Symptoms was presented as an acute abdomen associated with painful epigastric and left subcostal mass. The pathologic process infiltrated the retroperitoneal space simulated sarcoma or lymphoma. Diagnosis was established only at the second laparotomy, when histologic examination of the removed lymph node disclosed actinomycosis. The patient is completely free of symptoms 6 month after the second operation.

Abdomen↗

Effect of vibrational stress and spaceflight on regulation of heat shock proteins hsp70 and hsp27 in human lymphocytes (Jurkat).

Heat shock protein levels are increased in cells as a result of exposure to stress. To determine whether heat shock protein regulation could be used to evaluate stress in cells during spaceflight, the response of Jurkat cells to spaceflight and simulated space shuttle launch vibration was investigated by evaluating hsp70 and hsp27 gene expression. Gene expression was assessed by reverse transcription-polymerase chain reaction using mRNA extracted from vibrated, nonvibrated, space-flown, and ground control cells. Results indicate that mechanical stresses of vibration and low gravity do not up-regulate the mRNA for hsp70, although the gene encoding hsp27 is up-regulated by spaceflight but not by vibration. In ground controls, the mRNA for hsp70 and hsp27 increased with time in culture. We conclude that hsp70 gene expression is a useful indicator of stress related to culture density but is not an indicator of the stresses of launch vibration or microgravity. Up-regulation of hsp27 gene expression in microgravity is a new finding.

Cell Division↗

European Astronaut Candidates in training in the CIS.

For four weeks in October and November 1992, we--three European Astronaut Candidates from the European Astronauts Centre (EAC) in Cologne--were fortunate enough to have the opportuity to live and be trained in Star City. It proved to be a fascinating experience, both for us and the EAC Training Engineer, Antonio Torres, who accompanied us.

Aerospace Medicine↗

[Russian intra vehicular space suit and cold protection].

During space flights, astronauts use equipment allowing protection against many environmental factors. During tests realised in Russia, space suit efficiency was evaluated particularly concerning cold protection capacity in cold water (3 degrees C) and in cold air (-30 degrees C). Obtained results prove that this equipment allows to prevent hypothermia in cold water and ensure thermal comfort in cold air.

Cold Temperature↗

Thermal physiological consideration of precooling procedures in manned space craft.

OBJECTIVE: To explore a space craft precooling temperature at which excessive thermal stress on the crew member could be prevented or reduced in an overheated launch or reentry module. METHOD: Five young male volunteers wearing a space suit participated in 25 tests at sea level. The space suit was either ventilated in a volume air flow rate of 100 L/min (STPD) with ambient air at temperatures (Ta) of 15 degrees C, 10 degrees C, and 5 degrees C, respectively, or not ventilated. Rectal (Tr), mean skin (Tsk) and mean body (Tb) temperatures were measured. RESULT: At Ta 15 degrees C, Tr decreased without significance (from 37.0 +/- 0.2C to 36.7 +/- 0.3 degrees C) in 120-min tests, whereas mean Tsk and mean Tb decreased significantly, and subjects had local cold strain whether the space suit was ventilated or not; while at Ta 10 degrees C, Tr decreased from 37.0 +/- 0.3 degrees C to 36.3 +/- 0.3 degrees C (P < 0.05), subjects had a whole body cold strain, and both mean Tsk and Tb dropped continuously and significantly. CONCLUSION: Ambient temperature 15 degrees C, at which the thermal comfort states of crew was not significantly degraded, was acceptable after precooling in a space craft.

Adolescent↗

[Comparison between motion sickness induced by reversed vision and that by parallel swing].

OBJECTIVE: To make clear the characteristics of motion sickness induced by reversed vision and to see whether it can be used in motion sickness experiments. METHODS: 10 healthy young men experienced walking tests wearing up-down or left-right reversing prisms, and parallel swing test on different days with intervals of 5-7d. Ataxia and motion sickness symptoms induced by walking wearing reversing prisms and those by parallel swing were observed. The reversed vision tolerance index (RVTI) and linear acceleration tolerance index (LATI) were calculated by an empirical formula. RESULTS: Both types of reversing prisms can induce obvious ataxia and motion sickness symptoms. The ataxia is correlative (P<0.05) with the susceptibility to motion sickness. In comparison with symptoms of swing motion sickness, the symptoms of reversed vision motion sickness are not too serious and appear slowly. There are correlativities (P< 0.01) between the susceptibility to motion sickness induced by up-down and left-right reversing prisms. The susceptibilities to motion sickness induced by reversing prisms are not correlative completely with that by swing. CONCLUSION: Reversed vision test is simple and easy and can be used for simulating space motion sickness or training of adaptation to sensory conflict on the ground.

Acceleration↗

[Hydronephrosis in course of actinomycosis of female reproductive organs].

OBJECTIVES: Pelvic actinomycosis is a chronic suppurative granulomatous disease caused by an anaerobic Gram positive germ, Actinomyces. The most difficult task was to obtain the diagnosis in a patient with an intrauterine device and poor general health, signs of infection and a pelvic syndrome. RESULTS: This is a report of a case of hydronephrosis in course of actinomycosis of female reproductive organs in a patient aged 46 years with the intrauterine contraceptive device admitted to The Department of Gynecology & Obstetric in Hospital of Słupsk. Symptoms were presented as an acute abdomen associated with painful epigastric and mass in right adnexa. A pre-operative diagnosis of the right hydronephrosis, on ovarian tumor and uterus myoma were detected which lead to an extensive and difficult surgery. The pathologic process infiltrated the retroperitoneal space simulated sarcoma or lymphoma. The disease was serious and required hysterectomy with salpingo-oophorectomy and intra-abdominal drainage. Actinomycosis was confirmed by the postoperative histopathologic examination, and the patient was successfully treated with penicillin. The patient was completely free of symptoms two months within the operation. CONCLUSIONS: In patients who have intrauterine contraceptive devices or who have had them removed recently, abdominal pain, recurrent vaginal bleeding or adnexal masses should prompt a thorough search for potentially pathogenic actinomyces in the genital tract.

Actinomycosis↗

The influence of prior exercise at anaerobic threshold on decompression sickness.

This study was conducted to examine the effects of exercise prior to decompression on the incidence of altitude decompression sickness (DCS). In a balanced, two-period, crossover trial, 39 healthy individuals (29 males, 10 females) of mean (S.D.) age 32.5 (7.7) years and body mass index 23.7 (3.4) were each exposed twice, without denitrogenation, to an altitude of 6,400 m (21,000 ft) in a hypobaric chamber. Under the experimental condition, subjects exercised at their predetermined anaerobic threshold levels for 30 min each day for 3 d prior to altitude exposure; the other condition was a non-exercise control. Under both conditions, subjects performed exercise simulating space extravehicular activities at altitude for a period of 3 h, while breathing 100% oxygen. There were nine preferences (untied responses) for DCS, four under control and five under experimental conditions; all were Type I, pain-only bends. No carryover effect between exposures was detected, and the test for treatment differences showed p = 0.56 (95% confidence interval = 0.34-0.58) for symptoms. No significant difference in DCS preferences was found after subjects exercised up to their anaerobic threshold levels during the days prior to decompression.

Adult↗

The joint effects of person and situation factors on stress in spaceflight.

Psychologists can play an important role in spaceflight and exploration. Indeed, their input at four specific stages in spaceflight can help to ensure successful missions. Psychologists have a role to play in: 1) Selection; 2) Training; 3) Real or Simulated Space Missions; and 4) Post-Flight Problems. During selection, psychologists can provide guidelines as to the appropriate coping styles for reacting to mission-related stressors. During training, psychologists can help astronauts to plan for, and cope with, problems (e.g., group conflict). Training in social sensitivity, or in specific coping styles (i.e., to be high in task-oriented coping), would be beneficial so that astronauts are able to deal with unforeseen problems. Task-oriented coping is related to control and efficiency, and reduces stress and anxiety. Emotion-oriented coping relates to anxiety for controllable situations, and task-oriented coping is most efficacious. A primary role for psychologists would be the investigation of what problems could arise from living with others in a limited space and for long periods of times. As such, investigations into group dynamics, physical and psychological stress caused by such an environment, and the lack of normal ways to deal with these problems should all be considered. It is also clear that the impact of spaceflight on an individual does not end with physical re-entry. On the contrary, the astronaut will also have to make a psychological post-flight "re-entry" readjustment to life on Earth. Psychologists have an important role to play during all four stages of the space program, especially in regards to person by situation interactions. That is, space is a novel environment for human beings, and we need to investigate how we can better improve the fit between astronauts and space situational stressors. Not only are person by situation interactions relevant for each of the four stages discussed above, but each of the stages interacts with one another bidirectionally and even multidirectionally.

Adaptation, Psychological↗

HZE radiation effects for hereditary renal carcinomas.

Eker rat known as a model of hereditary renal carcinoma (RC) is an example of Mendelian dominantly inherited predisposition to a specific cancer in experimental animals. We investigate the effects of simulated space radiation on carcinogenesis using HIMAC. We estimated RBE from the Eker rats exposed to the heavy-ions, C (290 MeV/u) and Fe (500 MeV/u) ions, comparing to the effects of X-ray irradiation. Pregnant rats were exposed to C and Fe ions and X-rays with a single dose of 1 Gy, 2 Gy, 3 Gy on day 19 of gestation. The offspring were sacrificed at 8 weeks of age. We evaluated organ weights and tumor genesis. The weights of thymus, lung, liver, spleen were found to be no difference from the control at 1 Gy irradiation but 50% decrease at 3 Gy irradiation. We found in the irradiated animal that kidney, brain and testis were very sensitive organs of which the weight decreased to approximately 80% at 1 Gy and to 40% at 3 Gy irradiations. Based on the dose-response relationship of the radiation-induced carcinoma, averaged RBE ware calculated to be 1.1 for C-ion, 1.6 for Fe-ion.

Animals↗

[Mathematical model of intracranial blood-cerebrospinal fluid dynamics system applied to the study of extreme conditions].

A mathematical model of cerebral blood and lymph circulation that can be used to study various effects (simulated space flight factors, functional loads) on the human body was developed. Biophysical patterns that determine relationships between cerebral blood and lymph circulation as well as between fluid volumes and pressures (P and V) are discussed. Involvement of the mechanism of brain circulation autoregulation in cerebral blood and lymph circulation is considered. The model was applied to study responses of cerebral blood and lymph circulation to various exposures such as orthostatic and antiorthostatic tests and provocative tests which led to intracranial pressure shifts and modified the ratio between volumes and pressures in different hydrodynamic systems. The modelling data were consistent with clinical, physiological and experimental observations which demonstrate an adequacy of the above model.

Aerospace Medicine↗

[Nutritional corrections of histamine and serotonin levels in exposure to hypokinesia and neuro-emotional stress].

The content of histamine and serotonin was measured in test subjects exposed to: I experimental series--bed rest at an angle of +6, -2 or -6 degrees; II experimental series--neuro-emotional stress, III experimental series--an increased concentration of ammonium in the enclosure. The exposure to the factors that simulated space flight effects (i. e., orthostatic hypokinesia at -6 degrees and neuro-emotional stress and anticipation of rotation in the centrifuge) led to an increase of histamine and serotonin and a decrease of histaminepectic activity. Consumption of selected nutritional agents a day before and on the day of exposure to the neuro-emotional stress improved the content of histamine and serotonin as well as histamine-pectic activity.

Adult↗

[Potential use of ultrasonic bioecholocation as a noninvasive method for assessing human intracranial volumetric ratios].

Potential applications of the method of ultrasonic echo location for determining intracranial fluid volume relations are discussed. The data presented give evidence that variations in the attenuation coefficient and propagation pattern of the ultrasonic signal may reflect changes in both hemodynamics and intracranial pressure. Simultaneous invasive investigations may help quantitate ultrasonic echo location results. The review shows that ultrasonic echo location of the brain can be used to determine variations in the intracranial volume relations induced by simulated space flights and to make well documented diagnoses.

Adaptation, Physiological↗

[General patterns of bone atrophy in the absence of a weight load on the skeleton].

The rate of atrophic changes in spongy bones of the weightless man was estimated, using studies of human, dog and rat bones, as well as observations of neurological patients bed-stricken for a long time. Taking into consideration data on the literature on the bone status and mineral balance in real and simulated space flights, two models were built. The models make it possible to estimate osteoporosis of spongy bones of the axial skeleton in the absence of weight loading. One of the models--an intraspecies model for the human population--is based on the experimentally found rate of the physiological rearrangement of various spongy bones. The other--interspecies--model is built with reference to the parameters determining the rate, i. e. bone density and metabolism. The average monthly rates of axial bone losses calculated by means of the two independent methods are essentially identical. The data obtained allow prediction of the decrease of tolerance to head-to-feet impact acceleration as a function of flight duration.

Adult↗