Evaluación de afección en calidad de vida en adultos con dermatitis atópica / Assessment of quality of life illness in adult patients with atopic dermatitis

Introducción: la dermatitis atópica (DA) es una enfermedad con repercusión en la calidad de vida (CV) del paciente. Para la evaluación de la gravedad clínica de la enfermedad se han diseñado diversas herramientas como el Eczema Area and Severity Index (EASI), mientras que para la evaluación de la CV se han creado instrumentos específico, como el Dermatology Life Quality Index (DLQI) y el Quality of Life Index for Atopic Dermatitis (QoLIAD). Objetivo: definir cuál es la mejor herramienta para evaluar la afección a la CV de pacientes adultos con DA, en relación con el EASI. Material y métodos: se seleccionaron pacientes con DA (> 18 años) que aceptaran responder a los cuestionarios DLQI y QoLIAD, así como tener una exploración dermatológica reportada según el EASI. Se ajustaron tres modelos de regresión lineal simple para poder cuantificar la asociación entre el EASI con el DLQI y el QoLIAD. Un valor de p < 0.05, se consideró de significancia estadística. El modelo de afección a CV con el valor más alto de pseudo R2, se consideró como el que tuvo mayor asociación con EASI. Resultados: se captaron en total 72 pacientes. Los modelos de regresión cuantílica simple revelaron un coeficiente de regresión de 0.243 para DLQI (p = 0.002) y 0.252 para QoLIAD (p = 0.003). Los valores de pseudo R2 fueron de 0.15 para DLQI y 0.10 para QoLIAD, por lo que el DLQI tuvo una mayor correlación con el EASI. Conclusiones: el DLQI resultó ser el mejor instrumento para evaluar la afección a la CV en pacientes adultos con DA.

Background: Atopic dermatitis (AD) is a disease with an im- pact on the patient's quality of life (QoL). Several tools have been designed to assess the clinical severity of the disease, such as the Eczema Area and Severity Index (EASI), while specific instruments have been created to assess QoL, such as the Dermatology Life Quality Index (DLQI) and the Quality of Life Index for Atopic Dermatitis (QoLIAD). Objective: To define which tool is the best to assess the QoL condition of adult patients with AD in relation to the EASI. Material and methods: Patients with AD (> 18 years old) were selected who agreed to complete the DLQI and QoLIAD questionnaires, as well as to have a dermatologic examination reported according to the EASI. Three simple linear regression models were fitted in order to quantify the association between EASI with DLQI and QoLIAD. A value of p < 0.05 was considered statistically significant. The CV condition model with the highest pseudo R2 value was considered to have the strongest association with EASI. Results: A total of 72 patients were included. Simple quantile regression models revealed a regression coefficient of 0.243 for DLQI (p = 0.002) and 0.252 for QoLIAD (p = 0.003). The pseudo R2 values were 0.15 for DLQI and 0.10 for QoLIAD, so DLQI had a higher correlation with EASI. Conclusions: DLQI proved to be the best instrument to assess CV impairment in adult patients with AD.

Adaptive evolution and selection of stress-resistant Saccharomyces cerevisiae for very high-gravity bioethanol fermentation

Background: In industrial yeasts, selection and breeding for resistance to multiple stresses is a focus of current research. The objective of this study was to investigate the tolerance to multiple stresses of Saccharomyces cerevisiae obtained through an adaptive laboratory evolution strategy involving a repeated liquid nitrogen freeze­thaw process coupled with multi-stress shock selection. We also assessed the related resistance mechanisms and very high-gravity (VHG) bioethanol production of this strain. Results: Elite S. cerevisiae strain YF10-5, exhibiting improved VHG fermentation capacity and stress resistance to osmotic pressure and ethanol, was isolated following ten consecutive rounds of liquid nitrogen freeze­thaw treatment followed by plate screening under osmotic and ethanol stress. The ethanol yield of YF10-5 was 16% higher than that of the parent strain during 35% (w/v) glucose fermentation. Furthermore, there was upregulation of three genes (HSP26, HSP30, and HSP104) encoding heat-shock proteins involved in the stress response, one gene (TPS1) involved in the synthesis of trehalose, and three genes (ADH1, HXK1, and PFK1) involved in ethanol metabolism and intracellular trehalose accumulation in YF10-5 yeast cells, indicating increased stress tolerance and fermentative capacity. YF10-5 also showed excellent fermentation performance during the simultaneous saccharification and fermentation of VHG sweet potato mash, producing 13.40% (w/ v) ethanol, which corresponded to 93.95% of the theoretical ethanol yield. Conclusions: A multiple-stress-tolerant yeast clone was obtained using adaptive evolution by a freeze­thaw method coupled with stress shock selection. The selected robust yeast strain exhibits potential for bioethanol production through VHG fermentation.

Construction of industrial brewing yeast for fermentation under high temperature and high gravity condition / 生物工程学报

As a new beer fermentation technology, high temperature and high gravity fermentation has brought many benefits to brewery industry, but there are also a series of problems such as the decrease of yeast flocculation ability at the end of fermentation and the high concentration of higher alcohols. To increase yeast flocculation ability and reduce the production of higher alcohols in high temperature and high gravity fermentation of beer, BAT2 was replaced by the FLO5 expression cassette to obtain the mutant strain S6-BF2. Real-time quantitative PCR showed that the relative transcriptional level of FLO5 in S6-BF2 improved 17.8 times compared with that in S6. The flocculation ability of mutant S6-BF2 heightened by 63% compared to that of the original strain S6, and the concentration of higher alcohols decreased from 175.58 mg/L to 159.58 mg/L in high temperature and high gravity fermentation of beer. Moreover, the activity of mitochondrial branched-chain amino acid transferase was repressed, resulting in the production of higher alcohols of 142.13 mg/L, reduced by 18.4% compared to that of the original strain S6, meanwhile, the flocculation ability of mutant S6-BF2B1 kept unchanged compared to the mutant S6-BF2. The determination result of flavor compounds showed that the higher alcohols/ester ratio in beer was reasonable. This research has suggested an effective strategy for enhancing yeast flocculation ability and decreasing production of higher alcohols in high-temperature and high-gravity brewing.

Identification of Vestibular Organ Originated Information on Spatial Memory in Mice / 대한평형의학회지

OBJECTIVES: We aimed to study the role of vestibular input on spatial memory performance in mice that had undergone bilateral surgical labyrinthectomy, semicircular canal (SCC) occlusion and 4G hypergravity exposure. METHODS: Twelve to 16 weeks old ICR mice (n=30) were used for the experiment. The experimental group divided into 3 groups. One group had undergone bilateral chemical labyrinthectomy, and the other group had performed SCC occlusion surgery, and the last group was exposed to 4G hypergravity for 2 weeks. The movement of mice was recorded using camera in Y maze which had 3 radial arms (35 cm long, 7 cm high, 10 cm wide). We counted the number of visiting arms and analyzed the information of arm selection using program we developed before and after procedure. RESULTS: The bilateral labyrinthectomy group which semicircular canal and otolithic function was impaired showed low behavioral performance and spacial memory. The semicircular canal occlusion with CO₂ laser group which only semicircular canal function was impaired showed no difference in performance activity and spatial memory. However the hypergravity exposure group in which only otolithic function impaired showed spatial memory function was affected but the behavioral performance was spared. The impairment of spatial memory recovered after a few days after exposure in hypergravity group. CONCLUSIONS: This spatial memory function was affected by bilateral vestibular loss. Space-related information processing seems to be determined by otolithic organ information rather than semicircular canals. Due to otolithic function impairment, spatial learning was impaired after exposure to gravity changes in animals and this impaired performance was compensated after normal gravity exposure.

Enhanced ethanol production at commercial scale from molasses using high gravity technology by mutant S. cerevisiae

Abstract Very high gravity (VHG) technology was employed on industrial scale to produce ethanol from molasses (fermented) as well as by-products formation estimation. The effect of different Brix° (32, 36 and 40) air-flow rates (0.00, 0.20, 0.40, and 0.60 vvm) was studied on ethanol production. The maximum ethanol production was recorded to be 12.2% (v/v) at 40 Brix° with 0.2 vvm air-flow rate. At optimum level aeration and 40 Brix° VHG, the residual sugar level was recorded in the range of 12.5-18.5 g/L, whereas the viable cell count remained constant up to 50 h of fermentation and dry matter production increased with fermentation time. Both water and steam consumption reduced significantly under optimum conditions of Brix° and aeration rate with compromising the ethanol production. Results revealed VHG with continuous air flow is viable technique to reduce the ethanol production cost form molasses at commercial scale.

Overexpression of FKS1 to improve yeast autolysis-stress / 生物工程学报

With the development of high gravity brewing, yeast cells are exposed to multiple brewing-associated stresses, such as increased osmotic pressure, enhanced alcohol concentration and nutritional imbalance. These will speed up yeast autolysis, which seriously influence beer flavor and quality. To increase yeast anti-autolytic ability, FKS1 overexpression strain was constructed by 18S rDNA. The concentration of β-1,3-glucan of overexpression strain was 62% higher than that of wild type strain. Meantime, FKS1 overexpression strain increased anti-stress ability at 8% ethanol, 0.4 mol/L NaCl and starvation stress. Under simulated autolysis, FKS1 showed good anti-autolytic ability by slower autolysis. These results confirms the potential of FKS1 overexpression to tackle yeast autolysis in high-gravity brewing.

Three Cases of Spine Fractures after an Airplane Crash / 대한신경손상학회지

While injuries to the spine after an airplane crash are not rare, most crashes result in fatal injuries. As such, few studies exist that reported on spine fractures sustained during airplane accidents. In this report, we demonstrate three cases of spine fractures due to crash landing of a commercial airplane. Three passengers perished from injuries after the crash landing, yet most of the passengers and crew on board survived, with injuries ranging from minor to severe. Through evaluating our three spine fracture patients, it was determined that compression fracture of the spine was the primary injury related to the airplane accident. The first patient was a 20-year-old female who sustained a T6-8 compression fracture without neurologic deterioration. The second patient was a 33-year-old female with an L2 compression fracture, and the last patient was a 49-year-old male patient with a T8 compression fracture. All three patients were managed conservatively and required spinal orthotics. During the crash, each of these patients were subjected to direct, downward high gravity z-axis (Gz) force, which gave rise to load on the spine vertically, thereby causing compression fracture. Therefore, new safety methods should be developed to prevent excessive Gz force during airplane crash landings.

Hepatic inducible nitric oxide synthase expression increases upon exposure to hypergravity

Stimulation by a number of conditions, including infection, cytokines, mechanical injury, and hypoxia, can upregulate inducible nitric oxide synthase (iNOS) in hepatocytes. We observed that exposure to hypergravity significantly upregulated the transcription of the hepatic iNOS gene. The aim of this study was to confirm our preliminary data, and to further investigate the distribution of the iNOS protein in the livers of mice exposed to hypergravity. ICR mice were exposed to +3 Gz for 1 h. We investigated the time course of change in the iNOS expression. Hepatic iNOS mRNA expression progressively increased in centrifuged mice from 0 to 12 h, and then decreased rapidly by 18 h. iNOS mRNA levels in the livers of centrifuged mice was significantly higher at 3, 6, and 12 h than in uncentrifuged control mice. The pattern of iNOS protein expression paralleled that of the mRNA expression. At 0 and 1 h, weak cytoplasmic iNOS immunoreactivity was found in some hepatocytes surrounding terminal hepatic venules. It was noted that at 6 h there was an increase in the number of perivenular hepatocytes with moderate to strong cytoplasmic immunoreactivity. The number of iNOS-positive hepatocytes was maximally increased at 12 h. The majority of positively stained cells showed a strong intensity of iNOS expression. The expression levels of iNOS mRNA and protein were significantly increased in the livers of mice exposed to hypergravity. These results suggest that exposure to hypergravity significantly upregulates iNOS at both transcriptional and translational levels.

The use of dried spent yeast as a low-cost nitrogen supplement in ethanol fermentation from sweet sorghum juice under very high gravity conditions

Dried spent yeast (DSY) was used as a low-cost nitrogen supplement for ethanol fermentation from sweet sorghum juice under very high gravity (VHG) conditions by Saccharomyces cerevisiae NP 01. The fermentation was carried out at 30ºC in a 5-litre bioreactor. The results showed that DSY promoted ethanol production efficiencies. The ethanol concentration (P), productivity (Qp) and yield (Yp/s) of the sterile juice (total sugar of 280 g l-1) supplemented with 8 g l-1 of DSY were not different from those supplemented with yeast extract and/or peptone at the same amount. The initial yeast cell concentration of 5 x 10(7) cells ml-1 was found to be optimal for scale-up ethanol production. In addition, an increase in sugar concentration in inoculum preparation medium (from 10 to 100 g l-1) improved the ability of the inoculum to produce ethanol under the VHG conditions. When S. cerevisiae NP 01 grown in the juice containing 100 g l-1 of total sugar was used as the inoculum for ethanol fermentation, the P, Qp and Yp/s obtained were 108.98 +/- 1.16 g l-1, 2.27 +/- 0.06 g l-1 h-1 and 0.47 +/- 0.01 g g-1, respectively. Similar results were also observed when the ethanol fermentation was scaled up to a 50-litre bioreactor under the same conditions. The cost of the sweet sorghum for ethanol production was US$ 0.63 per litre of ethanol. These results clearly indicate the high potential of using sweet sorghum juice supplemented with DSY under VHG fermentation for ethanol production in industrial applications.

effect of microwave radiation on osteogenesis and osteolysis of rats in the hypergravity condition and the role of Rana sylvatica Le conte oil as a radioprotector

Microwave Thermotherapy has been gradually used in radiotherapy and it is reported that microwave radiation increases bone demineralization rate independently of temperature. Furthermore, it becomes more and more widespread that the damage caused by the synergistic effect of microwave radiation and hypergravity. The experiment was designed to investigate the effect of microwave radiation on osteogenesis and osteolysis of rats in the hypergravity condition and to observe the role of Rana sylvatica Le conte oil as a radioprotector. Wistar rats were exposed to microwave radiation of 200mW/cm[2] power density and +6G hypergravity, and the concentrations of osteocalcin, calcitionin, calcium, phosphorus, and hydroxyproline and the activity of alkaline phosphatase were detected in serum. The serum concentrations of osteocalcin and calcitionin and the activity of alkaline phosphatase decreased, while the calcium, phosphorus and hydroxyproline concentrations increased after the synergistic effect of microwave radiation and hypergravity. Rana sylvatica Le conte oil intervention inhibited significantly the decrease of osteocalcin concentration and restrained significantly the increases of hydroxyproline and calcium concentrations in serum. These results imply that the synergistic effect of microwave radiation and hypergravity inhibits osteogenesis and enhances osteolysis in rats causing bone metabolic disturbance, while the injury resulted from microwave radiation and hypergravity could be protected by intervention with Rana sylvatica Le conte oil and it provides an original direction in the investigation of radioprotectors

Impact of fermentation system initial status on oscillations in very high gravity ethanol continuous fermentation process and analysis of fermentation efficiency improvement / 生物工程学报

Prior research reported the oscillatory behavior characterized by long period and high amplitude during high gravity continuous ethanol fermentations at the dilution rate of 0.027 h(-1). In this paper, high gravity continuous ethanol fermentations using Saccharomyces cerevisia at different dilution rates were carried out. Similar oscillations were observed when the dilution rate was switched to 0.04 h(-1). Both oscillatory and steady processes can be achieved at dilution rates of 0.027 or 0.04 h(-1), which depends on the initial status of the fermentation system. However, compared to steady process at the same dilution rate of 0.04 h(-1), the average residual sugar concentration was lowered by 14.8% for the oscillatory process, while the average ethanol concentration and productivity were increased by 12.6% and 12.3%, respectively. Further investigation revealed that besides the lag time, oscillatory processes were different from steady ones in kinetics because a higher specific growth rate can be achieved at the same residual sugar and ethanol concentrations (increased by 53.8% in average).

Expression and distribution of connexin 43 in myocardium of rats after repeated positive acceleration exposures / 生理学报

The present study was designed to observe the expression and distribution of connexin 43 (Cx43) in myocardium of rats after repeated positive acceleration (+Gz) exposures. Thirty six male Sprague-Dawley rats were randomly divided into 3 groups (n=12): control group, +6Gz group and +10Gz group. The rats in +6Gz group were exposed to +6Gz for 3 min daily, 1 week, while rats in +10Gz group were subjected to +10Gz for 3 min daily, 1 week. All animals were anaesthetized and necropsied immediately, 1 d, 3 d and 7 d after the last exposure. The expression and distribution of Cx43 in the ventricles of hearts were examined by immunohistochemistry and Western blot analysis. The immunohistochemistry results showed that in control group abundant expression of Cx43 was observed with intense punctate labelling confined to the intercalated disks between cardiomyocytes. After +Gz exposure, there was a loss of the immuno-reactivity of Cx43, which was consistent with Western blot results, and distribution changes of Cx43, with an increase of Cx43 in side-to-side gap junction and a decrease of Cx43 in end-to-end gap junction. Western blot analysis revealed that Cx43 expression was modified in response to different exposure program and different recovery time. The protein expressions of Cx43 were lower at 4 time points after exposure in either +6Gz or +10Gz groups compared with that in the control group (P<0.001). Densitometry analysis of immunoblots revealed a decrease in the total amount of Cx43 signals immediately after exposure while an increase during the recovery time. After 7-day recovery, the amounts of Cx43 in two exposure groups were still lower than that in the control group (P<0.001). The decrease of Cx43 expression in +10Gz group was more significant than that in +6Gz group. The results demonstrated that the expression decrease and distribution disturbance of Cx43 in the ventricles of rats after repeated +Gz exposures could be recovered. These findings facilitate our understanding of the mechanisms of arrhythmias caused by +Gz and provide new protective measures.

c-fos mRNA Expression in the Vestibular System following Hypergravity Stimulation in Rats

Altered environmental gravity, including both hypo- and hypergravity, may result in space adaptation syndrome. To explore the characteristics of this adaptive plasticity, the expression of immediate early gene c-fos mRNA in the vestibular related tissues following an exposure to hypergravity stimulus was determined in rats. The animals were subjected to a force of 2 g (twice earth's gravity) for 1, 3, or 12 h, and were examined poststimulus at 0, 2, 6, 12, and 24 h. RT-PCR (reverse transcription polymerase chain reaction) and real-time quantitative RT-PCR were adopted to analyze temporal changes in the expression of c-fos mRNA. The hypergravity stimulus increased the expression of c-fos mRNA in the vestibular ganglion, medial vestibular nucleus, inferior vestibular nucleus, hippocampus, cerebellum, and cortex. The peak expression occurred at 0 h poststimulation in animals stimulated with hypergravity for 1 h, and at 6 h poststimulus in those stimulated for 3 h. In contrast, those stimulated for 12 h exhibited dual peaks at 0 and 12 h poststimulus. Bilateral labyrinthectomy markedly attenuated the degree of c-fos mRNA expression. Glutamate receptor antagonist also dramatically attenuated the degree of c-fos mRNA expression. These results indicate that expression of c-fos mRNA in response to hypergravity occurs in the vestibular related tissues of the central nervous system, in which peripheral vestibular receptors and glutamate receptors play an important role. The temporal pattern of c-fos mRNA expression depended on the duration of the hypergravity stimulus.

Role of the Peripheral Vestibular System on Neuroplasticity Induced by Hypergravity Stimulation

BACKGROUND AND OBJECTIVES: Altered environmental gravity, including both hypo- and hypergravity, may result in space adaptation syndrome. To explore the characteristics of this adaptive plasticity, the expression of immediate early gene c-fos mRNA in the vestibular system following an exposure to hypergravity stimulus was determined in rats. MATERIALS AND METHOD: The animals were subjected to 2 G force (two-fold earth's gravity) stimulus for 3 hours, and were examined at post-stimulus hours 0, 2, 6, 12, and 24. Real time reverse transcription-polymerase chain reaction (RT-PCR) was adopted to analyze temporal changes in the expression of c-fos mRNA. RESULTS: The hypergravity stimulation produced the expression of c-fos mRNA in the vestibular ganglion, medial vestibular nucleus, inferior vestibular nucleus, hippocampus, vestibulocerebellum, and vestibular cortex. The peak expression occurred at hour 6 in the animals hypergravity-stimulated for 3 hours. Bilateral labyrinthectomy significantly attenuated the degree of up-regulation in c-fos mRNA expression. MK-801, an NMDA receptor antagonist, also significantly attenuated the degree of up-regulation in c-fos mRNA expression. CONCLUSION: These results indicate that the adaptive neuroplasticity in response to an altered gravity occurs in the vestibular-related organs in the central nervous system, in which peripheral vestibular receptors and NMDA receptors play an important role.

Tilt-table testing as a predictor of + GZ tolerance.

BACKGROUND: G-tolerance assessment is an essential element of both military pilot and pilot candidate evaluation. AIMS: Attempt at prediction of individual relaxed + Gz tolerance on the basis of head-up tilt (HUT) testing. SETTINGS AND DESIGN: In two stages, 20 healthy men at the mean age 21.5 years took part in this study. The first stage, a 45 min, HUT test was performed using the Westminster protocol. During the second stage each underwent a centrifuge evaluation in response to gradual onset rate profiles. METHODS AND MATERIAL: In each subject, heart rate (HR) and blood pressure (BP) before and at 2, 15 and 45 min of the tilt-test were recorded. The gravity-load centrifuge (GOR) studies were carried out [following the standard GOR programme, at 0.1 G%divide;s rate of gravity load increase until the gravity load tolerance limit (loss of peripheral vision) was reached]. STATISTICAL ANALYSIS USED: Relationships between variables were explored using Kendall's tau-B correlation coefficient. The critical P-level was one-tailed 0.05. RESULTS: In four of 20 subjects (20%), vasovagal syncope occurred during the tilt test. G-level tolerance of this group (of +Gz accelerations) lay in the range from +4 to +8.1 Gz, (+5.72 ? 0.86 Gz average) and was comparable to the group without syncope. Loss of consciousness did not occur in any subjects during the centrifuge test. No statistically significant correlation was observed between HR and BP during tilt test and tolerance to +Gz accelerations. CONCLUSIONS: The result of tilt testing, carried out according to the Westminster protocol, was not useful in predicting individual tolerance to +Gz gravity loads.

Effects of dilution rates on the oscillatory behaviors of a very high gravity continuous ethanol fermentation system / 生物工程学报

Continuous ethanol fermentation using very high gravity medium containing 280 g/L glucose, 5 g/L yeast extract and 3 g/L peptone was run at the dilute rates of 0.006 h(-1), 0.012 h(-1), 0.017 h(-1), 0.024 h(-1) and 0.032 h(-1) (based on the total working volume) in a combined bioreactor system composed of a stirred tank and three-stage tubular bioreactors in series. Oscillations marked by big fluctuations of residual glucose, ethanol and biomass were observed at the dilution rate of 0.012 h(-1). The Hopf Bifurcation theory was used to analyze and predict the occurring of these oscillations and the dilution rates that incited oscillations. Theoretical analysis revealed that oscillations can occur at designated specific growth rates and was validated by experimental results. The benefits of oscillations for the fermentation system were also discussed by comparing the fermentation results with those without oscillations.

Frequency of the "Gravity Transition Effect" during Aerial Combat Mission of F-16 Aircraft, ROKAF / 항공우주의학회지

BACKGROUND: Current studies have focused mainly on the push-pull effect (PPE), the reduction of +Gz tolerance when hypergravity (>+1 Gz) preceded by hypogravity (<+1 Gz). However, the reduced G tolerance could be induced by any G-transition. The frequency and extent of maneuvers to cause G-transition effect (GTEM) have not been studied previously in fighter aircraft. METHODS: 26 HUD (head-up display) videotapes from F-16 aerial combat training missions were reviewed for the presence of GTEM. The frequency and magnitude of the +Gz profiles were analyzed. RESULTS: GTEMs were found in 34 (29.6%) of 115 engagements reviewed. PPEMs (maneuvers found to cause push-pull effect) and rPPEMs (maneuvers found to cause reversed PPE) were found in 7.8%, 11.3% respectively. Combined maneuver that rPPEM followed by PPEM consecutively was found in 10.4% of engagements. There was no difference the frequency of GTEMs between BFM and ACM engagements (28.8% vs. 30.9%). CONCLUSION: GTEMs including PPEMs and rPPEMs are present in aerial combat training missions of F-16 aircraft and represent a significant source for accidents. These findings support the necessity of continued research into the physiologic response to GTE.

+Gz protection provided by tilt-back seat and GZ-2 anti-G suit / 中国应用生理学杂志

<p><b>AIM</b>To investigate the +Gz protection provided by tilt-back seat and GZ-2 anti-G suit.</p><p><b>METHODS</b>6 subjects were exposed to centrifuge and onset rate is 3 G/s. First, their relaxed +Gz tolerances were determined while using tilt-back seat of 13 degrees. Secondly, it was their +Gz tolerance provided by pressurized GZ-2 anti-G suit and tilt-back seat of 13 degrees. Finally, their +Gz tolerances while using pressurized GZ-2 anti-G suit and tilt-back seat of 45 degrees were determined. The difference between the first and the third result was the +Gz protection that pressurized GZ-2 anti-G suit and tilt-back seat of 45 degrees offered.</p><p><b>RESULTS</b>+Gz protection of pressurized GZ-2 anti-G suit and tilt-back seat of 13 degrees was 3.06 G, and +Gz protection of pressurized GZ-2 anti-G suit and tilt-back seat of 45 degrees was 4.13 G, which had an increase of 1.06 G.</p><p><b>CONCLUSION</b>Tilt-back seat of 45 degrees can greatly enhance +Gz tolerances of human.</p>

Effects of repeated + Gz forces on masticatory muscles / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To study the effects of repeated + Gz forces on masticatory muscles.</p><p><b>METHODS</b>48 male Wistar rats were randomly divided into 4 groups. Group A was normally fed. Group B was only fixed with rat-kept devices for 5 minutes. Group C was borne + 1 Gz for 5 minutes. Group D was repeatedly exposed + 10 Gz (each for 30 s, onset rate about 0.5 G/s, 5 times/d with + 1 Gz 1 minute intervals, 4 d/wk, 3 weeks in total). The histological changes of the masseter, temporal and lateral pterygoid muscles were observed.</p><p><b>RESULTS</b>No abnormal changes were observed in Group A, B and C. But pathological changes could be found in group D. The wrench and deformation of muscular fibers, the dissolution of partial myofibril, the swelling of mitochondria, the reduce of hepatin from the masseter and lateral pterygoid muscles could be found.</p><p><b>CONCLUSIONS</b>Repeated + Gz stresses could induce the damage of masticatory muscles in different degrees.</p>

Effects of Positive Acceleration on Atrial Natriuretic Peptide (ANP), Plasma Renin Activity (PRA), Kidney and Testis / 대한비뇨기과학회지

Hypergravity has been shown to affect the human physiology, especially the kidney and heart. The kidney is affected during or after tests on positive acceleration. PRA was increased after positive acceleration. ANP has inverse relationship with renin, which has sodium and water retention. The experiment was design to investigate possible ANP decrease and changes in function and structure of the testis, kidney after exposure to 9G, 120 sec positive acceleratory forces as imposed on rat by the Human Centrifuge. As result, positive radial acceleration has made no change in concentration of ANP in statistically with increasing PRA, After acceleration, the glomerulus of the kidney showed no ischemic changes, but tubule of the kidney showed containing of cast. The seminiferous tubule of the testis showed normal.