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1.
Methoxyflurane and nitrous oxide have been compared as obstetric analgesics. The inhaled concentrations of these agents, given continuously, were adjusted by an anaesthetist to maintain each patient at the optimum state between reaction to pain and consciousness. Assessments were made continuously.Though the anaesthetist''s assessment showed no difference between the mean results, a greater proportion of the methoxyflurane patients were “satisfactory” for 90–100% of the time than of the nitrous oxide patients, particularly in regard to objective pain relief. The midwives'' opinion of those who had “complete” pain relief supported this. Nausea was significantly less among methoxyflurane patients, and vomiting during labour occurred only in patients who had nitrous oxide. It is concluded that nitrous oxide and methoxyflurane given in a continuously adjusted concentration are almost equally effective as obstetric analgesics, though there are certain features which favour methoxyflurane.  相似文献   

2.
Although minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) has widely been developed in patients with lumbar diseases, surgeons risk exposure to fluoroscopic radiation. However, to date, there is no studies quantifying the effective dose during MIS-TLIF procedure, and the radiation dose distribution is still unclear. In this study, the surgeons'' radiation doses at 5 places on the bodies were measured and the effective doses were assessed during 31 consecutive 1- to 3-level MIS-TLIF surgeries. The operating surgeon, assisting surgeon, and radiological technologist wore thermoluminescent dosimeter on the unshielded thyroid, chest, genitals, right middle finger, and on the chest beneath a lead apron. The doses at the lens and the effective doses were also calculated. Mean fluoroscopy times were 38.7, 53.1, and 58.5 seconds for 1, 2, or 3 fusion levels, respectively. The operating surgeon''s mean exposures at the lens, thyroid, chest, genitals, finger, and the chest beneath the shield, respectively, were 0.07, 0.07, 0.09, 0.14, 0.32, and 0.05 mSv in 1-level MIS-TLIF; 0.07, 0.08, 0.09, 0.18, 0.34, and 0.05 mSv in 2-level; 0.08, 0.09, 0.14, 0.15, 0.36, and 0.06 mSv in 3-level; and 0.07, 0.08, 0.10, 0.15, 0.33, and 0.05 mSv in all cases. Mean dose at the operating surgeon''s right finger was significantly higher than other measurements parts (P<0.001). The operating surgeon''s effective doses (0.06, 0.06, and 0.07 mSv for 1, 2, and 3 fusion levels) were low, and didn''t differ significantly from those of the assisting surgeon or radiological technologist. Revision MIS-TLIF was not associated with higher surgeons'' radiation doses compared to primary MIS-TLIF. There were significantly higher surgeons'' radiation doses in over-weight than in normal-weight patients. The surgeons'' radiation exposure during MIS-TLIF was within the safe level by the International Commission on Radiological Protection''s guidelines. The accumulated radiation exposure, especially to surgeon''s hands, should be carefully monitored.  相似文献   

3.
The purposes of this study were to examine whether or not self-regulation of physiological responses demonstrates day-to-day reliability, to determine the degree of individual subject consistency (or concordance) in the ability to self-regulate across several different physiological responses, and, finally, to explore the impact of biofeedback training on interresponse concordance. Twenty normal subjects participated in six bidirectional self-regulation sessions—the first and last sessions involving instructions only, and the remainder, biofeedback. Self-regulation scores consisted of the absolute difference between increase and decrease trial means. The average test-retest reliability coefficients (r s) for the self-regulation scores, across the four biofeedback sessions, were a highly significant .50, .68, .30, and .47 for EEG, EMG, HR, and SCL, respectively. By contrast, the average concordance among the self-regulation scores for the four feedback sessions, estimated by Kendall's coefficient of concordance, was a marginally significant 39% of the possible variance of the rank sums. This corresponds to an average between-responser s value only of .19. The concordance level from the initial no-feedback (i.e., instructions only) session was not significant. Multivariate concordance levels did increase during the first three feedback sessions, but declined at the fourth, and again was nonsignificant during the final no-feedback session. Among the individual self-regulation response pairings, only the EEG/EMG combination was consistently associated during the no-feedback sessions. The present results suggest that self-regulatory ability is neither a highly unitary “trait”-like phenomenon nor an entirely response-specific event, but may vary considerably as a function of subject factors, or the situational circumstances, under which it is measured.  相似文献   

4.
Malaria parasites develop as oocysts within the haemocoel of their mosquito vector during a period that is longer than the average lifespan of many of their vectors. How can they escape from the mosquito''s immune responses during their long development? Whereas older oocysts might camouflage themselves by incorporating mosquito-derived proteins into their surface capsule, younger stages are susceptible to the mosquito''s immune response and must rely on other methods of immune evasion. We show that the malaria parasite Plasmodium gallinaceum suppresses the encapsulation immune response of its mosquito vector, Aedes aegypti, and in particular that the parasite uses both an indirect and a direct strategy for immunosuppression. Thus, when we fed mosquitoes with the plasma of infected chickens, the efficacy of the mosquitoes to encapsulate negatively charged Sephadex beads was considerably reduced, whether the parasite was present in the blood meal or not. In addition, zygotes that were created ex vivo and added to the blood of uninfected chickens reduced the efficacy of the encapsulation response. As dead zygotes had no effect on encapsulation, this result demonstrates active suppression of the mosquito''s immune response by malaria parasites.  相似文献   

5.
Locomotor muscles often perform diverse roles, functioning as motors that produce mechanical energy, struts that produce force and brakes that dissipate mechanical energy. In many vertebrate muscles, these functions are not mutually exclusive and a single muscle often performs a range of mechanically diverse tasks. This functional diversity has obscured the relationship between a muscle''s locomotor function and its mechanical properties. I use hopping in toads as a model system for comparing muscles that primarily produce mechanical energy with muscles that primarily dissipate mechanical energy. During hopping, hindlimb muscles undergo active shortening to produce mechanical energy and propel the animal into the air, whereas the forelimb muscles undergo active lengthening to dissipate mechanical energy during landing. Muscles performing distinct mechanical functions operate on different regions of the force–length curve. These findings suggest that a muscle''s operating length may be shaped by potential trade-offs between force production and sarcomere stability. In addition, the passive force–length properties of hindlimb and forelimb muscles vary, suggesting that passive stiffness functions to restrict the muscle''s operating length in vivo. These results inform our understanding of vertebrate muscle variation by providing a clear link between a muscle''s locomotor function and its mechanical properties.  相似文献   

6.
Three types of stress were examined for their effects upon fixed-ratio 15 (FR-15) operant behavior in Sprague-Dawley rats before and after chronic dextroamphetamine to determine if cumulated drug could interact with stress to produce a state of behavioral toxicity. Six daily s.c. injections of saline were given to rats following 30-min behavioral sessions. Thirty minutes of exposure to a cold environment (7°C) or to electric footshock (2mA for 0.5 sec, 1 shock/min) had no significant effect upon FR-15 behavior beginning 15 min afterward. Five daily s.c. injections of 2.5 mg dextroamphetamine/kg after behavioral sessions suppressed behavior during the following days an average of 12%. Rats were again stressed twenty-two hours after the sixth injection. Footshock further suppressed behavior to 26% of the unstressed, chronic amphetamine-treated control group. Cold exposure failed to suppress behavior significantly below control levels. A similar experiment employing cold water exposure (15°C for 2 min) as the stressor showed that, although this stressor suppressed FR-15 behavior to 53% of the previous day's rates and reduced body temperature 2.1°C, chronic amphetamine failed to interact with the cold water stress to suppress behavior further. In a third experiment, 4.5 mg phencyclidine/kg, s.c., given after 30-min FR-15 sessions for six days, failed to interact with the footshock stress to cause behavioral suppression different from control treatment. While stress can interact with chronic treatment with lipophilic drugs, the quality of the stress, and the physical and pharmacologic properties of the drug are important determinants of the outcome upon conditioned behavior.  相似文献   

7.
OBJECTIVES--To test the hypothesis that there is an association between childhood leukaemia and the occupational exposure of fathers to ionising radiation before a child''s conception. DESIGN--Case-control study with eight matched controls per case. SETTING--Regions of Ontario, Canada, with an operating nuclear facility. SUBJECTS--Cases were children (age 0-14) who died from or were diagnosed as having leukaemia from 1950 to 1988 and were born to mothers living in the vicinity of an operating nuclear facility. Controls were identified from birth certificates, matched by date of birth and residence at birth. There were 112 cases and 890 controls. MAIN OUTCOME MEASURES--Paternal radiation exposure was determined by a record linkage to the Canadian National Dose Registry. RESULTS--Six fathers of cases and 53 fathers of controls had had a total whole body dose > 0.0 mSv before the child''s conception, resulting in an odds ratio of 0.87 (95% confidence interval 0.32 to 2.34). There was no evidence of an increased leukaemia risk in relation to any exposure period (lifetime or six months or three months before conception) or exposure type (total whole body dose, external whole body dose, or tritium dose), except for radon exposure to uranium miners, which had a large odds ratio that was not significantly different from the null value. CONCLUSIONS--The findings of this study in Ontario did not support the hypothesis that childhood leukaemia is associated with the occupational exposure of fathers to ionising radiation before the child''s conception.  相似文献   

8.
The unihemispheric slow-wave sleep, the ability to sleep during swimming with one open eye and the absence of paradoxical sleep in its form observed in all terrestrial mammals are unique features of sleep in cetaceans. Visual observation supplement electrophysiological studies and allow obtaining novel data about sleep of cetaceans. In the present study we examined behavior of 3 adult Commerson's dolphins Cephalorhynchus commersonii kept in the oceanarium Sea World (San Diego, CA, USA). The behavior of the dolphins can be subdivided into 5 swimming types: (1) active swimming marked by variable and irregular trajectory of movement (for 3 dolphins, on average, 35.1 ± 2.7% of the 24-h period) was the active wakefulness; (2) circular swimming was divided into the slow and fast swimming and occupied, on average, 44.4 ± 3.8 and 9.7 ± 0.8% of the 24-h period, respectively; during the circular swimming, dolphins performed from 1 to 6 circular swimming during one respiration pause; (3) quiet chaotic swimming (3.9 ± 1.2%) that occurred at the bottom and was not accompanied by signs of activity; (4) hanging, and (5) slow swimming at the surface (4.1 ± 0.5 and 2.8 ± 0.4%) respectively; the latter two swimming types were accompanied by frequent respiration (hyperventilation). We suggest that the sleep state in Commerson's dolphins occurs predominantly during the circular and quiet swimming. From time to time the dolphins decreased the speed, up to complete stop. Such episodes appeared to be the deepest sleep episodes. In all dolphins, muscle jerks as well erection in male are observed. Most jerks and erections occurred during the circular and quiet chaotic swimming. Thus, Commerson's dolphins, like other studied small cetaceans, are swimming for 24 h per day and they sleep during the swimming. Some muscle jerks that were observed in the dolphins in this study might have been brief episodes of paradoxical sleep.  相似文献   

9.
Sixteen patients suffering from tension or mixed headaches participated in a frontalis EMG treatment schedule of 15 sessions where the therapist was either actively present or almost completely absent. The aim of this study was to evaluate the impact of the therapist's active presence on the subject's ability to lower the EMG level. The active presence of the therapist consistently led to higher frontalis EMG level than that during the therapist's absence. Data also show that the EMG feedback administered was apparently effective in reducing subjective headache intensity along with EMG levels. The findings raise the question of an optimal dosage of presence and activity of the therapist during EMG feedback training.  相似文献   

10.
The objective of this study was to determine the time spent by children (0– 18 years old) in indoor places of leisure and also day-care centers. The sampling scheme was stratified by geographic region and size of town. This study was performed from September 2005 to March 2006. Families were asked to complete a diary by phone on their children's activities during the last week of school and the last week of a vacation period. The time spent in each place was then extrapolated for the winter period. We then evaluated the overall attendance and time (means and quartiles) spent by all of the children, and by those of children attending places. Information was collected on 2780 children. Gymnasiums were frequented the most (52.3% during the winter period) and were the places in which children spend the greatest amount of time (average: 19 min/day). Other places frequented the most included bars/restaurants (46.5%; average: 9 min/day), cinemas/theaters (42.2%; average: 10 min/day), and indoor pools (25.4%; average: 12 min/day). Our results should help in the prioritization of specific projects investigating exposure in children during indoor leisure activities and the evaluation of the risks associated with air pollutants in these places.  相似文献   

11.
Schlemm''s canal is an important structure of the conventional aqueous humor outflow pathway and is critically involved in regulating the intraocular pressure. In this study, we report a novel finding that prospero homeobox protein 1 (Prox-1), the master control gene for lymphatic development, is expressed in Schlemm''s canal. Moreover, we provide a novel in vivo method of visualizing Schlemm''s canal using a transgenic mouse model of Prox-1-green fluorescent protein (GFP). The anatomical location of Prox-1+ Schlemm''s canal was further confirmed by in vivo gonioscopic examination and ex vivo immunohistochemical analysis. Additionally, we show that the Schlemm''s canal is distinguishable from typical lymphatic vessels by lack of lymphatic vessel endothelial hyaluronan receptor (LYVE-1) expression and absence of apparent sprouting reaction when inflammatory lymphangiogenesis occurred in the cornea. Taken together, our findings offer new insights into Schlemm''s canal and provide a new experimental model for live imaging of this critical structure to help further our understanding of the aqueous humor outflow. This may lead to new avenues toward the development of novel therapeutic intervention for relevant diseases, most notably glaucoma.  相似文献   

12.
The exposure of midwives to nitrous oxide in four hospitals was measured with personal samplers. In three of the four hospitals the average exposure was not significantly less than 100 parts per million (ppm). In one hospital the average exposure was 360 ppm; this was reduced by a factor of about 2.5 when a trial scavenging system was used. Differences in working practices and in the layout, size, and ventilation of the labour suites contributed to the observed differences in average exposure. Midwives and other staff working in the labour room are potentially at risk from excessive occupational exposure to nitrous oxide.  相似文献   

13.
Infants'' sensitivity to social or behavioral contingency has been examined in the field of developmental psychology and behavioral sciences, mainly using a double video paradigm or a still face paradigm. These studies have shown that infants distinguish other individuals'' contingent behaviors from non-contingent ones. The present experiment systematically examined if this ability extends to the detection of non-humanoids'' contingent actions in a communicative context. We examined two- to three-year-olds'' understanding of contingent actions produced by a non-humanoid robot. The robot either responded contingently to the actions of the participants (contingent condition) or programmatically reproduced the same sequence of actions to another participant (non-contingent condition). The results revealed that the participants exhibited different patterns of response depending on whether or not the robot responded contingently. It was also found that the participants did not respond positively to the contingent actions of the robot in the earlier periods of the experimental sessions. This might reflect the conflict between the non-humanlike appearance of the robot and its humanlike contingent actions, which presumably led the children to experience the uncanny valley effect.  相似文献   

14.
Proposed increases in the average hours of surgery sessions of general practitioners as part of the government programme for improving primary health care may result in more use of deputising services to provide off duty cover. The satisfaction of patients with such a service was studied during one week of October 1987 at nine of the 29 branches of Air Call Medical Services in urban areas in Britain by means of a postal questionnaire. Of a sample of 4626 callers to the service, 3887 (84%) responded. An estimated 32% of the patients expected that a doctor from their own practice would have attended them, 19% expected that they would be admitted to hospital and 8% were admitted. Over 90% of patients were satisfied with the telephonist''s handling of the call; 79% of those visited were satisfied with the waiting time; and over 80% were satisfied with various aspects of the doctor''s handling of the visit (bedside manner, communication, taking of history, physical examination, and explanation of findings), the lowest figure being for explanation of findings (81%). Satisfaction was generally higher during the daytime; among the elderly, especially men; and among patients who did not anticipate that a doctor from their doctor''s practice would call. The results suggest that a high proportion of patients were satisfied with the deputising service they received.  相似文献   

15.

Background

The impact of low-to-moderate levels of alcohol consumption during pregnancy on child cognitive outcomes has been of recent concern. This study has tested the hypothesis that low-to-moderate maternal alcohol use in pregnancy is associated with lower school test scores at age 11 in the offspring via intrauterine mechanisms.

Methods

We used data from the Avon Longitudinal Study of Parents and Children (ALSPAC), a birth cohort study based in the South West of England. Analyses were conducted on 7062 participants who had complete data on: maternal and paternal patterns of alcohol use in the first trimester and at 18 weeks'' gestation, child''s academic outcomes measured at age 11, gender, maternal age, parity, marital status, ethnicity, household crowding, home ownership status and parental education. We contrasted the association of mother''s alcohol consumption during pregnancy with child''s National Curriculum Key Stage 2 (KS2) test scores with the association for father''s alcohol consumption (during the time the mother was pregnant) with child''s National Curriculum Key Stage 2 (KS2) test scores. We used multivariate linear regression to estimate mean differences and 95% confidence intervals [CI] in KS2 scores across the exposure categories and computed f statistics to compare maternal and paternal associations.

Findings and conclusions

Drinking up to 1 unit of alcohol a day during pregnancy was not associated with lower test scores. However, frequent prenatal consumption of 4 units (equivalent to 32 grams of alcohol) on each single drinking occasion was associated with reduced educational attainment [Mean change in offspring KS2 score was −0.68 (−1.03, −0.33) for maternal alcohol categories compared to 0.27 (0.07, 0.46) for paternal alcohol categories]. Frequent consumption of 4 units of alcohol during pregnancy may adversely affect childhood academic outcomes via intrauterine mechanisms.  相似文献   

16.
There is some evidence to suggest that exposure to mobile phones (MPs) can affect neural activity, particularly in response to auditory stimuli. The current investigation (n = 120) aimed to test recent findings in this area, namely that N100 amplitude and latency would decrease, and that P300 latency and reaction time (RT) would increase under active relative to sham exposure during an auditory task. Visual measures were also explored. A double blind, counterbalanced, crossover design was employed where subjects attended two sessions 1 week apart. In both sessions participants (1) performed auditory and visual oddball tasks while electroencephalogram (EEG) was recorded with a MP set to sham exposure mounted over the temporal region, and (2) performed the same tasks while the handset was set to active/sham. When active, the MP transmitted for 30 min at 895 MHz (average power 250 mW, pulse modulated at 217 Hz, average SAR 0.11 W/kg). Paired t-tests compared difference scores from the sham/sham session to those from the sham/active condition. The study was designed to detect differences of 1\4 of a standard deviation with a power of 0.80. There was no significant difference between exposure conditions for any auditory or visual event related potential (ERP) component or RT. As previous positive findings were not replicated, it was concluded that there is currently no evidence that acute MP exposure affects these indices of brain activity.  相似文献   

17.
Exposure to endotoxin in home environments has become a key issue in asthma and allergy research. Most studies have analyzed floor or mattress dust endotoxin, but its validity as a proxy for airborne exposure is unknown, while active airborne dust sampling is not feasible in large-scale population studies because of logistic and financial limitations. We therefore developed and evaluated a simple passive airborne dust collection method for airborne endotoxin exposure assessment. We explored an electrostatic dust fall collector (EDC), consisting of a 42- by 29.6-cm-sized folder with four electrostatic cloths exposed to the air. The EDC was tested during two 14-day periods in seven nonfarm and nine farm homes and in farm stables. In parallel, active airborne dust sampling was performed with Harvard impactors and floor dust collected by vacuuming, using nylon sampling socks. The endotoxin levels could be measured in all EDC cloth extracts. The levels (in EU/m2) between EDCs used simultaneously or in different sampling periods in the same home correlated strongly (r > 0.8). EDC endotoxin also correlated moderately to strongly (r = 0.6 to 0.8) with the endotoxin measured by active airborne dust sampling and living room floor dust sampling and—in farm homes—with the endotoxin captured by the EDC in stables. In contrast, endotoxin levels measured by floor dust sampling showed only a poor correlation with the levels measured by active airborne dust sampling. We therefore conclude that measuring endotoxin levels with the EDC is a valid measure of average airborne endotoxin exposure, while reproducibility over time is at least equivalent to that of reservoir dust analyses.  相似文献   

18.
Physical disturbance, particularly from iceberg scour, is a major structuring force in polar benthic communities at shelf depths. Scouring kills and damages benthic organisms providing food for the abundant scavenging fauna of coastal Antarctic waters. This trophic group is likely to be strongly affected by changes in iceberg scouring. A baited underwater camera system was used to examine the distribution of scavenging fauna in relation to the spatial variation in exposure to iceberg impacts experienced at different iceberg scouring conditions and depths within Ryder Bay. The results indicate that the relationships between depth and scavenger abundance and assemblage composition differed between high and low scour sites. Scavenger abundance increased with depth at high scour sites and fell with depth a low scour sites. There was also significant difference in community composition between sites within each scouring condition. Scavenger species richness also exhibited an increase with depth at most sites consistent with the established pattern of declining iceberg scouring frequency with depth. Shannon–Wiener diversity increased with depth but significantly more steeply in highly scoured sites. Our results suggest that depth and exposure to icebergs interact to shape the scavenger community. The significant differences within the high and low scour groups suggest that other factors remain to be investigated and that there is probably a nonlinear relationship between scouring intensity and the favourability of a site for scavengers.  相似文献   

19.
OBJECTIVE--To examine the association between environmental exposure to lead and children''s intelligence at age 11-13 years, and to assess the implications of exposure in the first seven years of life for later childhood development. DESIGN--Prospective cohort study. SUBJECTS--375 children born in or around the lead smelting town of Port Pirie, Australia, between 1979 and 1982. MAIN OUTCOME MEASURE--Children''s intelligence quotient (IQ) measured at 11-13 years of age. RESULTS--IQ was inversely associated with both antenatal and postnatal blood lead concentrations. Verbal, performance, and full scale IQ were inversely related to blood lead concentration with no apparent threshold. Multivariate analyses indicated that after adjustment for a wide range of confounders, the postnatal blood lead concentrations (particularly within the age range 15 months to 7 years) exhibited inverse associations with IQ. Strong associations with IQ were observed for lifetime average blood lead concentrations at various ages. The expected mean full scale IQ declined by 3.0 points (95% confidence interval 0.07 to 5.93) for an increase in lifetime average blood lead concentration from 0.48 to 0.96 mumol/l (10 to 20 micrograms/dl). CONCLUSION--Exposure to environmental lead during the first seven years of life is associated with cognitive deficits that seem to persist into later childhood.  相似文献   

20.

?

Claims have been made in a pilot study that a new form of short-term rehabilitation according to ?Best Practice' standards would change signs and symptoms of patients with scoliosis in the short-term. Aim of this study is to repeat the study published 2010 with a larger sample of patients using the same protocol. Both authors have undergone training in this special approach to scoliosis rehabilitation in 2010.

Materials and methods

34 patients with Adolescent Idiopathic Scoliosis (AIS), 32 girls and 2 boys, average age 13.7 years and an average Cobb angle of 28.7 degrees (21-43 degrees) underwent Scoliosis Short-Term Rehabilitation (SSTR) of seven days. Two days with an intensity of 3 × 90 min sessions/day, and five days with an intensity of 2 × 60 min sessions/day. Angle of trunk rotation (ATR) was measured before and after the time of treatment as well as the active correctability of the ATR after the programme as it has been done in the pilot investigation. Additionally to that, we also recorded the changes in Vital Capacity (VC) before and after the programme.

Results

ATR was reduced significantly from 11,5 degrees to 8,4 degrees, the active correctability as measured with the Scoliometer (TM) was also reduced significantly from the ATR after treatment 8,9 degrees to 6,5 degrees in the patients with thoracic curves. VC improved significantly (P < 0,05) from 2073 ml to 2326 ml.

Discussion

The results achieved in the pilot investigation published previously are repeatable. The deformity of the trunk can be reduced significantly after SSTR. During the pilot study VC was not investigated. In our study VC improved significantly. Therefore, also shorter rehabilitation times with an appropriate programme seem to be able to change signs and symptoms of a patient with scoliosis. Like the out-patient Schroth programme as described in a study from Turkey, the SSTR provides benefits leading to an improvement of the condition.

Conclusion

Out-patient rehabilitation following the Scoliologic (TM) ?Best Practice' standards seems to provide an improvement of signs and symptoms of scoliosis patients in this study using a pre-/post prospective design. The results of the pilot study therefore seem to be repeatable.  相似文献   

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