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Objective@#To establish a model for evaluating the upper limb load intensity of workers based on biomechanical methods, and to verify its effectiveness.@*Methods@#15 male volunteers participated in lifting test of 3 kinds of external force load in March 2015. Volunteers’ operating postures, forces, and subjective load intensities were collected. The biomechanical models of lifting operation were established with the input of operating postures and forces, and to output joint torque of shoulder, elbow and wrist. The simulation results were normalized by the maximum torque of each joint, and the relative joint torque was obtained. Then the upper limb load intensity evaluation model, which related with relative joint torque of shoulder, elbow and wrist, was established based on analytic hierarchy process. In order to validate the validity of the model, the assessment results of the model and the subjective load intensities of the volunteers were contrasted.@*Results@#The weight of shoulder joint (0.56) was larger than the weights of elbow and wrist (0.27 and 0.17) in the influence factors of the upper limb load. Pearson correlation analysis showed that the upper limb load intensities of the model were significantly correlated with the subjective load intensities of volunteers (r=0.863, P<0.05) . There was no significant difference between the two groups (t=0.105, P>0.05) .@*Conclusion@#The evaluation model of the upper limb load intensity based on biomechanical methods could be used for predicting and evaluating the upper limb load intensities of workers.
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BACKGROUND: Miniscrews have been widely used as "absolute anchorage" in orthodontic treatment, but high shedding rate has been a major flaw. Factors associated with the miniscrew stability mainly include its own factors, surrounding inflammation, implant method, angle, position and loading time of miniscrews. OBJECTIVE: To review the factors affecting the stability of miniscrews reported at home and abroad in recent years.METHODS: The first author searched CNKI and PubMed using computer for relevant articles published in recent 4 years, and the keywords were "miniscrews, stability, orthodontic anchorage" in Chinese and English, respectively. RESULTS AND CONCLUSION: A total of 52 articles were included. The surface modification of miniscrews effectively enhances bone binding capacity, and promotes bone regeneration, thereby improving the stability of miniscrews. The morphology, implanted angle and mode, bone density and load timing of miniscrews are closely related to the stability of miniscrews. Meanwhile, we should avoid damage to the root, nerves, blood vessels and maxillary sinus, and focus on the maintenance of postoperative healing.
ABSTRACT
BACKGROUND: Miniscrews have been widely used as "absolute anchorage" in orthodontic treatment, but high shedding rate has been a major flaw. Factors associated with the miniscrew stability mainly include its own factors, surrounding inflammation, implant method, angle, position and loading time of miniscrews. OBJECTIVE: To review the factors affecting the stability of miniscrews reported at home and abroad in recent years.METHODS: The first author searched CNKI and PubMed using computer for relevant articles published in recent 4 years, and the keywords were "miniscrews, stability, orthodontic anchorage" in Chinese and English, respectively. RESULTS AND CONCLUSION: A total of 52 articles were included. The surface modification of miniscrews effectively enhances bone binding capacity, and promotes bone regeneration, thereby improving the stability of miniscrews. The morphology, implanted angle and mode, bone density and load timing of miniscrews are closely related to the stability of miniscrews. Meanwhile, we should avoid damage to the root, nerves, blood vessels and maxillary sinus, and focus on the maintenance of postoperative healing.
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Abstract Acute localized exanthematous pustulosis is a localized variant of acute generalized exanthematous pustulosis, which is characterized by the eruption of multiple scattered pustules following drug administration. A 72-year-old woman presented with multiple erythematous pustules on her face, which had appeared two days after using cefoperazone and sodium sulbactam. Histopathological findings showed subcorneal pustules and mixed inflammatory cell infiltration in the dermis. The pustules resolved within about two weeks after the patient discontinued the antibiotics. This report discusses the case of a woman with a cutaneous drug reaction consistent with acute localized exanthematous pustulosis that occurred after cefoperazone and sodium sulbactam were administered.
Subject(s)
Humans , Female , Aged , Sulbactam/adverse effects , Cefoperazone/adverse effects , Acute Generalized Exanthematous Pustulosis/etiology , Acute Generalized Exanthematous Pustulosis/pathology , Anti-Bacterial Agents/adverse effects , Skin/pathology , Time Factors , BiopsyABSTRACT
Objective To investigate the plantar force characteristics during human walking and running under different gravity environment. Methods Seven healthy male volunteers walked and ran in vertical position on a weight-loss suspension treadmill under simulated Mars gravity (1/3 G) and lunar gravity (1/6 G), and traditional earth gravity (1 G) respectively at three different velocities (3, 7 and 10 km/h). During the exercise, parameters such as stance phase, plantar force, and gait balance in gait cycle were analyzed by using the F-scan insole pressure distribution measurement system. Results At the same velocity during a gait cycle, the contact phase was significantly shorter with the decrease of gravity, but the swing phase was significantly longer (P0.05). The peak and average plantar force, force integrity were significantly reduced with the decrease of gravity. Under normal gravity, the increase of velocity could lead to an obvious increase in peak and average plantar force and an obvious decrease in force integrity. While under simulated lunar and Mars gravity, no significant changes were found in plantar force (P>0.05). Under the three gravities, the ratio of vertical impact was quite different in between (P<0.05), but no significant difference was found in the phase symmetry index. Conclusions As compared to normal gravity environment, parameters benefiting for skeleton and muscle function such as plantar force and contact phase were found to be much smaller under low gravity environment, indicating the necessity of considering these factors when designing countermeasures or exercise prescriptions for space flight so as to sustain the astronaut’s normal function of skeleton and muscle.
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Objective To study the relationship between eye movement,HRV indexes and mental fatigue,find feasible objective indexes and build the comprehensive method to evaluate mental fatigue.Methods When twenty subjects executed the simulated monitoring task for 60 min,pupil diameter and ECG data were recorded by eye tracker system and Holter.The subjects were divided into 2 groups(fatigued group/scarcely fatigued group) according CFF(critical flicker frequency) and reaction time(RT).Based on comparison of various indexes between pre-and post-monitoring task,potent indexes were extracted to evaluate mental fatigue.Results After monitoring task,the change of fatigue feeling,Perclos,r-MSSD,PNN50,HF,LF and TP were significantly different in two groups.Conclusion It's suggested that psychology,Perclos and HRV indexes can be used to build the multilevel comprehensive method which can detect mental fatigue quantitatively and qualitatively.
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Objective To investigate the regulation of fluctuation of beat to beat cardiac cycle.Methods A cardio-electric cycle consists of cardio-electric activity called P-T interval and cardio-electric resting TP segment,P-R interval and Q-T interval constitute P-T interval.The cardiac cycles fluctuate along with the time span fluctuation of sub waves and segments.This paper firstly extracted sub waves and segments based on signal processing methods,then discussed the contribution ratio of all waves and segments toward cardiac cycle fluctuation according to statistics.Results Experimental results indicated that the cardiac cycle fluctuation was mainly consistent with the change of TP segment.The P-T interval varied consistently with P-R interval foremost.Conclusion It is revealed that rule of cardiac cycle fluctuation is very useful for further research to figure out the cardiac function and mechanism.