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Objective To investigate the translation and rotation of healthy elbow joints during active flexion and extension, so as to provide references for the treatment of elbow instability and injuries. Methods Ten healthy subjects with no history of upper extremity trauma were recruited. Dual fluoroscopic imaging system (DFIS) was applied to quantify six-degree-of-freedom (6-DOF) kinematics of humeroulnar and humeroradial joint from full extension to maximum flexion in supination position. Correlation analysis was used to evaluate the relationship between the 6-DOF kinematics of the elbow joint. Results Valgus angle of humeroulnar joint gradually decreased from 15.2°±3.1° to 5.3°±2.3° with the flexion increasing. Valgus angle of humeroradical joint gradually decreased from 19.7°±4.2° to 8.2°±2.4° from full extension to maximum flexion. The valgus angle of humeroulnar and humeroradial joint was linearly related to the flexion angle during flexion and extension. The internal rotation of humeroulnar joint was quadratic nonlinearly related to the flexion angle during motion. The maximum internal rotation of the ulnar was 4.0°±4.9° at 110° flexion, and the maximum external rotation was 5.1°±4.2°. The internal rotation of humeroulnar joint gradually increased from 3.2°±16.0° to 27.2°±18.0°. Conclusions During normal flexion and extension of the elbow, the valgus angle of humeroulnar joint decreased linearly, while the internal and external rotation angle showed a nonlinear change, which first rotated internally and then rotated externally. The valgus angle of humeroradial joint decreased linearly and the internal rotation angle increased linearly. Therefore, humeroulnar joint is not a hinge joint during elbow flexion and extension. There is a kinematic difference between humeroulnar joint and humeroracial joint. For clinical treatment of complex elbow injuries, elbow instability and elbow replacement, different motion characteristics in joints should be considered to improve the outcome after surgery.
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Inner ear is one of the most sensitive parts to microwave radiation.The effect of microwave radiation on the inner ear system is its damage to the vestibule and cochlea.The vestibular and cochlear injury is closely related to the balance of the human body and hearing loss.This article reviews the mechanism of microwave and effects of microwave radiation on the structure and function of the inner ear in order to provide data for future related research.
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By establishing a series of Dynamic Cervical Implants (DCI) within C5-C6 cervical spinal segments, the biomechanical finite element analysis for DCI with different width and thickness were carried out to investigate the influence of the width and thickness of DCI's curved section on its equivalent stress and range of motion (ROM), so as to provide some theoretical basis for the optimization of DCI's design. The results show that the width of DCI's curved section has more obvious influence on the ROM of lateral bending and torsion, in comparison with the thickness of DCI's curved section. By appropriate reduction in width, the ROMs of lateral bending and torsion increase obviously, i.e. the overall movement function of patients is improved. Furthermore, the increase of equivalent stress could be counteracted by corresponding increase of thickness.
Subject(s)
Humans , Biomechanical Phenomena , Cervical Vertebrae , Finite Element Analysis , Movement , Neck , Prostheses and Implants , Prosthesis Design , Range of Motion, ArticularABSTRACT
The transitional near-infrared (NIR) laser was defined as ranging from 1.3μm to 1.4μm, within which the most sensitive tissue to laser damage changed from the retina to the cornea.The ocular damage effect has attracted much attention due to the increased varieties and output power of laser in this spectrum region in recent years.Compared with visible and mid-and-far infrared wavelengths, the ocular damage effect induced by transitional NIR wavelengths has many peculiarities and impact factors due to the bulk absorptionby ocular media.This paper reviews the existing ocular damage threshold data and analyzes the characteristics, impact factors and unresolved issues relating to ocular effects induced by laser radiation over the transition zone.
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Objective To investigate the adverse effect of different doses of high power microwave(HPM) irradiation on oxidative stress in the brain of Wistar rats in order to contribute to establishing an animal model to evaluate protective agents which will be used for protection against microwave radiation.Methods Eighty male Wistar rats were randomly divided into 16 groups according to factor analysis.The average power density was 0,10,30 and 100 mW/cm2 and the sampling time was 6 h,1,3 and 7 d .The duration of exposure was 6 minutes for each radiation group.After exposure, the rats were sacrificed at each sampling time.Colorimetric method was used to measure the content of malondialdehyde(MDA) and protein carbonyl, the activity of GSH-px, SOD and CAT.Results The content of MDA and protein carbonyl of each radiation group was increased with the radiation dose, but decreased with the sampling time prolonged.The activity of superoxide dismutast(SOD),glutathion peroxidase(GSH-px) and catalase(CAT) in each radiation group was decreased with the radiation dose increased, and with the sampling time prolonged, but increased later.Conclusion Microwave radiation can cause oxidative stress in rats brain, as shown by the oxidative damage of lipid and protein and the decrease in the activity of antioxidant enzymes.Besides, the effect also depends on the radiation dose and sampling time.
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Along with the development of science and technology , microwaves are widely used in various fields .Though they have brought much convenience to people , their potential adverse health effects are becoming a concern of governments and researchers .High power microwaves ( HPMs) are widely used in high-tech and new concept weapons , increasing the chance that troops are exposed to HPM environments .It has been clearly confirmed that microwave radiation could cause varying degrees of damage to the nervous system , immune system , cardiovascular system and reproductive system under specific conditions .Therefore , it is of important significance to reduce adverse effects of HPM radiation and improve the combat capability of troops via effective medical protection while doing well in physical protection .According to the mecha-nism and characteristics of microwave radiation damage effects , recent advances in microwave radiation protection are re-viewed in this article , hoping to facilitate research on safer and better drugs .
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Objective To explore the protective effects of a new military functional food NB-5 on psychological stress-induced oxidative stress .Methods Rat whiskers were completely removed to induce the oxidative stress , and the concen-trations of MDA and protein carbonyl in various organs were detected to study the damage to membrane lipid and protein . Rats were fed with NB-5 for 4 weeks, and the oxidative stress was induced by whisker cutting .Biochemical marks men-tioned above were detected to explore the protective effects of NB-5.Results and Conclusion Lipid and protein peroxida-tion occurred in the brain , heart, liver, spleen and kidney after whisker removal due to emotional stress , while the catalase ( CAT) activity decreased significantly in these organs except the spleen .In this experiment model , NB-5 showed a good free radical scavenging activity to reduce the lipid and protein peroxidation among whisker -cutting rats fed with NB-5 in ad-vance.So NB-5 can serve as a good food for soldiers in case of emergency incidents .
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Based on observation and investigation of European research management,the thought of China's scientific research management and reform,this paper puts forward the idea of change,which involves reform,transformation and innovation in organization development,for Chinese research management.It expounds the theories,methods and strategies on change under the guidance of five-color theory.Further,the author analyses the issues of motivation,problems and solutions,et al.in the change of a research institute.Strategies for change are also proposed.
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Objective To investigate the expression of JAM-1 after microwave irradiation and its correlation with blood-brain barrier integrity. Methods A total of 160 male Wistar rats were divided into a sham radiation group and a radiation group. The radiation group was subdivided into three sub-groups treated with micrewaves at average power densities of 10, 30 and 100 mW/cm2. Rats in each group were sacrificed and their brain tissue sampled at 6 hours and 1, 3, 7 and 14 days after the irradiation. Evans blue ( EB ) dye, laser confocal microscopy,Western blotting, RT-PCR and image analysis were used to test the permeability of the blood-brain barrier and the expression of JAM-1 in protein and at the gene level in the rats' hippocampus and cortex. Results There was an increase of EB in the hippocampus 3 to 14 days after 10 and 100 mW/cm2 microwave irradiation. The EB level increased progressively in the 10 and 30 mW/cm2 groups within 7 d after irradiation but recovered by the 14th day. It also increased progressively in the 100 mW/cm2 group within 14 d after irradiation. In the hippocampus, EB was observed only in the lumens of the blood vessels in the sham group, but EB had diffused out of the blood vessels in the irradiated groups by the 3rd day after irradiation. After 10 or 30 mW/cm2 microwave irradiation, JAM-1 protein in the hippocampus and cortex decreased significantly within 7 d after irradiation but recovered by the 14th day. It decreased progressively in the 100 mW/cm2 group within 14 d after irradiation. The expression of JAM-1 mRNA in the hippocampus decreased significantly at 6 h after irradiation at all power levels, but it recovered within 7 days in the 10 and 30 mW/cm2 groups. Conclusions Microwave radiation can decrease the expression of JAM-1 in the hippocampus and cortex. The degree of decrease is positively correlated with the microwave radiation power. The change might involve increasing the permeability of the blood-brain barrier.
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This paper introduced the feasibility of flexible management from medical scientific re-search institutions, embarks on the aspects of construction contents such as value identity system, fuzzy eval-uation system, sharing mechanism of scientific management aims and information involving in implementing management. And the paper combined with the experience of the innovation projects in Chinese Academy of Sciences and our institution, and preliminarily expounds the construction connotations and keys of the "flexi-ble management system" in medical scientific research units to provide ideas for enriching the management thoughts of medical scientific research.