RESUMO
BACKGROUND:Mesenchymal stem cells are pluripotent stromal cells isolated from a variety of tissues,which can differentiate into osteoblasts under certain conditions.Photobiomodulation,as an external stimulus,can promote osteogenic differentiation combined with other inducers or alone,providing new ideas for solving a series of bone diseases. OBJECTIVE:To review the relevant literature and mechanisms of photobiomodulation-induced osteogenic differentiation of mesenchymal stem cells,which will lay a theoretical foundation for bone tissue engineering using mesenchymal stem cells as seed cells and may offer some suggestions for future studies. METHODS:Relevant articles were searched on CNKI,PubMed and Wed of Science databases with Chinese search terms of"photobiomodulation,low power laser,low level laser,light-emitting diode,mesenchymal stem cells,osteogenic differentiation,biomaterials"and English search terms of"photobiomodulation,low level laser(light),light-emitting diode(LED),mesenchymal stem cell,osteogenic differentiation,biomaterials".Finally,88 articles were included for analysis. RESULTS AND CONCLUSION:(1)Photobiomodulation represented by low level laser and diode laser has a positive effect on promoting the proliferation and differentiation of mesenchymal stem cells.(2)Photobiomodulation can induce osteogenic differentiation of mesenchymal stem cells,whose feasibility has been verified in cell and animal experiments.On one hand,photobiomodulation can promote the expansion and differentiation of stem cells in vitro by activating related signaling pathways and up-regulating the expression of osteogenic molecules.On the other hand,photobiomodulation can improve the survival rate of stem cells in vivo,promote homing effect and shorten the healing time of bone defects after stem cells are injected into the body.However,photobiomodulation has a biphasic dose effect,whose laser parameters,experimental environment,cell type and other factors in various studies are different,making the research results lack consistency and difficult to apply in the clinic.(3)Combined with biological materials,other physical factors and drugs,photobiomodulation can also accelerate osteogenic differentiation.(4)In conclusion,photobiomodulation has been used increasingly widely in the medical field with its advantages of non-invasive,efficient and less-side reactions,and its role in bone tissue engineering has gradually become prominent,which provides a new method for the treatment of bone defects and related diseases.Further exploration should be focused on the standardized treatment parameters of photobiomodulation.
RESUMO
Most studies have examined the association of ergonomic risk factors and musculoskeletal discomfort in developed countries. Meanwhile the data are still lacking in developing countries such as Malaysia. The aim of this study was to determine the relation between risk factors and musculoskeletal discomfort among manual material handling workers in Malaysian automotive industries. A total of211 manual material handling workers from automotive industries completed a set of questionnaire on the individual, physical and environmental factors and the prevalence of musculoskeletal discomfort. The Chi-Square test and logistics regression analysis were used to determine the relationship of the risk factors and musculoskeletal. The findings highlighted that job tenure was significantly correlated with musculoskeletal discomfort among the workers (OR=2.33-5.56). The most significant physical risk factor that was associated with musculoskeletal discomfort was bending the trunk forward slightly, hands above knee level, which was significantly related to lower back discomfort (OR=5.13, 95%CI=1.56-16.8), thigh discomfort (OR=5.1, 95%CI=1.01-25.53) and wrist discomfort (OR=3.65, 95%CI=1.06-12.53). Twisting of the trunk (over 45o) and bending sideways were significantly associated to lower back discomfort (OR=4.04, 95%CI=1.44-14.44), and thigh discomfort (OR=4.3, 95%CI=1.29-8.50). The findings also highlighted that environmental factors was associated with musculoskeletal discomfort (p < 0.05. Musculoskeletal discomfort can be reduced by lowering work-related risk factors among automotive manual material handling workers, particularly by focusing on significant factors, including job tenure, bending or twisting postures and environmental factors.
RESUMO
@#Physical factor therapy is commonly used in the treatment of nervous system damage. Recent years, physical factor therapy gets popular attention because of its good therapeutic effects, low cost, simple operation and widely application. This article respectively in-troduced the effects of electrical stimulation therapy, functional magnetic stimulation therapy and biofeedback therapy on neurogenic blad-der.
RESUMO
This study aims to evaluate CT (Computed Tomography) characteristics through the estimation of HU (Hounsfield Unit) and the corresponding variations using coefficient of variation values for various materials as a function of physical factor. HU values for various materials with varying densities as a function of physical factor were measured using MDCT (Siemens SOMATOM Sensation 4, Germany). The results showed that the HU values were decreased and increased as a function of kVp and material density, respectively. Especially, the HU values for bone and iodine at 140 kVp were 32% and 42% smaller than those at 80 kVp, respectively. In case of iodine, the HU values also decreased and increased as a function of kVp and concentration, respectively. While the HU values were fixed as a function of mAs. The decreased ratio of HU values between 80 keV and 140 keV was different at various concentration and maximum difference was shown as 1.73 at 3% concentration. These results indicated that it may be possible to separate composition of materials, e.g. iodine and bone, using single source CT. The results showed that dual energy techniques using single source CT can be applied to material separation and expand CT imaging techniques to other practical applications.
Assuntos
Iodo , SensaçãoRESUMO
This study aims to evaluate CT (Computed Tomography) characteristics through the estimation of HU (Hounsfield Unit) and the corresponding variations using coefficient of variation values for various materials as a function of physical factor. HU values for various materials with varying densities as a function of physical factor were measured using MDCT (Siemens SOMATOM Sensation 4, Germany). The results showed that the HU values were decreased and increased as a function of kVp and material density, respectively. Especially, the HU values for bone and iodine at 140 kVp were 32% and 42% smaller than those at 80 kVp, respectively. In case of iodine, the HU values also decreased and increased as a function of kVp and concentration, respectively. While the HU values were fixed as a function of mAs. The decreased ratio of HU values between 80 keV and 140 keV was different at various concentration and maximum difference was shown as 1.73 at 3% concentration. These results indicated that it may be possible to separate composition of materials, e.g. iodine and bone, using single source CT. The results showed that dual energy techniques using single source CT can be applied to material separation and expand CT imaging techniques to other practical applications.
Assuntos
Iodo , SensaçãoRESUMO
Objective To vividly display the forming principle of anthropometric ECG by using mannequin.Methods A mannequin was made using conductive paper with"heart" designed in left chest and its ECG was measured.Results The forming principles of ECG from mannequin and real people were identical.Mannequin had the same physical characteristics as real human body.Conclusion The change of ECG caused by pure physical factors can be studied by using the mannequin,which helps doctors properly analyze ECG and make accurate diagnosis.