Occupational Health

Actins ; metabolism ; Animals ; Antigens, CD ; metabolism ; Cadherins ; metabolism ; Carotid Artery Injuries ; metabolism ; pathology ; Endothelium, Vascular ; metabolism ; ultrastructure ; Fluorescent Antibody Technique ; Microscopy, Confocal ; Rats ; Troponin ; metabolism

Randomization is one of the four basic principles of research design. The meaning of randomization includes two aspects: one is to randomly select samples from the population, which is known as random sampling; the other is to randomly group all the samples, which is called randomized grouping. Randomized grouping can be subdivided into three categories: completely, stratified and dynamically randomized grouping. This article mainly introduces the steps of complete randomization, the definition of dynamic randomization and the realization of random sampling and grouping by SAS software.

The control principle is one of the four basic principles of research design. Without a control group, the conclusion of research will be unconvincing; furthermore, if the control group is not set properly, the conclusion will be unreliable. Generally, there is more than one control group in a multi-factor design. Problems like incomplete control and excessive control should be avoided. This article introduces the meaning and function of the control principle, common forms of control, common errors that researchers tend to make as well as analysis and differentiation of these errors.

The repetition principle is important in scientific research, because the observational indexes are random variables, which require a certain amount of samples to reveal their changing regularity. The repetition principle stabilizes the mean and the standard variation, so that statistics of the sample can well represent the parameters of the population. Thus, the statistical inference will be reliable. This article discussed the repetition principle from the perspective of common sense and specialty with examples.

0.05). After IL-1? was addied, densities of EGF, EGFR, TGF?R 1 were 224.00?31.59, 178.67?27.86 and 80.34?11.75 respectively in fibroblasts of normal skin; 128.75?18.31, 105.82?21.61 and 109.83?25.79 in fibroblasts of HS;113.01?24.71,93.34?30.71 and 118.75?19.27 in fibroblasts of keloid. Densities of EGF and EGFR in fibroblasts of normal skin was significantly higher than those in HS and keloid (P

Acupuncture Points ; Acupuncture Therapy ; Adult ; Aged ; Calcaneus ; Fasciitis, Plantar ; therapy ; Female ; Humans ; Male ; Middle Aged ; Musculoskeletal Manipulations ; Pain, Intractable ; therapy ; Pelvis ; injuries