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Objective:To observe the changes of phosphorylated N-methyl-D-aspartate receptor (P-NMDAR) subunit and calmodulin-dependent protein kinase Ⅱ (CaMK Ⅱ) protein expression in the brain tissue of rats with chronic fluorosis, and to explore the molecular pathogenesis of chronic fluorosis nerve injury.Methods:Eighteen one-month-old SD rats (half male and half female), weighing (100 ± 20) g, were randomly divided into three groups after adaptive feeding for 1 week: control group (drinking tap water, fluoride content < 0.5 mg/L), low fluoride group (drinking water fluoride content was 10.0 mg/L) and high fluoride group (drinking water fluoride content was 100.0 mg/L), with 6 rats in each group (half male and half female). Brain tissue was harvested after 180 days of feeding. HE staining was used to observe the morphological changes of rat brain tissue, Nissl staining was used to observe the changes of Nissl bodies in nerve cells, and immunohistochemical staining was used to observe the expressions of P-NMDAR subunits (P-NMDAR1, P-NMDAR2A) and CaMK Ⅱ protein in rat brain tissue.Results:Under light microscope, HE staining showed disordered arrangement of hippocampal neurons, nuclear hyperstaining and basophilic enhancement in the high fluoride group. The results of Nissl staining showed that the average optical density of Nissl bodies in nerve cells in the hippocampus of rats in the control group, low fluoride group, and high fluoride group were 0.024 4 ± 0.009 7, 0.024 0 ± 0.003 1, and 0.023 9 ± 0.013 8, respectively. There was no statistically significant difference between the groups ( F = 0.010, P > 0.05). Compared with the control group (0.011 8 ± 0.006 5, 0.065 6 ± 0.011 1, 0.143 8 ± 0.029 9) and low fluoride group (0.017 2 ± 0.006 8, 0.062 6 ± 0.017 8, 0.135 6 ± 0.029 6), the protein expressions of P-NMDAR1, P-NMDAR2A and CaMK Ⅱ in high fluoride group were significantly increased (0.026 3 ± 0.005 7, 0.086 3 ± 0.009 0, 0.210 9 ± 0.048 7, P < 0.05); and the protein expression of P-NMDAR1 in low fluoride group was higher than that in the control group ( P < 0.05). Conclusion:Long-term excessive fluoride intake can lead to nerve cell injury in rats, and the mechanism of injury maybe related to the excitotoxicity induced by calcium ion (Ca 2+) overload caused by overactivation of NMDAR subunits.
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Objective:To observe the change of growth and development, learning and memory, and oxidative stress in serum of offspring rats with fluorosis, and to explore the mechanism of fluoride on neurobehavioral development of offspring rats.Methods:Seventy-two SD rats (female and male ratio 3 ∶ 1) were fed adaptively for one week. According to their body mass [(80 ± 20) g], they were divided into control group (drinking tap water, containing less than 0.5 mg/L fluoride), low fluorine group (drinking water containing 10.0 mg/L of fluoride), and high fluorine group (drinking water containing 100.0 mg/L of fluoride) with random number table. After six months of feeding, they mated freely and gave birth in each group (24 rats with 18 females and 6 males). The rats in each group continued to be exposed to fluoride after giving birth, and the offspring rats were exposed to fluoride through breast milk feeding until the 28th day after birth. Body and brain weight, growth and development indicators (auricle separation, eyes opening, teeth eruption and hair growth) and neurobehavioral development indicators (cliff avoidance, auditory startle, surface righting and vibrissa positioning) were recorded. On the 28th day after birth, the learning and memory abilities (escape latency) of offspring rats were tested by Morris water maze; blood samples were taken from eyeballs to detect the content of nitric oxide (NO), the activity of nitric oxide synthase (NOS) and inducible nitric oxide synthase (iNOS).Results:On the 21st day and 28th day after birth, the differences of body weight among control group, low fluorine group and high fluorine group [21st day: (54.70 ± 3.02), (52.30 ± 2.58), (51.30 ± 2.71) g, 28th day: (91.70 ± 5.03), (90.40 ± 4.76), (86.00 ± 4.55) g] were statistically significant ( F = 3.96, 3.70, P < 0.05); on the 21st day, the body weight of high fluorine group was lower than that of control group ( P < 0.05); on the 28th day, the body weight of the high fluorine group was lower than those of control group and low fluorine group ( P < 0.05). On the 28th day, the difference of brain weight of control group, low fluorine group and high fluorine group was statistically significant ( F = 6.19, P < 0.05); and the low fluorine group and high fluorine group were lower than that of control group ( P < 0.05). Among the growth development indicators, the difference of time of completing eyes opening in control group, low fluorine group and high fluorine group was statistically significant ( F = 3.64, P < 0.05); and the high fluorine group was higher than that of control group ( P < 0.05). In neurobehavioral development indicators, the differences of time of completing cliff avoidance, surface righting between the control group, low fluorine group and high fluorine group were statistically significant ( F = 8.29, 7.69, P < 0.05); and the time of completing cliff avoidance in high fluorine group was higher than those of control group and low fluorine group ( P < 0.05), the time of completing surface righting was higher than that of control group ( P < 0.05). In Morris water maze, on the 4th day, the escape latencies of low fluorine group and high fluorine group were higher than that of control group ( P < 0.05). The results of oxidative stress in serum showed that there were statistically significant differences in serum NO content, NOS and iNOS activitives between the control group, low fluorine group and high fluorine group ( F = 4.86, 66.48, 70.95, P < 0.05); and the NO content of the high fluoirne group was higher than that of the control group ( P < 0.05), the activities of NOS and iNOS of the high fluoirne group were higher than those of control group and the low fluorine group ( P < 0.05). Conclusion:Excessive fluoride can increase the level of oxidative stress in serum, which may be closely related to the neurobehavioral retardation and the decline of learning and memory ability of offspring rats.
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OBJECTIVE@#To explore the application value of MAR algorithm in metal artifact removal of CT simulator.@*METHODS@#CT phantom with titanium plate was scanned using conventional algorithms and MAR algorithms, respectively. Artifact index(AI), contrast-to-noise ratio(CNR) and AI values at different slices were used to analyze the artifact images.@*RESULTS@#In artifact index, MAR algorithm (10.28±2.60) is significantly lower than conventional algorithm (20.65±5.04); In contrast-to-noise ratio index, MAR algorithm (7.81±1.12) is better than conventional algorithm (5.61±1.36). The above indicators were statistically significant in both algorithms (P<0.01). In the slices affected by metal artifacts, the artifact index decreased by 21.72%~88.40% after the MAR algorithm.@*CONCLUSIONS@#MAR algorithm can significantly reduce the metal artifacts and improve the clinical value of CT data.
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Algorithms , Artifacts , Metals , Phantoms, Imaging , Titanium , Tomography, X-Ray ComputedABSTRACT
OBJECTIVE@#To establish a set of evaluation system of digital radiography clinical value and provide foundation for the maturity assessment of digital radiography.@*METHODS@#The evaluation system of clinical value of digital radiography was established by literature survey,expert consultation,and percentage weight method.@*RESULTS@#The expert authority coefficients were 0.81 and 0.88,respectively.After two rounds of consultation,variation coefficients of each item ranged from 0 to 0.207,and the coefficient coordination were 0.599.The index system consisted of 5 first-level indexes and 12 second-level indexes.The weights of first-level indexes such as image quality,safety,usability,economic and social indicators share of the weight are 0.298,0.294,0.199,0.121 and 0.088 respectively.@*CONCLUSIONS@#A completed and scientific evaluation system was established,which provides a scientific assessment tool for clinical value of digital radiography.
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Delphi Technique , Radiographic Image Enhancement , Reference StandardsABSTRACT
OBJECTIVE@#To explore the high-risk fault risk of CT simulator and the main causes of the risk, and to put forward effective risk management strategies.@*METHODS@#The failure mode and effect analysis method was used to identify and control the operational fault risk of CT simulator.@*RESULTS@#5 major fault components, 8 fault failure models and 17 failure causes were analyzed. The top 5 failure causes are:anode target surface burn caused by direct scanning without warming up the tube (590.4), tube failure (518.2), burnout of joints caused by aging of high voltage cables (424.2), motor carbon brush wear (304.8) and belt break (296.4).@*CONCLUSIONS@#The failure mode and effect analysis method can effectively identify the risk of equipment failure, and thus specifically formulate risk management and control measures to ensure the normal operation of equipment and the safety of doctors and patients.
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Humans , Equipment Failure , Risk Management , Methods , Tomography, X-Ray Computed , Reference StandardsABSTRACT
Objective To observe the expression of phosphorylated N-methyl-D-aspartate receptor (P-NMDAR) protein in hippocampal neurons of rats with fluorosis and explore the mechanism of neuronal damage caused by fluorosis.Methods Sixteen Sprague-Dawley rats within 24 h after birth were selected,and hippocampus of the brain was isolated after sacrifice.The primary neurons were cultured in vitro.Observation of the cell morphology under an inverted microscope,neurons were identified by immunofluorescence staining.In the 7th day of cultivation,the neurons were divided into control group,low fluoride group,high fluoride group,antagonist group,low fluoride antagonist group and high fluoride antagonist group.The control group was treated with the same volume of medium as the experimental group.The concentration of NaF was 0.2 and 2.0 mmol/L in the low fluoride group and the high fluoride group,respectively.The antagonist group was treated with 10.0 μ mol/L NMDAR antagonist (MK-801).The low fluoride antagonist group and the high fluoride antagonist group were treated with 0.2 mmol/L NaF + 10.0 μmol/L MK-801,2.0 mmol/L NaF + 10.0 μmol/L MK-801,respectively.The culture time was 24 hours.The expression levels of phosphorylated protein (P-NMDAR1,P-NMDAR2A,P-NMDAR2B) of NMDAR subunits were detected by Western blotting.Results Under inverted microscope,the primary cell body of the cultured in vitro for 2-3 days became larger,and many protrusions appeared outward,showing a small spider shape;6-7 days,the cells synaptic long and slender,a network-like interlaced form.Under fluorescent microscope,NeuN positive cells (neurons) with red fluorescence were observed,and the cell purity exceeded 80％.There was no significant difference in the expression of P-NMDAR1 protein between the control group,the low fluoride group,the high fluoride group,the antagonist group,the low fluoride antagonist group and the high fluoride antagonist group (0.44 ± 0.12,0.46 ± 0.06,0.46 ± 0.12,0.56 ± 0.10,0.70 ± 0.12,0.46 ± 0.09,F=2.75,P ＞ 0.05);P-NMDAR2A and P-NMDAR2B protein expressions were statistically significant between the six groups (0.75 ± 0.17,0.74 ± 0.08,1.13 ± 0.27,0.87 ± 0.15,0.67 ± 0.11,0.66 ± 0.09;0.68 ± 0.24,0.66 ± 0.12,1.46 ±0.27,0.74 ± 0.16,0.56 ± 0.13,0.91 ± 0.35,F =3.68,6.11,P ＜ 0.05),and the expressions of P-NMDAR2A and P-NMDAR2B protein in high fluoride group were higher than those in the control group (P ＜ 0.05);the expressions in the high fluoride antagonist group were lower than those in the high fluoride group (P ＜ 0.05).Conclusion Excessive fluoride can increase the expressions of P-NMDAR2A and P-NMDAR2B protein of hippocampal neurons,and co-culture of MK-801 and NaF can antagonize the damage of fluoride to neurons.
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This paper introduces the technical features of hydrosurgery system and evaluates it from three aspects:safety and effectiveness, economy and technology maturity. The evaluation results show that the safety and effectiveness are high, and the safety mainly involves the misuse of the system, which cause the adverse events. A large number of literatures have proved that the system is more suitable for the debridement of fine parts. It is estimated that hydrosurgery system has better economic performance, but the cost and patients' cost is also increased correspondingly. In the aspect of technology maturity assessment, this technology is a patented technology, and the number of published papers both at home and abroad is on the rise, indicating that the initial application of the technology is better and the technology is in infancy stage. Therefore, hydrosurgery system has certain advantages in all aspects. Hospitals need to allocate the equipment according to their own needs and clinical application, while a wider range of clinical trials is needed to provide evidence-based evidence for clinical applications and promotion.
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Humans , Debridement , Equipment and Supplies , Water PurificationABSTRACT
This paper reviews the principle and clinical application of hydrosurgery system, including the burn debridement, diabetic foot wounds debridement and other trauma debridement. Meanwhile, this paper introduces the development direction of waterjet technology. Furthermore, the safety, effectiveness and suitability can be discussed.
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Humans , Burns , Therapeutics , Debridement , Methods , Foot Ulcer , Therapeutics , Hydrotherapy , Treatment Outcome , Wound HealingABSTRACT
This paper reviews the basic principles and calculation methods of MR specific absorption rate, discusses the clinical application of MR specific absorption rate.