Micromolar sodium fluoride mediates anti-osteoclastogenesis in Porphyromonas gingivalis-induced alveolar bone loss

Osteoclasts are bone-specific multinucleated cells generated by the differentiation of monocyte/macrophage lineage precursors. Regulation of osteoclast differentiation is considered an effective therapeutic approach to the treatment of bone-lytic diseases. Periodontitis is an inflammatory disease characterized by extensive bone resorption. In this study, we investigated the effects of sodium fluoride （NaF） on osteoclastogenesis induced by Porphyromonas gingivalis, an important colonizer of the oral cavity that has been implicated in periodontitis. NaF strongly inhibited the P. gingivalis-induced alveolar bone loss. That effect was accompanied by decreased levels of cathepsin K, interleukin （IL）-1β, matrix metalloproteinase 9 （MMP9）, and tartrate-resistant acid phosphatase, which were up-regulated during P. gingivalis-induced osteoclastogenesis. Consistent with the in vivo anti-osteoclastogenic effect, NaF inhibited osteoclast formation caused by the differentiation factor RANKL （receptor activator of nuclear factor KB ligand） and macrophage colony-stimulating factor （M-CSF）. The RANKL-stimulated induction of the transcription factor nuclear factor of activated T cells （NFAT） cl was also abrogated by NaF. Taken together, our data demonstrate that NaF inhibits RANKL-induced osteoclastogenesis by reducing the induction of NFATcl, ultimately leading to the suppressed expression of cathepsin K and MMP9. The in vivo effect of NaF on the inhibition of P. gingivalis-induced osteoclastogenesis strengthens the potential usefulness of NaF for treating periodontal diseases.

Toxicity of Sodium Fluoride to Caenorhabditis elegans

Objective To investigate the toxic effect of sodium fluoride（NaF） on the nematode Caenorhabditis elegans（C.elegans）.Methods Adult C.elegans were exposed to different concentrations of NaF（0.038 mmol/L,0.38 mmol/L,and 3.8 mmol/L） for 24 h.To assess the physiological effects of NaF,the brood size,life span,head thrashes,and body bend frequency were examined.Reactive oxygen species（ROS） and cell apoptosis were detected as parameters of biochemical response.The gene expressions were determined by real‐time polymerase chain reaction（PCR） to assess the molecular‐level response.Results At the physiological level,the brood size of C.elegans exposed to 0.038 mmol/L,0.38 mmol/L,and 3.8 mmol/L concentrations of NaF were reduced by 6%,26%,and 28% respectively in comparison with the control group.The maximum life spans of C.elegans exposed to 0.038 mmol/L,0.38 mmol/L,and 3.8 mmol/L concentrations of NaF were reduced by 3 days and 5 days,respectively.Head thrashes and body bend frequency both decreased with increasing concentrations of NaF.At the biochemical level,the production of ROS and the incidence of cell apoptosis increased with increasing concentrations of NaF（P0.05）.At the molecular level,different concentrations of NaF exposure raised the expression of stress‐related genes,such as hsp16.1,sod‐3,ctl‐2,dhs‐28,gst‐1,and cep‐1.Conclusion NaF exposure could induce multiple biological toxicities to C.elegans in a concentration‐dependent manner.These toxicities may be relevant to the oxidative stress induced by increased ROS production and accumulation in C.elegans.

Recovery of high specific area silica and sodium fluoride from sodium hexafluorosilicate

Sodium fluoride and high specific area silica were synthesized by using sodium hexafluorosilicate(Na2Si F6) and sodium carbonate decahydrate(Na2CO3·10H2O). The influencing factors of react temperature, contact time, sodium dodecyl sulfate(SDS) and molar ratio of Na2 Si F6 to Na2CO3·10H2O were investigated. The optimum process involves the reaction of 0.075 mol Na2 Si F6 and 150 m L, 0.225 mol Na2CO3·10H2O(molar ratio of 1:3) at 85 °C for 90 min, and 2.0×10-3 mol sodium dodecyl sulfate(SDS) as additive. The results show that the purities of Si O2 and Na F at extraction yields of 96.5% and 98.0% are 91.0% and 98.6%, respectively. The obtained Si O2 were characterized by X-ray diffraction(XRD), scanning electron microscope(SEM), Fourier transform infrared ray(FTIR), differential scanning calorimetry and thermogravimetric analysis(DSC-TGA), N2 absorption/desorption(BET) and laser particle size analyzer. The result demonstrates that Si O2 particles have a high BET surface area of 103 m2/g, and a mean grain size of 985 nm.

Determination of Trace Iron in High Purity Sodium Fluoride by Graphite Furnace Atomic Absorption Spectrometry

A method is described for the direct determination of iron in high purity sodium fluoride using graphite furnace atomic absorption spectrometry. Interferences caused by the matrix are investigated. It is shown that the ashing temperature can be increased to 1 400°C and matrix interferences eliminated, the sensitivity of iron increased in 1. 27 fold by the addition of nickel nitrate. The method is applied to the determination of iron in sodium fluoride and satisfactory results are obtained.

The leaf extracts of Camellia sinensis (green tea) ameliorate sodium fluoride-induced oxidative stress and testicular dysfunction in rats

Objective:To investigate the effect of Camellia(C.)sinensis in mitigating oxidative damage and reproductive toxicity in testis induced by sodium fluoride in a rat model.Methods:Twenty-four adult male Wister rats were divided into 4 groups,with 6 rats in each group.Group 1 orally received distilled water(1 mL/100 g body weight)daily and served as the control group,while group 2 received drinking water with 100 ppm sodium fluoride per day for 21 consecutive days,group 3 was administered with only C.sinensis extract by gavage at a dose of 100 mg/kg body weight and group 4 received drinking water with 100 ppm sodium fluoride and 100 mg/kg body weight C.sinensis leaf extract per day for 21 consecutive days.At the end of the treatment,the rats were sacrificed under light ether anesthesia.The gonado-somatic index,sperm count and motility,serum level of luteinizing hormone and testosterone were assayed.Lipid peroxidation[malondialdehyde(MDA)level],nitric oxide(NO)production,and activities of antioxidant enzymes-superoxide dismutase(SOD),catalase,and reduced glutathione level(GSH)were also analysed.Results:Sodium fluoride treatment significantly decreased gonado-somatic index,sperm count and motility as well as the serum level of luteinizing hormone and testosterone(P<0.05).The histological examination of testes revealed atrophy and degenerative changes in several seminiferous tubules,along with enhanced interstitial space and a reduced number of Leydig cells.There was a highly significant increase in NO and MDA production(P<0.05),while SOD,catalase activities and GSH level decreased significantly(P<0.05).However,C.sinensis significantly restored testicular weight,sperm parameter,hormonal level(P<0.05),and also reversed MDA and NO generation and antioxidant enzymes activities in the testicular tissue(P<0.05).Conclusions:C.sinensis may have an ameliorative role against sodium fluoride-induced oxidative damage in the testis probably because of its antioxidant property.

Sodium Fluoride Induces Hepato-Renal Oxidative Stress and Pathophysiological Changes in Experimental Animals

The liver is a primary site for xenobiotics detoxification, and its metabolism is readily altered by toxicity. The kidney is a common target for toxic xenobiotics due to its capacity to extract and concentrate toxic substances by highly specialized cells. So, they are the target organs of sodium fluoride toxicity. The aim of this review is to highlight on hepatorenal oxidative stress and pathophysiological changes induced by treatment of experimental animals with sodium fluoride. Our review shows fluoride toxicosis caused an elevation in the serum activities of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, acid phosphatase, and the level of total bilirubin, and reduction in the serum levels of total protein, albumin, and globulins, and serious histopathological changes in the hepaic tissues. Also, NaF administration caused increases in serum urea, creatinine, uric acid, sodium ions, and chloride ions levels and serious histopathological changes in the kidney tissues. Treatment of experimental animals with NaF induced oxidative stress in hepatic and renal tissues. It can be concluded that administration of sodium fluoride to experimental animals induced oxidative stress, serious hepatorenal histopathological changes, and disturbance in liver and kidney functions. So, human should be advised to decrease exposure to sodium fluoride to decrease the harmful effects of NaF on liver and kidney.

Bones and Crohn’s:No benefit of adding sodium fluoride or ibandronate to calcium and vitamin D

AIM: To compare the effect of calcium and cholecalciferol alone and along with additional sodium fluoride or ibandronate on bone mineral density (BMD) and fractures in patients with Crohn's disease (CD). METHODS: Patients (n =148) with reduced BMD (T-score < -1) were randomized to receive cholecalciferol (1000 IU) and calcium citrate (800 mg) daily alone(group A, n = 32) or along with additional sodium fluoride (25 mg bid) (group B, n = 62) or additional ibandronate (1 mg iv/3-monthly) (group C, n = 54). Dual energy X-ray absorptiometry of the lumbar spine (L1-L4) and proximal right femur and X-rays of the spine were performed at baseline and after 1.0, 2.25 and 3.5 years. Fracture-assessment included visual reading of X-rays and quantitative morphometry of vertebral bodies (T4-L4).RESULTS: One hundred and twenty three (83.1%) patients completed the first year for intention-to-treat (ITT) analysis. Ninety two (62.2%) patients completed the second year and 71 (47.8%) the third year available for per-protocol (PP) analysis. With a significant increase in T-score of the lumbar spine by +0.28 ± 0.35 [95% conf idence interval (CI): 0.162-0.460, P < 0.01], +0.33 ± 0.49 (95% CI: 0.109-0.558, P < 0.01), +0.43 ± 0.47 (95% CI: 0.147-0.708, P < 0.01) in group A, +0.22 ± 0.33 (95% CI: 0.125-0.321, P < 0.01); +0.47 ± 0.60 (95% CI: 0.262-0.676, P < 0.01), +0.51 ± 0.44 (95% CI: 0.338-0.682, P < 0.01) in group B and +0.22 ± 0.38 (95% CI: 0.111-0.329, P < 0.01), +0.36 ± 0.53 (95% CI: 0.147-0.578, P < 0.01), +0.41 ± 0.48 (95% CI: 0.238-0.576, P < 0.01) in group C, respectively, during the 1.0, 2.25 and 3.5 year periods (PP analysis), no treatment regimen was superior in any in- or between-group analyses. In the ITT analysis, similar results in all in- and between-group analyses with a significant in-group but non-significant between-group increase in T-score of the lumbar spine by 0.38 ± 0.46 (group A, P < 0.01), 0.37 ± 0.50 (group B, P < 0.01) and 0.35 ± 0.49 (group C, P < 0.01) was observed. Follow-up in ITT analysis was still 2.65 years. One vertebral fracture in the sodium fluoride group was detected. Study medication was safe and well tolerated. CONCLUSION: Additional sodium fluoride or ibandronate had no benefit over calcium and cholecalciferol alone in managing reduced BMD in CD.

Actions of Sodium Fluoride on Acetylcholinesterase Activities in Rats

This study was carried out to observe the effects of sodium fluoride on acetylcholinesterase (AChE) activities in the cerebral synaptic membranes (SPM) and the peripheral red blood cells (RBC) of rats by in vivo and in vitro experiments. In the in vivo study,pregnant rats ingested ad libitum fluorinated drinking water (5, 15, 50 ppm F ) during their gestation and lactation. It was shown that the AChE activities of the SPM and peripheral RBCs in maternal rats exposed 5 ~ 50 ppm F for 60 days were elevated significantly by 30. 0 ~ 67. 6 % and 12. 5 ~ 31. 9 % in a dose-dependent manner, respectively. The AChE activities of their offspring 80 days after birth were also increaased (8. 7 ~ 28. 7 % for SPM and20. 6 ~ 32. 4 % for RBC). In contrast, the AChE activities of SPM in vitro were inhibited by 5. 0~ 50 .0 mmol F /L treatment in a time-and dose dependent manner. Analaysis with the Hanes plots suggested that the enzymesubstrate kinetics are consistent with a mixed type ofinhibition.

Influence of sodium fluoride on alkaline phosphatase activity and bone gla protein synthesis in human yellow ligament cells in vitro

Objective To investigate the influence of sodium fluoride(NaF)on alkaline phosphatase(ALP)activity and bone gla protein(BGP)synthesis in yellow ligament cells from different surgical simples in vitro.Methods The human ligament cells

Histochemical pattern of gastrocnemius muscle in fluoride toxicity syndrome

Objective:To evaluate the effect of sodium fluoride(NaF) on cytochemical distribution of proteins,DNA,and RNA in the gastrocnemius muscle of rat in experimental fluorosis.Methods: Young Sprague Dawley albino rats were administered with NaF at 30,45,and 75 mg/kg bw/ day subcutaneously for 15 and 30 days,respectively.The control animals were given the vehicle(1cc deionized double distilled water/kg bw/day).Results:In the first phase of 15 days experimentation,the gastrocnemius muscle of rats intoxicated with NaF at 30,45,and 75 mg /kg bw/ day showed decline in proteins including a amino acids as compared to control. In the second phase of 30 days experimentation,the muscle fibers of rat showed elevation in sarcolemmal and sarcoplasmic proteins in 30 mg NaF dose group,and angulated fibers exhibited increase in sarcolemmal proteins in 45 mg NaF group.The marginal regions of angular and rim fibers showed deeply stained rings of sarcoplasmic proteins whereas the split fibers were faindy stained in rats treated with NaF at 75 mg/kg bw/day for 30 days.In rats treated with NaF at 30 mg/kg bw/day for 15 days,the hypertrophied peripheral muscle fibers contained more DNA,however the atrophied fibers had more RNA.In 45 mg NaF group,RNA was located in sarcolemmal regions,while DNA content decreased as compared to control.In 75 mg NaF group,the muscle fibers had dark and light staining regions of DNA and RNA.In the 30 days of experimentation,the DNA level decreased whereas RNA content increased in the gastrocnemius muscle fibers of the rat treated with NaF at 30 mg/kg bw/day.In treatment group with NaF at 45 mg/kg bw/day,the RNA content slighdy declined in comparison to control,in all treatments for 15 days as well as in treatment group with NaF at 30 mg/kg bw/day for 30 days whereas the amount of DNA slightly increased as compared to treatment group with NaF at 75 mg/kg bw/day for 15 days.The highest dose group revealed elevated amount of RNA whereas DNA content remained stable.Conclusions:The findings of present study demonstrate that certain concentrations of fluoride can induce muscle lesions and damage DNA,RNA,and protein in muscle cells and excessive intake and accumulation of fluoride is therefore a serious risk factor for muscular abnormalities in fluorosis.

Determination of Boron Trifluoride in Boron Trifluoride Complex by Fluoride Ion Selective Electrode

A method was proposed to determine boron trifluoride in boron trifluoride complex using fluoride ion selective electrode(ISE). Hydroxide was chosen to mask aluminum for the determination of 0.01—0.1 mol/L of fluoride. The simulation indicated that the permissible aluminum masked at a certain p H value was limited and hardly related to F-concentration and boric acid. It is better to control p H value below 11.5 and the aluminum concentration within 0.025 mol/L to minimize the interference of hydroxide to the fluoride ISE. The decomposition conditions of boron trifluoride by aluminum chloride were investigated. It is found that the F-detection ratio will approach 1.0 if the Al/F molar ratio is 0.3—0.7 and aluminum concentration is no more than 0.02 mol/L when heated at 80 ℃ for 10 min. In one word, hydroxide is quite fit to mask aluminum for samples which contain high content of fluoride and aluminum and the BF3 content can be successfully determined by this method.

Effect of fluoride ions on coordination structure of titanium in molten NaCl–KCl

The effects of fluoride ions(F^(-)) on the electrochemical behavior and coordination properties of titanium ions(Ti^(n+)) were studied in this work,by combining electrochemical and mathematical analysis as well as spectral techniques.The α was taken as a factor to indicate the molar concentration ratio of F^(-) and Ti^(n+).Cyclic voltammetry(CV),square wave voltammetry(SWV),and open circuit potential method(OCP)were used to study the electrochemical behavior of titanium ions under conditions of various α,and in-situ sampler was used to prepare molten salt samples when α equal to 0.0,1.0,2.0,3.0,4.0,5.0,6.0,and 8.0.And then,samples were analyzed by X-ray photoelectron spectroscopy(XPS) and Raman spectroscopy.The results showed that F^(-) in molten salt can reduce the reduction steps of titanium ions and greatly affects the proportion of valence titanium ions which making the high-valence titanium content increased and more stable.Ti^(2+) cannot be detected in the molten salt when α is higher than 3.0 and finally transferred to titanium ions with higher valence state.Investigation revealed that the mechanism behind those phenomenon is the coordination compounds(TiCl_(j) F_(i)^(m-)) forming.

STUDIES ON COMBINED MUTAGENIC EFFECT INDUCED BY FLUORIDE AND COAL TAR PITCH FUMES

The mutagenicity of fluoride and coal tar pitchfumes (CTPF) and the combined mutagenicity ofthe two materials were studied using Salmonellatyphimurium and mouse polychromatic erythrocytemicronucleus test(MNT).The sodium fluoride(NaF)showed significant effect on increasing thefrequencies of the micronucleated

Folic acid protects against fluoride-induced oxidative stress and testicular damage in rats

Objective:To investigate the effects of folic acid on testicular oxidative damage in sodium fluoride-induced male Wistar rats.Methods:A total of 24 male Wistar rats were divided into 4 groups:the control,sodium fluoride(fed with 100 mg/L sodium fluoride through drinking water orally for 21 days),folic acid(36μg/kg body weight/day,orally),and sodium fluoride plus folic acid(received similar dose orally)groups.At the end of 21 days,epididymal sperm parameters,biochemical analysis of testicular tissue,and serum hormonal levels were performed along with histopathological studies.Results:Sodium fluoride intoxication resulted in marked reduction in gonado somatic index,serum luteinizing hormone,and testosterone level along with 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase activities.In addition,reduction in sperm density,as well as loss of sperm motility and sperm viability,were also observed.Besides,increased levels of testicular malondialdehyde,nitrite,interleukin-6 and tumor necrosis factor-α as well as decreased levels of superoxide dismutase and catalase activities and reduced glutathione content were found to be associated with this toxicity.Folic acid co-treatment,on the other hand,could prevent all the sodium fluoride-induced testicular pathophysiology and oxidative stress related parameters.Histological examinations of testicular sections from the experimental rats supported these results.Conclusions:Combining all,this study suggests that being an antioxidant,folic acid plays a beneficial role against fluoride-induced adverse effects on the male reproductive system.

Bifluorid 12与脱敏糊剂治疗牙齿过敏症的临床研究

目的比较Bifluorid 12、脱敏糊剂与传统脱敏剂氟化钠对牙齿洁治术后牙齿过敏症的脱敏效果。方法选取2013年6月~2015年6月上海宝山中西医结合医院口腔科门诊洁牙后牙齿过敏症患者82例,239颗患牙,按随机数字表法分成4组进行脱敏治疗,A组20例(62颗牙)使用Bifluorid 12,B组21例(58颗牙)使用脱敏糊剂,C组20例(60颗牙)联合使用Bifluorid 12和脱敏糊剂,D组21例(59颗牙)使用75%的氟化钠,评价四组脱敏剂使用后的即刻脱敏效果、3个月后脱敏效果和6个月后脱敏效果。结果 A组和C组的即刻脱敏效果均明显高于B组和D组,差异有统计学意义(P<0.05)。A、B、C组的3个月后脱敏效果均高于D组(P<0.05)。B组、C组6个月后脱敏效果明显高于A组、D组(P<0.05)。结论各组脱敏剂均有牙本质脱敏的效果,其中即刻效果Bifluorid 12最好,脱敏糊剂能维持较长时间的脱敏效果,氟化钠的脱敏效果无法长期维持。

低浓度氟化钠对人牙髓细胞的成骨/成牙本质分化的影响

目的探讨低浓度氟化钠对人牙髓细胞(human dental pulp cells,hDPCs)成骨/成牙本质分化的影响。方法本研究已通过单位伦理委员会审查批准。原代培养hDPCs,采用MTT法检测不同浓度氟化钠对hDPCs增殖的影响;选取合适浓度的氟化钠加入成骨/成牙本质分化诱导培养液中,对hDPCs进行体外诱导,通过茜素红染色检测hDPCs成骨/成牙本质分化能力的变化,RT⁃qPCR检测分化相关基因的mRNA表达;同时通过RT⁃qPCR和Western blot检测hDPCs成骨/成牙本质分化过程中内质网应激相关基因的表达。结果低浓度氟化钠(0.1 mmol/L)在体外可刺激hDPCs增殖,高浓度氟化钠(5~10 mmol/L)可抑制hDPCs增殖(P<0.05)。选取0.1 mmol/L氟化钠体外混合成骨/成牙本质分化诱导培养后hDPCs的茜素红染色增加,成骨/成牙本质分化相关基因牙本质涎磷蛋白(dentin sialophosphoprotein,DSPP)、骨涎蛋白(bone sialoprotein,BSP)和骨钙蛋白(osteocalcin,OCN)mRNA表达水平升高(P<0.05)。同时在此过程中RT⁃qPCR检测出mRNA水平hDPCs内质网应激相关基因:剪切x盒结合蛋白1(splicing x⁃box binding protein⁃1,sXBP1)、葡萄糖调节蛋白78(glucose⁃regulated protein 78,GRP78)以及活化转录因子4(activating transcription factor 4,ATF4)表达升高(P<0.05);Western blot检测出氟化钠混合成骨/成牙本质分化培养后细胞磷酸化真核起始因子⁃2α(phosphorylated eukary⁃otic initiation factor⁃2α,p⁃eIF2α)、磷酸化蛋白激酶样内质网激酶(phosphorylated the RNA⁃activated protein kinase⁃like ER⁃resident kinase,p⁃PERK)和ATF4蛋白表达增加(P<0.05)。结论低剂量氟化钠促进人牙髓细胞的成骨/成牙本质分化并伴有内质网应激水平的升高。

氟暴露对大鼠心肌组织凋亡的影响

目的:探究慢性氟中毒对心肌的毒性作用及其对JNK介导的凋亡影响。方法:将Wistar大鼠随机分为4组,分别为对照组及不同浓度的氟化钠溶液(50、100、200 mg·L^(-1) NaF)处理组,各处理组大鼠自由饮用各自浓度的氟化钠溶液,对照组大鼠饮用去离子水。4个月后获得慢性氟中毒大鼠模型,通过HE染色法比较不同浓度NaF对大鼠心肌组织结构的影响,观察心肌组织的损伤情况;使用Western blot法对心肌组织凋亡相关蛋白的表达进行检测,观察NaF对凋亡蛋白表达量的影响,主要包括p-JNK、Bcl-2、Bax和Caspase-3蛋白表达情况。结果:4个月后建立了慢性氟中毒大鼠模型,氟中毒各组大鼠心肌组织出现肌纤维结构紊乱、肌纤维断裂、肌细胞萎缩、肌间隙增宽、横纹消失等;Western blot检测的结果表明,与对照组相比,慢性氟中毒各组大鼠心肌Bcl-2蛋白表达量明显降低(P<0.05),Bax、Caspase-3和p-JNK的蛋白表达明显上调(P<0.05)。结论:慢性氟中毒可能通过激活JNK信号通路引起心肌凋亡,细胞凋亡参与了氟对心肌组织的损伤。

单宁酸缓解氟化钠诱导小鼠卵母细胞氧化应激的研究

【目的】研究单宁酸(TA)对氟化钠(NaF)诱导小鼠卵母细胞氧化应激损伤的保护作用,从而为开发氟中毒解毒剂提供理论依据。【方法】在小鼠卵母细胞体外成熟培养液中添加0(对照)、0.25、0.50、0.75 mmol/L NaF,通过检测卵母细胞第一极体排出率,确定NaF最适作用浓度。以最佳作用浓度NaF处理小鼠卵母细胞后,通过添加不同浓度TA(0、1、10、100μg/L),确定最佳TA作用浓度。在上述试验基础上设置对照组、毒性组(NaF)和解毒剂组(NaF+TA),利用免疫荧光染色检测小鼠卵母细胞内活性氧(ROS)、谷胱甘肽(GSH)以及线粒体膜电位(MMP)水平;统计各组小鼠卵母细胞受精率、卵裂率和囊胚率,测定丙二醛(MDA)含量以及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性。【结果】与对照组相比,0.25~0.75 mmol/L NaF组卵母细胞第一极体排出率均极显著降低(P<0.01),后续以0.25 mmol/L NaF作为有效毒性剂量进行试验。小鼠卵母细胞经NaF处理后,与0μg/L TA组相比,10μg/L TA组卵母细胞第一极体排出率极显著升高(P<0.01)。免疫荧光检测结果显示,与对照组相比,NaF组小鼠卵母细胞ROS水平显著上升(P<0.05),GSH、MMP水平和SOD、GSH-Px活性显著或极显著下降(P<0.05;P<0.01)。与NaF组相比,NaF+TA组小鼠卵母细胞GSH、MMP水平以及SOD和GSH-Px活性显著或极显著升高(P<0.05;P<0.01),ROS水平和MDA含量显著或极显著降低(P<0.05;P<0.01)。早期胚胎发育统计结果显示,NaF组小鼠卵母细胞的受精率、卵裂率和囊胚率均极显著低于对照组(P<0.01);NaF+TA组小鼠卵母细胞受精率、卵裂率以及囊胚率均极显著高于NaF组(P<0.01),且与对照组相比无显著差异(P>0.05)。【结论】NaF通过提高卵母细胞内ROS和MDA水平诱导小鼠卵母细胞产生氧化应激,并降低细胞MMP水平,影响早期胚胎发育。添加10μg/L TA可以缓解NaF诱导小鼠引起的氧化应激,提高小鼠卵母细胞成熟质量,从而促进体外受精和胚胎发育潜力。

氟化钠提纯工艺研究

经过处理后的氟化钠原料中含有较多的硅酸钠杂质。为了去除其中的杂质,提高氟化钠的纯度,获得更高的工业价值。利用溶出硅胶与蒸发结晶操作过程相结合,设计了溶出硅胶-蒸发结晶提纯氟化钠工艺,提高了氟化钠的纯度,降低了硅的含量,并且改善了氟化钠产品的外观。在溶出硅胶实验中,考察了硫酸用量比、温度、时间、搅拌速率对脱硅过程的影响,并进行了正交试验。结果表明,在溶出硅胶实验中,综合效果最好的脱硅条件为硫酸的用量比(硫酸与氟化钠原料的质量比)为0.04、反应温度为25℃、反应时间为30 min、搅拌速率为300 r/min。在蒸发结晶实验中,当蒸发时间为60 min时,蒸发结晶提纯氟化钠的综合效果最好。在最佳的实验条件下,能得到纯度>98%,二氧化硅质量分数<0.5%的氟化钠产品。研究表明,硫酸与硅酸钠反应能溶出硅胶,再过滤分离能达到除硅的效果,而通过蒸发结晶,能进一步提高氟化钠的纯度。该研究可为提纯氟化钠、回收氟硅资源提供新思路。

含氟废液资源化制备氟化钠的工艺研究

萤石资源的短缺导致氟类资源紧张,为缓解氟资源的压力,需充分提高氟资源的有效利用率。以含氟化铵或氢氟酸废水为原料,采用沉淀法将含氟废液中的游离氟资源化制备氟化钠,研究了制备过程中反应时间、温度、p H和钠盐对氟化钠产品品质的影响,探究了反应后滤液的回用次数及效果。研究结果表明:氟化铵废液在反应时间为120 min、反应温度为85℃的条件下,氟离子与氯化钠中钠离子的物质的量比为1∶1反应时,制备的氟化钠品质最佳(98.30%),产率为67.92%,反应后滤液除氟后蒸发,氯化铵的含氮质量分数为24.47%,达到农业用氯化铵合格品要求;含氢氟酸废液通过中和法加氢氧化钠调节pH至6,制备的氟化钠的质量分数为98.15%,且滤液至少能回用5次。该研究实现了不同成分的含氟废液均可资源化制备氟化钠的工艺流程,极大程度减少了氟资源的浪费,使氟资源得到充分有效的利用。