氟化钠对雄性小鼠精子畸形的影响

为探讨氟化钠对雄性小鼠精子畸形的影响,选取50只成年雄性小鼠随机分为5组：氟化钠染毒高剂量组（34mg／kg）、中剂量组（17mg／kg）、低剂量组（8．5mg／kg）、环磷酰胺阳性对照组（50mg／kg）、生理盐水空白对照组,采用经口灌胃染毒,1次／d,连续5d,于首次染毒后的第35天颈椎脱臼将小鼠处死,取睾丸和附睾称质量,计算脏器系数;同时取附睾制片,观察精子形态,计数小鼠精子畸形率。结果表明,氟化钠染毒各组睾丸、附睾脏器系数与空白对照组比较,差别无统计学意义（P〉0．05）,染毒各组精子畸形率普遍高于空白对照组,差别有统计学意义（P〈0．001）,且随着染毒剂量的增加精子畸形率也有相应升高,呈现一定的剂量一反应关系（r=0．954,F=20．098,P〈0．05,R^2=0．909）。提示氟化钠能使雄性小鼠精子畸形率明显升高,具有一定的生殖毒性,能影响小鼠生殖功能,对小鼠生殖功能造成损害。     

氟化钠对小鼠骨髓细胞微核率的影响

为探讨氟化钠对小鼠骨髓细胞微核率的影响,选取50只小鼠随机分为5组:氟化钠染毒高剂量组(34 mg/kg)、中剂量组(17 mg/kg)、低剂量组(8.5 mg/kg)、环磷酰胺阳性对照组(50 mg/kg)、生理盐水空白对照组,采用经口灌胃染毒,1 次/d,连续2 d,第3天处死小鼠取胸骨骨髓制片观察小鼠骨髓细胞微核...     

氟化钠对大鼠血清微量元素的影响

为探讨氟化钠（NaF）对大鼠血清四种微量元素含量的影响,将80只2月龄SPF级SD大鼠,雌雄各半,随机分成8组：对照组[幼年（CS）、成年（AS）]和用药组[幼年高氟（CHS）、成年高氟（AHS）平订幼年低氟（CLS）、成年低氟（ALS）组,长期高氟（HS）和低氟（LS）组];对照组灌胃生理盐水,刖药组分别按相应时阃给予不同剂量的NaF灌胃。结果表明,与CS组相比,CYIS组和CLS组的P分别增加100％（P〈0．05）和193．8％（P〈0．05）;与As组相比,HS组的Ca、Zn分别下降了20．5％（P〈0．05）和40％（P〈0．05）,而P则增加了74％（P〈0．05）,LS组的Zn也下降了33．3％（P〈0．05）。提示：长期使用氟化钠可导致幼年大鼠血中化学元素代谢紊乱。     

亚慢性钐染毒对雄性小鼠精子质量的影响

为探讨稀土元素钐对雄性小鼠精子的毒性作用, 让5组小鼠自由饮用含硝酸钐0, 5, 50, 500, 2000 mg·L-1的溶液3个月后, 观察钐对小鼠精子活力、数量、畸形率及顶体完整率的影响. 结果表明: 各处理组精子活力、数量都有所降低, 其中2000 mg·L-1剂量组与对照组相比, 各指标值均有极显著差异(P《0.01); 50, 500, 2000 mg·L-1剂量组的精子畸形率与对照组相比也具有极显著差异(P《0.01), 且染毒剂量与精子总畸形率呈现出直线变化的剂量对数-效应关系. 因此精子畸形率可作为稀土元素钐作用于雄性生殖系统的标志指标; 各处理组的顶体完整率也均低于对照组. 说明亚慢性钐暴露对小鼠精子具有一定的毒性作用.     

运动加强氟化钠对去卵巢大鼠骨元素代谢的影响效应

用测定骨元素含量的方法,观察了运动对氟化钠（NaF）抗去卵巢大鼠骨元素代谢的影响效应。将健康4月龄雌性SD大鼠30只,用抽签法随机分成5组：正常对照组,假去卵巢组,去卵巢组,去卵巢＋NaF组和去卵巢＋NaF＋运动组;去卵巢＋NaF组和去卵巢＋NaF＋运动组大鼠于去卵巢手术后第2天开始给予NaF溶液灌胃,1mg／（kg·BW）,1次／d,持续11周;去卵巢＋NaF＋运动组大鼠于去卵巢术后第7天开始运动训练,每周5d,每天连续匀速跑45min,16m／min,跑道倾角0。,持续10周。结果表明,去卵巢大鼠骨Ca、S、Mg、Zn、Co、Mn等元素含量显著降低,骨P含量增加;NaF可使去卵巢大鼠降低的骨Ca、S、Mg、Co、Mn等元素含量回升,骨P含量回降;运动与NaF联合应用能使骨Ca、S、Mg、Zn、Co、Mn等元素含量显著回升,骨P含量显著回降。提示运动可加强NaF对抗由于去卵巢引起的大鼠骨元素代谢紊乱的作用。     

Calorimetric Investigations of Some Phases in the System Sodium Fluoride - Aluminium Fluoride

Beside the two well-known minerals cryolite, Na₃AlF₆, and chiolite, Na₅Al₃F₁₄, the binary system NaF-AlF₃ also contains a third compound, NaAlF₄, sodium tetrafluoroaluminate. Solid NaAlF₄ has been prepared from its vapour under controlled conditions. The stability of NaAlF₄ has been investigated by differential scanning calorimetry. It is shown that the disproportionation of the compound: 5NaAlF_4(s)=Na₅Al₃F_14(s)+2AlF_3(s) takes place at considerable rate between 700 and 900 K. The enthalpy of this reaction is calculated and found to be -66.9 kJ. Enthalpies of the two solid state transitions α-Na₃AlF₆ → β-Na₃AlF₆ and α-AlF₃ → β-AlF₃ have also been measured and new values are reported. The enthalpy of formation of chiolite, Na₅Al₃F₁₄, at 900 K has been recalculated from enthalpy increment data obtained by drop calorimetry. A value of ΔH₉₀₀ ^o = -7513.6±12.0 kJ mol^-1 has been obtained. This value is in disagreement with the recommended value given in JANAF Thermochemical Tables given at 900 K ΔH_f ^o = -7559.2 kJ mol^-1. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effect of Saffron Extract on the Hepatotoxicity Induced by Copper Nanoparticles in Male Mice

Background: Nanotechnology application has widespread use in many products. Copper nanoparticles (CuNPs) are widely used in industrial applications. The present study was conducted to investigate the effect of the ethanolic saffron extract (ESE) as a natural antioxidant on the hepatotoxicity induced by CuNPs in male mice. Methods: The characterization of CuNPs was determined using ultraviolet–visible absorption spectroscopy, particle size analysis, zeta potential, Fourier-transform infrared spectroscopy, and electron microscope. The effect of saffron on the hepatotoxicity induced by CuNPs in mice was evaluated by evaluating the survival rate of the mice, oxidative stress, antioxidant capacity, DNA evaluation, as well as its effect on the histology and transmission electron microscope of the liver. Results: The results revealed that all parameters were affected in a dose-dependent manner by CuNPs. These effects have been improved when the treatment of CuNPs is combined with ethanolic saffron extract. Conclusions: We can conclude that saffron and its bioactive crocin portion can prevent CuNP-induced oxidative liver damage. This substance should be useful as a new pharmacological tool for oxidative stress prevention.     

氟化钠对小鼠的急性毒性实验研究

为探讨氟化钠对小鼠的急性毒性及反应,采取灌胃法给小鼠一次性给药,观察了7 d内35.00、55.56、88.18、139.97、222.18、352.67、559.79 mg/kg等7个剂量组小鼠的毒性反应和死亡情况,计算了氟化钠经口半数致死量(LD50)及95%可信限.结果表明,各剂量组中毒小鼠均出现不同程度的抽搐、...     

Thermodynamics of Lanthanum Fluoride in Aqueous Sodium Perchlorate

The solubility-product constant of LaF,(s) was obtained by potentiometric titration of sodium fluoride with lanthanum perchlorate in sodium perchlorate solutions of various ionic strengths. The limiting value of pK_s.p were found to be 17.65 and 17.95 at 20° and 25°C, respectively. Thermodynamic calculation from these values gives δG° =-102.46 kJ mol^?1, δH° = 100.40 kJ mol^?1 and δS° = 680.40 JK^?1 for the reaction, La⁺³ (aq)+3F-(aq)=LaF,(s), and δG° =-1613.8kJ mol-1, δH₁° =-1594.0kJ mol^?1 and S° =433.1 J K^?1 mol^?1 for the formation of LaF₂,(s) at 25°C. The mean activity coefficients and solubilities of LaF₂,(s) in NaCIO₄ solution at various ionic strengths at 25°C were evaluated.     

Effect of Sodium dodecyl sulfate on the Mass Transfer Rate between Styrene and Water

Summary: The effect of sodium dodecyl sulfate (SDS) on the mass transfer rate between styrene and water has been investigated. SDS increases the solubility of styrene in water even below the critical micelle concentration (CMC) and therefore increases the thermodynamic driving force for the mass transfer. The mass transfer coefficient however is not altered by SDS, even if the interface is almost saturated with emulsifier.     

Effect of Dissolved Oxygen on the Corrosion Rate of Stainless Steel in a Sodium Chloride Solution

Russian Journal of Electrochemistry - The corrosion currents of 17-4РН stainless steel in an NaCl solution at various contents of dissolved oxygen are obtained by the method of Tafel...     

The Effect of Sodium Fluoride Solution on the Hydrolysis of β-tricalcium Phosphate and the Solubility of its Hydrolysate

β-Tricalcium phosphate (β-Ca₃(CO₄)₂; β-TCP) is one of the main inorganic components of bone and teeth. In addition, in hydraulic calcium phosphate cements β-TCP has been considered to be an important phase^[1]. Since the anticaries effect of fluoride was found in 1940's, much effort was made in the aspect of the fluoridation of HAP. However, to our knowledge no article published on the effect of fluoride ion on the hydrolysis of β-TCP. The purposes of this study were to investigate the hydrolysis characteristic of β-TCP in NaF solutions and the solubility of the hydrolysates.     

探究钠与酸溶液的反应速率

通过实验证实钠投入盐酸中的反应速率随盐酸浓度的增大先增大后减小,当盐酸的浓度大于1mol/L时,反应速率较钠投入水中的反应速率要慢。钠在溶液中的反应速率与产物的扩散速率有关。     

An Efficient Friedlander Condensation Using Sodium Fluoride as Catalyst in the Solid State

Abstract

Sodium fluoride catalyzed Friedlander condensation of 2-aminonicotinaldehye with various carbonyl compounds containing α-methylene group in the solid state furnished corresponding 1,8-naphthyridines. The reaction proceeds efficiently at room temperature in high yields and in a state of excellent purity.     

氟对别洛索夫-扎鲍京斯基振荡反应的影响

报道了氟离子对Ce(SO4) 2 KBrO3 CH2 (COOH) 2 H2 SO4(B Z)振荡体系的干扰 ,考察了在 5× 10 - 5～ 1× 10 - 3 mol L范围内 ,F- 的浓度与振荡反应周期的改变ΔTP 之间的关系。结合FKN机理模型 ,提出了F- 干扰振荡反应的机理 ,为其应用奠定基础     

Protective Effect of Resveratrol against Hexavalent Chromium-Induced Genotoxic Damage in Hsd:ICR Male Mice

The aim of this study is to examine the ability of resveratrol to counteract hexavalent chromium [Cr(VI)]-induced genetic damage, as well as the possible pathways associated with this protection. Hsd:ICR male mice are divided into groups of the following five individuals each: (a) control 1, distilled water; (b) control 2, ethanol 30%; (c) resveratrol, 50 mg/kg by gavage; (d) CrO₃, 20 mg/kg intraperitoneally; (e) resveratrol + CrO₃, resveratrol administered 4 h prior to CrO₃. The assessment is performed on peripheral blood. Micronuclei (MN) kinetics are measured from 0 to 72 h, while 8-hydroxydeoxyguanosine (8-OHdG) adduct repair levels, endogenous antioxidant system biomarkers, and apoptosis frequency were quantified after 48 h. Resveratrol reduces the frequency of Cr(VI)-induced MN and shows significant effects on the 8-OHdG adduct levels, suggesting that cell repair could be enhanced by this polyphenol. Concomitant administration of resveratrol and Cr(VI) results in a return of the activities of glutathione peroxidase and catalase to control levels, accompanied by modifications of superoxide dismutase activity and glutathione levels. Thus, antioxidant properties might play an important role in resveratrol-mediated inhibition of Cr(VI)-induced oxidant genotoxicity. The increase in apoptotic cells and the decrease in necrosis further confirmed that resveratrol effectively blocks the actions of Cr(VI).     

宜昌茶叶的氟含量及氟浸出率的测定

利用氟离子选择电极,测定了湖北宜昌几种茶叶中的氟含量及氟的浸出率。结果表明,这几种茶叶氟含量在46．8—357．1μg／g之间,茶叶氟的浸出率在72．9％-80．1％之间,宜昌茶叶可作为一种安全的氟来源。     

抗氧剂亚硫酸钠、亚硫酸氢钠及焦亚硫酸钠氧化反应速率常数的测定

为评价抗氧剂的抗氧化能力, 测定了抗氧剂亚硫酸钠、亚硫酸氢钠及焦亚硫酸钠在水溶液中与氧反应的速率常数. 在溶液中连续通入足量的氧气, 维持溶解氧浓度恒定. 用碘量法测定亚硫酸钠、亚硫酸氢钠及焦亚硫酸钠在水溶液中不同时刻的浓度, 用氧电极测定溶液中溶解氧的浓度, 作出亚硫酸钠、亚硫酸氢钠及焦亚硫酸钠的降解曲线, 计算亚硫酸钠、亚硫酸氢钠及焦亚硫酸钠氧化反应速率常数. 结果表明, 亚硫酸钠、亚硫酸氢钠及焦亚硫酸钠在水溶液中与氧的反应均为零级反应. 由于在溶液中这三种抗氧剂存在解离平衡, 当溶液的pH值相同时这三种抗氧剂实质上是一样的, 其平均表观反应速率常数在25 ℃温度和pH 6.8, 4.0及9.2条件下分别为(1.34±0.03)×10^－3, (1.20±0.02)×10^－3和(6.58±0.02)×10^－3 mol•L^－1•h^－1.     

离子色谱法同时测定氟化钠中微量氯离子和硫酸根离子

建立抑制电导检测离子色谱法同时测定氟化钠中微量氯离子和硫酸根离子的方法。采用IonPac AS11–HC阴离子交换分离柱,以氢氧化钾溶液为流动相。氯离子的质量浓度在0.1~0.4 mg/L范围内与色谱峰面积线性良好,r=0.999 9;硫酸根离子的质量浓度在0.2~1.0 mg/L范围内与色谱峰面积线性良好,r=0.999 6。氯离子、硫酸根离子测定结果的相对标准偏差分别为2.14%,1.22%(n=6),加标回收率分别为98.0%,95.4%,检出限分别为0.011,0.014 mg/L。该方法选择性好,灵敏度高,可作为氟化钠中微量氯离子和硫酸根离子的质量控制方法。     

钠与苯酚反应速率为何比钠与乙醇反应速率慢

1 问题提出 高中化学新课程苏教版<实验化学>(2006年2月第1版)第25页课题"乙醇和苯酚的性质"中"实验一乙醇、苯酚与金属钠的反应"内容为:"在2支干燥的试管里各加入2 mL乙醚,向其中一支试管中加入1 mL乙醇,向另一支试管中加入约1.5 g苯酚,振荡.