氟化物对鸡骨骼强度的影响

实验采用172只星杂288品系的雌性雏鸡,随机分成四组。从4周龄开始至24周龄。各组分别自由饮用含氟0.16、100、200、300ppm的水。在12、16、20、24周龄,从各组中随机抽取10只左右进行测定。结果表明:饮水中高剂量的砜化物(200、300ppm)能使鸡胫骨、股骨、肱骨的弯曲最大负荷及弯曲强度显著降低,并导致骨皮质层略为增厚及骨灰分中F、Mg、Zn含量和血清中F含量显著升高;但未引起骨灰分中Ca、P含量及血清中Ca、P、Mg的含量发生显著变化。     

用氟离子选择电极测定土壤中氟化物方法的改进

用氢氧化钠熔融土样，盐酸调节ｐＨ到８～９，使干扰阳离子形成难溶物。静置，取上清液，加入总离子强度剂，用氟离子选择电极测定电极电势来定量。     

Crystallization of poly(vinylidene fluoride)-SiO2 hybrid composites prepared by a Sol-gel process

Organic-inorganic hybrid composites consisting of poly(vinylidene fluoride) (PVDF) and SiO₂ were prepared through a sol-gel process and the crystallization behavior of PVDF in the presence of SiO₂ networks was investigated by spectroscopic, thermal and x-ray diffraction measurements. The hybrid composites obtained were relatively transparent, and brittleness increased with increasing content of tetraethoxysilane (TEOS). It was regarded from FT-IR and DSC thermal analyses that at least a certain interaction existed between PVDF molecules and the SiO₂ networks. X-ray diffraction measurements showed that all of the hybrid samples had a crystal structure of PVDFγ-phase. Fresh gel prepared from the sol-gel reaction showed a very weak x-ray diffraction peak near 2θ=21° due to PVDF crystallization, and intensity increased gradually with time after gelation. The crystallization behavior of PVDF was strongly affected by the amount of SiO₂ networks. That is, SiO₂ content directly influenced preference and disturbance for crystallization. In polymer-rich hybrids, SiO₂ networks had a favorable effect on the extent of PVDF crystallization. In particular, the maximum percent crystallinity of PVDF occurred at the content of 3.7 wt% SiO₂ and was higher than that of pure PVDF. However, beyond about 10 wt% SiO₂, the crystallization of PVDF was strongly confined.     

黑龙江省肇源县地方性氟中毒的环境特征及成因分析

肇源县居民长期饮用氟含量超标的浅层第四系孔隙潜水,导致氟中毒的发生,严重影响了当地居民的身心健康,制约了社会经济的发展。针对该区存在的上述问题,利用地下水调查监测数据,系统分析了地质、水文地质条件,结合流行病学调查数据,开展了氟中毒流行区的环境特征和高氟水成因研究,为防治氟中毒的发生提供科学依据。     

氟化物对FRTL细胞甲状腺激素代谢相关基因表达的影响

为探讨氟对FRTL细胞甲状腺球蛋白(TG),甲状腺过氧化物酶(TPO)和钠碘转运体(NIS)基因表达的影响,传代培养FRTL细胞,在对数生长期用氟化钠处理,使培养液中的氟浓度分别为20、10、5、2.5、1.25 mg/L,同时设空白对照细胞.培养72 h后收集细胞;采用半定量RT-PCR分析FRTL细胞TG、TPO、NIS mRNA和β-actin表达水平.试验结果表明,与对照细胞相比,较低浓度氟化钠处理的FRTL细胞TG基因表达量代偿性升高,随氟质量浓度增加(5.0 mg/L以上),TG表达量显著降低(P<0.05);各个浓度氟化钠处理的FRTL细胞TPO、NIS基因表达量均下降或显著下降(P<0.05).由此可知,氟化物降低了甲状腺细胞TG、TPO、NIS基因表达水平,造成甲状腺摄取和利用碘、甲状腺激素合成、贮存、分泌功能障碍,进而导致甲状腺结构和功能异常.     

松嫩平原高氟地下水化学特征及开发利用模式研究

嫩平原是一个潜水普遍分布,包括第四系和前第四系承压水在内的多层叠置结构的大型蓄水盆地.受地质、地貌和水文地质条件的影响,各含水层地下水具有不同的化学特征.广泛分布的第四系潜水,原生环境较差,易受人为污染,且在松嫩低平原的中部氟含量超标严重,易引发氟中毒,不适宜饮用.第四系承压水主要分布于松嫩中部低平原和东部高平原区,低平原区第四系承压水受原生环境影响,氟含量较高,不适宜饮用;高平原区第四系承压水水质较好,氟含量较低,适宜饮用,分布范围有限.前第四系承压水主要分布于除西部山前倾斜平原之外的广大地区,水质较好,氟含量满足饮用水要求,但水量变化较大;分布于低平原之下的新近系大安组、古近系依安组水量丰富,但埋深较大,补给条件差,虽然适宜饮用,但要控制开采;东部高平原之下分布的白垩系含水层组,水质较好,氟含量较低,适宜饮用,但分布不均,所以要科学开发.提出了松嫩平原地下水科学合理的开发利用模式,为政府决策提供依据.     

日粮中不同氟含量对AA肉鸡的影响

本研究对ＡＡ肉鸡在一月龄内饲喂不同氟含量日粮。日粮氟含量分别为２５０,５００,１０００ｍｇ／ｋｇ,比较其临床症状,、增重,主要脏器病理组织学变化,腿骨Ｘ光检查及胫骨氟含量测定。结果显示,高氟日粮使ＡＡ雏鸡生长发育受到不同程度的抑制,尤其对骨骼发育影响严重。日粮中２５０ｍｇ／ｋｇ的氟含量对ＡＡ雏鸡并不安全 。     

氟离子选择电极法测定植物性食品基质中的氟化物

建立了植物性食品中氟化物的氟离子选择电极测定法,并对不同基质中氟化物含量进行了测定。对GB/T 5009.18—2003第三法（氟离子选择电极法）中标准曲线的线性范围和不同基质的称样量范围进行了优化,确定了方法的定量限,并对准确度、精密度进行了验证。结果表明：本方法在0.20~10.00 mg/L范围内线性良好,方程的斜率及相关系数均符合测定要求;称样量范围优化为2.5~5.0 g（茶叶基质0.2~0.5 g）,平均加标回收率为99.97%~109.83%,相对标准偏差为0.41%~2.65%,均符合国家标准要求;除茶叶以外的基质,当称样量为2.5 g,定容体积为50 mL时,方法定量限为4.00 mg/kg;对于茶叶基质,当称样量为0.2 g,定容体积为50 mL时,方法定量限为50.00 mg/kg。该氟离子选择电极法适用于植物性食品基质中氟化物的快速检测。     

不同条件下生态缓冲带对氟化物面源污染的阻控效果

生态缓冲带可有效截留阻控非点源污染物向水体中迁移.选取紫花苜蓿(Medicago sativa L.)、高羊茅(Festuca elata Keng ex E.Alexeev)、草木樨(Melilotus officinalis(Linn.))、早熟禾(Poa annua L.)和黑麦草(Lolium perenne ...     

Glycine alleviates fluoride-induced oxidative stress,apoptosis and senescence in a porcine testicular Sertoli cell line

Glycine is a well-known free radical scavenger in the cellular antioxidant system that prevents oxidative damage and apoptosis. Excessive fluoride exposure is associated with multiple types of cellular damage in humans and animals. The objective of the present study was to investigate the protective effects of glycine on sodium fluoride (NaF) exposure and the possible underlying mechanisms in a porcine testicular Sertoli cell line model. Cellular viability and proliferation were examined following NaF exposure and glycine supplementation, and glycine dramatically ameliorated the decreases in NaF-induced porcine testicular Sertoli cell viability and proliferation. Further investigations revealed that glycine decreased NaF-induced intracellular reactive oxygen species production, DNA fragment accumulation and the apoptosis incidence in the porcine testicular Sertoli cell line; in addition, glycine improved mitochondrial function and ATP production. Notably, results of the SPiDER-β-Gal analysis suggested that glycine alleviated NaF-induced cellular senescence and downregulated P53, P21, HMGA2 and P16INK4a gene expression in the porcine testicular Sertoli cell line. Collectively, the beneficial effects of glycine alleviate NaF-induced oxidative stress, apoptosis and senescence, and together with our previous findings, support the hypothesis that glycine plays an important role in protecting against NaF exposure-induced impairments in the porcine testicular Sertoli cell line.