Vanadium in foods and in human body fluids and tissues

Using neutron activation analysis, vanadium was analysed in a range of foods, human body fluids and tissues. On the basis of these results and those of other workers, it was concluded that daily dietary intake amounts to some tens of micrograms. Analysis of body fluids (including milk, blood and excreta) and organs and tissues provided an estimate for the total body pool of vanadium in man of about 100 μg. Vanadium was not detectable in blood and urine at the level of 0.3 ng/g, while low levels were found in muscle, fat, bone, teeth and other tissues. The relationship between dietary intake to pulmonary absorption is discussed in relation to the occurrence of vanadium in man-made air particulates. The very low levels found in milks and eggs suggest minimal vanadium requirements in growth. The findings are discussed in the light of previous results and also in relation to the possible essentiality of vanadium.     

Iodine-129 in thyroid and urine in Ukraine and Denmark

Human thyroids collected from Gomel in Belarus, sheep thyroid from Jutland and human urine from Zealand in Denmark were analysed for 129I and 127I concentrations. The ratios of 129I/127I in human thyroid in Gomel are 2.65-11.0 x 10(-9) with an average of 7.21 x 10(-9), which is one order of magnitude higher than those from Asia and South America (10(-10)), but significantly lower than those observed in west Europe (10(-8)). A weak negative correlation (P < 0.05) between 129I/127I ratio in human thyroid and the age of the subjects was observed in Gomel. The average ratio of 129I/127I in sheep thyroids from Jutland of Denmark is 1.81 x 10(-7), which is two orders of magnitude higher than those in south hemisphere, and Asia. It is also significantly higher than those observed in other west European countries before 1984 and that in human thyroid in Gomel. The high thyroid 129I level in Jutland is attributed to the release of reprocessing plants in France and UK. The 129I/127I ratios in human urine in Zealand of Denmark are 0.86-2.86 x 10(-8). The possibility of using urine 129I to evaluate the thyroid exposure to 129I is investigated.     

儿童青少年近视的防控研究进展

儿童青少年近视率一直处于高位并持续上升,严重影响了我国儿童青少年的学习和生活,本研究通过查阅国内外治疗儿童青少年近视相关著作及文献,针对目前儿童青少年近视防控手段的进展,对各治疗方案进行分析和研究。     

德国城乡景观与中国景观问题

2003年,笔者获得德国DAAD(德国国际学术交流基金会)奖励资助,作为访问学者在德国逗留了4个月(4月～8月).在这期间,笔者还考察了法国、丹麦、瑞典和意大利,但我认为还是德国的景观最为优雅和美丽.     

广义文脉与规划设计教育

城市规划设计教育不仅应关注历史化,还应关注自然、社会和经济;不仅应关注地方和传统,还应关注全球和未来。城市规划教育应掌握正确的发展观和方法论,肩负起发展地万脉的历史使命,保护社会公众的利益,推动城市持续发展。     

Perchlorate in raw and drinking water sources in England and Wales

A well‐known use of perchlorate is as a rocket fuel propellant; however, more widespread uses include in munitions and fireworks, and it also occurs naturally. Perchlorate suppresses the thyroid, which can lead to a variety of adverse effects. It is a widespread contaminant in the United States, but limited occurrence data in the United Kingdom exist, and even less for drinking water. Monitoring of 20 raw and treated drinking water sites in England and Wales, covering four seasonal periods, showed that perchlorate is a low‐level background contaminant of raw and treated drinking water. Low concentrations (treated drinking water: <0.020–2.073 μg/L, mean 0.747 μg/L) were detected at every higher‐risk site. The concentrations were comparable in each of the four sampling exercises and no significant trends were apparent relating to the time of year, the type of risk or the method of chlorination. Limited data showed that removal by ion exchange and granular‐activated carbon may occur.     

Lead and cadmium contents in cereals and pulses in north-eastern China

It is known that, unlike Japanese, Koreans or southern Chinese who depend on rice as a major source of energy for daily life, people in north-eastern China rely not only on rice, but on wheat and other cereals and to a lesser extent also on pulses. Cereal and pulse samples were collected from open markets in north-eastern China, and analyzed by inductively-coupled plasma spectrometry (ICP-MS) for two potentially hazardous heavy metals — lead (Pb) and cadmium (Cd). The average Pb level in cereals (31.3 ng Pb/g as a geometric mean) and that of pulses (25.7 ng Pb/g) were similar to each other with no significant difference. Among the cereals, Pb contents were higher in foxtail millet (54.3 ng/g) and lower in maize (35.4 ng Pb/g; grain and flour in combination), wheat flour (28.8 ng Pb/g) and rice flour (22.7 ng Pb/g). Lead levels in two important types of pulses, kidney bean and soybean (24.6 and 30.8 ng Pb/g, respectively), were comparable to the levels in rice and wheat. In contrast, Cd levels were substantially higher in pulses (55.7 ng Cd/g) than in cereals (9.2 ng Cd/g), and among the pulses, Cd in soybean (55.7 ng Cd/g) was significantly higher than that in kidney bean (23.8 ng Cd/g). The possible public health implication of the Pb and Cd levels, especially the high Pb level in foxtail millet (54.3 ng Pb/g) and the high Cd level in soybean (73.5 ng Cd/g), is discussed.     

武汉城市景观文化生态保护建设的问题与对策

城市文化生态是形成城市特色的文化要素。历史古迹,优秀建筑,空间形态,环境特色,作为城市文化生态的显现部分,既是城市文化底蕴直观生动的反映,也是市民的情感港湾和精神家园。理应得到珍惜和保护。该文在系统地概括武汉景观文化生态特点的基础上,重点分析了当前武汉城市景观规划建设中的文化生态问题,提出了武汉今后改进城市景观文化生态规划建设的对策建议。     

创新创业教育在高校实践教学中的研究与探索

大学生创新创业教育的开展对高校人才培养体系的完善具有非常重要的意义。针对目前我国高校创新创业教育模式的问题与不足进行探讨,分析研究了创新创业教育的实质,最后重点阐述了在实践教学中如何加强创新思路的引导,建立有效激励机制,开展创新及创业教育的应对策略,促进对大学生实践创新能力、创业就业能力和持续发展能力的培养。     

中国菜——中美两国大不同

<正>中国食物很受美国人的青睐。有人说美国的中餐和中国本土的菜肴大相径庭。那么究竟不同在哪里呢?用餐的感受在中国的餐厅用餐与在美国的餐厅用餐的感受是不同的。两者的氛围与菜单完全相反。在中国的餐厅,你会发现菜单上布满了花花绿绿的诱人图片。中国人点餐通常是根据图片来点的。但在美国,人     

大长度大高度大吨位现浇段支架设计与施工

针对世界最大跨径连续刚构桥——重庆石板坡长江复线桥3、4号现浇段超长、超高、超重的特点,介绍了现浇段支架方案设计、计算和预拉及混凝土浇筑施工工艺及组织、控制措施。     

精于心&#183;简于形

在北京的机场高速路旁耸立着一块广告牌,上书六个大字:"精于心,简于形".我为之震撼.     

概念和建造上的卓越与创新

“当代建筑欧洲联盟奖——密斯·凡·德·罗奖”是欧洲当代最高建筑奖项。也是当代全球范围内最重要的建筑奖项。它表彰的是每两年间最好的建筑作品.而不是建筑师。     

春、夏季杭州湾北部近岸水域水化学及营养状况评价

为了解杭州湾北部近岸水域水化学状况及其污染程度,利用2011—2015年间对杭州湾北部近岸水域春、夏季9个水化学因子的调查结果,分析了该水域水化因子的变化特征、相关性及氮磷营养盐结构特征,并采用潜在性富营养化法和有机污染指数法,进行了该水域潜在性富营养化程度及污染状况的评价。结果表明:调查期间,杭州湾北部近岸水域,2011—2015年春、夏季pH平均值分别为8.05±0.11和7.96±0.27;春、夏季DO平均值分别为(8.13±0.33)、(7.42±0.31)mg/L,DO饱和度均在88%以上;受潮汐、径流和降水影响,盐度波动范围较大,春、夏季盐度平均值分别为11.67±5.60和12.06±3.28;春、夏季CODMn平均值均小于3 mg/L,符合《海水水质标准》二类水质标准;总氨氮(TAN)、NO-2-N含量均维持在较低状态,符合《渔业水质标准》及经济鱼虾类生长安全浓度的要求;三态氮含量依次为NO-3-N>TAN>NO-2-N,NO-3-N占DIN的69%~97%;pH与氮磷营养盐均为负相关,氮、磷间均呈正相关;潜在性富营养化法计算结果表明,2011—2014年春季,调查水域营养级均为ⅥP,2014年夏季—2015年,N/P值明显下降,营养级过渡到ⅤP,调查水域受磷限制富营养化程度有所降低;采用海水水质一类标准评价,5年所有站位有机污染指数A值均大于4,达到严重污染程度。研究表明,杭州湾北部近岸水域有机污染严重,亟待有效控制与科学管理。     

我国招标投标中存在的问题及对策

分析了建筑工程招投标在具体操作中存在的问题，针对这些问题提出了应该采取的对策及措施，指出应本着保护国有资产，保护市场正常竞争秩序，大力推广招投标制度，促进招投标事业的发展。     

中外建筑师与近现代建筑设计

本文以来华建筑师和中国建筑师的活动为线索，通过对近现代建筑的特征描述，来梳理这段时期中国境内建筑所包含的设计要素。来华建筑师带来的设计理念实际上是西方建筑思潮的延续；中国建筑师虽然接受了西方正统的学院派教育，但几千年的传统文化影响根深蒂固。从复兴中国固有式建筑潮流到设计现代式建筑时的细部装饰，这种民族精神无处不在。     

在前进中发展 在发展中提高

80年代初我市在学习和比较了大板体系、混凝土中型砌块体系和小型砌块体系后,根据当时的经济、技术发展水平,确定将混凝土小型砌块建筑体系作为建筑业的发展方向.     

道路桥梁施工管理中存在的问题及优化措施

介绍了道路桥梁施工管理的现状,对道路桥梁施工管理过程中存在的问题进行了分析,并结合实际情况,提出了相应的解决措施,以期提升道路桥梁管理的有效性。     

民用工程厨卫渗漏与防治

针对民用工程中渗漏这一质量通病,从原材料、施工工艺、成品保护等方面分析了厨房、卫生间渗漏的原因,介绍了相应的防治措施,经过实践应用,效果明显,保证了用户的使用安全。