上海地区高空气流长距离输送轨迹及其与酸雨的关系

分析了影响上海地区的高空气流输送轨迹。不同月份影响上海的高空气流来向不一。轨迹输送路径与天气系统的变化密切有关,且与上海地区出现的酸雨有关。研究表明,上海地区的酸雨,除与局地污染有关外,还与远处输送的外来污染有关。这些外来污染影响,主要来自上海西南向的北部湾和两广等地。也有部分来自东北——东方向的南朝鲜和日本西部地区。     

Preliminary study on organic contaminants in the water of northwest part of the Lake Chao

The waterquality of the downstream of Nanfei River and the northwest area of Lake Chao is evaluated from organic analysis aspect. PAHs such as fluoranthene, pyrene are detected in the waters collected from downstream river and river mouth. More phenolic compounds are found in the river water. Some halogenated hydrocarbons are present in the river and lake waters. A great many of aliphatic hydrocarbons and benzene hydrocarbons found in all the water samples are about one third of the total organics detected. The hydrophobic components are found to be present not only in water but also in suspended sediment. The ratio of the amount existing is 0.4 in sediment and 1 in particle-free water. The quantity of humic materials existing in lake water is larger than that in river water. The proportion of the humic materials in lake water to that in river water is 1.9 to 1. In the lake water, some natural substances, such as dimethyl disulfide, alpha-pinene, azulene, and 6- methyl -2-heptanone are observed.     

Prenatal diagnosis in two cases of de novo complex balanced chromosomal rearrangements. Three-year follow-up in one case

We report two cases of apparently balanced complex de novo chromosomal rearrangements (BCCR) detected prenatally at 17 weeks and 10 weeks of gestation, respectively. Chromosomes were studied using GTG-banding and fluorescent in situ hybridization (FISH). In one case four chromosomes and in the other case three chromosomes were involved in the rearrangements. One of the pregnancies was terminated and no external or internal abnormalities were detected at autopsy. The other pregnancy continued to term. Level III ultrasound examination showed no abnormalities. The child is now 3 years old and has neither congenital anomalies nor evidence of delayed psychomotor development.     

Prenatal diagnosis of β thalassaemia by reverse phase HPLC

Reverse phase HPLC of radioactive globin chains has been compared to classical carboxy methyl cellulose chromatography for the prenatal diagnosis of β thalassaemia. The two methods correlated highly (r = 0.97 p < 0.0005) and provided an identical diagnosis for 40 fetal blood samples of fetuses homozygous or heterozygous for β thalassaemia. The HPLC procedure was much faster and required fewer biochemical steps (no globin preparation). It was at least as accurate and more sensitive than the classical chromatography. A single column can be used for 150 analyses and is always ready to be used. Last but not least it is much less expensive than CMC chromatography.     

Prenatal sonographic assessment of early,rapidly growing fetal cervical teratoma

Although malignant transformation of fetal cervical teratoma is extremely rare, perinatal morbidity is high and usually related to the size of the tumour, which may compromise fetal swallowing and subsequently lead to upper airway obstruction. We present a case in which mid-trimester serial sonography demonstrated markedly rapid early growth of a lesion of this type between 17 and 19 weeks' gestation indicating the aggressive nature of this tumour, assisting parental decision to terminate the pregnancy. Histopathology confirmed grade 3 immaturity of the lesion.     

近期和长远时段内北极生态系统结构受到的影响

生物在物种水平上对全球气候变暖和紫外线B(UV-B)辐射增强的反应受到其群落内其他物种以及生态系统内养分循环的调节,所有的这些反应将会导致生态系统结构的变化.根据高纬度地区坏境因子的可能变化而做的控制试验表明,由夏季变暖而引起苔原植被的变化要小于增加施肥而引起的变化,试验涉及的某些环境因子对北极生态系统的结构有非常强烈地影响,但是这些影响因地区而异,观测结果表明,处于最寒冷地区的植物群落和无脊椎动物群落对全球气候变暖和紫外线B辐射的增强反应最为强烈.尽管微生物量和养分储存量相对稳定,北极无脊椎动物群落还是很可能会对全球变暖产生迅速的反应.试验结果显示,加强紫外线B辐射会改变革兰氏阴性细菌和真菌的群落组成结构,但不会对植物群落的组成产生影响.由夏季气温升高而提高的植物生产力将会控制食物网的动态变化,以苔原植被和亚极地森林植物为基础的食物网中的营养流动会明显地影响到几种优势动物种群数量的周期性波动,在某些年分这些动物的种群数量会达到峰值.小型啮齿动物和食叶昆虫如秋毛虫种群数量的周期性变化则会影响苔原和森林苔原植物的组成结构和多样性,同时也会影响到一些专性捕食者和寄生虫的变化.在暖冬,雪表形成冰壳可能会减少旅鼠的植物食物来源,然而较深的雪也可以使它们免受雪地表面上捕食者对它们的捕食.在芬诺斯堪的亚地区,已有证据表明小型啮齿类动物群落结构和种群动态的显著变化会导致专门以小型啮齿类动物为食物的捕食者的数量减少.气候还可能改变昆虫在白桦森林生态系统中的作用,因为暖冬可以增加这些昆虫卵的成活率,并且扩大其分布范围.此外,在夏季困扰驯鹿的昆虫会由于夏季气候的变暖而扩大其分布范围、增加种群数量并且种群更为活跃;同时在另一方面也会对驯鹿不利,即那些昔日驯鹿/北美驯鹿的避难场所--冰川和未融的成片的雪--在这样温暖的夏季则可能会消失.     

In situ preparation of g-C3N4/Bi4O5I2 complex and its elevated photoactivity in Methyl Orange degradation under visible light

A graphite carbon nitride(g-C_3N_4) modified Bi_4O_5I_2 composite was successfully prepared insitu via the thermal treatment of a g-C_3N_4/Bi OI precursor at 400°C for 3 hr.The as-prepared g-C_3N_4/Bi_4O_5I_2 showed high photocatalytic performance in Methyl Orange(MO) degradation under visible light.The best sample presented a degradation rate of 0.164 min~(-1),which is 3.2 and 82 times as high as that of Bi_4O_5I_2 and g-C_3N_4,respectively.The g-C_3N_4/Bi_4O_5I_2 was characterized by X-ray powder diffractometer(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),Raman,X-ray photoelectron spectroscopy(XPS),ultraviolet-visible diffuse reflectance spectra(DRS),electrochemical impedance spectroscopy(EIS) and transient photocurrent response in order to explain the enhanced photoactivity.Results indicated that the decoration with a small amount of g-C_3N_4 influenced the specific surface area only slightly.Nevertheless,the capability for absorbing visible light was improved measurably,which was beneficial to the MO degradation.On top of that,a strong interaction between g-C_3N_4 and Bi_4O_5I_2 was detected.This interplay promoted the formation of a favorable heterojunction structure and thereby enhanced the charge separation.Thus,the g-C_3N_4/Bi_4O_5I_2 composite presented greater charge separation efficiency and much better photocatalytic performance than Bi_4O_5I_2.Additionally,g-C_3N_4/Bi_4O_5I_2 also presented high stability.·O_2~-and holes were verified to be the main reactive species.     

Effect of long-term fertilization on soil nitrate distribution

ＩｎｔｒｏｄｕｃｔｉｏｎＦｅｒｔｉｌｉｚａｔｉｏｎｉｓｅｓｓｅｎｔｉａｌｆｏｒａｇｒｉｃｕｌｔｕｒａｌｐｒｏｄｕｃｔｉｏｎ ,ｂｕｔｕｎｒｅａｓｏｎａｂｌｙａｐｐｌｙｉｎｇｆｅｒｔｉｌｉｚｅｒｓｃｏｕｌｄｒｅｓｕｌｔｉｎｓｅｒｉｅｓｏｆｐｒｏｂｌｅｍｓｓｕｃｈａｓｃｒｏｐｑｕａｌｉｔｙｄｅｃｌｉｎｅ,ｆｅｒｔｉｌｉｚｅｒｕｓｅｅｆｆｉｃｉｅｎｃｙｄｅｃｒｅａｓｅ,ｒｅｓｉｄｕａｌｆｅｒｔｉｌｉｚｅｒｓｐｏｌｌｕｔｉｏｎ ｇｒｏｕｎｄｗａｔｅｒａｎｄｒｉｖｅｒｓａｎｄｎｉｔｒｏｇｅｎｃｏｎｔｅｎｔｅｄ …     

Extraction of DNA from amniotic fluid cells for the early prenatal diagnosis of genetic disease

Ten-ml samples of amniotic fluid were taken from pregnancies being terminated at 8–14 weeks' gestation. DNA was extracted from the amniotic cells by sequential centrifugation and analysed using the polymerase chain reaction (PCR). Fifteen samples were analysed for evidence of maternal contamination using Mfd5 oligo-nucleotide primers for repeat polymorphisms. Ten amniotic fluid samples were tested for the Delta-F₅₀₈ deletion characteristic of cystic fibrosis to demonstrate a diagnostic application for the technique. In each case, DNA extracted from fetal tissue from the same pregnancy was included in the controls. In 14 of the 15 cases tested with the Mfd5 primers, both the amniotic fluid DNA and the fetal DNA showed no evidence of contaminating DNA. In one case, neither the amniotic fluid cells nor the fetal cells yielded results. In nine of the ten cases tested with the Delta-F₅₀₈ primers, the amniotic fluid cell DNA provided accurate information about the genetic status of the fetus; in the tenth, the fetal DNA failed to amplify. The results indicate that adequate DNA can be extracted from amniotic fluid from 8 weeks' gestation onward and these samples are suitable for prenatal diagnosis using PCR.