羌塘高原美马错自然保护区的初步评价

拟建的羌塘高原美马错自然保护区是我国青藏高原高寒草原生态系统保存最完好的地区之一,区内含有野牦牛、藏野驴、藏羚等多种珍稀野生动物,其密度之高为西藏所仅见。该地区具有极高的自然保护价值,应作为代表青藏高原高寒草原生态系统的典型地区,列为国家级自然保护区。     

Intrauterine manometry: Technique and application to fetal pathology

A technique is described for measuring pressure within the amniotic cavity and within fetal vessels and/or body compartments. Two saline-filled catheters were connected at one end to needles inserted during indicated invasive procedures and at the other to silicon strain gauge transducers. In 36 pregnancies with normal liquor volume, stable intra-amniotic pressure (IAP, range 1–14 mmHg) increased with gestation (r=0·48, p<0·01). In pregnancies complicated by severe oligohydramnios, IAP was ≤ 1 mm Hg and rose to normal levels with saline amnioinfusion. Raised IAP (range 17–26 mm Hg), found in pregnancies with gross polyhydramnios, fell with drainage of amniotic fluid. Subtraction manometry was used to determine supra-amniotic pressure within the intervillus space, umbilical vein, umbilical artery, abdominal and thoracic cavities, and the urinary tract in normal and/or pathological fetuses. Low intravesical and intrapelvicalyceal pressures (median 6·5, range 2–10 mmHg) were noted in fetuses with obstructive uropathies. Intrauterine subtraction manometry appears to be a useful tool in the understanding of fetal pathophysiology and may be of clinical benefit in the therapeutic drainage and infusion of amniotic fluid and in the assessment of certain fetal disease states.     

假单胞杆菌抗镉基因的克隆

以pBR322为载体,将抗镉的假单胞杆菌R4染色体的抗镉基因克隆至大肠杆菌HB101,从5000个重组体中筛选出一株抗镉基因克隆株,命名为大肠杆菌HB101(pBC311)。重组质粒pBC311经PstⅠ酶解和琼脂糖凝胶电泳证实抗镉基因位于3.6kb长的PstⅠ片段上。克隆菌株可在含100μg/ml CdCl_2的L-肉汤中生长,其生长停滞期比受体大肠杆菌HB101短得多,说明克隆菌株含有抗镉基因。     

Maternal serum thyroid antibodies in early pregnancy and fetal Down's syndrome

Thyroid antibodies were measured in mid-trimester antenatal serum samples from 77 pregnancies affected by fetal Down's syndrome and 385 unaffected control pregnancies. Using a haemagglutination technique, thyroglobulin antibodies were detected in 5·2 per cent of cases (4) and 2·9 per cent of controls (11), and thyroid microsomal antibodies were detected in 22 per cent (17) and 15 per cent (59), respectively. Using an enzyme-linked immunosorbent assay (ELISA) for thyroglobulin antibodies and a cut-off level of 50 KIU/1, positive results were found in 25 per cent of cases (19) and 22 per cent of controls (84). Using an ELISA for thyroid microsomal antibodies and the same cut-off level, the proportions were 52 per cent (40) and 39 per cent (149), respectively. While not statistically significant, the differences were consistent with the previously reported increased levels of thyroid antibody found in nonpregnant women who had had pregnancies associated with Down's syndrome.     

柴油添加剂的研究——有机钡盐的消烟助燃作用

本文介绍一种以有机钡盐为主的复合型柴油添加剂,其主要成分是过氧化钡与环烷酸在焦化汽油中反应所生成的环烷酸钡。台架实验结果表明,该添加剂在柴油中添加量为0.5—1.5‰(重量,以钡计)时,取得了消烟率40.9—66.3％、节能0.36—4.42％的效果。行车试验也证明本添加剂具有优良的消烟节能作用,当添加量为1.0‰(重量,以钡计)时,平均消烟率为67.7％,节油5.21％。     

First-trimester prenatal diagnosis of severe alpha-thalassemia

By means of chorion biopsy together with restriction endonuclease analysis of fetal DNA, first trimester diagnoses were successfully made in 33 fetuses at risk for Bart's hydrops fetalis. Seven pregnancies with Hb H or hydrops fetalis were therapeutically terminated before 4 months of gestation. Of the 26 pregnancies intended to continue, 18 have come to term with normal deliveries; one with threatened abortion was terminated at the end of the first trimester and, seven are progresssing normally.     

论民国时期河南灾荒的社会成因

民国年间河南灾荒现象异常突出，虽与当时整体气候背景及河南特殊的地理特征相关，但灾荒背后的社会原因更应引起我们的关注。其主要表现为：一、社会经济乏力，百姓抗灾能力低；二、政治腐败，体现在政府的赋税名目繁多、政府官员失职渎职以及挪用、贪污河防公款等几个方面；三、战争与灾荒；四、帝国主义列强对中国的残酷掠夺。     

美国环保超级基金制度的实施及问题

对美国环保超级基金制度作了简要的介绍,指出了其实施过程中的成功与不足,以期为我国环境法制的完善提供有益的借鉴.     

跨界原生质体融合工程菌株改进合成制药废水生物处理的有效性研究

用常规生物法处理合成制药废水难以去除持久性有机污染物POPs，且存在不能稳定达标的问题，应通过用跨界原生质体融合技术，构建出具有高降解性、高絮凝性、高适应性的基因工程菌株来解决上述问题。为检验基因工程茵的有效性，对基因工程茵进行了抗生素遗传性能鉴定和电子显微镜(SEM)的形态鉴定，并在制药废水的污水处理厂进行了基因工程茵的培养和接种。结果表明：基因工程菌株能成功取代原有土著茵并具有显著的优点。     

Experimental study on Cr(Ⅵ) reduction by Pseudomonas aeruginosa

Investigation on Cr( Ⅵ ) reduction was conducted using Pseudomonas aeruginosa. The study demonstrated that the Cr(Ⅵ) canbe effectively reduced to Cr( Ⅲ ) by Pseudomonas aeruginosa. The effects of the factors affecting Cr( Ⅵ ) reduction rate including carbon source type, pH, initial Cr(Ⅵ) concentration and amount of calls inoculum were thoroughly studied. Malate was found to yield maximum biotransformation, followed by succinate and glucose, with the reduction rate of 60.86%, 43. 76% and 28.86% respectively. The optimum pH for Cr( Ⅵ ) reduction was ?.0, with reduction efficiency of 61.71 % being achieved. With the increase of initial Cr(Ⅵ) concentration,the rate of Cr(Ⅵ) reduction decreased. The reduction was inhibited strongly when the initial Cr(Ⅵ) concentration increased to 157 mg/L. As the amount of cells inoculum increased, the rate of Cr( Ⅵ ) reduction also increased. The mechanism of Cr( Ⅵ ) reduction and final products were also analysed. The results suggested that the soluble enzymes appear to be responsible for Cr (Ⅵ) reduction by Pseudomonas aeruginosa, and the reduced Cr( Ⅲ ) was not precipitated in the form of Cr(OH)3.