全文获取类型
收费全文 | 257篇 |
免费 | 2篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 1篇 |
废物处理 | 1篇 |
环保管理 | 2篇 |
综合类 | 231篇 |
基础理论 | 7篇 |
污染及防治 | 8篇 |
评价与监测 | 7篇 |
社会与环境 | 1篇 |
灾害及防治 | 5篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 4篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2014年 | 1篇 |
2013年 | 9篇 |
2012年 | 1篇 |
2011年 | 3篇 |
2010年 | 4篇 |
2009年 | 4篇 |
2008年 | 2篇 |
2007年 | 2篇 |
2006年 | 1篇 |
2005年 | 6篇 |
2003年 | 2篇 |
2001年 | 1篇 |
1995年 | 49篇 |
1994年 | 27篇 |
1993年 | 41篇 |
1992年 | 43篇 |
1991年 | 28篇 |
1990年 | 16篇 |
1989年 | 8篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有263条查询结果,搜索用时 171 毫秒
211.
Greigh I. Hirata MD Marsha L. Matsunaga Arnold L. Medearis Patricia Dixon Lawrence D. Platt 《黑龙江环境通报》1990,10(8):507-512
A case of a prenatally recognized hepatic mesenchymal hamartoma is presented and the literature reviewed. These tumors are benign and usually present in early infancy with symptoms that are related to the mass effect on adjacent organs. Radiologic methods used in the past to image this tumor include angiography and ultrasound. However, there is no specific radiologic finding, and, therefore, the diagnosis is usually made during surgery. Once the tumor is removed, the prognosis is generally good. With the increasing use of high resolution ultrasound in prenatal diagnosis, this rare tumor should be considered in the differential diagnosis of any multicystic mass found in the fetal abdomen. The recognition of a mass should then alert the physician to the need for early neonatal intervention. 相似文献
212.
213.
The livebirth prevalence of autosomal chromosomal anomalies is determined by several factors, including maternal age distribution and the impact of prenatal cytogenetic diagnosis (PCD). The impact of PCD varies between countries, as the indications and the uptake vary. In a previous study we described differences in Down syndrome prevalence and the proportion of older mothers. We have now made a survey of the official PCD policies in 25 regions in 13 European countries for the period 1989–1991. In two countries, termination of pregnancy was not available. In the other 11 countries, international agreement existed on five indications: advanced maternal age, a previous child with a chromosomal anomaly, parents who are carriers of a balanced translocation, mothers who are carriers of an X-linked disorder, and malformations at ultrasound. The exact limit for advanced maternal age varied from 35 to 38 years. There was a considerable variation for the indications advanced paternal age, amniocentesis for AFP or DNA, parental anxiety, a previous child with a congenital anomaly, abnormal maternal serum markers, and exposure to radiation/chemotherapy. The PCD uptake for mothers above the maternal age limit varied from 10 to 88 per cent. International harmonization of the indications for PCD is not considered feasible at present, because of the rapid changes in PCD policies even within countries. 相似文献
214.
J. A. Maat-Kievit MD D. Oepkes N. G. Hartwig C. Vermeij-Keers I. L. Van Kamp J. J. P. Van De Kamp 《黑龙江环境通报》1993,13(5):377-384
The facial tumour described here is the first reported case of a large retinoblastoma detected early in pregnancy and adds another item to the differential diagnosis of facial tumours visualized by prenatal ultrasound examination. Ultrasound examination of the fetal eyes can be offered in cases of retinoblastomas where prenatal DNA diagnosis is otherwise impossible. 相似文献
215.
Gastrointestinal tract atresia has an incidence of 1 in 10 000 live-births, while gastric outlet obstruction comprises only approximately 1 per cent of these malformations. A prenatally diagnosed case is described, followed by a discussion regarding the diagnosis and possible associated abnormalities. 相似文献
216.
217.
Finn Stener Jørgensen MD Jens Bang Anne-Marie Lind Britta Christensen Claes Lundsteen John Philip 《黑龙江环境通报》1992,12(4):277-283
Genetic amniocentesis performed at 7–14 weeks of gestation was studied in a series of 138 patients of whom 50 wanted termination of pregnancy (⩽ 12 weeks). The material for analysis consisted of 132 samples due to two sampling failures and four samples being handled incorrectly. Forty-eight samples (36 per cent) were taken at 7–12 weeks of gestation, mainly transvaginally (36/48:75 per cent). The success rate of culture and karyotyping increased with the duration of pregnancy, but was only satisfactory from week 11 onwards. The time until harvest was then 14–15 days. The transvaginal approach is easy to perform and was accepted by the women, but we experienced bacterial or fungal overgrowth in 17 per cent of these samples, whereas no infection occurred in the samples taken transabdominally (n = 96). We conclude that genetic amniocentesis is feasible from week 11, but further studies concerning side effects, especially focusing on the procedure-related abortion risk, should be carried out before early amniocentesis is routinely applied. 相似文献
218.
219.
Catherine Donner MD Jean-Christophe Noel Françoise Rypens Jean van Kerkem Freddy Avni Frédéric Rodesch 《黑龙江环境通报》1995,15(1):60-63
A 29-year-old woman was referred for suspicion of twin-twin transfusion syndrome (TTTS). Several ultrasonographic and neonatal criteria of TTTS were encountered in this twin pregnancy. The peculiar observations in this case were, firstly, the demonstration of superficial anastomosis by Doppler ultrasound and, secondly, that one single therapeutic amniocentesis could have been sufficient to partially correct the progression of the syndrome, as after amniocentesis it was no longer possible to demonstrate the vascular communication. This observation suggests that superficial anastomoses could also have a role in the genesis of TTTS. Their effect could be monitored by Doppler ultrasound and could be more easily corrected by therapeutic amniocentesis. 相似文献
220.
Prenatal transvaginal diagnosis of the ectrodactyly,ectodermal dysplasia,cleft palate (EEC) syndrome
Transvaginal ultrasonography performed at 14 weeks' gestation demonstrated a bilateral cleft lip and lobster-claw deformities of the hands and feet, in keeping with the diagnosis of EEC syndrome (ectrodactyly or lobster-claw deformity, ectodermal dysplasia, and cleft lip and palate). The fetus was aborted and the diagnosis of EEC syndrome was confirmed. 相似文献