全文获取类型
收费全文 | 1664篇 |
免费 | 25篇 |
国内免费 | 11篇 |
专业分类
安全科学 | 91篇 |
废物处理 | 3篇 |
环保管理 | 5篇 |
综合类 | 1535篇 |
基础理论 | 13篇 |
污染及防治 | 5篇 |
评价与监测 | 13篇 |
社会与环境 | 8篇 |
灾害及防治 | 27篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 11篇 |
2021年 | 16篇 |
2020年 | 11篇 |
2019年 | 7篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 3篇 |
2014年 | 12篇 |
2013年 | 11篇 |
2012年 | 21篇 |
2011年 | 67篇 |
2010年 | 59篇 |
2009年 | 45篇 |
2008年 | 58篇 |
2007年 | 80篇 |
2006年 | 88篇 |
2005年 | 86篇 |
2004年 | 91篇 |
2003年 | 84篇 |
2002年 | 94篇 |
2001年 | 76篇 |
2000年 | 2篇 |
1999年 | 11篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1995年 | 85篇 |
1994年 | 79篇 |
1993年 | 75篇 |
1992年 | 59篇 |
1991年 | 58篇 |
1990年 | 52篇 |
1989年 | 61篇 |
1988年 | 47篇 |
1987年 | 50篇 |
1986年 | 29篇 |
1985年 | 42篇 |
1984年 | 44篇 |
1983年 | 21篇 |
1982年 | 21篇 |
1981年 | 16篇 |
排序方式: 共有1700条查询结果,搜索用时 15 毫秒
81.
Andrew D. Dorfmann Jeane Perszyk Patricia Robinson Susan H. Black Joseph D. Schulman 《黑龙江环境通报》1992,12(11):899-902
This paper reports eight cases of non-mosaic, rare, and typically lethal trisomies diagnosed in chorionic villi and not confirmed by amniocentesis. Four cases were 47,XX, + 16; two cases were 47,XX, +2; one was 47,XX, + 12; and one was 47,XY, +7. There have been no known complications in any of these gestations. These eight cases were found in a series of approximately 12 000 samples processed in our laboratory (0.07 per cent). We conclude that (1) rare non-mosaic trisomy not reflecting the fetal condition is an occasional source of diagnostic ambiguity in chorionic villus sampling; and (2) when encountered, a follow-up amniocentesis should be recommended to the patient to confirm or rule out the abnormality. We propose the term ‘confined placental abnormality’ to describe non-mosaic trisomies and other related abnormalities found only in chorionic tissue. 相似文献
82.
A pleural effusion associated with congenital pulmonary lymphangiectasia was detected in a fetus in utero but was absent at the time of delivery. The pleural effusion was unilateral although the disease involved both lungs. In this case there was an association between polyhydramnios and congenital pulmonary lymphangiectasia. 相似文献
83.
Mucolipidosis IV (ML 1V) is a lysosomal storage disease presenting in infancy with cloudy cornea and psychomotor retardation. Our experience with 12 pregnancies at risk for ML IV, monitored by transmission electron microscopy (TEM) studies of cultured amniotic fluid cells, is presented. The prenatal diagnoses were confirmed in the 3 affected and the 8 un- affected pregnancies. In the one pregnancy where no definite diagnosis was reached the pregnancy was terminated. TEM examination of fetal tissues from this pregnancy showed no abnormal lysosomal storage bodies and a review of the cultured amniotic fluid cell sections revealed that the diagnosis of a normal fetus could have been made. 相似文献
84.
85.
Emanuela Terzian Jillian Boreham Howard S. Cuckle Nicholas J. Wald Martin Bobrow Richard Lindenbaum A. C. Turnbull 《黑龙江环境通报》1985,5(6):401-414
A survey was conducted of the results of mid-trimester diagnostic amniocenteses in the Oxford Region from 1974 to 1981. The survey used data relating to all 4357 singleton pregnancies in which an amniocentesis was performed during this period. Follow-up information on outcome was obtained in respect of 4284 (98 per cent) pregnancies. A cell culture to determine karyotype and an alpha-fetoprotein determination was carried out in all cases. From 1974 to 1981 amniocenteses became increasingly common, rising from 2 to 32 per 1000 births. The most common indication for amniocentesis was a high risk of a chromosome abnormality–56 per cent of all amniocenteses. Within this group advanced maternal age was responsible for 89 per cent of the cases. The next most common indication was a high risk of a neural tube defect (37 per cent of all amniocenteses)–in 1974 a raised maternal serum alpha-fetoprotein level accounted for only 4 per cent of these; by 1981 this had risen to 67 per cent. There were seven false-positive and 132 true-positive diagnoses of neural tube defect; since 1981, with the introduction of amniotic fluid acetylocholinesterase determination as a secondary diagnostic test for neural tube defects, there have been no further false-positive diagnoses. In 1981 76 per cent of women aged 35 years or more did not have an amniocentesis. It is not known to what extent this was due to not offering women in this age group amniocentesis or to women not accepting such an offer. 相似文献
86.
J. H. A. M. Tuerlings MD A. S. P. M. Breed R. Vosters G. J. P. A. Anders 《黑龙江环境通报》1993,13(4):301-306
A 70,XXX, +18 karyotype was found by chorionic villus sampling, while the fetal fibroblast culture of the affected fetus revealed a 47,XX,+ 18 karyotype. From several possible mechanisms, we assume that a second gamete fusion occurred after the first cell division of the zygote. According to this interpretation, the mosaicism arose in very early pregnancy (at the two-cell stage). This discrepancy can therefore be explained by selection pressure, due to the differentiation processes in the embryonic tissues. 相似文献
87.
Ottavia Cavicchioni Denise Molina Gomes Brigitte Leroy François Vialard Yvette Hillion Jacqueline Selva Yves Ville 《黑龙江环境通报》2005,25(10):876-878
We present a case of prenatal diagnosis of a de novo (7;19)(q11.2;q13.3) translocation associated with ultrasound features, including enlarged cisterna magna, normal vermis, thick corpus callosum, micrognathia, small and low-set ears and right hyperechogenic kidney. Karyotyping was performed at 24 weeks of gestation. Termination of pregnancy was accepted at the parents' request. Postmortem examination confirmed the prenatal findings, but revealed bilateral Wilms tumors of the kidneys. Parental karyotype was normal. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
88.
Urinary tract anomalies are common. Prenatal diagnosis is important and enables either special obstetric management or termination of pregnancy and probably in the future, intrauterine intervention. Transvaginal sonography (TVS) allows visualization of the normal and anomalous fetal urinary tract at an early stage. One thousand nine hundred and forty women were examined via TVS at an early stage of pregnancy between 10 and 16 weeks from the last menstrual period (LMP) and 35 anomalies (1·8 per cent) were clearly identified: 29 cases of low urinary tract obstruction, 2 cases of multicystic dysplastic kidney, 2 cases of polycystic kidney (infantile type), 1 case of double collecting system, and 1 case of horseshoe kidney. Potter syndrome could be ruled out in three patients who had delivered fetuses suffering from this anomaly in previous pregnancies. The concise and early identification of anomalies makes TVS an important aid in the hands of the obstetrician, ultrasonographer, and neonatologist. 相似文献
89.
There has been tremendous development in the field of prenatal diagnosis of cardiac disease in the last 30 years. Early work centered on the technical aspects of providing an accurate assessment of cardiac structure and function. Techniques of fetal cardiac screening have been developed and utilized throughout the world. More recently, investigators have begun to explore the ramifications of fetal cardiac diagnosis by assessing measures of outcome. In this article, the field of fetal echocardiography, as a screening tool for identifying congenital heart disease, and its impact on disease outcome is reviewed. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
90.
Stéphanie Couvreur-Lionnais Thierry Rousseau Nicole Laurent Christel Thauvin-Robinet Eve Senet-Lacombe Anne Lise Delezoïde Francine Mugneret Christine Durand Laurence Faivre Paul Sagot 《黑龙江环境通报》2005,25(2):172-175
Juberg–Hayward syndrome is a rare autosomal recessive syndrome characterised by the association of growth retardation, microcephaly, cleft lip and palate, and thumb and radial ray abnormalities. To date, no prenatal cases have been reported. Here, we report on the first prenatal case of Juberg–Hayward syndrome. The diagnosis was established following fetopathological study. Besides the cardinal features of the syndrome, this prenatal case was remarkable for the severity of the short arm malformation and by the finding of big toe agenesis and cerebral abnormalities including hydrocephalus, agenesis of corpus callosum, and cerebellar hypoplasia. We conclude that the diagnosis of Juberg–Hayward syndrome can be discussed prenatally following ultrasound diagnosis of the association of intrauterine growth restriction, microcephaly, thumb/radial anomalies, and cleft lip/palate. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献