全文获取类型
收费全文 | 2160篇 |
免费 | 27篇 |
国内免费 | 16篇 |
专业分类
安全科学 | 75篇 |
废物处理 | 3篇 |
环保管理 | 10篇 |
综合类 | 2049篇 |
基础理论 | 19篇 |
污染及防治 | 9篇 |
评价与监测 | 11篇 |
社会与环境 | 10篇 |
灾害及防治 | 17篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 8篇 |
2021年 | 21篇 |
2020年 | 7篇 |
2019年 | 8篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2014年 | 8篇 |
2013年 | 12篇 |
2012年 | 32篇 |
2011年 | 128篇 |
2010年 | 123篇 |
2009年 | 92篇 |
2008年 | 94篇 |
2007年 | 128篇 |
2006年 | 121篇 |
2005年 | 121篇 |
2004年 | 121篇 |
2003年 | 114篇 |
2002年 | 132篇 |
2001年 | 97篇 |
2000年 | 7篇 |
1999年 | 6篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 109篇 |
1994年 | 96篇 |
1993年 | 77篇 |
1992年 | 61篇 |
1991年 | 60篇 |
1990年 | 55篇 |
1989年 | 62篇 |
1988年 | 48篇 |
1987年 | 50篇 |
1986年 | 29篇 |
1985年 | 42篇 |
1984年 | 47篇 |
1983年 | 24篇 |
1982年 | 21篇 |
1981年 | 16篇 |
排序方式: 共有2203条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Jean-Marc Costa Alexandra Benachi Evelyne Gautier Jean-Marie Jouannic Pauline Ernault Yves Dumez 《黑龙江环境通报》2001,21(12):1070-1074
An Erratum has been published for this article in Prenatal Diagnosis 22(13) 2002, 1241. Fetal sex prediction can be achieved using PCR targeted at the SRY gene by analysing cell-free fetal DNA in maternal serum. Unfortunately, the results reported to date show a lack of sensitivity, especially during the first trimester of pregnancy. Therefore, determination of fetal sex by maternal serum analysis could not replace karyotype analysis following chorionic villus sampling. A new highly sensitive real-time PCR was developped to detect an SRY gene sequence in maternal serum. Analysis was performed on 121 pregnant women during the first trimester of pregnancy (mean gestational age: 11.8 weeks). Among them, 51 had at least one previous male-bearing pregnancy. Results were compared with fetal sex. SRY PCR analysis of maternal serum was in complete concordance with fetal sex. Among the 121 pregnant women, 61 were bearing a male fetus and 60 a female fetus. No false-negative results were observed. Furthermore, no false-positive results occurred, even though 27 women carrying a female fetus during the current pregnancy had at least one previous male-bearing pregnancy. This study demonstrates that a reliable, non-invasive sex determination can be achieved by PCR analysis of maternal serum during the first trimester of pregnancy. This non-invasive approach for fetal sex prediction should have great implications in the management of pregnant women who are carriers of an X-linked genetic disorder. Prenatal diagnosis might thus be performed for male fetuses only, avoiding invasive procedures and the risk of the loss of female fetuses. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
6.
7.
8.
9.
Dario Paladini Maria Giovanna Russo Antonio Tartaglione Annamaria Loffredo Pasquale Martinelli 《黑龙江环境通报》2002,22(13):1185-1187
Toriello–Carey syndrome is a rare malformative complex, described for the first time in 1988, characterized by agenesis of the corpus callosum, facial anomalies, cardiac defects and hypotonia. Relatively few neonatal cases have been reported. We describe here the first prenatal ultrasound diagnosis of the syndrome based on the detection of agenesis of the corpus callosum and spongious cardiomyopathy in a 22-week-old fetus of a couple with positive family history. The first sib of the couple was diagnosed with Toriello–Carey syndrome at 1 year of age, and had, in addition to the typical facial anomalies not detectable by ultrasound, agenesis of the corpus callosum and the same heart lesion (spongious cardiomyopathy). This report demonstrates that prenatal diagnosis of Toriello–Carey syndrome is feasible in the second trimester of pregnancy. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
10.
The most widely used method for fetocide in late termination of pregnancy for fetal abnormalities (TOPFA) consists of injecting of potassium chloride (KCl) into the fetal heart and is likely to be painful after 22 weeks of gestation. We studied ten consecutive women undergoing TOPFA between 22 and 38 weeks. This technique for fetocide consisted of a single umbilical vein puncture under ultrasound guidance with injections of sufentanil 5 µg followed by KCl 2 g. No electrocardiographic modifications could be observed and maternal plasma potassium levels did not show any significant variation throughout the procedure. Fetal umbilical phlebotomy for fetal analgesia followed by fetocide therefore appears to be a safe procedure for the mother and allows the fetus to die without pain when late termination of pregnancy (TOP) is indicated. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献