全文获取类型
收费全文 | 1614篇 |
免费 | 25篇 |
国内免费 | 9篇 |
专业分类
安全科学 | 65篇 |
废物处理 | 3篇 |
环保管理 | 4篇 |
综合类 | 1527篇 |
基础理论 | 13篇 |
污染及防治 | 3篇 |
评价与监测 | 9篇 |
社会与环境 | 8篇 |
灾害及防治 | 16篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 8篇 |
2021年 | 15篇 |
2020年 | 6篇 |
2019年 | 7篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 3篇 |
2014年 | 7篇 |
2013年 | 10篇 |
2012年 | 21篇 |
2011年 | 65篇 |
2010年 | 58篇 |
2009年 | 44篇 |
2008年 | 58篇 |
2007年 | 80篇 |
2006年 | 87篇 |
2005年 | 84篇 |
2004年 | 90篇 |
2003年 | 83篇 |
2002年 | 94篇 |
2001年 | 75篇 |
2000年 | 2篇 |
1999年 | 5篇 |
1998年 | 1篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 84篇 |
1994年 | 75篇 |
1993年 | 73篇 |
1992年 | 57篇 |
1991年 | 57篇 |
1990年 | 51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1648条查询结果,搜索用时 15 毫秒
931.
932.
933.
934.
935.
Preimplantation genetic diagnosis (PGD) is a technique used for determining the genetic status of a single cell biopsied from embryos or oocytes. Genetic analysis from a single cell is both rewarding and challenging, especially in PGD. The starting material is very limited and not replaceable, and the diagnosis has to be made in a very short time. Different whole genome amplification (WGA) techniques have been developed to specifically increase the DNA quantities originating from clinical samples with limited DNA contents. In this review, currently available WGA techniques are introduced and, among them, multiple displacement amplification (MDA) is discussed in detail. MDA generates abundant assay-ready DNA to perform broad panels of genetic assays through its ability to rapidly amplify genomes from single cells. The utilization of MDA for single-cell molecular analysis is expanding at a high rate, and MDA is expected to soon become an integral part of PGD. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
936.
937.
The neural cell adhesion molecule L1 is a transmembrane glycoprotein belonging to the immunoglobulin superfamily of cell adhesion molecules (CAMs). Its expression is essential during embryonic development of the nervous system and it is involved in cognitive function and memory. Mutations in the L1CAM gene are responsible for four related L1 disorders; X-linked hydrocephalus/HSAS (H ydrocephalus as a result of S tenosis of the A queduct of S ylvius), MASA (M ental retardation, A phasia, S huffling gait, and A dducted thumbs) syndrome, X-linked complicated spastic paraplegia type I (SPG1) and X-linked A genesis of the C orpus C allosum (ACC). These four disorders represent a clinical spectrum that varies both between and within families. The main clinical features of this spectrum are C orpus callosum hypoplasia, mental R etardation, A dducted thumbs, S pastic paraplegia and H ydrocephalus (CRASH syndrome). Since there is no biochemically assayed disease marker, molecular analysis of the L1CAM gene is the only means of confirming a clinical diagnosis. Most L1CAM mutations reported to date are point mutations (missense, nonsense, splice site) and only a few patients with larger rearrangements have been documented. We have characterised a rare intragenic deletion of the L1CAM gene in a sample of DNA extracted from a chorionic villus biopsy (CVB) performed at 12 weeks' gestation. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
938.
939.
J. Van Keirsbilck M. Cannie C. Robrechts T. de Ravel S. Dymarkowski T. Van den Bosch D. Van Schoubroeck 《黑龙江环境通报》2006,26(8):684-688
We present a case of sirenomelia diagnosed on a first trimester ultrasound at 10 weeks' gestation and confirmed on 3D-ultrasound and MRI. The pregnancy was terminated at 15 gestational weeks and the post-mortem examination, including RX and microscopy, is presented. The sirenomelia sequence is a rare and lethal anomaly characterized by fusion, rotation, hypotrophy or atrophy of the lower limbs and severe urogenital abnormalities leading to oligohydramnios in the second half of pregnancy. Our case illustrates that the diagnosis of sirenomelia can be reliably made in the first trimester. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
940.