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排序方式: 共有671条查询结果,搜索用时 296 毫秒
1.
Sonoelasticity imaging of prostate cancer: in vitro results 总被引:2,自引:0,他引:2
2.
L E Ressler 《The Gerontologist》1991,31(3):364-370
This study's goal was to better explain memory and its decline in a natural setting to improve social work practice among the elderly. The effect that bimodal (verbal and visual) presentation of information has on delayed incidental recall was compared with unimodal (verbal only) presentation. A significant increase occurred in overall recall and verbatim recall. Gist recall improved, but not significantly. 相似文献
3.
Screening for early ovarian cancer 总被引:5,自引:0,他引:5
4.
A great deal is now known about the mechanisms of conditioned fear acquisition and expression. More recently, the mechanisms
of inhibition of conditioned fear have become the subject of intensive study. The major model system for the study of fear
inhibition in the laboratory is extinction, in which a previously fear conditioned organism is exposed repeatedly to the fear-eliciting
cue in the absence of any aversive event and the fear conditioned response declines. It is well established that extinction
is a form of new learning as opposed to forgetting or “unlearning” of conditioned fear, and it is hypothesized that extinction
develops when sensory pathways conveying sensory information to the amygdala come to engage GABAergic interneurons through
forms of experience-dependent plasticity such as long-term potentiation. Several laboratories currently are investigating
methods of facilitating fear extinction in animals with the hope that such treatments might ultimately prove to be useful
in facilitating exposure-based therapy for anxiety disorders in clinical populations. This review discusses the advances that
have been made in this field and presents the findings of the first major clinical study to examine the therapeutic utility
of a drug that facilitates extinction in animals. It is concluded that extinction is an excellent model system for the study
of fear inhibition and an indispensable tool for the screening of putative pharmacotherapies for clinical use. 相似文献
5.
Hintergrund.
Unter CRASH-Syndrom wird eine Gruppe von X-chromosomal vererbten Erkrankungen zusammengefasst, die eine Mutation im L1CAM-Gen vorweisen und nach dem Akronym CRASH folgende Symptome vorweisen k?nnen: Corpus-callosum-Hypoplasie, Retardierung, adduzierte Daumen, spastische Paraplegie und Hydrozephalus. Eine Erkrankung aus dieser Reihe ist der X-chromosomal gebundene Hydrozephalus, erstmals beschrieben von Bickers und Adams 1949 als Hydrozephalus mit ?quaduktstenose (HSAS). 相似文献6.
The vascularity of 49 renal masses (26 malignant and 23 benign lesions) was investigated with duplex Doppler ultrasound. Doppler signals obtained at the margins of renal masses were defined as "tumor signals" when the Doppler-shifted frequency of the lesion exceeded the frequency shift in the ipsilateral main renal artery. These exceeded 2.5 kHz with a 3-MHz insonating frequency. Among the 26 renal masses that subsequently proved to be malignant, tumor signals were obtained in 15 of 18 (83%) untreated renal cell carcinomas, in three of four Wilms tumors, and in two patients with metastases to the kidney, but not in the one patient with lymphoma. None of the 23 benign renal masses demonstrated tumor signals. Tumor vascularity in malignant lesions gives rise to abnormal, high-velocity, Doppler-shifted signals that can help in the differential diagnosis of renal masses. 相似文献
7.
Detection of reactive oxygen species (ROS) and apoptosis in human fragmented embryos 总被引:8,自引:2,他引:8
Yang HW; Hwang KJ; Kwon HC; Kim HS; Choi KW; Oh KS 《Human reproduction (Oxford, England)》1998,13(4):998-1002
In human in-vitro fertilization (IVF)-embryo transfer, the in-vitro culture
environment differs from in-vivo conditions in that the oxygen
concentration is higher, and in such conditions the mouse embryos show a
higher concentration of reactive oxygen species (ROS) in simple culture
media. ROS are believed to cause damage to cell membranes and DNA
fragmentation in somatic cells. This study was conducted to ascertain the
level of H2O2 concentration within embryos and the morphological features
of cell damage induced by H2O2. A total of 62 human oocytes and embryos (31
fragmented, 15 non-fragmented embryos, 16 unfertilized oocytes) was
obtained from the IVF-embryo transfer programme. The relative intensity of
H2O2 concentrations within embryos was measured using
2',7'-dichlorodihydrofluorescein diacetate by Quanti cell 500 fluorescence
imaging and DNA fragmentation was observed with transmission electron
microscopy and an in-situ apoptosis detection kit. The H2O2 concentrations
were significantly higher in fragmented embryos (72.21 +/- 9.62, mean +/-
SEM) compared to non-fragmented embryos (31.30 +/- 3.50, P < 0.05) and
unfertilized oocytes (30.75 +/- 2.67, P < 0.05). Apoptosis was observed
only in fragmented embryos, and was absent in non-fragmented embryos.
Electron microscopic findings confirmed apoptotic bodies and cytoplasmic
condensation in the fragmented blastomeres. We conclude that there is a
direct relationship between increased H2O2 concentration and apoptosis, and
that further studies should be undertaken to confirm these findings.
相似文献
8.
9.
This article examines the functional approach to attitudes for its potential contribution to improving models of attitude-behavior consistency and to demonstrate its potential application to social marketing. To this end, a study of children's attitudes toward bicycle helmets is reported on and its results examined. The study was undertaken to plan Israel's first-ever media campaign to encourage the use of helmets by children. Responses of the 783 Israeli children (ages 7 to 14 years) who participated in the study are analyzed to test the hypothesis generated by this application of functional theory--that children's attitudes toward wearing bicycle helmets serve primarily an expressive function. The results suggest cautious support for the functional hypothesis. In conclusion, possible extensions of this approach to other areas of social marketing are discussed. 相似文献
10.
Pathways to care for alcohol use disorders 总被引:1,自引:0,他引:1