全文获取类型
收费全文 | 254篇 |
免费 | 14篇 |
国内免费 | 1篇 |
专业分类
儿科学 | 9篇 |
妇产科学 | 6篇 |
基础医学 | 39篇 |
口腔科学 | 3篇 |
临床医学 | 19篇 |
内科学 | 56篇 |
皮肤病学 | 1篇 |
神经病学 | 45篇 |
特种医学 | 4篇 |
外科学 | 46篇 |
预防医学 | 9篇 |
药学 | 10篇 |
中国医学 | 1篇 |
肿瘤学 | 21篇 |
出版年
2021年 | 7篇 |
2020年 | 2篇 |
2019年 | 4篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2014年 | 7篇 |
2013年 | 11篇 |
2012年 | 10篇 |
2011年 | 8篇 |
2010年 | 7篇 |
2009年 | 5篇 |
2008年 | 12篇 |
2007年 | 8篇 |
2006年 | 11篇 |
2005年 | 15篇 |
2004年 | 9篇 |
2003年 | 7篇 |
2002年 | 10篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 12篇 |
1998年 | 2篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1992年 | 8篇 |
1991年 | 9篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 4篇 |
1974年 | 1篇 |
1972年 | 3篇 |
1971年 | 5篇 |
1970年 | 3篇 |
1969年 | 4篇 |
1968年 | 10篇 |
1967年 | 1篇 |
1966年 | 6篇 |
1965年 | 1篇 |
排序方式: 共有269条查询结果,搜索用时 724 毫秒
1.
Ishii M Kanai Y Kanai-Azuma M Tajima Y Wei TT Kidokoro T Sanai Y Kurohmaru M Hayashi Y 《Anatomy and embryology》2005,209(6):485-494
MFG-E8, a secreted integrin-binding protein, consists of two EGF domains containing a RGD motif and two discoidin domains. In mouse embryogenesis, MFG-E8 is highly expressed in gonadal stromal cells near mesonephros at 11.5–12.5 dpc, but its function in gonadogenesis has not been characterized. To clarify a possible role of MFG-E8 in developing gonads, we analyzed the adhesion activity of 10.5–15.5 dpc gonadal cells to recombinant proteins of EGF or discoidin domains of MFG-E8. In EGF-coated wells, the gonadal cells at 11.5–12.5 dpc revealed a significantly higher adhesion activity as compared to those at 10.5 and 15.5 dpc, while discoidin domains showed a constant number of the adhered cells throughout these stages. To identify the adhesive cells of 11.5-dpc gonads, immunohistochemistry with anti-SF1/Ad4Bp antibody (a specific marker for supporting, steroidogenic, and coelomic epithelial cells) and staining for alkaline phosphatase (a germ cell marker) were carried out. As a result, EGF domains, as well as discoidin domains, were capable of binding to all three groups of SF1/Ad4Bp-positive and negative somatic cells, and germ cells of 11.5-dpc gonads. These findings therefore suggest that MFG-E8 mediates the cell-to-cell interaction among several somatic cell types and germ cells in mouse early gonadogenesis. 相似文献
2.
3.
The adrenal medulla is innervated by sympathetic preganglionic nerve fibers in the splanchnic nerve. Synaptic activation of the adrenal medulla causes catecholamine secretion which is known to be modified by various neuropeptides and other factors. To understand the neuronal control mechanism of catecholamine secretion, it is necessary to know the transfer function at the synapse and how it is affected by such factors. By using a large photodiode array in combination with a voltage-sensitive dye, membrane potential changes in a slice of the rat adrenal gland were recorded upon brief local electrical stimulation. Electrical signals were recorded only on the portion of the diode array corresponding to the medulla. In a typical record, a spike and an underlying slow potential were observed following a small deflection due to a presynaptic nerve action potential. Both the spike and slow potential were blocked in Ca(2+)-free solution or by hexamethonium, a nicotinic antagonist, but were not affected by atropine, a muscarinic antagonist. The slow potential was interpreted as a nicotinic synaptic potential in the chromaffin cells and the spike as a population action potential. A double pulse experiment revealed that the chromaffin cell action potential began to fail only when the stimulus interval was less than 50 ms (20 Hz). When the stimulus intensity was reduced, the minimal response was found to behave in an all-or-none fashion. This suggested that one nerve fiber is innervating a cluster of chromaffin cells, which may correspond to a previously histologically identified "complex" of cells [Hillarp (1946) Acta. anat. 4, Suppl. 1]. Each complex was innervated by approximately four nerve fibers.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
4.
5.
6.
7.
8.
9.
Toshihiko Okumura Jun-ichi Kawada Masaharu Tanaka Kotaro Narita Tomonori Ishiguro Yuji Hirayama Sho Narahara Genki Tsuji Yuichiro Sugiyama Michio Suzuki Takeshi Tsuji Shin Hoshino Masahiro Nakatochi Hideki Muramatsu Hiroyuki Kidokoro Yoshiyuki Takahashi Yoshiaki Sato 《Journal of infection and chemotherapy》2019,25(5):346-350
Background
Mycoplasma pneumoniae pneumonia (MPP) is generally a self-limiting disease, but it may become refractory. It is thought that refractory MPP is linked to the excessive immunologic responses of the host. Consequently, the use of adjunctive systemic corticosteroids may have beneficial effects. In this study, we compared the effects of high- and low-dose corticosteroid therapy in a pediatric population with refractory MPP.Methods
We retrospectively collected data from 91 pediatric MPP patients treated with adjunctive systemic corticosteroids between April 2014 and October 2016. The patients were divided into the following two groups: high-dose corticosteroid group (2 mg/kg/day or more of prednisolone equivalents; n = 38) and low-dose corticosteroid group (<2 mg/kg/day; n = 53). Additionally, we compared the number of febrile days post-corticosteroid administration. We used 25 paired patients in a propensity score matching analysis to correct for confounding factors both by age and by days (from onset till corticosteroid therapy initiation).Results
We observed that in the high-dose corticosteroid group defervescence following corticosteroid therapy initiation was achieved significantly earlier and length of hospitalization was significantly shorter (0.8 ± 1.0 vs. 1.5 ± 1.4 days and 8.2 ± 2.4 vs. 10.7 ± 2.7 days, respectively). In the propensity score matching, we observed that significant differences in the length of fever following corticosteroid therapy initiation and hospitalization were still present. Further, neither of the groups developed corticosteroid-related adverse events.Conclusion
Our results suggest that patients with refractory MPP treated with high-dose corticosteroid could achieve defervescence earlier and have a shorter hospitalization. 相似文献10.
1. Excitation-contraction coupling was studied in myotomal muscles of amphioxus, Branchiostoma californiense.2. The action potential of a muscle cell produces a twitch with a rise time of 30-40 msec at 11 degrees C and its Q(10) is about 2.2.3. The twitch increases in amplitude with increasing external Ca concentration and is abolished in Ca-free saline (1 mM-EGTA and 55.7 mM-MgCl(2)); the twitch amplitude is suppressed by Co or La ions.4. Caffeine at concentrations above 1 mM in the external saline causes a prolongation of the action potential and a contracture which lasts several minutes.5. After exposure to caffeine the responsiveness of the muscle to subsequent applications of caffeine recovers in normal saline in 20-30 minutes but not in Ca-free saline.6. The amplitude of the caffeine contracture is independent of the external Ca concentration and is unaltered after the twitch is eliminated in Ca-free saline.7. After exposure to caffeine a full-sized twitch can be obtained before the responsiveness to caffeine shows any significant recovery.8. It is concluded that the twitch is produced by the Ca influx resulting from the increased permeability of the muscle cell membrane to Ca during the action potential and that the Ca mobilized by caffeine is not necessary to the initiation of the twitch.9. Electronmicroscopy shows the existence of sarcoplasmic reticulum. 相似文献