全文获取类型
收费全文 | 683篇 |
免费 | 79篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 18篇 |
妇产科学 | 10篇 |
基础医学 | 68篇 |
口腔科学 | 25篇 |
临床医学 | 88篇 |
内科学 | 164篇 |
皮肤病学 | 5篇 |
神经病学 | 26篇 |
特种医学 | 113篇 |
外科学 | 41篇 |
综合类 | 72篇 |
预防医学 | 71篇 |
眼科学 | 5篇 |
药学 | 42篇 |
中国医学 | 1篇 |
肿瘤学 | 24篇 |
出版年
2022年 | 5篇 |
2021年 | 7篇 |
2020年 | 7篇 |
2019年 | 5篇 |
2018年 | 10篇 |
2017年 | 6篇 |
2016年 | 12篇 |
2015年 | 9篇 |
2014年 | 8篇 |
2013年 | 18篇 |
2012年 | 7篇 |
2011年 | 13篇 |
2010年 | 26篇 |
2009年 | 31篇 |
2008年 | 18篇 |
2007年 | 23篇 |
2006年 | 10篇 |
2005年 | 12篇 |
2004年 | 15篇 |
2003年 | 10篇 |
2002年 | 14篇 |
2001年 | 14篇 |
2000年 | 16篇 |
1999年 | 13篇 |
1998年 | 35篇 |
1997年 | 32篇 |
1996年 | 32篇 |
1995年 | 30篇 |
1994年 | 18篇 |
1993年 | 22篇 |
1992年 | 14篇 |
1991年 | 7篇 |
1990年 | 20篇 |
1989年 | 18篇 |
1988年 | 24篇 |
1987年 | 28篇 |
1986年 | 24篇 |
1985年 | 11篇 |
1984年 | 12篇 |
1983年 | 14篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1980年 | 12篇 |
1979年 | 20篇 |
1978年 | 15篇 |
1977年 | 11篇 |
1976年 | 9篇 |
1975年 | 6篇 |
1973年 | 7篇 |
1968年 | 5篇 |
排序方式: 共有774条查询结果,搜索用时 31 毫秒
1.
2.
In a prospective, randomized, double-blind study, 49 patients underwent lumbar myelography using iotrol (24 patients) or metrizamide (25 patients). The diagnostic imaging adequacy of iotrol was comparable with that of metrizamide. After iotrol myelography, adverse reactions were fewer, less severe, and of shorter duration than were those following metrizamide myelography. Thirteen of 24 patients (54%) receiving iotrol reported some adverse reactions compared with 24 of 25 patients (96%) receiving metrizamide. Five moderate and one severe adverse reaction occurred in the group receiving iotrol. Fourteen moderate and eight severe adverse reactions occurred in the group receiving metrizamide. Thirty-eight patients underwent electroencephalography both before and after myelography (19 iotrol and 19 metrizamide). None of the EEGs obtained after iotrol myelography changed from baseline, while seven of the EEGs obtained after metrizamide myelography showed changes from baseline. Iotrol was judged superior to metrizamide as a contrast medium in this patient population. 相似文献
3.
4.
5.
6.
7.
Studies of proteins that inhibit tissue factor activity have generally been conducted using either an extracted tissue homogenate ("thromboplastin") or tissue factor protein reconstituted into phospholipid vesicles rather than with tissue factor expressed in cell membranes (its physiological environment). In the present study, a human fibroblast cell strain was used to evaluate the effects of lipoprotein associated coagulation inhibitor (LACI), placental anticoagulant protein (PAP), and apolipoprotein A-II (apo A-II) on human tissue factor in cell membranes. LACI was tested from 7.8 to 500 pmol/L on fibroblasts cultured at cell densities ranging from 3,500 to 9,925 cells/well, and caused a progressive inhibition of tissue factor activity. PAP was tested from 3.9 nmol/L to 1 mumol/L at cell densities ranging from 4,500 to 15,400 cells/well and caused up to 83% inhibition of tissue factor activity. Inhibition by these proteins appeared to be influenced by cell density as well as whether the cells were intact or disrupted. Apo A-II, up to 1 mumol/L, did not inhibit the tissue factor activity of intact or disrupted fibroblasts at any cell density examined even though it did inhibit the activity of tissue factor in phospholipid vesicles. Of these inhibitors of tissue factor-dependent activation of factor X, LACI was the most effective in suppressing the generation of factor Xa activity. The effects obtained with apo A-II are clearly dependent on the nature of the tissue factor preparation with which it is tested. The disparity between the inhibitory effect of apo A-II on the activity of tissue factor reconstituted into lipid vesicles and the absence of effect on the activity of tissue factor remaining in cell membranes serves to reemphasize the necessity of reexamining results obtained with model systems using as nearly physiological reagents as possible. 相似文献
8.
R E Martin G P Sackett V M Gunderson B L Goodlin-Jones 《Developmental psychobiology》1988,21(3):251-260
Heart rate (HR) responses evoked by 1 sec of 85-dB white noise were studied in 12 1-year-old pigtailed macaques, 6 of which were raised in social isolation and 6 with mothers and peers. Tests were given for 5 days, with 25 trials each day. Although baseline HR did not differ between groups, the pattern of change from baseline was not the same. Isolates showed only HR acceleration, returning to baseline within 10-11 sec of stimulus onset. Socially reared monkeys had a 10- to 11-sec biphasic response of acceleration followed by deceleration, with subsequent return to baseline. The same group difference in HR pattern occurred when subjects were tested with a less intense 65-dB stimulus. These findings were discussed in terms of activity, emotionality, and autonomic regulatory functions. It was concluded that early rearing experiences may affect later physiological processes involving autonomic nervous system balance. This conclusion was related to observations of persistent individual differences in HR by human children classified as inhibited. 相似文献
9.
Myosin VIIA gene: heterogeneity of the mutations responsible for Usher syndrome type IB 总被引:8,自引:1,他引:8
Levy G; Levi-Acobas F; Blanchard S; Gerber S; Larget-Piet D; Chenal V; Liu XZ; Newton V; Steel KP; Brown SD; Munnich A; Kaplan J; Petit C; Weil D 《Human molecular genetics》1997,6(1):111-116
Usher syndrome is recognized as the most frequent cause of hereditary
deaf-blindness. Usher syndrome type I (USH1), the most severe form of the
disease, is characterized by profound congenital sensorineural deafness,
constant vestibular dysfunction, and retinitis pigmentosa of prepubertal
onset. This form is genetically heterogeneous and five loci (USH1A-E) have
been mapped thusfar. However, only the gene responsible for USH1 B (which
accounts for approximately 75% of USH1 cases) has been characterized. It
encodes a long-tailed unconventional myosin, myosin VIIA, with a predicted
2215 amino acid sequence. Primers covering the complete myosin VIIA coding
sequence as well as the 3' non coding sequence were designed, allowing
direct sequence analysis of each of the 48 coding exons and flanking splice
sites in seven patients affected by USH1. Four novel mutations were thereby
identified. The possibility should now be considered of a sequence-based
prenatal diagnosis in some of the families affected by this very severe
form of Usher syndrome.
相似文献
10.