全文获取类型
收费全文 | 1194篇 |
免费 | 98篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 85篇 |
妇产科学 | 11篇 |
基础医学 | 115篇 |
口腔科学 | 27篇 |
临床医学 | 104篇 |
内科学 | 197篇 |
皮肤病学 | 31篇 |
神经病学 | 36篇 |
特种医学 | 136篇 |
外科学 | 131篇 |
综合类 | 145篇 |
预防医学 | 77篇 |
眼科学 | 4篇 |
药学 | 95篇 |
中国医学 | 39篇 |
肿瘤学 | 72篇 |
出版年
2023年 | 7篇 |
2022年 | 15篇 |
2021年 | 27篇 |
2020年 | 26篇 |
2019年 | 17篇 |
2018年 | 19篇 |
2017年 | 16篇 |
2016年 | 21篇 |
2015年 | 28篇 |
2014年 | 45篇 |
2013年 | 40篇 |
2012年 | 48篇 |
2011年 | 53篇 |
2010年 | 73篇 |
2009年 | 63篇 |
2008年 | 30篇 |
2007年 | 36篇 |
2006年 | 45篇 |
2005年 | 35篇 |
2004年 | 22篇 |
2003年 | 27篇 |
2002年 | 16篇 |
2001年 | 19篇 |
2000年 | 12篇 |
1999年 | 24篇 |
1998年 | 50篇 |
1997年 | 59篇 |
1996年 | 54篇 |
1995年 | 44篇 |
1994年 | 33篇 |
1993年 | 35篇 |
1992年 | 14篇 |
1991年 | 12篇 |
1990年 | 13篇 |
1989年 | 30篇 |
1988年 | 24篇 |
1987年 | 23篇 |
1986年 | 22篇 |
1985年 | 10篇 |
1984年 | 12篇 |
1983年 | 4篇 |
1982年 | 12篇 |
1981年 | 12篇 |
1980年 | 11篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 15篇 |
1976年 | 14篇 |
1975年 | 4篇 |
1958年 | 4篇 |
排序方式: 共有1311条查询结果,搜索用时 218 毫秒
21.
Fatty acid balance studies in term infants fed formula milk containing long-chain polyunsaturated fatty acids 总被引:1,自引:0,他引:1
C Morgan L Davies F Corcoran J Stammers J Colley SA Spencer D Hull 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(2):136-142
Long-chain polyunsaturated fatty acids (LCP) are thought to be required for optimal nervous system development in the newborn. A commercial milk formula containing LCP (Aptamil-LCP) with a fatty acid profile closely resembling breast milk, has recently been introduced for term infants. The absorption of fatty acids in term infants was examined in a double-blind randomized controlled trial comparing Aptamil-LCP ( n = 20) and standard Aptamil ( n = 20). Formula-fed newborn infants were studied from birth for 14 d. Fat balances (3 d) were performed from d 10. A 3-d stool collection was performed from d 10 in a parallel breastfed group ( n = 21). Plasma samples were taken on d 6. Median fat excretion (mg kg−1 ) was 897.1, 615.0 and 355.2 with Aptamil, Aptamil-LCP and breastfeeding, respectively. The median total fat absorption coefficient in Aptamil-LCP-fed infants was higher than in those fed standard Aptamil ( p < 0:01). These findings were accounted for by differences in the excretion and absorption of long-chain saturated fatty acids (C14:0, C16:0 and C18:0). Higher fat excretion was associated with bulkier and firmer stools. Only trace amounts of LCP were detected in the stools of all groups. This accounted for less than 4% of dietary intake in Aptamil-LCP-fed infants. No differences in the utilization of LCP from Aptamil-LCP and breast milk feeding were apparent. Plasma phospholipid fatty acid composition data reflected differences in dietary LCP intake. Thus, PL LCP levels were highest in the breastfed infants and lowest in the Aptamil-fed infants, with values for the Aptamil-LCP-fed group falling in between. 相似文献
22.
Characterization of the insulin-like growth factor axis in a human hepatoma cell line (PLC) 总被引:4,自引:0,他引:4
Scharf JG; Schmidt-Sandte W; Pahernik SA; Ramadori G; Braulke T; Hartmann H 《Carcinogenesis》1998,19(12):2121-2128
23.
24.
Muckle–Wells Cryopyrinopathy: Complex Phenotyping and Response to Therapy in a New Multiplex Kindred
Alexander P. Headley Frank Cordingley Phillip N. Hawkins D. Sean Riminton 《Inflammation》2014,37(2):396-401
Muckle–Wells syndrome (MWS) is a member of the cryopyrin-associated periodic syndrome family of auto-inflammatory diseases, originally described as a triad of urticaria, sensorineural deafness and amyloidosis. IL-1 blockade is a proven therapy for MWS. The clinical, laboratory and genotypic characteristics of a novel kindred of five individuals with Muckle–Wells syndrome are described. Response to IL-1 blockade therapy in the proband was evaluated. All five affected family members experienced symptoms of multi-organ inflammation. Lead time between symptom onset and diagnosis was approximately 30 years in the proband. Fever was not a universal feature in all affected family members. Anti-IL-1 therapy in the proband resulted in improvements in patient-reported symptoms, inflammatory markers, auditory acuity and reversal of her infertility. Muckle–Wells syndrome is a rare, multisystem, auto-inflammatory syndrome. Delay in diagnosis prevents effective treatment. We propose reversal of infertility to be among the potential benefits of IL-1 inhibition in this disease. 相似文献
25.
26.
Interactions between vascular endothelial cells and blood platelets have been investigated using a model microcirculation consisting of microcarrier beads colonized with human umbilical vein endothelial cells (HUVECs) and perfused with washed platelet suspensions. To simulate the effects of endothelial desquamation and exposure of subendothelium, fibrillar collagen in suspension was coinjected with the platelets. In this model, neither the passage of platelets alone nor collagen alone stimulated prostacyclin (PGI2) production by the HUVECs. Platelets activated by coinjection with collagen released thromboxane A2 (TXA2), and this was associated with the simultaneous production of PGI2 by the HUVECs. By means of double-isotope experiments with [3H]arachidonic acid (AA) incorporated into platelets and [14C]-AA into HUVECs, it was shown that all the PGI2 generated was derived from platelet AA and/or endoperoxides. This interpretation was strengthened by the finding that PGI2 production was not prevented by treatment of HUVECs with indomethacin followed by perfusion with collagen-stimulated platelets. AA metabolites in double-isotope label experiments were further characterized by reverse-phase chromatography, and it was shown that both cyclooxygenase and lipoxygenase products of the HUVECs were derived from platelet membrane lipid. Thrombin regularly produced transient PGI2 release, but showed rapid tachyphylaxis. Platelet-derived compounds including ADP, ATP, and platelet-activating factor (PAF) did not produce PGI2 release by HUVECs in this system. Thus, the transfer of AA and metabolites from collagen- stimulated platelets is likely to be the mechanism for PGI2 production in the context of minor degrees of endothelial desquamation. 相似文献
27.
N Senst M Llacuachaqui J Lubinski H Lynch S Armel S Neuhausen P Ghadirian P Sun SA Narod 《Clinical genetics》2013,84(1):43-46
The objective is to estimate the risk of breast cancer in women who carry a deleterious BRCA1 or BRCA2 mutation, according to parental origin of mutation. We conducted a cohort study of women with a BRCA1 mutation (n = 1523) or BRCA2 mutation (n = 369) who had not been diagnosed with breast or ovarian cancer. For each woman, the pedigree was reviewed and the origin of the mutation was assigned as probable paternal or maternal. The hazard ratio (HR) for developing breast cancer in the follow‐up period was estimated for women with a paternal mutation compared to a maternal mutation. The risk of breast cancer was modestly higher in women with a paternal BRCA1 mutation compared to women with a maternal BRCA1 mutation (HR = 1.46; 95% CI = 0.99–2.16) but the difference was not significant (p = 0.06). The parental mutation origin did not affect the risk in women with a BRCA2 mutation. Our results are consistent with the hypothesis that there is an increased risk of breast cancer among women with a paternally inherited BRCA1 mutation compared to a maternally inherited mutation. However, the data are not sufficiently compelling to justify different screening recommendations for the two subgroups. 相似文献
28.
MB Delatycki M Wolthuizen MA Aitken C Hickerton SA Metcalfe KJ Allen 《Clinical genetics》2013,84(3):286-289
Hereditary hemochromatosis (HH) is a common preventable disorder of iron overload that can result in liver cirrhosis and reduced lifespan. Most HH is due to homozygosity for the HFE p.C282Y substitution. We conducted a study of screening for p.C282Y in high schools where p.C282Y heterozygotes (CY) individuals were informed of their genotype by letter. We studied whether these individuals understood the implications of their genotype, whether this resulted in anxiety or reduced health perception and whether cascade testing was higher in families of CY than wild‐type homozygous (CC) individuals. We found 586 of 5757 (1 in 10) screened individuals were CY. One month after receiving their result, 83% correctly answered that they have one copy of p.C282Y. There was no adverse change in anxiety or health perception from prior to screening to 1 month after receiving results. Significantly more family members of CY individuals than CC individuals were informed about HH and had testing for HH. In conclusion, we found that informing CY individuals of their genotype does not increase anxiety and the implications are generally well understood. This leads to cascade testing in a minority of families. CY individuals should be informed of their genetic status when identified by population screening. 相似文献
29.
目的:对蒙药苏格木勒-3水提物进行化学成分研究,构建较为全面的化学成分谱,为苏格木勒-3水提物有效物质基础研究奠定基础。方法:采用超高液相色谱串联四级杆飞行时间质谱(UPLC-Q-TOF-MS)技术,使用ESI离子源,通过mzCloud与mzVoult软件以及质谱裂解规律,并结合对照品及相关文献资料比对进行定性分析。结果:经过分析,从蒙药苏格木勒-3水提物中共鉴定出42个成分,主要包括氨基酸、酚酸类、黄酮类、内酯类、生物碱类及其他类等6类成分,并对各成分的药材来源进行归属。结论:本研究全面、快速、准确地分析了蒙药苏格木勒-3水提物的化学成分,为其药效物质基础和质量控制等研究奠定了基础。 相似文献
30.
Molecular heterogeneity in acute leukemia lineage switch 总被引:1,自引:0,他引:1
Gagnon GA; Childs CC; LeMaistre A; Keating M; Cork A; Trujillo JM; Nellis K; Freireich E; Stass SA 《Blood》1989,74(6):2088-2095
Six cases of acute leukemia that underwent lineage switch from acute lymphocytic leukemia to acute myelogenous leukemia are reported. The mean age of the patients was 24 years, time to conversion was 36 months, and survival after conversion was only 3 months. Of the three cases which showed abnormal metaphases at both diagnosis and conversion, two (cases 2, 5) showed related cytogenetic abnormalities, and the third showed (case 3) independent chromosomal changes. Molecular analysis for immunoglobulin heavy chain and T-cell receptor beta chain genes showed that five of the six cases had rearrangement of at least one of these lymphoid associated genes at conversion to acute myelogenous leukemia. The single case (case 3) in which there were no lymphoid gene rearrangements at conversion was also the only case in which independent karyotypic abnormalities at diagnosis and conversion were demonstrated. Our findings suggest that lineage switch can represent either relapse of the original clone with heterogeneity at the molecular level or the emergence of a second new leukemic clone without molecular heterogeneity. 相似文献