全文获取类型
收费全文 | 1783篇 |
免费 | 134篇 |
国内免费 | 44篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 90篇 |
妇产科学 | 19篇 |
基础医学 | 111篇 |
口腔科学 | 35篇 |
临床医学 | 189篇 |
内科学 | 251篇 |
皮肤病学 | 33篇 |
神经病学 | 75篇 |
特种医学 | 163篇 |
外科学 | 121篇 |
综合类 | 232篇 |
一般理论 | 1篇 |
预防医学 | 165篇 |
眼科学 | 14篇 |
药学 | 252篇 |
中国医学 | 76篇 |
肿瘤学 | 126篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 15篇 |
2021年 | 35篇 |
2020年 | 29篇 |
2019年 | 17篇 |
2018年 | 42篇 |
2017年 | 36篇 |
2016年 | 29篇 |
2015年 | 48篇 |
2014年 | 67篇 |
2013年 | 90篇 |
2012年 | 123篇 |
2011年 | 133篇 |
2010年 | 99篇 |
2009年 | 107篇 |
2008年 | 130篇 |
2007年 | 115篇 |
2006年 | 79篇 |
2005年 | 79篇 |
2004年 | 64篇 |
2003年 | 57篇 |
2002年 | 61篇 |
2001年 | 44篇 |
2000年 | 38篇 |
1999年 | 29篇 |
1998年 | 26篇 |
1997年 | 30篇 |
1996年 | 26篇 |
1995年 | 19篇 |
1994年 | 13篇 |
1993年 | 14篇 |
1992年 | 11篇 |
1991年 | 25篇 |
1990年 | 15篇 |
1989年 | 22篇 |
1988年 | 20篇 |
1987年 | 17篇 |
1986年 | 14篇 |
1985年 | 16篇 |
1984年 | 10篇 |
1983年 | 10篇 |
1982年 | 11篇 |
1981年 | 14篇 |
1980年 | 29篇 |
1979年 | 12篇 |
1978年 | 8篇 |
1977年 | 8篇 |
1976年 | 5篇 |
1975年 | 7篇 |
排序方式: 共有1961条查询结果,搜索用时 15 毫秒
1.
HA Carpay P Matthijsse M Steinbuch PGH Mulde 《Cephalalgia : an international journal of headache》1997,17(5):591-595
In an open, randomized cross-over study in 124 patients, we compared the efficacy, safety and patient preference of oral and subcutaneous sum triptan in the acute treatment of migraine. Patients were treated for 3 attacks or 3 months and then crossed over. Primary clinical efficacy was defined as a reduction in headache severity on a four-point self-rating scale from severe (3) or moderate (2) to mild (1) or none (0), or mild (1) to none (0). Efficacy was evaluated 2 h after the administration of subcutaneous and 4h after the administration of oral sumatriptan. Subcutaneous sumatriptan was significantly more effective than oral sumatriptan in relieving headache (over all three attacks 78% vs 61% improvement), improving clinical disability (55% vs 41 % improvement) and relieving nausea (69% vs 53%), vomiting (72% vs 32%) and phono- or photophobia (67% vs 49%). Median time to recurrence was shorter after subcutaneous (12.5 h) than after oral sumatriptan (18 h); the number of patients experiencing a recurrence was similar Patients reported more adverse events after subcutaneous sumatriptan (1.32 per attack) than after the oral form (0.85 per attack), but all adverse events were mild to moderate in intensity and of short duration. Patient opinion was more often positive after subcutaneous sumatriptan. These results may be useful in counselling patients to choose between the available marketed formulations of sumatriptan. 相似文献
2.
3.
J M G?tz A J Nielander P J Brouwers C H ten Napel 《Nederlands tijdschrift voor geneeskunde》1992,136(33):1611-1613
Transfusion-associated symptomatic HIV infection in four patients led to death in two patients and to development of serious neurological sequelae in a third patient who also transmitted HIV infection to his spouse. The tardy diagnosis of HIV-associated disease in all cases can be ascribed to ignoring the earlier blood transfusion as a possible cause of HIV infection. This was due partly to advanced age of the patients and partly to lack of familiarity of the attending physicians with HIV-associated problems. This resulted in a substantial doctor's delay. 相似文献
4.
5.
超细β-磷酸三钙/聚-L-乳酸复合材料的制备与骨折内固定器的加工 总被引:3,自引:0,他引:3
目的:制备分散性良好的超细β-磷酸三钙(β-TCP)/聚-L-乳酸(PLLA)复合材料及新型可吸收骨折内固定器。方法:通过研磨方法制备β-TCP超细粒子,用一缩二乙二醇作分散剂研磨β-TCP后,再将β-TCP与PLLA超声混合,制得复合材料,经注塑加工制成可吸收骨钉,并采用扫描电镜等方法进行表征。结果与结论:用一缩二乙二醇作分散剂研磨β-TCP后再经超声混合,可以使β-TCP超细粒子在复合材料中分散均匀,粒子大小仅为300nm左右,β-TCP与PLlA基体之间结合良好。超细β-TCP/PLLA复合材料可加工成可吸收骨钉,弯曲强度达到100MPa左右,完全满足松质骨内固定的要求。 相似文献
6.
MN Tabrizi† C Chams-Davatchi† N Esmaeeli† P Noormohammadpoor† F Safar† H Etemadzadeh† HA Ettehadi‡ F Gorouhi† 《Journal of the European Academy of Dermatology and Venereology》2007,21(1):79-84
BACKGROUND: Pemphigus vulgaris (PV) is a severe blistering disease involving the skin and mucous membranes. The most common causes of death in these patients are adverse effects of drugs, and infection. Skin lesions are one of the important sources of infection. Thus, any local treatment that could reduce healing time of lesions and consequently reduce the total dosage of drugs needed to treat is favourable. OBJECTIVE: To evaluate the efficacy of epidermal growth factor (EGF) in reducing healing time of lesions in patients with pemphigus vulgaris. METHODS: In this randomized, double-blind, within-patient, left/right, controlled trial, 20 hospitalized patients with pathologial and immunohistologial (direct and indirect immunoflourecence) proven pemphigus vulgaris (PV) were chosen. In addition, all patients had at least one appropriate pemphigus lesion on each side of the body that had not healed after 2-week systemic therapy and sterile saline washing. EGF (10 microg/g) in 0.1% silver sulfadiazine cream vs. 0.1% silver sulfadiazine cream alone was applied randomly on one side of the body. RESULTS: Kaplan-Meier survival analysis suggested that median time to heal with application of EGF plus silver sulfadiazine cream was 9 days, in comparison with 15 days for silver sulfadiazine cream alone (log-rank test, P=0.0003). No intervention-related adverse effect was observed during the study. CONCLUSIONS: EGF can significantly reduce healing time of skin lesions in patients with pemphigus vulgaris, at least when this cream base is applied (Cochrane skin group identifier: CSG20). 相似文献
7.
Androgen receptor YAC transgenic mice carrying CAG 45 alleles show trinucleotide repeat instability 总被引:1,自引:15,他引:1
La Spada AR; Peterson KR; Meadows SA; McClain ME; Jeng G; Chmelar RS; Haugen HA; Chen K; Singer MJ; Moore D; Trask BJ; Fischbeck KH; Clegg CH; McKnight GS 《Human molecular genetics》1998,7(6):959-967
X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG
repeat expansion in the first exon of the androgen receptor (AR) gene.
Disease-associated alleles (37-66 CAGs) change in length when transmitted
from parents to offspring, with a significantly greater tendency to shift
size when inherited paternally. As transgenic mice carrying human AR cDNAs
with 45 and 66 CAG repeats do not display repeat instability, we attempted
to model trinucleotide repeat instability by generating transgenic mice
with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions
in their genomic context. Studies of independent lines of AR YAC transgenic
mice with CAG 45 alleles reveal intergenerational instability at an overall
rate of approximately 10%. We also find that the 45 CAG repeat tracts are
significantly more unstable with maternal transmission and as the
transmitting mother ages. Of all the CAG/CTG repeat transgenic mice
produced to date the AR YAC CAG 45 mice are unstable with the smallest
trinucleotide repeat mutations, suggesting that the length threshold for
repeat instability in the mouse may be lowered by including the appropriate
flanking human DNA sequences. By sequence-tagged site content analysis and
long range mapping we determined that one unstable transgenic line has
integrated an approximately 70 kb segment of the AR locus due to
fragmentation of the AR YAC. Identification of the cis - acting elements
that permit CAG tract instability and the trans -acting factors that
modulate repeat instability in the AR YAC CAG 45 mice may provide insights
into the molecular basis of trinucleotide repeat instability in humans.
相似文献
8.
Neulen J; Raczek S; Pogorzelski M; Grunwald K; Yeo TK; Dvorak HF; Weich HA; Breckwoldt M 《Molecular human reproduction》1998,4(3):203-206
Vascularization is a prominent event during corpus luteum formation,
providing low density lipoproteins for steroid biosynthesis and enabling
transport of secreted steroids. The process of vascularization is
controlled by specific regulators. Vascular endothelial growth factor
(VEGF), otherwise named vascular permeability factor (VPF), induces
endothelial cell proliferation as well as angiogenesis in vivo and
increases capillary permeability. Here we report the expression of VEGF/VPF
mRNA by cultured human luteinized granulosa cells (GC) for at least 10
days. Without HCG VEGF/VPF expression declined after day 4 and by day 10
was reduced to approximately 30% of the value at day 4. However, after
culture in the presence of 1 U/ml human chorionic gonadotrophin (HCG),
expression of VEGF/VPF mRNA by GC was four times greater than control
experiments by day 10, and increased 100% from day 4 to day 10.
Simultaneously, HCG supplementation increased VEGF/VPF secretion by GC.
Medium VEGF/VPF on day 3 was 13 pM without and 11 pM with HCG. Medium
VEGF/VPF on day 10 was 6 pM without HCG and 29 pM with HCG. These results
suggest that vascularization of the corpus luteum is induced by
HCG-mediated effects of VEGF/VPF.
相似文献
9.
蒙药毛勒日—达布斯—4汤中微量元素及氨基酸含量的测定 总被引:1,自引:0,他引:1
目的:测定蒙药毛勒日-达布斯-4汤中微量元素和氨基酸的含量。方法:用原子吸收分光光度计,测定蒙药毛勒日-达布斯-4汤中几种重要的微量元素含量;用氨基酸自动分析仪测定氨基酸的含量。结果与结论:蒙药毛勒日-达布斯-4汤中含有较高的Mn、Fe、Zn和Mg;含有17种氨基酸,包括7种人体必需氨基酸,氨基酸总量为4.615%(mg/g)。 相似文献
10.
Anne Sophie Kruit Kaj Brouwers Dominique van Midden Her Zegers Erik Koers Nens van Alfen Stefan Hummelink Dietmar J. O. Ulrich 《Transplant international》2021,34(2):365-375
The current standard for composite tissue preservation is static cold storage (SCS) and is limited to 6 h until irreversible muscle damage occurs. Extracorporeal perfusion (ECP) is a promising technique for prolonged preservation, however, functional results have been scarcely researched. This article assessed neuromuscular function and compared results to histological alterations to predict muscle damage after ECP. Forelimbs of twelve Dutch landrace pigs were amputated and preserved by 4 h SCS at 4–6 °C (n = 6) or 18 h mid-thermic ECP with University of Wisconsin solution (n = 6). Limbs were replanted and observed for 12 h. Sham surgery was performed on contralateral forelimbs (n = 12). Histology analysis scored four subgroups representing different alterations (higher score equals more damage). Muscle contraction after median nerve stimulation was comparable between ECP, SCS, and sham limbs (P = 0.193). Histology scores were higher in ECP limbs compared to SCS limbs (4.8 vs. 1.5, P = 0.013). This was mainly based on more oedema in these limbs. In-vivo muscle contraction was well preserved after 18 h ECP compared to short SCS, although histology seemed inferior in this group. Histology, therefore, did not correlate to muscle function at 12 h after replantation. This leads to the question whether histology or neuromuscular function is the best predictor for transplant success. 相似文献