全文获取类型
收费全文 | 2057篇 |
免费 | 215篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 104篇 |
妇产科学 | 28篇 |
基础医学 | 269篇 |
口腔科学 | 39篇 |
临床医学 | 185篇 |
内科学 | 539篇 |
皮肤病学 | 28篇 |
神经病学 | 93篇 |
特种医学 | 300篇 |
外科学 | 125篇 |
综合类 | 55篇 |
预防医学 | 163篇 |
眼科学 | 161篇 |
药学 | 115篇 |
中国医学 | 1篇 |
肿瘤学 | 69篇 |
出版年
2021年 | 16篇 |
2019年 | 15篇 |
2018年 | 21篇 |
2017年 | 26篇 |
2016年 | 22篇 |
2015年 | 27篇 |
2014年 | 37篇 |
2013年 | 48篇 |
2012年 | 51篇 |
2011年 | 43篇 |
2010年 | 64篇 |
2009年 | 64篇 |
2008年 | 77篇 |
2007年 | 80篇 |
2006年 | 86篇 |
2005年 | 69篇 |
2004年 | 77篇 |
2003年 | 75篇 |
2002年 | 51篇 |
2001年 | 47篇 |
2000年 | 38篇 |
1999年 | 45篇 |
1998年 | 63篇 |
1997年 | 81篇 |
1996年 | 63篇 |
1995年 | 56篇 |
1994年 | 65篇 |
1993年 | 59篇 |
1992年 | 46篇 |
1991年 | 42篇 |
1990年 | 51篇 |
1989年 | 56篇 |
1988年 | 60篇 |
1987年 | 47篇 |
1986年 | 56篇 |
1985年 | 47篇 |
1984年 | 20篇 |
1983年 | 33篇 |
1982年 | 25篇 |
1981年 | 31篇 |
1980年 | 31篇 |
1979年 | 17篇 |
1978年 | 21篇 |
1977年 | 31篇 |
1976年 | 27篇 |
1975年 | 31篇 |
1973年 | 19篇 |
1972年 | 16篇 |
1971年 | 15篇 |
1970年 | 14篇 |
排序方式: 共有2276条查询结果,搜索用时 15 毫秒
31.
Critical care family needs in an urban teaching medical center 总被引:4,自引:0,他引:4
32.
33.
J. V. Forrester G. R. Sutherland M. McDonald 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》1977,204(2):101-112
Summary Vitreous haemorrhages were induced in rabbits and the echographic appearances on A and B scan were correlated with the gross and histologic appearances over a period of twenty weeks. In all cases, visible vitreous opacities produced distinct echo patterns. As the haemorrhages cleared, the echo amplitudes became progressively weaker. Several patterns of vitreous membranes on B scan were also observed. Pathological examination revealed that such membranes were composed of red cells, macrophages and condensed vitreous collagen. It is suggested that haematogenous vitreous membranes of this type are readily diagnosed by combined A- and B-scan ultrasonic examination, and are probably amenable to surgery. 相似文献
34.
Marrow regeneration after mechanical depletion 总被引:1,自引:0,他引:1
The origin of marrow regeneration after mechanical depletion was reinvestigated in mouse chimeras. The results were compatible with the local origin of stem cells from remnants of incompletely removed marrow, but not with their origin from a common precursor of both bone and hemopoietic cell lines. In transplanted femurs depleted by a modified technique of in vivo evacuation of marrow, hemopoietic regeneration failed to occur. The presence of hemopoietic stem cells in the Haversian canals was thus excluded. The demonstration of ample hemopoiesis with minimal bone formation in nondepleted controls in which bone marrow initially became necrotic provided new evidence that osteogenesis was not a prerequisite of hemopoietic regeneration. 相似文献
35.
JE McMICHAEL 《Journal of paediatrics and child health》1997,33(1):1-3
An understanding of the neurodevelopmental outcome of long-term survivors of neonatal intensive care is essential for the informed management of preterm or high risk infants. This annotation looks at the current status of neonatal follow-up services in Australasia and highlights problems in the collection and interpretation of data. It suggests that we should work towards achieving a consensus on standard definitions and test regimes and on national data collection. 相似文献
36.
L Patel PE Clayton ME Jenney JE Ferguson TJ David 《Archives of disease in childhood》1997,76(6):505-508
Cross sectional studies have reported impaired growth in children with atopic dermatitis. If this growth impairment is irreversible, it would be expected to adversely influence final height attainment. The standing heights and other anthropometric parameters were assessed in 35 adults with onset of atopic dermatitis before 5 years of age and a control group of 35 adults with adult onset contact dermatitis or psoriasis. There was no significant difference in the standing height SD score, mid-parental height SD score, sitting height SD score, subischial leg length SD score, nor body mass index between the atopic dermatitis and control groups. The standing height SD score was not significantly different among: (a) patients with atopic dermatitis affecting less than 50% of their body surface area and those with greater than 50% affected; (b) patients using the four different potency topical corticosteroids; and (c) patients with atopic dermatitis without asthma and those with coexisting asthma. It is concluded that short stature is not a feature of our group of adult patients with onset of atopic dermatitis before 5 years of age, continuing into adulthood, and severe enough to require specialist care. This suggests that if growth impairment occurs in childhood, it is likely to be temporary and reversible. 相似文献
37.
Dietary polyamines promote the growth of azoxymethane-induced aberrant crypt foci in rat colon 总被引:1,自引:1,他引:1
We have examined whether dietary polyamines influence the formation and
initial growth of azoxymethane (AOM)-induced aberrant crypt foci (ACF) in
rat colon. Effects of a combination of dietary polyamines at three dose
levels (putrescine: 50, 280, 740 nmol/g; spermidine: 10, 261, 763 nmol/g;
spermine: 1, 31, 91 nmol/g) in the polyamine-poor AIN-76A diet were studied
in animals in two different experimental situations: animals treated with
AOM alone and animals treated with AOM + difluoromethylornithine (DFMO), a
specific inhibitor of endogenous polyamine synthesis. In both experimental
situations, dietary polyamines enhanced the growth of ACF, expressed as the
number of large ACF (foci with three or more aberrant crypts, ACF > or =
3), whereas the formation of ACF, expressed as the number of ACF, was
apparently not altered. In animals treated with AOM alone, maximal growth
enhancing effect on ACF was nearly obtained with the median level of
dietary polyamine. In rats fed a low polyamine diet, basic AIN-76A, DFMO
reduced the growth of AOM-induced ACF by 83%. This inhibitory effect of
DFMO was counteracted by dietary polyamines in a dose- dependent manner,
and it was abolished at the highest level of polyamines. In conclusion, it
was demonstrated that dietary polyamines are able to enhance the growth of
AOM-induced ACF. Further, dietary polyamines reversed the DFMO-caused
inhibition of ACF growth, probably by compensating for the DFMO-reduced
endogenous polyamine synthesis.
相似文献
38.
Hansen LA; Malarkey DE; Wilkinson JE; Rosenberg M; Woychik RE; Tennant RW 《Carcinogenesis》1998,19(10):1837-1845
We previously reported that papillomas can arise from the follicular
epithelium of v-Ha-ras transgenic TGxAC mice. Since the viable-yellow
mutation (A(vy)) of the mouse agouti gene which regulates coat color
pigmentation by acting within the micro-environment of the hair follicle
has been shown to function as a tumor promoter in the liver, we
hypothesized that it may also play a role in TGxAC skin tumorigenesis.
Endogenous agouti protein product was detected in the outer root sheath of
anagen hair follicles following plucking of the hair shaft, but not in the
interfollicular epithelium, in TGxAC mice on an FVB/N genetic background.
It was also detected in papillomas from these mice produced by
12-O-tetradecanoylphorbol-13-acetate (TPA) treatment or plucking.
Expression of the A(vy) allele in the v-Ha-ras transgenic TGxAC mouse line
results in an approximately 2-fold increase in papilloma development
compared with controls which did not carry the A(vy) allele following
twice-weekly treatment with 1.25, 2.5 or 5.0 microg TPA. In addition,
TPA-treated, papilloma-bearing F1 mice which carried the A(vy) allele, but
not F1 mice which did not carry the A(vy) allele, exhibited a syndrome of
humoral hypercalcemia mediated by parathyroid hormone-related protein
(PTHrP) that led to weight loss, hypercalcemia and hypophosphatemia. Thus,
we conclude that the A(vy) allele can influence the development of skin
tumors and PTHrP-mediated humoral hypercalcemia in v-Ha-ras transgenic
TGxAC mice.
相似文献
39.
40.
Rudolf L. Roddy James S. Forrester Harold Landow 《American journal of obstetrics and gynecology》1939,37(6):1037-1040
An outbreak of infectious diarrhea of undiscovered etiology, affecting 14 of 28 infants in a hospital nursery for the newborn, is reported. No deaths occurred. A method of management is described, by which the addition of new susceptibles to the infected group is avoided, without interruption of the maternity service. 相似文献