全文获取类型
收费全文 | 795篇 |
免费 | 41篇 |
国内免费 | 77篇 |
专业分类
儿科学 | 37篇 |
妇产科学 | 16篇 |
基础医学 | 83篇 |
口腔科学 | 18篇 |
临床医学 | 120篇 |
内科学 | 227篇 |
皮肤病学 | 44篇 |
神经病学 | 17篇 |
特种医学 | 103篇 |
外科学 | 70篇 |
综合类 | 32篇 |
预防医学 | 35篇 |
眼科学 | 5篇 |
药学 | 79篇 |
1篇 | |
中国医学 | 1篇 |
肿瘤学 | 25篇 |
出版年
2022年 | 9篇 |
2021年 | 10篇 |
2020年 | 10篇 |
2019年 | 13篇 |
2018年 | 23篇 |
2017年 | 14篇 |
2016年 | 9篇 |
2015年 | 24篇 |
2014年 | 19篇 |
2013年 | 14篇 |
2012年 | 23篇 |
2011年 | 28篇 |
2010年 | 23篇 |
2009年 | 16篇 |
2008年 | 19篇 |
2007年 | 79篇 |
2006年 | 27篇 |
2005年 | 25篇 |
2004年 | 13篇 |
2003年 | 9篇 |
2002年 | 5篇 |
2001年 | 11篇 |
2000年 | 17篇 |
1999年 | 17篇 |
1998年 | 24篇 |
1997年 | 34篇 |
1996年 | 26篇 |
1995年 | 27篇 |
1994年 | 24篇 |
1993年 | 19篇 |
1992年 | 18篇 |
1991年 | 19篇 |
1990年 | 29篇 |
1989年 | 18篇 |
1988年 | 22篇 |
1987年 | 20篇 |
1986年 | 24篇 |
1985年 | 25篇 |
1984年 | 8篇 |
1983年 | 8篇 |
1982年 | 15篇 |
1981年 | 15篇 |
1980年 | 9篇 |
1979年 | 5篇 |
1978年 | 12篇 |
1977年 | 8篇 |
1976年 | 8篇 |
1975年 | 8篇 |
1973年 | 5篇 |
1966年 | 5篇 |
排序方式: 共有913条查询结果,搜索用时 421 毫秒
1.
2.
K Thomsen B J Riis J S Johansen C Christiansen P R?dbro 《Gynecological endocrinology》1987,1(2):169-175
Bone turnover before and after withdrawal of estrogen/gestagen treatment was studied in a randomized trial with 110 healthy female volunteers, who had passed a natural menopause 6 months to 3 years before the start of the study. Urinary excretion of intravenously injected 99m-technetium diphosphonate was measured as an index of bone turnover; plasma bone Gla protein and serum alkaline phosphatase were measured as indices of bone formation; and fasting urinary excretion of hydroxyproline and calcium were measured as estimates of bone resorption. During 2 years of hormone treatment, all variables decreased highly significantly (p less than 0.001) to a constant low level. Three months after withdrawal all variables increased highly significantly (p less than 0.001) towards, but not above, pretreatment and placebo levels. We conclude that withdrawal of estrogen/gestagen replacement therapy in postmenopausal women increases bone turnover, but not in excess of pretreatment values. This indicates that bone loss (after withdrawal) is similar to that seen in the placebo group and that a rebound phenomenon is unlikely. 相似文献
3.
4.
5.
Conservative treatment for acute rupture of the Achilles tendon 总被引:1,自引:0,他引:1
Summary Sixty-six patients with acute ruptures of the Achilles tendon were treated by immobilisation in a plaster cast for 12 weeks. Fifty-seven were followed up for a mean time of 70 months. Four re-ruptures occurred shortly after the initial treatment. Most patients had no or only slight complaints, three had moderate and one severe, problems. The activity level dropped slightly from 5.3 to 5.03 (Tegner score). The results are satisfactory with a low complication rate. The method is an alternative to operative repair, especially in patients declining operation and in those in whom operation or anaesthesia is contraindicated.
Résumé Soixante-six malades ont fait l'objet d'une étude à long terme concernant le traitement non-chirurgical des ruptures aiguës du tendon d'Achille. Le recul moyen était de 70 mois. Les patients avaient été immobilisés dans un plâtre pendant 12 semaines. 4 ruptures itératives survinrent précocément (6%). La plupart des malades n'avaient pas ou peu de séquelles, trois seulement se plaignaient d'une gêne modérée et 1 d'une gêne importante. Le niveau d'activité avait légérement diminué, de 5.3 à 5.03 (selon le score de Tegner). Les résultats paraissaient satisfaisants dans l'ensemble, avec une taux peu élevé de ruptures itératives ou d'autres complications. La méthode constitue une alternative valable au traitement chirurgical, notamment chez les sujets qui ne veulent pas être opérés ou chez ceux qui présentent des contrindications à l'anesthésie ou à la chirurgie.相似文献
6.
Kundel HL; Gefter W; Aronchick J; Miller W Jr; Hatabu H; Whitfill CH; Miller W Sr 《Radiology》1997,205(3):859
7.
P Riis 《Journal of medical ethics》1991,17(1):41
The complex of cultural, political and societal affiliations, both in a historic and a contemporary perspective, is expressed by a special term in the Nordic languages, 'faellesskab', often with the addition of 'folkelig', as 'folkeligt faellesskab', where 'folkelig' means of the people. No corresponding term exists in English. For medical ethics the concept 'faellesskab', or whatever wording is chosen to serve the semantics of this term, is vital. In research ethics and clinical decision-making complex ethical analyses and normative evaluations are necessary. They cannot be based solely on moral relativism, whether being based on results of opinion polls or on a widespread 'every man minds his own business' concept. 'Faellesskab' possesses the necessary base of common values. 相似文献
8.
CTLA-4 is required for the induction of high dose oral tolerance 总被引:5,自引:3,他引:5
Samoilova EB; Horton JL; Zhang H; Khoury SJ; Weiner HL; Chen Y 《International immunology》1998,10(4):491-498
Mucosal and systemic administrations of high dose antigens induce long-
lasting peripheral T cell tolerance. We and others have shown that high
dose peripheral T cell tolerance is mediated by anergy or deletion and is
preceded by T cell activation. Co-stimulatory molecules B7-1 (CD80)/B7-2
(CD86) and their counter-receptors CD28/CTLA-4 play pivotal roles in T cell
activation and immune regulation. In the present study, we examined the
roles of the B7 co-stimulation pathway in the generation of high dose
peripheral T cell tolerance. We found that blocking B7:CD28/CTLA-4
interaction at the time of tolerance induction partially prevented T cell
tolerance, whereas selective blockade of B7:CTLA-4 interaction completely
abrogated peripheral T cell tolerance induced by either oral or i.p.
antigens. These results suggest that CTLA-4-mediated feedback regulation
plays a crucial role in the induction of high dose peripheral T cell
tolerance.
相似文献
9.
Molecular genetic characterization of XRCC4 function 总被引:2,自引:0,他引:2
XRCC4 is a generally expressed protein of 334 amino acids that is involved
in the repair of DNA double-strand breaks and in V(D)J recombination, but
its function is unknown. In this study, we have used a mutational approach
and the yeast two-hybrid method to perform an initial characterization of
this protein. We show that the XRCC4 protein is located in the nucleus. We
also demonstrate that several potential phosphorylation sites are not
required for XRCC4 function in a transient V(D)J recombination assay. In
addition, we show that XRCC4 forms a homodimer in vivo with the
homodimerization domain being located within amino acids 115-204. Finally,
we define a core domain of XRCC4 that functions in V(D)J recombination and
comprises amino acids 18-204. Potential functions of XRCC4 are discussed.
相似文献
10.
Liu JQ; Bai XF; Shi FD; Xiao BG; Li HL; Levi M; Mustafa M; Wahren B; Link H 《International immunology》1998,10(8):1139-1148
Induction of mucosal tolerance by inhalation of soluble peptides with
defined T cell epitopes is receiving much attention as a means of
specifically down-regulating pathogenic T cell reactivities in autoimmune
and allergic disorders. Experimental autoimmune encephalomyelitis (EAE)
induced in the Lewis rat by immunization with myelin basic protein (MBP)
and Freund's adjuvant (CFA) is mediated by CD4+ T cells specific for the
MBP amino acid sequences 68-86 and 87-99. To further define the principles
of nasal tolerance induction, we generated three different MBP peptides
(MBP 68-86, 87-99 and the non- encephalitogenic peptide 110-128), and
evaluated whether their nasal administration on day -11, -10, -9, -8 and -7
prior to immunization with guinea pig MBP (gp-MBP) + CFA confers protection
to Lewis rat EAE. Protection was achieved with the encephalitogenic
peptides MBP 68-86 and 87-99, MBP 68-86 being more potent, but not with MBP
110-128. Neither MBP 68-86 nor 87-99 at doses used conferred complete
protection to gp-MBP-induced EAE. In contrast, nasal administration of a
mixture of MBP 68-86 and 87-99 completely blocked gp-MBP-induced EAE even
at lower dosage compared to that being used for individual peptides. Rats
tolerized with MBP 68-86 + 87-99 nasally showed decreased T cell responses
to MBP reflected by lymphocyte proliferation and IFN-gamma ELISPOT assays.
Rats tolerized with MBP 68-86 + 87-99 also had abrogated MBP-reactive
IFN-gamma and tumor necrosis factor-alpha mRNA expression in lymph node
cells compared to rats receiving MBP 110-128 nasally, while similar low
levels of MBP-reactive transforming growth factor-beta and IL-4 mRNA
expressing cells were observed in the two groups. Nasal administration of
MBP 68-86 + 87-99 only slightly inhibited guinea pig spinal cord
homogenate-induced EAE, and passive transfer of spleen mononuclear cells
from MBP 68-86 + 87-99-tolerized rats did not protect naive rats from EAE.
Finally, we show that nasal administration of MBP 68-86 + 87-99 can reverse
ongoing EAE induced with gp-MBP, although higher doses are required
compared to the dosage needed for prevention. In conclusion, nasal
administration of encephalitogenic MBP peptides can induce antigen-specific
T cell tolerance and confer incomplete protection to gp-MBP-induced EAE,
and MBP 68-86 and 87-99 have synergistic effects. Non-regulatory mechanisms
are proposed to be responsible for tolerance development after nasal
peptide administration.
相似文献