全文获取类型
收费全文 | 64077篇 |
免费 | 3233篇 |
国内免费 | 231篇 |
专业分类
耳鼻咽喉 | 1318篇 |
儿科学 | 3333篇 |
妇产科学 | 1709篇 |
基础医学 | 6929篇 |
口腔科学 | 3059篇 |
临床医学 | 5296篇 |
内科学 | 12283篇 |
皮肤病学 | 1684篇 |
神经病学 | 4893篇 |
特种医学 | 2258篇 |
外国民族医学 | 3篇 |
外科学 | 11244篇 |
综合类 | 910篇 |
现状与发展 | 1篇 |
一般理论 | 26篇 |
预防医学 | 3526篇 |
眼科学 | 1762篇 |
药学 | 4144篇 |
4篇 | |
中国医学 | 435篇 |
肿瘤学 | 2724篇 |
出版年
2024年 | 73篇 |
2023年 | 578篇 |
2022年 | 670篇 |
2021年 | 1367篇 |
2020年 | 889篇 |
2019年 | 1195篇 |
2018年 | 1969篇 |
2017年 | 1511篇 |
2016年 | 1645篇 |
2015年 | 1520篇 |
2014年 | 1919篇 |
2013年 | 3012篇 |
2012年 | 4356篇 |
2011年 | 5018篇 |
2010年 | 2348篇 |
2009年 | 1483篇 |
2008年 | 3907篇 |
2007年 | 4348篇 |
2006年 | 4216篇 |
2005年 | 4341篇 |
2004年 | 4259篇 |
2003年 | 4076篇 |
2002年 | 3787篇 |
2001年 | 1819篇 |
2000年 | 1773篇 |
1999年 | 1180篇 |
1998年 | 485篇 |
1997年 | 397篇 |
1996年 | 354篇 |
1995年 | 256篇 |
1994年 | 209篇 |
1993年 | 171篇 |
1992年 | 222篇 |
1991年 | 188篇 |
1990年 | 173篇 |
1989年 | 157篇 |
1988年 | 128篇 |
1987年 | 121篇 |
1986年 | 125篇 |
1985年 | 119篇 |
1984年 | 102篇 |
1983年 | 95篇 |
1982年 | 97篇 |
1981年 | 77篇 |
1980年 | 69篇 |
1979年 | 79篇 |
1978年 | 69篇 |
1977年 | 65篇 |
1976年 | 61篇 |
1974年 | 50篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
A. Barutçu 《European journal of plastic surgery》1994,17(6):316-318
Summary Pedicled temporoparietal fascial flaps have been used extensively in head and neck reconstruction for many years. Also, the fascia has been grafted, and the skin graft transformed into a vascularized pedicled flap (prefabricated temporoparietal fasciocutaneous flap). On the other hand, some authors have used free temporoparietal fascial flaps for defects that require to be filled in lower and upper extremity wounds. In this case, a free prefabricated temporoparietal fascio-chondro-cutaneous flap having only an arterial inflow was used in eyelid reconstruction.Presented at the 14th Congress of Turkish Plastic and Reconstructive Surgery, Ankara, Turkey, October 1992 相似文献
83.
H Koyuncuo?lu Y Uresin Y Esin F Aricio?lu 《Pharmacology, biochemistry, and behavior》1992,43(2):479-482
Both morphine (M) and naloxone (NL) have been reported to have NMDA receptor blocking effects, regarded as the reason of opiate physical dependence development. On the other hand, glutamate (GLU) has been known to induce the contraction of isolated guinea pig ileum via acetylcholine release. Therefore, different concentrations of M or NL were investigated on the 1 mM GLU-induced contraction of isolated guinea pig ileum fixed at a resting tension of 1 g in isolated organ bath. The mean value (359.3 +/- 20 mg) of the GLU-elicited contraction force was significantly reduced (318.4 +/- 19.4) by 25 nM M concentration in the medium. Consequently, 500 and 750 nM M caused further decreases in a rather dose-dependent manner (270.8 +/- 17.4 and 167.8 +/- 16.5 mg, respectively). One micromolar M contraction nearly abolished (8.0 +/- 8.2 mg) the GLU-induced contraction. A similar effect was obtained with the naloxone concentrations of 10, 20, 40, and 50 microM. In addition, NL has been shown to elicit the contraction of the isolated M-dependent guinea pig ileum. In the present study, 20- and 30-microM NL concentrations in the bathing medium caused the contraction of the ileum made M-dependent by preincubation with M (333.0 +/- 32.4 and 309.5 +/- 17.7 mg, respectively). These contraction forces were significantly reduced when the NL concentration was increased to 40 microM. And, 50 microM NL concentration not only failed to induce contraction but caused a relaxation (-10.6 +/- 2.3) as well. The results were considered supporting evidence for the fact that both M and NL are NMDA receptor blockers.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
84.
We have performed this technique bilaterally on 39 patients with chronic subluxation and 13 patients with recurrent dislocation since 1985 and have had good results with patient satisfaction. These patients had significantly higher articular eminences than normal control individuals. Also, we have used echography as a new application of an old technique, to evaluate the patients objectively in the preoperative and postoperative periods. 相似文献
85.
S. Doğru-Abbasoğlu G. Aykaç-Toker H. A. Hanagasi H. Gürvit M. Emre M. Uysal 《Neurological sciences》2007,28(1):31-34
Abstract Alzheimer's disease (AD) is defined pathologically by the presence of β-amyloid plaques, neurofibrillary tangles and extensive
neuronal loss. Evidence indicates that increased DNA damage may contribute to neuronal loss in AD. Recently, it has been shown
that in AD neurons have a reduced capacity for some types of DNA repair. Polymorphisms in DNA repair genes may be associated
with differences in repair efficiency of DNA damage. Variants of several DNA repair genes, including the base excision repair
gene XRCC1, have been described previously. We hypothesised that Arg194Trp polymorphism of XRCC1 gene may contribute to genetic susceptibility for AD. In order to test this hypothesis, we investigated
Arg194Trp polymorphism at the XRCC1 gene in the DNA samples of 98 patients with AD and 95 healthy subjects. The frequency of the Trp allele was more pronounced among cases (11.2%) compared with controls (5.8%). On combining the homozygous and heterozygous
variants of each codon, the variants seemed to be at twofold risk of AD, although the risk estimates were not statistically
significant (OR=1.95, 95% CI 0.88–4.34, p=0.09). In addition, the 194Trp allele revealed a borderline significance (OR=2.05, 95% CI 0.96–4.37, p=0.056). According to our results, it may be speculated that the polymorphic variants of XRCC1 codon 194 have a role in the
development of AD. 相似文献
86.
87.
Jean-Luc Dubois Jean-François Trani 《ALTER. European Journal of Disability research, Journal europeen de recherche sur le handicap》2009,3(3):192-218
Amartya Sen looks at people's well-being in terms of functioning and freedom, rather than in terms of the amount of goods or services consumed. The capability approach, developed by Sen, deals with what people are able to achieve by using these commodities. Concerning disability, he wrote: “We must take note that a disabled person may not be able to do the many things that an able-bodied individual can, with the same bundle of commodities” [Sen, A. K. (1985). Commodities and capabilities. Oxford: Oxford University Press [1999], p. 7]. The capability approach makes it possible to analyse the economic situation of people with disabilities in a different way. What becomes important is their functioning, i.e. what they are able to achieve within a given context. In fact, the capability set includes not only what a person is effectively able to achieve, but also the potential functionings that he/she can choose. This expresses the degree of freedom that a person with disability benefits from in a given environment. The challenge is therefore to reduce the constraints that the environment adds to a person's impairment in order to expand their capability set and to allow them to live a life which they value. This paper reviews the paradigms that address disability and the ways of assessing a person's capability set within this framework. Achieved functionings are easily measured through cross-sectional surveys, using counterfactual analysis to compare the situations of disabled and non-disabled people. This was done in 2005 in Afghanistan when a national disability survey was carried out on a random sample of households. Measuring detailed capabilities, especially their freedom dimension, is quite complex and requires identifying people's potential choices in an ever-changing environment. This implies a need to extend the philosophical framework and to adopt appropriate statistical methodologies. 相似文献
88.
L Abbaso?lu F Gün F T Salman A Celik A Unüvar O G?rgün 《Zeitschrift für Kinderchirurgie》2003,13(4):236-239
The role of surgery in intraabdominal Burkitt's lymphoma remains controversial and different opinions are present in the literature. In our institution, forty patients (30 boys and 10 girls) with intraabdominal Burkitt's lymphoma with ages ranging from 3 to 12 years have been treated and followed from 1989 through 2000. In ten cases, the patients underwent surgery because of their acute abdominal diseases (intestinal obstruction in 5, intussusception in 3, intestinal perforation in one, and acute appendicitis in one). The remaining thirty patients were referred to our clinic because of their abdominal masses, pain, anorexia and fatigue. Twelve children had localized tumors and total resection could be performed. There was one death in this group due to central nervous system involvement during chemotherapy. In the remaining 28 children, extensive intraabdominal diseases were detected. In four of them, debulking procedures were performed, while in 24 children only biopsies could be made; 8 of them underwent a second-look operation. In the debulking procedures group, two children were lost (50 %) due to tumorlysis and acute renal failure. In the biopsy group, there were six deaths (25 %). All patients received chemotherapy after operative recovery. In conclusion, our results suggest that when the tumor is localized, total resection results in a good outcome. However, in the presence of extensive intraabdominal diseases instead of resection, the operation should be limited to biopsy only. 相似文献
89.
Naz M. Aghatabay A. Ba A. Kircali G. en M.B. Yaziciolu F. Gücin B. Dülger 《European journal of medicinal chemistry》2009,44(11):4681-4689
Series of new mixed aza-oxo-thia macrocyclic ligands 1,9(2,6)-ditriazina-2,8,10,16-tetraaza-3,7,11,15-tetraoxo-5,13-dithia-cyclohexadecaphan-14,94-diphenyl (L1); 1,10(2,6)-ditri azina-2,9,11,18-tetraaza-3,8,12,17-tetraoxo-5,6,14,15-tetrathia-cyclooctadecaphan-14,104-diphenyl (L2); 1,11(2,6)-ditriazina-2,10,12,20-tetraaza-3,9,13,19-tetraoxo-6,16-dithia-cyclocosa-phan-14,114-diphenyl (L3); 1,12(2,6)-ditriazina-2,11,13,22-tetraaza-3,10,14,21-tetraoxo-6,7,17,18-tetrathia-cyclodocosaphan-14,124-diphenyl (L4) were synthesised. The structural features of the compounds have been studied by elemental analyses, Mass, FT-Raman, FT-IR, 1H and 13C NMR spectroscopy. The antimicrobial activities of the ligands were evaluated using disk diffusion method in dimethyl sulfoxide (DMSO) as well as the minimal inhibitory concentration (MIC) dilution method, against several bacteria and yeast cultures. The obtained results from both methods were assessed in side-by-side comparison with commercial antibacterial and antifungal agents. In most cases, the compounds show strong antifungal activity in the comparison tests. Cytotoxic activities of the ligands against two different human cancer cell lines, stomach (23132/87) and lung (A549) were determined by MTT assay. DNA fragmentation assay tested cell lines were used to analyze the DNA ladder formation which is a characteristic of apoptotic cell death. The binding of the ligands with calf thymus DNA (CT-DNA) has also been investigated by absorption spectroscopy. 相似文献
90.