全文获取类型
收费全文 | 22730篇 |
免费 | 2461篇 |
国内免费 | 50篇 |
专业分类
耳鼻咽喉 | 300篇 |
儿科学 | 866篇 |
妇产科学 | 566篇 |
基础医学 | 3489篇 |
口腔科学 | 347篇 |
临床医学 | 3007篇 |
内科学 | 4503篇 |
皮肤病学 | 414篇 |
神经病学 | 1808篇 |
特种医学 | 587篇 |
外科学 | 2556篇 |
综合类 | 526篇 |
一般理论 | 33篇 |
预防医学 | 2683篇 |
眼科学 | 320篇 |
药学 | 1704篇 |
中国医学 | 14篇 |
肿瘤学 | 1518篇 |
出版年
2023年 | 200篇 |
2022年 | 329篇 |
2021年 | 606篇 |
2020年 | 391篇 |
2019年 | 566篇 |
2018年 | 616篇 |
2017年 | 479篇 |
2016年 | 504篇 |
2015年 | 552篇 |
2014年 | 674篇 |
2013年 | 939篇 |
2012年 | 1376篇 |
2011年 | 1425篇 |
2010年 | 727篇 |
2009年 | 598篇 |
2008年 | 1021篇 |
2007年 | 1187篇 |
2006年 | 1041篇 |
2005年 | 1092篇 |
2004年 | 1021篇 |
2003年 | 941篇 |
2002年 | 914篇 |
2001年 | 529篇 |
2000年 | 575篇 |
1999年 | 515篇 |
1998年 | 247篇 |
1997年 | 212篇 |
1996年 | 203篇 |
1995年 | 199篇 |
1994年 | 179篇 |
1993年 | 166篇 |
1992年 | 397篇 |
1991年 | 371篇 |
1990年 | 357篇 |
1989年 | 349篇 |
1988年 | 286篇 |
1987年 | 298篇 |
1986年 | 278篇 |
1985年 | 297篇 |
1984年 | 212篇 |
1983年 | 180篇 |
1982年 | 151篇 |
1981年 | 115篇 |
1980年 | 112篇 |
1979年 | 219篇 |
1978年 | 146篇 |
1977年 | 112篇 |
1974年 | 121篇 |
1973年 | 109篇 |
1972年 | 111篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
Kirsty E Amos Shahram Anari Charlotte A Buswell Emma J McNeill Athanasia Printza Stephen J Ray Isam Rustom 《Annals of general psychiatry》2006,5(1):1-5
Background
The aim of the current study is to investigate the relationship between physical anhedonia and psychopathological parameters, pharmacological parameters or motor side-effects in a sample of inpatients with schizophrenia in an acute episode of their illness. 相似文献43.
Parvalbumin 3 is an Abundant Ca2+ Buffer in Hair Cells 总被引:3,自引:0,他引:3
Stefan Heller Andrea M. Bell Charlotte S. Denis Yong Choe A.J. Hudspeth 《Journal of the Association for Research in Otolaryngology》2002,3(4):488-498
Ca2+ signaling serves distinct purposes in different parts of a hair cell. The Ca2+ concentration in stereocilia regulates
adaptation and, through rapid transduction-channel reclosure, underlies amplification of mechanical signals. In presynaptic
active zones, Ca2+ mediates the exocytotic release of afferent neurotransmitter. At efferent synapses, Ca2+ activates the
K+ channels that dominate the inhibitory postsynaptic potential. A copious supply of diffusible protein buffer isolates the
three signals by restricting the spread of free Ca2+ and limiting the duration of its action. Using cDNA subtraction and a
gene expression assay based on in situ hybridization, we detected abundant expression of mRNAs encoding the Ca2+ buffer parvalbumin
3 in bullfrog saccular and chicken cochlear hair cells. We cloned cDNAs encoding this protein from the corresponding inner-ear
libraries and raised antisera against recombinant bullfrog parvalbumin 3. Immunohistochemical labeling indicated that parvalbumin
3 is a prominent Ca2+-binding protein in the compact, cylindrical hair cells of the bullfrog's sacculus, and occurs as well
in the narrow, peanut-shaped hair cells of that organ. Using quantitative Western blot analysis, we ascertained that the concentration
of parvalbumin 3 in saccular hair cells is approximately 3 mM. Parvalbumin 3 is therefore a significant mobile Ca2+ buffer,
and perhaps the dominant buffer, in many types of hair cell. Moreover, parvalbumin 3 provides an early marker for developing
hair cells in the frog, chicken, and zebrafish. 相似文献
44.
Ward J M Videler Volkert B Wreesmann Freerk W van der Meulen Paul P Knegt Wytske J Fokkens 《Otolaryngology--head and neck surgery》2006,134(4):586-591
OBJECTIVES: Endoscopic sinus surgery (ESS) is considered to be the golden standard for surgery in patients with chronic rhinosinusitis and nasal polyposis. However, there is still a small group of patients unresponsive despite repetitive surgery. Radical surgery aimed at reduction of the inflammatory burden and optimization of drainage of the sinuses has been suggested as a last resort for these patients. STUDY DESIGN: A prospective, questionnaire-based study was conducted in a group of 23 patients who underwent Denker's procedure for refractory chronic rhinosinusitis. Symptoms were evaluated before Denker's procedure and 12 months and 2 years after surgery. RESULTS: Patients reported improvement of feelings of congestion in 74%, rhinorrhea in 70%, and nasal obstruction in 60% of the cases. The following postoperative improvements were statistically significant: rhinorrhea (P = 0.001), feelings of congestion (P = 0.02), and nasal obstruction (P = 0.03). Reduced olfactory perception and asthma did not improve. CONCLUSION: Radical surgery may be a viable treatment option in case of recurrent ESS failure. EBM rating: C-4. 相似文献
45.
Kathleen A. Ward Sinead A. McKernan Natalina N. Durnien Wallace W. Dinsmore 《Journal of the European Academy of Dermatology and Venereology》1995,4(2):160-165
Objective Detection of HPV DNA in oral and genital lesions of a heterosexual male. 4 months after oral and vaginal intercourse with a woman with vulvar warts. Passible modes of acquisition of oral HPV infection in the male sexual partner are discussed. Setting Genitourinary Medicine clinic. Methods Polymerase chain reaction amplification of genomic DNA from oral and genital lesions. HPV DNA typing by dot blot hybridization. Results HPV DNA types 6 and 11 were identified in a polypoid tongue lesion and in a penile wart from the male sexual partner. Conclusions The acquisition of oral HPV infection in the male sexual partner may have resulted from genital-oral HPV transfer, either by direct contact with vulvar warts or by digital self-inoculation. 相似文献
46.
Indications and results of relaxing retinotomy 总被引:8,自引:0,他引:8
The authors report their results of a consecutive series of 40 eyes undergoing relaxing retinotomy during vitrectomy to achieve retinal reattachment for the following indications: proliferative vitreoretinopathy (PVR), 21 eyes (52%); trauma, 10 eyes (25%); diabetic retinopathy, 6 eyes (15%); and expulsive choroidal hemorrhage, 3 eyes (8%). Thirty eyes (75%) had undergone previous vitreoretinal procedures. Extended tamponade was achieved in all cases with either silicone oil (27 eyes, 68%) or long-acting gas (13 eyes, 32%). Retinotomy size ranged from 45 degrees to 360 degrees. Intraoperative retinal attachment was possible in all eyes with 33 (83%) achieving total or subtotal retinal attachment including the macula for 5 months or more. Twenty-seven eyes (68%) achieved 3/200 visual acuity or better and 10 (37%) achieved 20/400 or better. Thirteen eyes (32%) failed to achieve 3/200 visual acuity secondary to recurrent detachment (18%), corneal decompensation (8%), macular dysfunction (5%), and glaucoma (3%). 相似文献
47.
48.
49.
The affinity of morphine, normorphine, methadone, Tyr-D-Ala-Gly-MePhe-NH(CH2)2(N-O)(CH3)2 (RX 783030), [D-Ala2,D-Leu5]enkephalin (DADLE), ketazocine and ethylketocyclazocine (EKC) were determined for their pharmacological receptors in two bioassay tissues, the guinea-pig ileum and the mouse vas deferens (MVD). The method involved the use of the irreversible antagonist, beta-chlornaltrexamine (beta-CNA), and the method of partial receptor blockade. The agonist concentration-effect curves were displaced to the right with decreasing maximum effect, a pattern typical of partial, irreversible blockade of receptors. The concentrations of beta-CNA required to produce a rightward displacement in the concentration-effect curves for different agonists, ranged between 2 and 3000 nM. No similarity was found between the IC50 and the dissociation constant (KA), values predicted to be equivalent only if a linear relationship exists between receptor occupation and observed effect; the dissociation constant for the agonists were between 3 and 218 times larger than the IC50 values. When methadone was used as the agonist in the guinea-pig ileum, beta-CNA produced parallel displacement of the concentration-effect curve, regardless of the blocking concentration chosen, preventing the determination of KA for this agonist, in this tissue; this problem was not encountered in the mouse vas deferens. The KA of morphine, RX 783030 and ketazocine were found not to differ in the guinea-pig ileum and mouse vas deferens. As expected, DADLE had significantly different affinity in the two tissues, showing 117-fold lower affinity in the guinea-pig ileum. Surprisingly, the normorphine affinity was found to be 7-fold higher in the guinea-pig ileum. While the difference in affinity of DADLE may be due to the suggested lack of functional delta receptors in the guinea-pig ileum, the difference in affinity seen with normorphine, but not morphine, in the two tissues is difficult to explain. Taken together with the insensitivity of methadone to beta-CNA blockade in the guinea-pig ileum, but not mouse vas deferens, the difference in the affinity of normorphine in these tissues may suggest the possibility of differences in local milieu of mu receptors or of mu receptor subtypes in the two tissues. The results provide fundamental information regarding opioid agonist affinity in two standard bioassays in vitro, and support the view of (1) a difference in receptors activated by DADLE in the guinea-pig ileum (mu) and mouse vas deferens (delta), as well as (2) possible differences in mu-receptors in these tissues. 相似文献
50.