全文获取类型
收费全文 | 215487篇 |
免费 | 3121篇 |
国内免费 | 168篇 |
专业分类
耳鼻咽喉 | 1697篇 |
儿科学 | 8971篇 |
妇产科学 | 3683篇 |
基础医学 | 21238篇 |
口腔科学 | 2694篇 |
临床医学 | 15283篇 |
内科学 | 38535篇 |
皮肤病学 | 1822篇 |
神经病学 | 18810篇 |
特种医学 | 10085篇 |
外科学 | 34675篇 |
综合类 | 3613篇 |
一般理论 | 18篇 |
预防医学 | 19999篇 |
眼科学 | 4267篇 |
药学 | 13462篇 |
1篇 | |
中国医学 | 985篇 |
肿瘤学 | 18938篇 |
出版年
2023年 | 363篇 |
2022年 | 1037篇 |
2021年 | 1757篇 |
2020年 | 985篇 |
2019年 | 1126篇 |
2018年 | 23116篇 |
2017年 | 18143篇 |
2016年 | 20663篇 |
2015年 | 2289篇 |
2014年 | 2865篇 |
2013年 | 3125篇 |
2012年 | 10182篇 |
2011年 | 23985篇 |
2010年 | 20540篇 |
2009年 | 12879篇 |
2008年 | 21503篇 |
2007年 | 23738篇 |
2006年 | 2565篇 |
2005年 | 3909篇 |
2004年 | 5000篇 |
2003年 | 5704篇 |
2002年 | 3650篇 |
2001年 | 1054篇 |
2000年 | 1125篇 |
1999年 | 752篇 |
1998年 | 472篇 |
1997年 | 419篇 |
1996年 | 317篇 |
1995年 | 291篇 |
1994年 | 262篇 |
1993年 | 192篇 |
1992年 | 393篇 |
1991年 | 421篇 |
1990年 | 480篇 |
1989年 | 410篇 |
1988年 | 339篇 |
1987年 | 281篇 |
1986年 | 259篇 |
1985年 | 256篇 |
1984年 | 192篇 |
1983年 | 148篇 |
1982年 | 95篇 |
1981年 | 79篇 |
1980年 | 111篇 |
1979年 | 113篇 |
1978年 | 81篇 |
1977年 | 92篇 |
1976年 | 75篇 |
1974年 | 73篇 |
1970年 | 67篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
This study investigates whether tissue recoil or patient intrinsic factors influence the final position of the nipple areola
complex (NAC) after reduction mammoplasty.
The age, pre-operative ptosis, BMI and weight of the tissue resected were recorded as patient intrinsic factors in 37 patients
undergoing reduction mammoplasty. The “spring-back” value was defined as the distance from the sternal notch to a nipple landmark
on the breast meridian with the patient sitting up, minus the same measurement repeated with the patient recumbent to eliminate
the pull of gravity on the breast. Spring back was measured pre-operatively for the nipple and nipple mark then post-operative
for the nipple. The difference in centimeters between the final post-operative distance from the sternal notch to the nipple
and the level intended by the pre-operative nipple mark was termed the “judgment error.” The final position of the post-operative
nipple and the judgment error was compared to the spring-back values and patient intrinsic factors.
Pre-operative ptosis was statistically related to increasing patient BMI and mass of tissue resected per breast. Pre-operative
spring-back values for the nipple increased with increasing ptosis, BMI and decreasing age. Spring-back values were greater
in the lower pole of the breast than in the upper pole. The final position of the nipple was higher than the pre-operative
mark in 65% of cases, lower in 8% and as marked in 27% of cases. The post-operative NAC was, on average, 0.6 cm higher than
planned pre-operatively. The post-operative distance from the sternal notch to the nipple increased with increasing pre-operative
ptosis, mass of breast tissue resected per breast and all three spring-back values. The difference between the level of the
pre-operative mark and the final nipple position showed a weak correlation with post-operative spring-back values.
The parameters of ptosis, BMI, weight of tissue resected per breast and pre-operative nipple spring back reflect body habitus
and breast size. Spring-back values vary between the upper and lower pole of the breast. The final NAC position was higher
than that intended at pre-operative marking in the majority of cases. The surgeon instinctively marks the nipple lower in
patients with greater pre-operative ptosis and in whom a larger resection is anticipated. Judgment error did not relate to
intrinsic factors nor to pre-operative spring-back values; hence, these parameters cannot be applied as predictive tools for
more accurate pre-operative marking of the nipple position. This study suggests that the pre-operative nipple mark should
be placed, with the patient sitting up, at least 23 cm from the sternal notch and 0.6 cm lower than the final position estimated
using the inframammary crease as a landmark.
An invited commentary on this paper is available at . 相似文献
42.
43.
Jamshid Shirani Jagat Narula William C. Eckelman Navneet Narula Vasken Dilsizian 《Journal of nuclear cardiology》2007,14(1):100-110
Conclusions Noninvasive imaging of neurohumoral upregulation in remodeled myocardium suggests that an imaging strategy can be developed
for predicting the rate of remodeling and likelihood of HF development. This should allow a more judicious use of neurohumoral
antagonists especially in subjects who do not have manifest HF.74 In others specific targeted imaging may allow timely selection of individualized treatment strategies and ensure optimization
of therapeutic intervention. Similar to ACE and AII receptors, multiple other targets in the hormonal cascades can identify
the likelihood of adverse and favorable remodeling.74 相似文献
44.
45.
The present study reveals our experience in the medical management of 30 cases of progressive/malignant exophthalmos, employing costicosteroid, b-blocker, diuretic and a preparation containing proteolytic enzymes. There was encouraging improvement in terms of symptoms, proptosis and optic nerve compression, while reduction of ophthalmoplegia was not so satisfactory. However, none of the patients needed decompression surgery. 相似文献
46.
Restriction maps of the rDNA cistron of twelve species of mosquitoes in six genera of the subfamily Culicinae were constructed using eight 6 bp recognition restriction enzymes. Anopheles albimanus was used as an outgroup. The size of the rDNA cistron ranged from 8.5 kb in Aedes katherinensis to 12.9 kb in Ae. polynesiensis. A total of twenty-six sites were scored; eighteen were polymorphic among ingroup taxa. The proportion of polymorphic nucleotide sites (Pnuc) was 0.059 and the heterozygosity per nucleotide site (Hnuc) was 0.028. Wagner and Fitch Parsimony, Dollo Parsimony and Nei-Li distance/neighbour-joining methods were used to construct phylogenetic trees. The rDNA RFLP dataset did not provide a well-supported phylogeny among culicine taxa. The RFLP phylogenies are incongruent with the morphology character based and molecular phylogenies and derived relationships did not correspond with current taxonomic classifications. The lack of resolution was due to homoplasy arising from frequent independent loss or gain of restriction sites among unrelated taxa. 相似文献
47.
A retrospective longitudinal study of 105 penetrating keratoplasties for vascularized corneal opacities was done. The results of cases with an etiology of healed trachoma or healed corneal ulcers were compared. The vascularization was graded from Grade I to V depending on the quadrant and type of vascularization. Graft clarity of 2+ or more in cases of trachomatous opacity was achieved in 93% of cases and that after postinfectious opacity in 71.8%. Prognosis was poor in cases where deep vascularization was present in more than two quadrants or more than 180 degrees. 相似文献
48.
M S Sachdev H Kumar A K RoopJain R Arora V K Dada 《Indian journal of ophthalmology》1990,38(4):184-186
A case of destructive ocular myiasis resulting in complete loss of the globe in two days time is documented. To the best of our knowledge this is the first report of such a severe involvement in a healthy and non-compromised host. Mechanical removal and good local hygiene helped heal the wound. The larvae were isolated to be that of Chrysomyia bezziana (screwworm fly). This is possibly the first report of destructive ocular myiasis caused by Chrysomyia bezziana from the Indian subcontinent and the second in world literature. Infestation of human eyes with larvae of flies (myiasis) has been reported. Serious consequences of destructive myiasis are seen in emaciated and diseased patients. Only one report of total destruction of the globe by maggots of Chrysomyia bezziana exists in the literature. As in previous communications, the patient in this report had no predisposing factors both systemic and local. We here in document a case of orbital myiasis leading to rapid destruction of the globe within two days in a healthy and a non-compromised patient. 相似文献
49.
50.
Volker Heinemann 《Breast cancer research and treatment》2003,81(1):43-48
Single-agent chemotherapy of metastatic breast cancer is the treatment of choice in patients with slow tumor progression and asymptomatic disease. In this patient group, the choice of drugs is based more on good tolerability than on efficacy. By contrast, symptomatic or rapidly progressing disease requires the use of highly active regimens where more weight is put on reliable antitumor activity. While anthraycline-based combination regimens have set the standard of effective treatment, the addition of docetaxel (and to a lesser extent paclitaxel) has improved tumor response, but failed to induce a consistent prolongation of survival. Based on retrospective analyses, it is hypothesised that the combined use of anthracyclines and taxanes in first-line therapy may be most beneficial in defined subgroups: after adjuvant chemotherapy, in patients with HER-2 gene amplification, possibly also in patients with rapidly progressing visceral disease. 相似文献