全文获取类型
收费全文 | 25580篇 |
免费 | 2094篇 |
国内免费 | 737篇 |
专业分类
耳鼻咽喉 | 195篇 |
儿科学 | 707篇 |
妇产科学 | 3680篇 |
基础医学 | 3005篇 |
口腔科学 | 265篇 |
临床医学 | 1915篇 |
内科学 | 1419篇 |
皮肤病学 | 253篇 |
神经病学 | 694篇 |
特种医学 | 1124篇 |
外国民族医学 | 20篇 |
外科学 | 2148篇 |
综合类 | 3777篇 |
现状与发展 | 4篇 |
预防医学 | 903篇 |
眼科学 | 158篇 |
药学 | 1300篇 |
18篇 | |
中国医学 | 633篇 |
肿瘤学 | 6193篇 |
出版年
2024年 | 71篇 |
2023年 | 380篇 |
2022年 | 789篇 |
2021年 | 1100篇 |
2020年 | 907篇 |
2019年 | 796篇 |
2018年 | 757篇 |
2017年 | 927篇 |
2016年 | 1027篇 |
2015年 | 1012篇 |
2014年 | 1661篇 |
2013年 | 1797篇 |
2012年 | 1389篇 |
2011年 | 1432篇 |
2010年 | 1173篇 |
2009年 | 1107篇 |
2008年 | 1259篇 |
2007年 | 1213篇 |
2006年 | 1215篇 |
2005年 | 1065篇 |
2004年 | 867篇 |
2003年 | 754篇 |
2002年 | 634篇 |
2001年 | 567篇 |
2000年 | 496篇 |
1999年 | 385篇 |
1998年 | 368篇 |
1997年 | 324篇 |
1996年 | 339篇 |
1995年 | 300篇 |
1994年 | 288篇 |
1993年 | 213篇 |
1992年 | 194篇 |
1991年 | 194篇 |
1990年 | 158篇 |
1989年 | 143篇 |
1988年 | 128篇 |
1987年 | 102篇 |
1986年 | 103篇 |
1985年 | 117篇 |
1984年 | 116篇 |
1983年 | 70篇 |
1982年 | 85篇 |
1981年 | 94篇 |
1980年 | 76篇 |
1979年 | 69篇 |
1978年 | 48篇 |
1977年 | 43篇 |
1976年 | 33篇 |
1975年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Infantile myofibromatosis is a mesenchymal tumor most commonly seen in infancy. The tumors have a variable appearance on
CT/MR and often simulate a more aggressive neoplasm. This report describes CT/MR findings in cases of infantile myofibromatosis
with pathologic correlation. Discussion into the success of imaging in suggesting the correct diagnosis is also addressed.
Infantile myofibromatosis is a mesenchymal disorder of infancy characterized by the presence of tumorous nodules in the skin,
subcutaneous tissue, muscle, viscera, and bone. Cases of solitary and multiple lesions have been described. We present the
clinical, histologic, and radiographic findings of one case of the solitary form of infantile myofibromatosis that was recently
diagnosed at our hospital. 相似文献
22.
Akio Tanaka Motoyoshi Okamoto Dai Yoshizawa Shigeru Ito Patricia González Alva Fumio Ide Kaoru Kusama 《Journal of oral pathology & medicine》2007,36(7):400-404
BACKGROUND: Although it has been reported that ghost cells are present in odontomas, the generation mechanism of these cells is unclear. To evaluate the presence of ghost cells and involvement of the Wnt signaling pathway, we examined the expression of hard keratins, beta-catenin and Lef-1 in odontomas. METHODS: Sixty-nine cases of odontoma were examined immunohistochemically with the use of antibodies against human hair proteins, beta-catenin and Lef-1. RESULTS: Expression of hard keratins was found only in the cytoplasm of ghost cells in 46 (66.7%) of the 69 odontomas. Compound odontomas (78.8%) showed a higher incidence of ghost cells than complex odontomas (29.4%). Histopathologically, ghost cells were found within odontogenic epithelium adjacent to immature enamel and in the centre of Liesegang-ring-like calcified materials. Expression of beta-catenin and Lef-1 was observed in the cytoplasm and nucleus of odontogenic epithelial cells adjacent to the ghost cells in immature odontomas. CONCLUSION: These findings suggest that odontoma is a hard keratin-expressing tumor-like lesion, and that the Wnt signaling pathway may be involved in the formation of ghost cells in odontomas. 相似文献
23.
目的:提高对小儿早期睾丸卵黄囊瘤的诊断与治疗水平。方法:回顾性分析12例小儿早期睾丸卵黄囊瘤的病例资料。结果:12例患者术前行阴囊B超示睾丸增大,内部回声不均匀,7例可见睾丸内积液改变;甲胎蛋白(AFP)值均明显升高。12例均行根治性睾丸切除术,术后行病理检查确诊。术前、术后均未行化疗,9例随诊5年未见复发,2002年就诊的3例目前未见复发症状。结论:小儿早期睾丸卵黄囊瘤可根据相关检查结果,结合病理检查确诊。治疗方法为行根治性睾丸切除,可不作化疗,预后较好。 相似文献
24.
Karen G. Louie Thomas C. Hamilton Robert H. Shoemaker Robert C. Young Robert F. Ozols 《Investigational new drugs》1992,10(2):73-78
Summary Five compounds which were identified as potential new anticancer drugs inin vitro screening with the human tumor colony forming assay were selected for further evaluation usingin vitro andin vivo models of human ovarian cancer. Three of five compounds were found to inhibitin vitro colony formation of ovarian cancer cell lines derived from both untreated and combination chemotherapy refractory patients. One compound was also found to prolong survival in a human ovarian carcinoma xenograft model system. This compound, chloroquinoxaline sulfonamide, was selected for development and has shown preliminary indication of activity in phase I clinical testing. 相似文献
25.
A. Jouvet E. Derrington J. Pialat C. Lapras M. Fèvre-Montange R. Besançon M. F. Belin G. Saint-Pierre 《Acta neuropathologica》1994,88(4):334-348
We have studied 20 pineal parenchymal tumors (PPT) and 4 normal or cystic pineal glands both by light and electron microscopy and immunohistochemistry with antibodies against glial markers [glial fibrillary acidic protein (GFAP) and protein S-100] or neural/neuroendocrine markers [neurofilaments (NF), synaptophysin and chromogranin A]. Light microscopy revealed the cellular organization of pinealocytes in the normal gland and in different morphological types of pineal tumors (typical pineocytomas, PPT with intermediate differentiation, mixed PPT exhibiting elements of both pineocytoma and pineoblastoma and pineoblastomas). Immunohistochemistry showed the presence of GFAP and protein S-100 in interstitial cells in nonneoplastic pineal gland. Cell processes were labeled with anti-synaptophysin and anti-NF antibodies. No immunoreactivity was found for chromogranin A in non-neoplastic pineal gland. In pineocytomas, GFAP and protein S-100 were observed in interstitial cells. Synaptophysin and NF were present in the large rosettes of pineocytomas. Synaptophysin, NF and chromogranin A were present in pineocytomas with a lobular arrangement of cells. Anti-chromogranin A immuno-reactivity was also seen in lobular areas of some PPT with intermediate differentiation. Analysis of normal human pineal gland by electron microscopy showed the presence of vesicle-crowned rodlets (VCR or synaptic ribbons), fibrous filaments (F), paired twisted filaments but few dense-core vesicles (DCV) in normal pinealocytes. Tumoral pineal cells appeared to differentiate either towards a neurosensory pathway characterized by the presence of sensory cells elements (VCR and F), or towards a neuroendocrine pathway, with the occurrence of many DCV. Immunogold labeling demonstrated the presence of chromogranin A in neurosecretory granules.Supported by grants from the Région Rhône Alpes and from INSERM (CJF 90-10) 相似文献
26.
Timo Laatikainen Henri Kurunmäki Aarne Koskimies 《Journal of assisted reproduction and genetics》1988,5(1):14-17
Of 70 cycles stimulated with clomiphene and human menopausal gonadotropin (hMG) for an in vitro fertilization-embryo transfer (IVF-ET) program, a short luteal phase of 11 days or less was found in 18. In this group the mean estradiol and progesterone levels were elevated in the early luteal phase. Despite the elevated initial values, progesterone levels fell rapidly at the mid luteal phase as a sign of premature luteolysis. The mean total amount of gonadotropin administered and the mean number of follicles punctured and of oocytes recovered did not show any significant difference between the groups of normal and short luteal phases. The present findings support the theory that hyperestrogenism in the early luteal phase may initiate the premature luteolysis observed in clomiphene-menopausal gonadotropin-stimulated cycles. 相似文献
27.
60 intracranial tumors have been studied immunohistochemically to determine the proliferation rate by staining for the monoclonal antibody KI-67, which recognizes a nuclear antigen expressed by cells in proliferation. In gliomas a clear correlation of stained nuclei to the histologically determined degree of malignancy was found: slow growing astrocytomas and oligodendrogliomas had an average proliferation rate of 1%, more malignant forms of 7–10%. Glioblastomas were found to have a growth fraction of 15%. Metastases had an even higher rate of 20% proliferating cells. In meningiomas the proliferation rate was mainly about 1%, but in three cases it was between 5% and 7%. Whether this is indicative for a higher risk of tumor recurrence, remains to be correlated to the clinical course. Hemangiopericytomas had a proliferation rate of 9% and 16%, respectively, the latter recurring within four months. It may be concluded from the results of this study, that investigation of intracranial tumors with KI 67 may be of prognostic value and can possibly contribute to an individualized tumor therapy. 相似文献
28.
Gianaroli L.; Ferraretti A.P.; Feliciani E.; Tabanelli C.; Magli C.; Fortini D. 《Human reproduction (Oxford, England)》1994,9(2):220-225
In a prospective, controlled, randomized study where two differentagonists were used, we compared three different long desensitizationprotocols for induction of multiple follicular growth in medicallyassisted conception cycles. In protocol A, 30 patients wereinjected with buserelin twice a day for 15 days prior to ovarianstimulation until human chorionic gonadotrophin (HCG) administration.In protocol B, 30 patients were injected with a single doseof long acting Triptorelin (3.75mg) 15 days before the ovarianstimulation onset. In protocol C, 30 patients were injectedwith the long acting Triptorelin 4 weeks before ovarian stimulationfollowed by daily administration of 0.1 mg of the same agonistuntil HCG injection. There was no difference in the ovarianresponse to exogenous gonadotrophin stimulation, except forthe presence of premature luteinization in two patients in groupB. A significantly higher number of mature oocytes was collectedfrom patients with protocol A; however, the fertilization andcleavage rate demonstrated no significant difference among thethree groups of patients. The ongoing pregnancy rate and theimplanation rate per treatment cycle were very similar in thethree study groups. When the convenience, cost and side-effectsfor the patient are being considered, protocol B should be selectedas the first choice when the agonist is utilized for the purposeof inducing pituitary desensitization before and during ovarianstimulation. 相似文献
29.
Fluid-fluid levels in cavernous hemangioma of soft tissue 总被引:3,自引:0,他引:3
Shigeru Ehara M.D. Miyuki Sone Yoshiharu Tamakawa Jun Nishida Masataka Abe Junichi Hachiya 《Skeletal radiology》1994,23(2):107-109
Five cases of cavernous hemangioma with fluid-fluid levels on magnetic resonance imaging and/or computed tomography are reported. The signal characteristics were those of blood and histological analysis of the fluid-fluid levels showed that they were blood-filled cavities in the tumor. Although this finding itself is not specific, it may help in confirming the diagnosis of cavernous hemangioma. 相似文献
30.
S Lipitz Z Ben-Rafael D Bider J Shalev S Mashiach 《Human reproduction (Oxford, England)》1991,6(10):1478-1479
A patient who suffered from polycystic ovarian disease and anovulation, was treated with pure follicle stimulating hormone for induction of ovulation. The treatment was stopped and human chorionic gonadotrophin was not administered because of high serum oestradiol levels and multiple follicular development. Ovulation occurred 11 days after pure follicle stimulating hormone was discontinued, the patient developed third-degree ovarian hyperstimulation syndrome and conceived with a quintuplet pregnancy. 相似文献