全文获取类型
收费全文 | 174367篇 |
免费 | 7932篇 |
国内免费 | 556篇 |
专业分类
耳鼻咽喉 | 2469篇 |
儿科学 | 5769篇 |
妇产科学 | 4693篇 |
基础医学 | 23851篇 |
口腔科学 | 4884篇 |
临床医学 | 11715篇 |
内科学 | 39870篇 |
皮肤病学 | 5681篇 |
神经病学 | 13974篇 |
特种医学 | 4372篇 |
外国民族医学 | 32篇 |
外科学 | 22218篇 |
综合类 | 995篇 |
一般理论 | 42篇 |
预防医学 | 17607篇 |
眼科学 | 3625篇 |
药学 | 12569篇 |
2篇 | |
中国医学 | 559篇 |
肿瘤学 | 7928篇 |
出版年
2023年 | 946篇 |
2022年 | 1606篇 |
2021年 | 3802篇 |
2020年 | 2014篇 |
2019年 | 3725篇 |
2018年 | 5089篇 |
2017年 | 3232篇 |
2016年 | 3257篇 |
2015年 | 3601篇 |
2014年 | 4756篇 |
2013年 | 6952篇 |
2012年 | 10389篇 |
2011年 | 10757篇 |
2010年 | 5989篇 |
2009年 | 5153篇 |
2008年 | 8858篇 |
2007年 | 9311篇 |
2006年 | 9076篇 |
2005年 | 9077篇 |
2004年 | 8432篇 |
2003年 | 7794篇 |
2002年 | 7490篇 |
2001年 | 5403篇 |
2000年 | 5552篇 |
1999年 | 4640篇 |
1998年 | 1414篇 |
1997年 | 1080篇 |
1996年 | 1017篇 |
1995年 | 866篇 |
1994年 | 748篇 |
1992年 | 2312篇 |
1991年 | 2219篇 |
1990年 | 2060篇 |
1989年 | 1843篇 |
1988年 | 1683篇 |
1987年 | 1654篇 |
1986年 | 1547篇 |
1985年 | 1481篇 |
1984年 | 1095篇 |
1983年 | 936篇 |
1979年 | 1030篇 |
1978年 | 688篇 |
1975年 | 703篇 |
1974年 | 907篇 |
1973年 | 868篇 |
1972年 | 748篇 |
1971年 | 706篇 |
1970年 | 759篇 |
1969年 | 717篇 |
1968年 | 682篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
D-dimer has proved a useful diagnostic tool for the exclusion of deep venous thrombosis (DVT). The objective of this paper was to evaluate the diagnostic performance of a diagnostic algorithm combining clinical probability and D-dimer in outpatients receiving oral anticoagulant treatment (OAT) similar to those regularly applied to nonanticoagulated individuals. We enrolled 70 outpatients on OAT who presented with clinically suspected DVT; a standard diagnostic algorithm including clinical evaluation using the modified Wells score and a quantitative immunoturbidimetric D-dimer assay (STA Liatest D-Di; Diagnostica Stago, Asniéres sur Seine, France) was used. A 3-month follow-up period was applied for those patients in whom DVT was initially excluded. The prevalence of DVT was 18.5% (13/70); four of the diagnoses were made during the 3-month follow-up period. The sensitivity, specificity and negative predictive value of D-dimer were 69.2% (95 confidence interval, 42.4-87.3), 47.4% (95% confidence interval, 35.0-60.1) and 87.1% (95% confidence interval, 71.1-94.9), respectively. In conclusion, D-dimer is of limited value in outpatients on OAT presenting with clinically suspected DVT and should be omitted in such individuals; these patients should always undergo compression venous ultrasound, and repeat ultrasonography within 1 week might be warranted in cases with an initial negative examination. 相似文献
83.
A Parra F Gabi?o A Ramírez H Valencia I Coria A Espinosa de los Monteros 《Contraception》1991,44(5):541-547
The study was undertaken to analyze the basal and metoclopramide-stimulated serum PRL levels in healthy parous women users (group 1, n = 12) and non-users (group 2, n = 12) of a TCu-380 IUD. All women had regular menses and were studied between days 18 to 22 of their cycle; none had lactated nor regularly ingested any type of medication during the last six months. After a 10-12 hour overnight fast, peripheral venous blood samples were obtained through an indwelling catheter at -30, -15 and 0 minutes and at 60, 90 and 120 minutes after oral metoclopramide (10 mg). There were no significant differences in serum PRL between both groups, in basal levels nor throughout the test, whether analyzing the mean values at each sampling time, the sum of PRL levels from 60-120 minutes, or the peak levels. No correlation was observed between PRL levels and any of the clinical or obstetric characteristics of the women in both groups. Serum progesterone was greater than or equal to 4.0 ng/ml in all women. Thus, the use of alpha TCu-380 IUD did not induce any significant changes in basal nor in stimulated serum PRL levels. 相似文献
84.
A 59-year-old man developed dystonia and reflex sympathetic dystrophy after receiving high doses of ergotamine for migraine treatment. Ischemia is suggested as the precipitating factor. 相似文献
85.
J. M. Bellón N. García-Honduvilla N. Serrano M. Rodríguez G. Pascual J. Buján 《Hernia》2005,9(4):338-343
The component of a composite prosthesis, which makes contact with the visceral peritoneum, can be reabsorbable or non-reabsorbable,
and laminar or reticular. This study was designed to determine whether the composition of this second, barrier component could
improve its behavior at this interface. Abdominal wall defects in rabbits were repaired using a polypropylene prosthesis (PP),
or the composites Sepramesh (PP+h) or Vicryl (PP+v). Fourteen days after surgery, the implants were evaluated by light and
scanning electron microscopy, and immunohistochemistry. Prosthetic areas occupied by adhesions (PP: 71.08±5.09, PP+h: 18.55±4.96,
P+v: 69.69±16.81%), neoperitoneal thickness (PP: 256.17±21.68, PP+h: 83.11±19.63, PP+v:213.72±35.90 μm) and macrophage counts
(PP: 8.73±1.16, PP+h: 27.33±4.13, PP+v: 31.24±3.08%) showed significant differences (P<0.05). The tested biomaterials induced an optimal recipient tissue infiltration. Least adhesion formation was observed on
the PP+h implants. This suggests that the second component, although reabsorbable, should be smooth in structure. 相似文献
86.
87.
88.
Hyper-IgM syndrome with CHARGE association 总被引:1,自引:0,他引:1
Pilar Bahillo Teresa Cantero Pilar Solís Paz Aragón Samuel Gómez Rosario Cambronero 《Pediatric allergy and immunology》2003,14(6):487-489
A girl with coloboma of the iris, sensorineural deafness, growth delay, distinctive face, and cranial nerve dysfunction was diagnosed of CHARGE association in the first year of life. She presented with repeated otitis. At 3 yr of age, the patient suffered a septicemia ( Streptococcus pneumoniae , Corynebacterium sp.). The immunoglobulin G (IgG) and IgA serum levels were decreased, IgM increased and cellular immunity parameters were normal, supporting the diagnosis of hyper-IgM (HIM) syndrome. The sequence of CD40 ligand and cytidine deaminase genes were normal. From then on, she was receiving immunoglobulin intravenously with an excellent outcome . Here, we report the first case of CHARGE association and HIM syndrome in the same patient. Although the cause could not be identified, a non-random link is likely. 相似文献
89.
Jose M. Fernández-Cebrián Peter Vorwald Kuborn Mar Pardo de Lama Alfonso Sanjuanbenito Dehesa Manuel Nevado Santos Pedro A. Pacheco Martínez Beatriz Fernández-Escudero 《Clinical & translational oncology》2005,7(3):101-109
Colorectal cancer is one of the best studied of all malignant diseases interms of genetics and/or molecular prognostic factors. These factors, and relationships with prognosis, may have important implications especially in the design of surgical and adjuvant chemo-radiotherapy options. However, the true prognostic significance of all known factors has yet to be realised. We have reviewed the literature with specific focus on the role of molecular markers involved in prognosis and the prediction of response to adjuvant treatment. 相似文献
90.
The present study was performed in order to follow the response of astroglial cells in the rat hippocampus to chronic low-level lead exposure. The experiments combined immunohistochemistry using anti-glial fibrillary acidic protein (GFAP) antibody and conventional transmission electron microscopy (EM). Chronic administration with drinking water [1 g% w/v (subclinical dose) of lead acetate dissolved in distilled water] was started through the mother's milk when pups were 7 days old. Following weaning, experimental offspring were treated for 3 months with the same concentration of adulterated water. The group of intoxicated animals and their controls were sacrificed by perfusion-fixation at 30, 60, and 90 days of exposure. After 60 days of lead treatment, staining of GFAP-positive cells demonstrated an astroglial transformation from the quiescent to the reactive state, characterized by an increase in GFAP. In control rats no changes in GFAP immunostaining were observed. The intensity of the astroglial response was enhanced after 90 days of lead intoxication, showing an increment of GFAP immunoreactivity. Quantification of these changes was made by computerized image analysis, confirming that the sectional areas of the astroglia in lead-exposed animals were larger than those in controls. These results are consistent with the ultrastructural alterations. Simultaneously with the increment in gliofilaments, intranuclear inclusions were seen in some astrocytes. The mechanisms by which lead affects astrocytes are unknown. Probably the astroglial changes induced by lead intoxication produce microenvironmental modifications that may disturb the neuronal function. 相似文献