全文获取类型
收费全文 | 48232篇 |
免费 | 2577篇 |
国内免费 | 132篇 |
专业分类
耳鼻咽喉 | 764篇 |
儿科学 | 2015篇 |
妇产科学 | 846篇 |
基础医学 | 6176篇 |
口腔科学 | 1161篇 |
临床医学 | 3121篇 |
内科学 | 11363篇 |
皮肤病学 | 1575篇 |
神经病学 | 4122篇 |
特种医学 | 1334篇 |
外科学 | 7164篇 |
综合类 | 388篇 |
一般理论 | 16篇 |
预防医学 | 3934篇 |
眼科学 | 1302篇 |
药学 | 2990篇 |
中国医学 | 224篇 |
肿瘤学 | 2446篇 |
出版年
2023年 | 350篇 |
2022年 | 319篇 |
2021年 | 1196篇 |
2020年 | 597篇 |
2019年 | 1319篇 |
2018年 | 2108篇 |
2017年 | 1285篇 |
2016年 | 1163篇 |
2015年 | 1033篇 |
2014年 | 1266篇 |
2013年 | 2166篇 |
2012年 | 3580篇 |
2011年 | 4061篇 |
2010年 | 1974篇 |
2009年 | 1190篇 |
2008年 | 2951篇 |
2007年 | 3035篇 |
2006年 | 2787篇 |
2005年 | 2834篇 |
2004年 | 2659篇 |
2003年 | 2609篇 |
2002年 | 2291篇 |
2001年 | 1604篇 |
2000年 | 2102篇 |
1999年 | 1109篇 |
1998年 | 321篇 |
1997年 | 235篇 |
1996年 | 200篇 |
1995年 | 183篇 |
1994年 | 126篇 |
1993年 | 117篇 |
1992年 | 172篇 |
1991年 | 129篇 |
1990年 | 124篇 |
1989年 | 125篇 |
1988年 | 134篇 |
1987年 | 94篇 |
1986年 | 77篇 |
1985年 | 114篇 |
1984年 | 97篇 |
1983年 | 95篇 |
1982年 | 73篇 |
1981年 | 62篇 |
1980年 | 65篇 |
1979年 | 79篇 |
1978年 | 81篇 |
1977年 | 64篇 |
1976年 | 58篇 |
1975年 | 61篇 |
1973年 | 60篇 |
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
51.
Atrial natriuretic peptide (ANP) is a hormone release into the circulation by atrial cardiocytes (Gutkowska et al. 1984). Extracellular fluid volume expansion acts as a powerful stimulus for ANP secretion and results in the augmentation of its plasma concentration (Lang et al. 1985). Patients with active acromegaly demonstrate the increased extracellular fluid volume (Falkheden et al. 1964), while a successful treatment of the disease results in the disappearance of hypervolemia (Strauch et al. 1977). We have recently demonstrated that in patients with active acromegaly the increased total body plasma volumes are accompanied by the elevated plasma ANP concentrations, whereas, in the successfully treated patients, both: total plasma volumes and plasma ANP levels do not differ significantly from these in healthy subjects (Czekalski et al. 1988b). 相似文献
52.
P. Priego E. Lobo G. Rodríguez J. Cabañas J. Pérez de Oteyza V. Fresneda 《Clinical & translational oncology》2007,9(2):106-109
Abstract
Background and study aims: The advent of endoscopic techniques in the last decades has produced a change in the approach of the oesophageal leiomyoma.
The aim of the study is to explain our experience in the laparoscopic surgery of the oesophageal leiomyoma.
Materials and methods: We realised a retrospective study of the oesophageal leiomyoma operated on in our centre by the endoscopic approach between
2001 and 2004. There were two females and two males. All were symptomatic and pyrosis was the most frequent symptom. The preoperative
study was an oral endoscopy and barium swallow. In all the cases enucleation was performed, two by thoracoscopy and two by
laparoscopy approach.
Results: The mean operating time was 230 min. No deaths or intraoperative complications occurred and there were no cases of conversion
to open surgery either. The mean postoperative hospital stay was 3.25 days (range 2–4 days). There was no case of recurrence.
Conclusions: The enucleation is an easier procedure and constitutes the therapy of choice of the oesophageal leiomyoma. We think that muscle
borders should be closed after enucleation and that biopsy is not indicated preoperatively. 相似文献
53.
Carlos Ferrer Albiach Antonio Conde Moreno Marta Rodríguez Cordón Virginia Morillo Macías Ana Bouché Babiloni Inmaculada Beato Tortajada Ángel Sánchez Iglesias Alicia Francés Muñoz 《Clinical & translational oncology》2010,12(1):22-26
Hypoxia is related to poor prognosis because it is associated to chemo-and radioresistance. During recent years the evolution
of imaging methods like PET/CT and MRI has meant the appearance of new perspectives with direct implications in radiation
therapy. We discuss previous experiences in staging, planning and in the follow-up process with these techniques for measuring
tumour hypoxia. 相似文献
54.
Eva Maria Valesky Diamant Thai Markus Meissner Christian Beier Manfred Wolter Helmut Schfer Roland Kaufmann 《Journal der Deutschen Dermatologischen Gesellschaft》2007,5(9):770-772
With 1–1.5 million cases reported every year cutaneous leishmaniasis represents an increasing health problem. The course of cutaneous leishmaniasis varies from a single self‐healing ulcer to a persistent ulcer or progressive mucosal disease with nasopharyngeal destruction. An enormous array of topical and systemic treatment modalities has been endorsed. The response to treatment depends on the species of parasite as well as the host's immunological and genetic status. Species‐specific treatment guidelines based on evidence from controlled studies are highly desirable. We present two cases of cutaneous leishmaniasis, one in a child and one during pregnancy, reviewing various diagnostic and therapeutic measures with special attention to problems in young and pregnant patients. 相似文献
55.
Ayhan Ozturk C Elif Ozturk Burcu Ozdemirli Muhterem Yucel Talat Bah?eba?i 《Seizure》2007,16(2):147-152
It is well known that there might be an epidemiological association between Helicobacter pylori infection and extraintestinal diseases. This study aimed at determining H. pylori infection in epileptic patients. Forty-seven cryptogenic epileptic patients (Group 1) and 35 healthy people (Group 2) participated in this study. Presence of H. pylori infection was examined by H. pylori stool antigen (HpSA), H. pylori IgG, and IgM. HpSA was detected in 21 participants (44.6%) in Group 1 and in 3 participants (8.5%) in Group 2. H. pylori IgM was positive in 27 participants (57.4%) in Group 1 and in 8 participants (22.8%) in Group 2. H. pylori IgG was positive in 37 participants (78.7%) in Group 1 and in 13 participants (38%) in Group 2. The difference of rates of HpSA, H. pylori IgM and IgG in Groups 1 and 2 were found statistically significant (chi2=4.18, p=0.04; chi2=9.18, p=0.0017; chi2=14.58, p<0.001, respectively). We also compared presence of H. pylori infection between the epileptic patients with poor and good prognosis; HpSA positivity was detected in 15 (62.5%) of 24 and 6 (26%) of 23, respectively, and the differences were statistically significant (chi2=6.30, p=0.012). H. pylori IgM positivity was detected in 16 (66%) of 24 patients with poor prognosis and 11 (47.8%) of 23 patients with good prognosis (p>0.05). H. pylori IgG positivity was detected in 18 (75%) of 24 patients with poor prognosis and 19 (82.6%) of 23 patients with good prognosis. The differences of H. pylori IgM and IgG positivity rates in epileptic patients with poor and good prognosis were not found statistically significant (p>0.05). These results suggest a probable association between the acute H. pylori infection and epilepsy, especially with poor prognosis. 相似文献
56.
Sergi Sastre Francisco Maculé Sandra Lasurt Josep-María Segur Lluis Lozano Montse Nuñez Santiago Suso 《European journal of orthopaedic surgery & traumatology : orthopedie traumatologie》2007,17(4):393-397
Five patients with idiopathic transient osteoporosis were examined. Bone scanning and MRI was helpful in the diagnosis to differentiate of necrosis and all patients recovered completely with conservative and symptomatic treatment. There was no history of trauma in all patients. MRI was realized previously in all cases to confirm the diagnosis and after the resolution of symptomathology. 相似文献
57.
Eser Tüfek?i Thomas E Merrill Maria R Pintado John P Beyer William A Brantley 《American journal of orthodontics and dentofacial orthopedics》2004,125(6):733-739
Teeth with white spot lesions (WSL) might be more prone to enamel loss during bracket debonding. This in vitro study compared enamel loss from teeth with (n = 14) and without (n = 14) WSL after polishing with low-speed finishing burs or disks (Sof-Lex, 3M ESPE, St Paul, Minn). Debonded surfaces were analyzed with a contact stylus profilometer, and digitized data were compared with baseline readings by using AnSur NT software (Regents, University of Minnesota, Minneapolis, Minn). Specimen surfaces were also examined with a scanning electron microscope. Two-way analysis of variance was performed to analyze the data. In teeth without WSL, the volume losses were 0.16 mm(3) for the bur group and 0.10 mm(3) for the disk group; the mean maximum depths were 47.7 microm for the bur group and 54.3 microm for the disk group. In teeth with WSL, the volume losses were 0.06 and 0.17 mm(3), and the mean maximum depths were 35.1 and 48.7 microm for the bur and disk groups, respectively. There were no significant differences in enamel loss between the 2 groups of teeth without WSL (P =.12). However, in teeth with WSL, the burs removed less enamel than the disks (P = 0.006). Scanning electron microscope examination showed that any damage on the enamel surface was usually located in the cervical third of the teeth. On most specimens, even though tooth surfaces appeared resin-free to the naked eye, there were remnants of it. The differences between groups were so small that they might be clinically insignificant. 相似文献
58.
59.
M. I. Manrique-Poyato A. J. Muñoz-Pajares V. Loreto M. D. López-León J. Cabrero J. P. M. Camacho 《Chromosome research》2006,14(6):693-700
We have analysed B chromosome frequency for three consecutive years, B transmission rate at population and individual levels,
clutch size, egg fertility and embryo–adult viability in a natural population of the grasshopper Eyprepocnemis plorans containing two different B chromosome variants, i.e. B2 and B24, the second being derived from the first and having replaced it in nearby populations. From 2002 to 2003 the relative frequency
of both variants changed, although the differences did not reach significance. A mother–offspring analysis showed no significant
effect of any of the two B variants on clutch size, egg fertility or embryo–adult viability, but B24 was more efficiently transmitted than B2 through males from the 2002 season, which explains the observed frequency change. Controlled crosses, at individual level,
showed significant drive through some females for B24 but not for B2, suggesting that this difference in transmission rate might also be important for the substitution process. The analysis
of relative fitness for B2 and B24 carriers for all fitness components, as a whole, showed a significantly better performance of B24-carrying individuals, suggesting that the cumulative effect of these slight differences might contribute to the replacement
of B2 by B24.
Electronic Supplementary Material Supplementary material is available for this article at . 相似文献
60.