全文获取类型
收费全文 | 14010篇 |
免费 | 723篇 |
国内免费 | 115篇 |
专业分类
耳鼻咽喉 | 82篇 |
儿科学 | 460篇 |
妇产科学 | 318篇 |
基础医学 | 1561篇 |
口腔科学 | 536篇 |
临床医学 | 1189篇 |
内科学 | 3653篇 |
皮肤病学 | 299篇 |
神经病学 | 1422篇 |
特种医学 | 500篇 |
外科学 | 2006篇 |
综合类 | 47篇 |
一般理论 | 2篇 |
预防医学 | 598篇 |
眼科学 | 149篇 |
药学 | 880篇 |
中国医学 | 11篇 |
肿瘤学 | 1135篇 |
出版年
2023年 | 117篇 |
2022年 | 217篇 |
2021年 | 389篇 |
2020年 | 210篇 |
2019年 | 285篇 |
2018年 | 362篇 |
2017年 | 283篇 |
2016年 | 321篇 |
2015年 | 373篇 |
2014年 | 488篇 |
2013年 | 615篇 |
2012年 | 878篇 |
2011年 | 950篇 |
2010年 | 537篇 |
2009年 | 484篇 |
2008年 | 827篇 |
2007年 | 854篇 |
2006年 | 817篇 |
2005年 | 807篇 |
2004年 | 710篇 |
2003年 | 648篇 |
2002年 | 574篇 |
2001年 | 272篇 |
2000年 | 273篇 |
1999年 | 295篇 |
1998年 | 127篇 |
1997年 | 116篇 |
1996年 | 93篇 |
1995年 | 96篇 |
1994年 | 68篇 |
1993年 | 69篇 |
1992年 | 161篇 |
1991年 | 161篇 |
1990年 | 148篇 |
1989年 | 131篇 |
1988年 | 116篇 |
1987年 | 115篇 |
1986年 | 104篇 |
1985年 | 88篇 |
1984年 | 79篇 |
1983年 | 60篇 |
1982年 | 37篇 |
1981年 | 40篇 |
1980年 | 32篇 |
1979年 | 64篇 |
1978年 | 25篇 |
1977年 | 25篇 |
1976年 | 33篇 |
1974年 | 27篇 |
1969年 | 30篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
921.
HV(MNE) is an Epstein-Barr virus (EBV)-like lymphocryptovirus (LCV) originally isolated from a Macaca nemestrina with CD8(+) T cell mycosis fungoides/cutaneous T cell lymphoma (Blood 98 (2001), 2193). HV(MNE) transforms rabbit T cells in vitro and causes T cell lymphoma in New Zealand white rabbits. Here we demonstrate that HV(MNE) also immortalizes T cells from mustached tamarins but not those from owl monkeys, common marmosets, squirrel monkeys, black-capped capuchins, and humans. Cytogenetic and FACS analysis revealed the true origin and T cell lineage of the transformed tamarin T cell lines. Tamarin T cells contained HV(MNE) DNA sequence and displayed a decreased requirement for the IL-2 cytokine for growth. Thus, this EBV-like virus from M. nemestrina differs from the other EBV-like viruses found in nonhuman primates inasmuch as it appears to preferentially transform T cells. 相似文献
922.
Voxel-based morphometry in hypocretin-deficient narcolepsy 总被引:2,自引:0,他引:2
Overeem S Steens SC Good CD Ferrari MD Mignot E Frackowiak RS van Buchem MA Lammers GJ 《Sleep》2003,26(1):44-46
STUDY OBJECTIVES: Recent studies suggest that narcolepsy is caused by degeneration of hypocretin (orexin) producing neurons. To find evidence for this hypothesis, we aimed to detect structural changes in the hypothalamus and/or hypocretin projection areas of patients with narcolepsy. DESIGN: We used voxel-based morphometry (VBM), an unbiased MRI morphometric method with a high sensitivity for subtle changes in gray and white matter volumes. SETTING: Image acquisition was carried out in the department of Radiology at Leiden University Medical Center; image post-processing was performed in the Wellcome Department of Cognitive Neurology, London. PARTICIPANTS: Fifteen narcoleptic patients were studied, all having cataplexy and typical findings on Multiple Sleep Latency Testing. All patients were HLA-DQB1*0602 positive and hypocretin-1 deficient. The control group consisted of 15 age and sex matched healthy subjects. MEASUREMENTS AND RESULTS: We found no differences in global gray or white matter volumes between patients and controls. Furthermore, regional gray or white matter volumes in the hypothalamus and hypocretin projection areas did not differ between patients and controls. CONCLUSIONS: VBM failed to show structural changes in the brains of patients with narcolepsy. This suggests that narcolepsy either is associated with microscopic changes undetectable by VBM or that functional abnormalities of hypocretin neurons are not associated with structural correlates. 相似文献
923.
OBJECTIVES: Most endometrial cancer relapses are either pelvic or distant metastases. Recurrences in the laparotomy scar are extremely rare, as to our knowledge this is only the sixth reported case and the first treated with brachytherapy. We also present a review of the literature with an emphasis on radiation therapy treatment. CASE: A 64-year-old woman underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy for IIIA endometrial adenocarcinoma, followed by systemic chemotherapy and pelvic external-beam radiotherapy. Three years later, a recurrence in the laparotomy scar was resected and additional chemotherapy was administered. A solitary mass in the abdominal wound was then found 4 years after that and was reirradiated by combining external-beam radiation therapy and interstitial brachytherapy after complete resection. Histology of the abdominal wall implants was very similar to that of the primary tumour. CONCLUSIONS: Laparotomy wound recurrence (LWR) for endometrial cancer usually appears as a solitary mass that grows slowly without concomitant failure sites a few years after hysterectomy. In these six patients there is no common histology pattern that could suggest predictive factors for LWR. Common postoperative irradiation does not deliver sufficient a dose to the anterior abdominal wall to prevent this kind of failure. 相似文献
924.
Anniballo R Ubaldi F Tesarik J Micheli P Rienzi L Greco E Sorrentino M 《Fertility and sterility》2003,79(1):237-8; author reply 238
925.
926.
927.
928.
OBJECTIVE: To assess the endocrine and clinical effects of luteinizing hormone (LH) activity supplementation administered in the midfollicular phase during controlled ovarian hyperstimulation to poor responders who were candidates for in vitro fertilization (IVF)--embryo transfer. STUDY DESIGN: Prospective, controlled, nonrandomized trial with historical controls. Twenty-five IVF patients who had shown a poor response to standard, long-protocol GnRH-a and FSH only in a preceding cycle (cycle A), were stimulated in the next cycle after six months with hCG supplementation (50 I.U. subcutaneously daily) starting on day 7 during standard, long-protocol GnRH-a and FSH (cycle B). The comparative analysis of clinical effects (duration of stimulation, total highly purified (HP)-FSH dose, number of oocytes retrieved and pregnancy rate) and endocrine responses (serum E2, follicular E2 and androstenedione levels) were determined between cycles A and B. RESULTS: Maximum serum E2 levels and clinical pregnancy rate were higher in cycle B, with hCG supplementation. Also, the follicular E2 and androstenedione levels were higher in cycle B. No differences were noted between cycles as regards the duration of stimulation, total HP-FSH dose and number of oocytes retrieved. CONCLUSION: LH activity supplementation in the midfollicular phase yields favorable pregnancy results in low responders. This may be due to enhanced release of follicular precursors for greater synthesis of E2. 相似文献
929.
Zuppa AA Girlando P Florio MG Cota F Romagnoli C Tortorolo G 《European journal of obstetrics, gynecology, and reproductive biology》2002,102(2):131-136
AIM: To evaluate the effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) in preterm neonates with suspected sepsis and severe neutropenia (<1500 mm(3)), and to define the influence of maternal preeclampsia on rhG-CSF activity. METHODS: Twenty neonates of normotensive mothers (NNMs) (GA 29.2+/-0.5 weeks and BW 1.024+/-81 g) and 20 born to preeclamptic mothers (NPMs) (GA 29+/-0.4 weeks and BW 946+/-55 g) were treated with rhG-CSF, 10 microg/kg per day for 3 days. Complete blood counts were obtained at day 0 (before rhG-CSF administration) and 1-4, 6, 9, 20 and 30 days later. RESULTS: Absolute neutrophil count (ANC) increased rapidly (three-fold within 24h), and significantly (maximum approximately 20-25 times starting values) and remained within normal range in both groups. However, in NNMs a two-phase increase occurred with an early peak on day 2 and a further peak on day 6 giving significantly higher ANC (P<0.001) than for NPMs at days 2-4 and 6. NPMs showed a gradual ANC increase with a single late peak occurring 3 days later than NNMs (day 9). The highest peak values for ANC were similar (15,900+/-1395 mm(-3) for NNMs and 13,880+/-1097 mm(-3) for NPMs). Neutropenia was completely resolved within 2 days in NNMs and within 4 days in NPMs. CONCLUSION: Preeclampsia seemed to influence the course of the ANC in spite of rhG-CSF administration, and a higher daily-dose for NPMs with neutropenic sepsis may more rapidly resolve neutropenia by overcoming the preeclampsia-associated inhibitor of rhG-CSF through a dose-dependent mechanism. 相似文献
930.
BACKGROUND: The aim of this paper was to examine the present situation of adolescents admission for respiratory emergency, management of these patients, identify strategies for the best therapeutic options and better collaboration. METHODS: We have gathered data of adolescent patients who were referred to the Emergency Unit of "G. Gaslini" Children's Hospital, and "San Martino" Hospital in Genoa and to the Intensive Care Unit of both Hospitals and to the Emergency Service 118 in Liguria district. Respiratory emergency in adolescence is a rare condition and it is usually due to a poor control of respiratory chronic diseases, i.e. respiratory distress in patients with asthma. RESULTS: We found that there is an increased number of respiratory emergencies because of psychological problems, drugs addiction, multiple trauma; in other words, we had an increased number of admissions due to behavioural problems. Temporary in-patients care has been showed to be the best therapeutic option after the admission in the Emergency Unit. CONCLUSIONS: In conclusion, adolescent patients need to be hospitalized, but appropriate spaces and structures need to be found either in pediatric or adult Hospitals and qualified personnel must be trained. 相似文献