全文获取类型
收费全文 | 13020篇 |
免费 | 901篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 121篇 |
儿科学 | 497篇 |
妇产科学 | 357篇 |
基础医学 | 1993篇 |
口腔科学 | 354篇 |
临床医学 | 1608篇 |
内科学 | 2566篇 |
皮肤病学 | 339篇 |
神经病学 | 1238篇 |
特种医学 | 323篇 |
外科学 | 1017篇 |
综合类 | 93篇 |
一般理论 | 4篇 |
预防医学 | 1174篇 |
眼科学 | 199篇 |
药学 | 823篇 |
中国医学 | 15篇 |
肿瘤学 | 1229篇 |
出版年
2024年 | 11篇 |
2023年 | 99篇 |
2022年 | 155篇 |
2021年 | 295篇 |
2020年 | 275篇 |
2019年 | 328篇 |
2018年 | 319篇 |
2017年 | 285篇 |
2016年 | 336篇 |
2015年 | 428篇 |
2014年 | 519篇 |
2013年 | 710篇 |
2012年 | 1058篇 |
2011年 | 1040篇 |
2010年 | 623篇 |
2009年 | 533篇 |
2008年 | 863篇 |
2007年 | 904篇 |
2006年 | 869篇 |
2005年 | 832篇 |
2004年 | 798篇 |
2003年 | 727篇 |
2002年 | 655篇 |
2001年 | 115篇 |
2000年 | 69篇 |
1999年 | 96篇 |
1998年 | 151篇 |
1997年 | 130篇 |
1996年 | 82篇 |
1995年 | 81篇 |
1994年 | 68篇 |
1993年 | 66篇 |
1992年 | 41篇 |
1991年 | 42篇 |
1990年 | 24篇 |
1989年 | 28篇 |
1988年 | 29篇 |
1987年 | 23篇 |
1986年 | 13篇 |
1985年 | 18篇 |
1984年 | 24篇 |
1983年 | 27篇 |
1982年 | 17篇 |
1981年 | 17篇 |
1980年 | 19篇 |
1978年 | 13篇 |
1977年 | 22篇 |
1975年 | 10篇 |
1974年 | 10篇 |
1967年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
A Systematic Overview of Radiation Therapy Effects in Cervical Cancer (Cervix Uteri) 总被引:2,自引:0,他引:2
Nina Einhorn Claes Trop Mona Ridderheim Karin Boman Bengt Sorbe Eva Cavallin-st hl 《Acta oncologica (Stockholm, Sweden)》2003,42(5):546-556
A systematic review of radiation therapy trials in several tumour types was performed by The Swedish Council of Technology Assessment in Health Care (SBU). The procedures for evaluation of the scientific literature are described separately (Acta Oncol 2003; 42: 357-365). This synthesis of the literature on radiation therapy for cervical cancer is based on data from 1 meta-analysis and 34 randomized trials. In total, 35 scientific articles are included, involving 7 952 patients. The results were compared with those of a similar overview from 1996 including 34 024 patients. The conclusions reached can be summarized in these points: There are limited scientific data supporting that postoperative pelvic radiotherapy improves disease-free survival in early cervical cancer. No firm conclusion can be drawn.There is moderate scientific evidence that external beam radiotherapy combined with brachytherapy gives a similar disease-free and overall survival rate as radical hysterectomy in early cervical cancer.There is strong scientific evidence that concomitant radiochemotherapy improves disease-free and overall survival compared to radiotherapy alone in early cervical cancer.The NCI has recently published an announcement stating that cisplantin-based chemotherapy should be used concomitantly with radiotherapy in cervical cancer. No solid documentation for this statement can be found concerning locally advanced stages (>IIB).There is a strong scientific evidence that cisplatin-based chemotherapy given concomitantly with radiotherapy is superior to concomitant chemotherapy with hydroxyurea.There is no scientific evidence to show that neoadjuvant chemotherapy followed by radiotherapy improves disease-free or overall survival compared to radiotherapy alone in patients with localized cervical cancer.There is moderate scientific evidence that high-dose-rate brachytherapy gives the same local control rate as low-dose-rate brachytherapy but with fewer rectal complications. 相似文献
102.
CT-based delineation of lymph node levels and related CTVs in the node-negative neck: DAHANCA, EORTC, GORTEC, NCIC,RTOG consensus guidelines. 总被引:25,自引:0,他引:25
Vincent Grégoire Peter Levendag Kian K Ang Jacques Bernier Marijel Braaksma Volker Budach Cliff Chao Emmanuel Coche Jay S Cooper Guy Cosnard Avraham Eisbruch Samy El-Sayed Bahman Emami Cai Grau Marc Hamoir Nancy Lee Philippe Maingon Karin Muller Hervé Reychler 《Radiotherapy and oncology》2003,69(3):227-236
BACKGROUND AND PURPOSE: The appropriate application of 3-D CRT and IMRT for HNSCC requires a standardization of the procedures for the delineation of the target volumes. Over the past few years, two proposals--the so-called Brussels guidelines from Grégoire et al., and the so-called Rotterdam guidelines from Nowak et al.--emerged from the literature for the delineation of the neck node levels. Detailed examination of these proposals however revealed some important discrepancies. MATERIALS AND METHODS: Within this framework, the Brussels and Rotterdam groups decided to review their guidelines and derive a common set of recommendations for delineation of neck node levels. This proposal was then discussed with representatives of major cooperative groups in Europe (DAHANCA, EORTC, GORTEC) and in North America (NCIC, RTOG), which, after some additional refinements, have endorsed them. The objective of the present article is to present the consensus guidelines for the delineation of the node levels in the node-negative neck. RESULTS AND CONCLUSIONS: First a short discussion of the discrepancies between the previous Brussels and the Rotterdam guidelines is presented. The general philosophy of the consensus guidelines and the methodology used to resolve the various discrepancies are then described. The consensus proposal is then presented and representative CTVs that are consistent with these guidelines are illustrated on CT sections. Last, the limitations of the consensus guidelines are discussed and some concerns about the direct applications of these guidelines to the node-positive neck and the post-operative neck are described. 相似文献
103.
Tomas Norlander Sam-Hyun Kwon Gert Henriksson Karl Magnus Westrin Karin Sandstedt Pontus Stierna 《The Laryngoscope》1998,108(3):411-417
To investigate possible effects of corticosteroids on polyp formation and local bacterial colonization, pneumococcal sinusitis was experimentally induced in rabbits pretreated with betamethasone or saline. After 7 days, macroscopic polyps were counted post-mortem and on histologic slides after serial sectioning. Histologic sections were also examined with light microscopy. Macroscopic polyps were significantly fewer in animals given betamethasone, while there was no difference regarding the number of microscopic polyps. Ingrowth of pathogenic microorganisms was found in five of eight rabbits given placebo but in none of the animals treated with corticosteroids (P < 0.05). The reduced number of pathogenic strains in these animals may be explained by a better-preserved local host defense. The lower number of macroscopic polyps in the same animals could be because of a delayed mucosal repair and subsequent polyp formation. 相似文献
104.
M. Johansson A. Tommy Bergenheim Roland D’Argy Karin Edman Per-Olov Gunnarsson Anders Widmark Roger Henriksson 《Cancer chemotherapy and pharmacology》1998,41(4):317-325
Estramustine (EaM), a carbamate ester of 17β-estradiol and nor-nitrogen mustard, is a cytotoxic compound with antitumoral
effect in malignant glioma in vitro and in vivo . However, knowledge of the pharmacokinetics of EaM in experimental glioma
is limited. The objective of this study was therefore to investigate further the distribution of EaM in the BT4C rat glioma
model. Assessment of EaM uptake and distribution was performed by quantitative whole-body autoradiography. In addition, the
uptake of EaM and its metabolites estromustine (EoM), estradiol, and estrone were analyzed by gas chromatography. EaM was
taken up from the circulation and was found to be the main product in glioma tissue. Whole-body autoradiography after [14C]-EaM administration revealed a strong 14C label simultaneously in tumor and normal brain tissue at 0.5 h after drug administration. In tumor tissue, sustained high
levels of 14C label were detected at 12 h after drug administration. In contrast to the tumor, radioactivity in normal brain tissue rapidly
leveled off, indicating a retention of radioactivity in the tumor. The tumor/brain radioactivity ratio reached a peak of 4.5
at 12 h after drug administration. High levels of 14C label were also found in pulmonary tissue. By gas chromatography, EoM was found to be the main metabolite in plasma. However,
EaM reached higher levels in tumor tissue, with the mean tumor/plasma ratio being 11.7 as compared with 2.0 for EoM. Only
low plasma levels of the estrogen metabolites were detected. In conclusion, EaM is taken up in the BT4C rat glioma tissue
and is retained in the tumor as compared with normal brain tissue and plasma. EaM showed a greater selectivity for tumor tissue,
exhibiting a high tumor/plasma ratio as compared with EoM. The distribution pattern after administration of EaM, as evaluated
by both whole-body autoradiography and gas chromatography, supports the earlier suggestion that the uptake is related to a
protein with EaM-binding characteristics.
Received: 12 January 1997 / Accepted: 28 August 1997 相似文献
105.
Rosie Ashbolt Jenny Barralet Robert Bell Dennis Bittisnich Andrew Black Barry Combs Christine Carson Scott Crerar Craig Dalton Joy Gregory Michelle Harlock Gillian Hall Geoff Hogg Martyn Kirk Karin Lalor Tony Merritt Sally Munnoch Jennie Musto Lillian Mwanri Leonie Neville Chris Oxenford Rhonda Owen Jane Raupach Cameron Sault Russell Stafford Barbara Telfer Hassan Vally Kefle Yohannes 《Communicable diseases intelligence》2005,29(1):85-88
106.
Catharina Wising Jozef Azem Madeleine Zetterberg Liselott A Svensson Karin Ahlman Teresa Lagerg?rd 《Toxicon》2005,45(6):767-776
We investigated the impact of highly purified Haemophilus ducreyi cytolethal distending toxin (HdCDT) on the apoptosis and necrosis of various human cells; including myeloid cells, epithelial cells, keratinocytes, and primary fibroblasts. The levels of apoptosis and necrosis induced in these cells were compared to those induced by HdCDT in human T cells and in the Jurkat T cell line. Levels of caspase-3 activity were measured, and membrane changes like phosphatidylserine (PS) translocation was evaluated after double-staining with the fluorescein isothiocyanate (FITC)-labeled annexin V and propidium iodide (PI) using flow cytometry. HdCDT induced various degrees of apoptosis and necrosis in dose- and time-dependent manners in cells of various lineages. Early and late apoptosis (annexin V-stained cells) were induced in more than 90% of T cells and monocytes after treatment with 100 ng/ml HdCDT for 24 and 48 h, respectively. The corresponding numbers for epithelial cells, keratinocytes, and fibroblasts were 26-32% after treatment with 100 ng/ml HdCDT for 48 h. HdCDT appears to eliminate effectively by inducing apoptosis those cells that are involved in immune responses. Epithelial cells, keratinocytes and fibroblasts, which are important for the healing of chancroid ulcers, are eliminated by apoptosis or necrosis after contact with HdCDT, albeit slower and to a lesser extent than T cells. 相似文献
107.
Cholecystectomy: costs and health-related quality of life: a comparison of two techniques. 总被引:3,自引:0,他引:3
Erik Nilsson Axel Ros Mikael Rahmqvist Karin B?ckman Per Carlsson 《International journal for quality in health care》2004,16(6):473-482
BACKGROUND: Outcomes of previous health economic evaluations comparing minilaparotomy cholecystectomy and laparoscopic cholecystectomy have been inconsistent. OBJECTIVE: To compare costs for minilaparotomy cholecystectomy and laparoscopic cholecystectomy and to study changes in quality of life induced by these operations. DESIGN: Single-blind, randomized controlled trial, run from 1 March 1997 to 30 April 1999. SETTING: One university hospital and four non-university hospitals in Sweden. MAIN MEASURE: : Cost and perceived health estimation according to the global quality of life instrument EuroQol-5D. RESULTS: Of 1719 cholecystectomy patients at five centres, 724 entered the trial and were treated with minilaparotomy cholecystectomy or laparoscopic cholecystectomy, 362 in each group. Total health care costs were less for minilaparotomy cholecystectomy than for laparoscopic cholecystectomy (median values US$2428 for minilaparotomy cholecystectomy versus US$2613 or US$3006 for laparoscopic cholecystectomy with 100 operations per year and reusable trocars or 50 operations per year and disposable trocars, respectively). There was no significant difference in total costs (including costs due to loss of production) between minilaparotomy cholecystectomy and laparoscopic cholecystectomy with 100 operations per year and reusable trocars in laparoscopic cholecystectomy (US$3731 versus US$3649, respectively). However, in calculations assuming 50 operations per year and disposable trocars in laparoscopic cholecystectomy, this technique was more expensive than minilaparotomy cholecystectomy (US$4042 versus US$3731). Health-related quality of life was slightly but significantly lower for the minilaparotomy cholecystectomy group 1 week after surgery. One month and 1 year postoperatively no difference between the randomized groups was found. CONCLUSION: Total costs did not differ between minilaparotomy cholecystectomy and laparoscopic cholecystectomy with high-volume surgery and disposable trocars, whereas laparoscopic cholecystectomy was more expensive with fewer operations and disposable trocars. The gain in health-related quality of life with laparoscopic cholecystectomy compared with minilaparotomy cholecystectomy was small and of limited duration. 相似文献
108.
Karin Ishikawa Tomihiko Tanino Yuichiro Ohtake Itaru Kimura Hiroshi Miyata Yukihiko Mashima 《Japanese journal of ophthalmology》2004,48(1):90-91
Purpose To review the outcome of surgery for strabismus due to ethmoid sinus surgery.Cases and Methods The series comprised 13 cases, 1 of inferior rectus paresis, 1 of superior oblique paresis, 6 of medial rectus paresis, and 5 of medial rectus muscle palsy due to third nerve palsy. In the cases of paresis of the rectus muscle, resection of the rectus muscles was mainly performed. In the cases of palsy of the rectus muscle, transposition of the extraocular muscle with simultaneous recession of the lateral rectus muscle was performed. The major aim of surgery was to bring both eyes into alignment and to eliminate diplopia in the primary position.Results The mean preoperative horizontal deviation of 18.1 degrees of exotropia in the paresis cases was reduced to 1.4 degrees of exotropia after surgery. The mean preoperative vertical deviation of 3.8 degrees of hypertropia was reduced to 1.4 degrees of hypertropia postoperatively. The mean preoperative horizontal deviation of 35.6 degrees of exotropia in the palsy cases was reduced to 9.4 degrees of exotropia after surgery. The mean preoperative vertical deviation of 2.0 degrees of hypertropia was increased to 2.6 degrees of hypertropia postoperatively. Postoperatively, diplopia was absent in 11 cases with a slightly compensatory head posture.Conclusions Surgery for strabismus due to sinus surgery induces improvements in eye position and diplopia.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc 107:425–432, 2003) 相似文献
109.
Gunilla Sydsj? Katarina Ekholm Selling Karin Nystr?m Cecilia Oscarsson Svante Kjellberg 《The European journal of contraception & reproductive health care》2006,11(2):117-125
OBJECTIVE: To investigate the knowledge of reproductive physiology and anatomy among adolescents and young adults in Sweden, and to evaluate the education obtained on these issues. METHODS: Two hundred and nine study specific questionnaires were distributed, of which 206 were answered by students in primary school, upper secondary school and at first year of university. A total knowledge score based on 21 out of the 35 questions in the questionnaire was calculated. As only 44 of the 206 respondents answered all the questions a revised score was also calculated, in which partial dropouts were interpreted as wrong answers. RESULTS: The mean of the total knowledge score was 28.7 out of 54 among the 44 respondents answering all questions, and the revised knowledge score was 24.0. The level of knowledge tended to be higher in older age groups, among women, as well as among respondents who had visited a Youth clinic. The time of ovulation was known by 21.4% of men compared to 63.4% of women. Almost 50% of the students knew one mechanism whereby oral contraceptives act to protect against pregnancy. Of the respondents, 77.2% knew of Chlamydia trachomatis but the knowledge of other STIs, like condyloma, was poorer (16.5%). Reasons for infertility were relatively well known among the respondents. Of the respondents, 57.5% stated that they had not received enough information on reproductive issues. CONCLUSIONS: The students have not achieved sufficient knowledge concerning sexual and reproductive matters that they, according to the national curriculum, should have attained by the end of the 9th grade. An improvement of the quality of the education, adapted to the students' age and pre-existing knowledge, and a review of the contents of the education is therefore needed. 相似文献
110.
BACKGROUND: Fatal venous thromboembolism (VTE) is a rare complication of combined oral contraceptive (COC) treatment. This study aims to determine incidences of fatal VTE in relation to the type of COC and the percentage of cases reported to the Swedish Adverse Drug Reactions Advisory Committee (SADRAC). A further aim is to compare the characteristics of reported and not reported cases. METHODS: This retrospective study is a separate analysis using data from a larger study that included women aged 15-44 years between 1990 and 1999 with VTE coded as the underlying or contributory cause of death in the Swedish Cause of Death Register. COC use within 2 months of the date of symptom onset or death was identified in 28 cases. Sales data were obtained from the National Corporation of Swedish Pharmacies. Reported cases were identified in the SADRAC database. RESULTS: After excluding two cases where the type of COC was unknown, the crude incidences of fatal VTE were 5.1 (95% CI 2.3, 9.6), 8.6 (95% CI 4.3, 15.4) and 9.1 (95% CI 3.3, 19.8) cases per million women per year for levonorgestrel-, desogestrel- and norethisterone-containing COCs, respectively. Age-adjusted incidences were approximately twice as high for desogestrel- and norethisterone-containing COCs compared with levonorgestrel-containing COCs, although differences were not statistically significant. Thirty-six percent of cases were reported. Reporting was positively associated with information in medical records relevant to the VTE diagnosis that the patient was a COC user and was significantly higher in northern Sweden. CONCLUSION: Results from this study support a higher incidence of fatal VTE with desogestrel-containing COCs than with levonorgestrel-containing COCs. 相似文献