全文获取类型
收费全文 | 2873篇 |
免费 | 139篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 120篇 |
妇产科学 | 77篇 |
基础医学 | 364篇 |
口腔科学 | 33篇 |
临床医学 | 267篇 |
内科学 | 477篇 |
皮肤病学 | 108篇 |
神经病学 | 144篇 |
特种医学 | 129篇 |
外科学 | 346篇 |
综合类 | 161篇 |
预防医学 | 172篇 |
眼科学 | 146篇 |
药学 | 225篇 |
中国医学 | 54篇 |
肿瘤学 | 197篇 |
出版年
2023年 | 12篇 |
2022年 | 29篇 |
2021年 | 71篇 |
2020年 | 29篇 |
2019年 | 39篇 |
2018年 | 58篇 |
2017年 | 51篇 |
2016年 | 77篇 |
2015年 | 64篇 |
2014年 | 90篇 |
2013年 | 148篇 |
2012年 | 173篇 |
2011年 | 147篇 |
2010年 | 134篇 |
2009年 | 80篇 |
2008年 | 122篇 |
2007年 | 141篇 |
2006年 | 98篇 |
2005年 | 100篇 |
2004年 | 109篇 |
2003年 | 82篇 |
2002年 | 70篇 |
2001年 | 69篇 |
2000年 | 80篇 |
1999年 | 65篇 |
1998年 | 65篇 |
1997年 | 61篇 |
1996年 | 49篇 |
1995年 | 39篇 |
1994年 | 40篇 |
1993年 | 49篇 |
1992年 | 28篇 |
1991年 | 43篇 |
1990年 | 46篇 |
1989年 | 60篇 |
1988年 | 42篇 |
1987年 | 42篇 |
1986年 | 26篇 |
1985年 | 23篇 |
1984年 | 22篇 |
1983年 | 22篇 |
1982年 | 18篇 |
1981年 | 14篇 |
1980年 | 15篇 |
1979年 | 19篇 |
1977年 | 10篇 |
1976年 | 13篇 |
1975年 | 11篇 |
1969年 | 11篇 |
1941年 | 11篇 |
排序方式: 共有3044条查询结果,搜索用时 15 毫秒
21.
Alphafetoprotein (AFP), an oncofetal antigen, plays very important roles in the early embryonic life and oncogenesis. Under various physiological and pathological conditions AFP exhibits microheterogeneity, probably as a result of differential expression of its epitopes. To analyse the epitopes we have developed a panel of monoclonal antibodies against human AFP purified by a new and efficient method using an immunoadsorbent consisting of polyclonal antibodies immobilized on cyanogen bromide activated Sepharose. Clones producing antibodies of various isotypes, e.g. IgG1, IgG2a, IgG2b, IgA and IgM have been subcloned and characterized. The antibodies showed high avidity for AFP (with half-maximal binding concentrations between 0.012 and 3.87 nM). Mutual inhibition efficiencies of a panel of 14 monoclonal antibodies were determined by RIA. Based on these inhibition data a computer program was used to group these antibodies with respect to their "epitope specificity distance". As a result of this grouping, clones have been identified which can recognize at least five different epitopes on AFP. This panel of antibodies may be very useful for analysis of the epitopic variation of AFP under various physiological and pathological conditions. 相似文献
22.
Lissoni P Mandalà M Rovelli F Casu M Rocco F Tancini G Scardino E 《European urology》2000,37(5):569-572
OBJECTIVE: In addition to sex steroids, prolactin (PRL) may also stimulate prostate cancer growth. Abnormally high blood levels of PRL have been noted in metastatic prostate cancer patients. However, most studies have been limited to the evaluation of basal levels of PRL rather than to investigate its secretion in response to classical endocrine dynamic tests. This study was carried out to analyze PRL secretion in metastatic prostate cancer patients both at basal conditions and in response to L-Dopa and metoclopramide, which represents the most classical inhibitory and stimulatory tests for PRL secretion, respectively. METHODS: The study included 12 patients with metastatic prostate cancer. On separate occasions, PRL secretion was evaluated in response to L-Dopa (500 mg orally) and to metoclopramide (10 mg i.v. as a bolus). Serum levels of PRL were measured by RIA. RESULTS: Mean PRL concentrations significantly increased after metoclopramide administration, even though no PRL response occurred in 6 of 12 patients. L-Dopa was unable to reduce PRL levels, which, in contrast, paradoxically significantly increased in response to L-Dopa, with mean values comparable to those achieved after metoclopramide injection. CONCLUSION: By showing a paradoxical stimulatory effect of L-Dopa on PRL secretion and a lack of response to metoclopramide in some patients, this study would suggest the existence of evident alterations in the neuroendocrine regulation of PRL release in advanced prostate cancer. 相似文献
23.
M Mandalà G Curigliano P Bucciarelli G Ferretti P M Mannucci M Colleoni A Ventura G Peruzzotti G Severi P G Pelicci R Biffi F Orsi S Cinieri A Goldhirsch 《Annals of oncology》2004,15(4):590-593
BACKGROUND: To analyze the influence of the prothrombotic gene mutation factor V G1691A (factor V Leiden) and prothrombin G20210A on the risk of a first episode of catheter-related deep venous thrombosis (DVT) in a group of patients with breast cancer treated with chemotherapy. PATIENTS AND METHODS: Between January 1999 and February 2001, the occurrence of a first symptomatic DVT was investigated in a cohort of 300 consecutive patients with locally advanced or metastatic breast cancer treated at a single institution with fluorouracil-based chemotherapy, administered continuously through a totally implanted access port. A nested case-control study included 25 women (cases) with catheter-related DVT and 50 controls without DVT matched with cases for age, identical chemotherapy, stage of disease and prognostic features. The G1691A factor V and G20210A prothrombin mutation genotypes were analyzed. RESULTS: Five cases [20%; 95% confidence interval (CI) 9% to 39%)] and two controls (4%; 95% CI 1% to 14%) were heterozygous carriers of G1691A factor V (P = 0.04). The age-adjusted odds ratio for catheter-related DVT was 6.1 (95% CI 1.1-34.3). Only one patient (case) had the G20210A prothrombin gene mutation. Time from start of chemotherapy infusion to DVT was not significantly different between patients with (median 31 days) and without (median 43 days) G1691A factor V mutation (P = 0.6). CONCLUSIONS: Factor V Leiden carriers with locally advanced or metastatic breast cancer have an increased risk of developing catheter-related DVT during chemotherapy. 相似文献
24.
25.
We report a case of a 40-year-old man who had presented with a spontaneous suprapubic urinary leak from a well-healed suprapubic cystostomy tract scar, 20 years following a successful scrotal tube substitution urethroplasty done for a post-traumatic urethral stricture. Preoperative contrast studies suggested a recurrent bulbomembranous urethral stricture. Excision biopsy of the suprapubic fistulous tract revealed scar cancer infiltrating the bladder wall. Of 3 similar cases reported in the past, only 1 had bladder involvement. Ours is the second such case with bladder involvement. 相似文献
26.
A study was carried out to find out the effects of prior physical activity, sports participation and prior military training on the incidence of stress fractures among Gentlemen Cadets (GC''s) undergoing military training at Indian Military Academy (IMA). One thousand and fourteen GC''s were followed up for a period of 12 weeks. Thirty-seven GC''s developed stress fractures during the study period. The incidence of stress fractures was significantly higher in GC''s without any prior military training (p=0.0009). They were compared with 100 healthy controls drawn from the study population to study the influence of the other mentioned factors. There was no significant association between prior physical activity and stress fractures (OR=0.74, 95% CL=0.26 to 2.05, p=0.688). There was also no significant relationship between sports participation and stress fractures (OR=0.79. 95% CCL=0.35 to 1.81, p=0.684).KEY WORDS: Risk factors, Stress fractures 相似文献
27.
Role of clinical, radiological, and neurophysiological changes in predicting the outcome of tuberculous meningitis: a multivariable analysis 下载免费PDF全文
Misra UK Kalita J Roy AK Mandal SK Srivastava M 《Journal of neurology, neurosurgery, and psychiatry》2000,68(3):300-303
OBJECTIVES: The role of EEG and evoked potentials has not been evaluated in predicting the prognosis of tuberculous (TB) meningitis. The present study was aimed at evaluating the prognostic significance of clinical, radiological, and neurophysiological variables using multi-variable analysis. METHODS: Patients with TB meningitis diagnosed on the basis of clinical, radiological, and CSF criteria have been prospectively evaluated. All the patients were subjected to a detailed neurological evaluation. The outcome was defined 6 months after starting treatment on the basis of the Barthel index (BI) score into poor (BI <12) and good recovery (BI> or =12). Death was included in the poor recovery group for statistical analysis. Thirteen clinical (age, sex, seizure, focal weakness, stage of meningitis, Glasgow coma scale score, methyl prednisolone therapy), CT (infarction, hydrocephalus, tuberculoma) and neurophysiological (EEG, motor and somatosensory evoked potentials) variables were evaluated employing single variable logistic regression followed by multivariable logistic regression analysis. The best set of predictors were obtained by stepdown logistic regression analysis. RESULTS: Fifty four patients were included in the present study. Their age ranged between 5 and 62 years, 11 were children younger than 12 years and 14 were female. Nine patients were in stage I meningitis, 12 in stage II, and 33 in stage III. On single variable logistic regression analysis the significant predictors of 6 months outcome of TB meningitis included focal weakness, Glasgow coma scale (GCS), motor evoked potential (MEP) and somatosensory evoked potential (SEP). On multivariable analysis the best set of predictors comprised focal weakness, GCS, and SEP. CONCLUSIONS: In patients with TB meningitis focal weakness, GCS, and SEP are the best predictors of 6 month outcome. 相似文献
28.
29.
30.
Joan SK Ng FRCS William Wong FRCP Ricky WK Law FRCS Joannie Hui MRCP Esther N Wong MRCP Dennis SC Lam FRCOphth 《Clinical & experimental ophthalmology》2001,29(4):239-243
Purpose : To investigate ocular complications arising from nephrotic syndrome and/or its treatments in children. Methods : A cross‐sectional study was conducted in a teaching hospital. A total of 31 paediatric patients with nephrotic syndrome were studied. Comprehensive ophthalmic assessments on best‐corrected visual acuity, intraocular pressure, slit‐lamp and fundus examination were taken. Information regarding histological diagnosis of nephrotic syndrome and its treatment regimen in each patient was reviewed and analysed. Results : Bilateral posterior subcapsular cataracts were detected in three of 29 patients (10.3%) who received steroid therapy. Two had normal vision while one had visual acuity reduced to 6/15 in both eyes. The age of onset of the nephrotic syndrome in these three patients was 2 years, which was significantly younger than those without cataract (5.4 ± 3.2 years, P < 0.001). Three patients (9.7%) had isolated asymptomatic fundal findings of tortuous and dilated retinal vessels. Hypertensive retinopathy was found in one patient (3.2%). No steroid‐induced glaucoma, uveitis, ocular infection, or other eye complications related to the use of steroids or other immunosuppressive agents were noted. Conclusions : Children who have nephrotic syndrome often require prolonged, intermittent high dose of systemic corticosteroid therapy. Paediatricians should be aware of the potential risk of developing steroid‐related complications, especially posterior subcapsular cataract. It appears to have a higher risk when steroid therapy is used in very young patients. Early detection would help to prevent amblyopia development, particularly in the group of immature eyes. 相似文献