全文获取类型
收费全文 | 3081篇 |
免费 | 200篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 46篇 |
儿科学 | 78篇 |
妇产科学 | 71篇 |
基础医学 | 422篇 |
口腔科学 | 34篇 |
临床医学 | 266篇 |
内科学 | 838篇 |
皮肤病学 | 35篇 |
神经病学 | 242篇 |
特种医学 | 107篇 |
外科学 | 552篇 |
综合类 | 18篇 |
预防医学 | 200篇 |
眼科学 | 48篇 |
药学 | 154篇 |
中国医学 | 6篇 |
肿瘤学 | 171篇 |
出版年
2023年 | 11篇 |
2022年 | 19篇 |
2021年 | 53篇 |
2020年 | 37篇 |
2019年 | 58篇 |
2018年 | 62篇 |
2017年 | 48篇 |
2016年 | 63篇 |
2015年 | 71篇 |
2014年 | 84篇 |
2013年 | 125篇 |
2012年 | 212篇 |
2011年 | 208篇 |
2010年 | 92篇 |
2009年 | 89篇 |
2008年 | 155篇 |
2007年 | 192篇 |
2006年 | 168篇 |
2005年 | 147篇 |
2004年 | 142篇 |
2003年 | 147篇 |
2002年 | 120篇 |
2001年 | 73篇 |
2000年 | 98篇 |
1999年 | 97篇 |
1998年 | 45篇 |
1997年 | 26篇 |
1996年 | 29篇 |
1995年 | 24篇 |
1994年 | 27篇 |
1993年 | 20篇 |
1992年 | 48篇 |
1991年 | 52篇 |
1990年 | 35篇 |
1989年 | 33篇 |
1988年 | 38篇 |
1987年 | 39篇 |
1986年 | 36篇 |
1985年 | 34篇 |
1984年 | 16篇 |
1983年 | 15篇 |
1981年 | 11篇 |
1979年 | 23篇 |
1978年 | 11篇 |
1977年 | 13篇 |
1975年 | 11篇 |
1971年 | 9篇 |
1969年 | 9篇 |
1933年 | 13篇 |
1932年 | 10篇 |
排序方式: 共有3288条查询结果,搜索用时 15 毫秒
1.
2.
Validation of a simplified technique for using the POPQ pelvic organ prolapse classification system 总被引:3,自引:2,他引:1
Steven Swift Sarah Morris Vikki McKinnie Robert Freeman Eckhard Petri Richard J. Scotti Peter Dwyer 《International urogynecology journal》2006,17(6):615-620
Our objective was to determine the inter-examiner agreement of a simplified pelvic organ prolapse quantification (POPQ) exam and to assess its correlation with the standard POPQ exam. This study consists of two parts; both were preformed in a prospective, randomized, blinded fashion on women presenting with complaints attributed to pelvic organ support defects. The first study was done to determine the inter-examiner reliability of a simplified POPQ exam. The simplified POPQ exam is based on the POPQ with similar ordinal staging but with only four points measured instead of nine. Forty-eight women underwent exams by five different investigators. The order of exams was randomized and the examiners were blinded to the results of each other’s findings. The results of these two exams were compared using weighted kappa statistics. The second part of the study was done to determine the inter-system agreement between the simplified vs standard POPQ exam. A group of 49 women were examined by four different investigators: one using the simplified and the other using standard POPQ exams. The order of the exams was randomized and the examiners were blinded to the results of each other’s exam. Kendall’s tau-b statistics were used to determine the inter-system agreement. For the inter-examiner reliability of the POPQ exam, the average age was 60±13 years. The weighted kappa statistics for the inter-examiner reliability of the simplified prolapse classification system were 0.86 for the overall stage, 0.89 and 0.86 for the anterior and posterior vaginal walls, respectively, 0.82 for the apex/cuff, and 0.72 for the cervix. All demonstrate significant agreement. For the inter-system association between the simplified POPQ and standard POPQ, the average age was 61±15 year. The Kendall’s tau-b value for overall stage was 0.90, 0.83, and 0.87 for the anterior and posterior walls respectively, and 0.78 for the cuff/apex and 0.98 for the cervix. There is good inter-examiner agreement of a simplified POPQ classification system and it appears to have good inter-system association with the POPQ.IUGA Standardization of Terminology Committee members: Robert Freeman MD (chairman), Steven Swift, Eckhard Petri MD, Richard J. Scotti MD, and Peter Dwyer MD. 相似文献
3.
Summary Five different isolates of influenza C virus which were isolated over a period of 32 years and from four different continents were compared by RNA genome oligonucleotide fingerprinting analyses. The earliest isolate of influenza C virus was reported in 1949 byTaylor (19) and served as a reference strain for this study.The results obtained using this technique of comparing relatedness between viruses clearly showed that all strains are distinct. However, the similarities in the pattern of the oligonucleotide fingerprints are marked for the more recent virus isolates (1966–1979), whereas the reference strain C/Taylor shows more pronounced differences.The results are consistant with the high degree of serological crossreaction amongst influenza C viruses isolated over a long period of time, a property which sets this group of viruses apart from type A and B members of the orthomyxoviridae.With 3 Figures 相似文献
4.
Niclas Petri Ebba Bergman Patrik Forsell Mikael Hedeland Ulf Bondesson Lars Knutson Hans Lennern?s 《Drug metabolism and disposition》2006,34(7):1182-1189
The aim of this study in pigs was to investigate the local pharmacokinetics of fexofenadine in the intestine and liver by using the pig as a model for drug transport in the entero-hepatobiliary system. A parallel group design included seven pigs (10-12 weeks, 22.2-29.5 kg) in three groups (G1, G2, G3), and a jejunal single-pass perfusion combined with sampling from the bile duct and the portal, hepatic, and superior caval veins was performed. Fexofenadine was perfused through the jejunal segment alone (G1: 120 mg/l, total dose 24 mg) or with two different verapamil doses (G2: 175 mg/l, total dose 35 mg; and G3: 1000 mg/l, total dose 200 mg). The animals were fully anesthetized and monitored throughout the experiment. Fexofenadine had a low liver extraction (E(H); mean +/- S.E.M.), and the given doses of verapamil did not affect the E(H) (0.13 +/- 0.04, 0.16 +/- 0.03, and 0.12 +/- 0.02 for G1, G2, and G3, respectively) or biliary clearance. The E(H) for verapamil and antipyrine agreed well with human in vivo data. Verapamil did not increase the intestinal absorption of fexofenadine, even though the jejunal permeability of fexofenadine, verapamil, and antipyrine showed a tendency to increase in G2. This combined perfusion and hepatobiliary sampling method showed that verapamil did not affect the transport of fexofenadine in the intestine or liver. In this model the E(H) values for both verapamil and antipyrine were similar to the corresponding values in vivo in humans. 相似文献
5.
Ohne Zusammenfassung 相似文献
6.
Endothelin modulation of neuroeffector transmission in rat and guinea pig vas deferens 总被引:4,自引:0,他引:4
N P Wiklund A Ohlén C U Wiklund P Hedqvist L E Gustafsson 《European journal of pharmacology》1990,185(1):25-33
The effects of endothelin-1 (human, porcine) on contractions induced by transmural nerve stimulation, exogenous ATP or noradrenaline, and on the release of [3H]noradrenaline were studied in guinea pig and rat vas deferens. Endothelin enhanced nerve-induced contractile responses, increased basal muscle tone and increased the contractile response to exogenous ATP in both guinea pig and rat vas deferens. Endothelin did not affect the contractile responses to exogenous noradrenaline. The calcium channel blocker felodipine antagonized the stimulating effects of endothelin in the rat vas deferens, whereas blockade of lipoxygenase and cyclooxygenase pathways by a combination of BW 755C and indomethacin was without effect. In rat vas deferens preparations preincubated with [3H]noradrenaline, endothelin inhibited the 3H overflow induced by transmural stimulation, although the contractile responses were enhanced by endothelin. Pretreatment with forskolin or felodipine did not abolish the endothelin inhibition of radiotracer overflow. In conclusion, endothelin can modulate adrenergic and purinergic neuroeffector transmission in both guinea pig and rat vas deferens via inhibitory prejunctional and stimulant postjunctional mechanisms. The stimulant postjunctional effect seemed to predominate in our experiments. 相似文献
7.
Petri Koivunen Niko Rantala Kalevi Hyrynkangas Kalevi Jokinen Olli-Pekka Alho 《European archives of oto-rhino-laryngology》2002,259(10):543-546
A population-based survey was conducted in northern Finland in order to study the incidence rate and survival in patients with pharyngeal cancer diagnosed between 1986 to 1996. A total of 95 new patients with hypopharyngeal, oropharyngeal or nasopharyngeal cancers were identified. The overall age-adjusted incidence rates (per 100,000 years) were 1.28 in men and 0.60 in women, giving an overall incidence rate of 0.89. Most of the tumours were diagnosed at stage IV, and the median disease-specific survival times were 27.6 months for the patients with oropharyngeal cancer, 13.5 months for nasopharyngeal cancer and 17.7 for hypopharyngeal cancer. The most important factors that were associated with a poor prognosis were stage IV in oropharyngeal [Hazard ratio (HR) 3.68, 95% confidence interval (CI) 0.97-13.92] and hypopharyngeal cancer (HR 3.99, CI 1.51-10.67) and age over 65 years in nasopharyngeal cancer (HR 9.28, CI 1.79-47.99). 相似文献
8.
A. Petri S. Karácsonyi K. Kalmár Nagy 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》1993,378(6):322-324
Cavernous haemangiomas of the liver were surgically treated in 36 women and 14 men over a 10-year period. The tumours were solitary in 42 cases and multiple in 8. Locations were the right lobe in 39 cases, the left one in 5 and both lobes in 6. The size of the tumours ranged from 0.4 to 14 cm in diameter. Enucleation of tumours was carried out in 29 cases, an atypical liver resection in 19 cases, anatomical lobectomy in 2 cases and a right trisegmentectomy in 1 case. There was no mortality. Morbidity rate seems to be lower in patients who underwent enucleation. The authors indicate the importance of enucleation for removal of liver haemangiomas of various sizes.
Chirurgische Behandlung kavernöser Hämangiome der Leber
Zusammenfassung Über einen Zeitraum von 10 Jahren wurden kavernöse Hämangiome der Leber bei 36 Frauen und 14 Männern chirurgisch behandelt. Bei 42 Patienten waren die Tumoren solitär, bei 8 multipel. Sie waren in 39 Fällen im rechten, bei 5 Patienten im linken und bei 6 in beiden Leberlappen lokalisiert, ihr Durchmesser betrug 0,4 bis 14 cm. In 29 Fällen wurde eine Enukleation, in 19 eine atypische Leberresektion, in 2 eine anatomische Lobektomie und in einem Falle eine rechtsseitige Trisegmentektomie durchgeführt. Die Mortalität war gleich Null; die Morbiditätsrate scheint bei den Patienten geringer, die mit Enukleation behandelt wurden. Der Beitrag hebt die Bedeutung der Enukleation zur Beseitigung von Leberhämangiomen unterschiedlicher Größe hervor.相似文献
9.
Changes in nitric oxide release in vivo in response to vasoactive substances. 总被引:2,自引:0,他引:2 下载免费PDF全文
1. Changes in the release of nitric oxide (NO) in vivo were studied in rats following the administration of endothelium-dependent and -independent vasodilators as well as the NO synthesis inhibitor, NG-nitro-L-arginine methyl ester (L-NAME). NO production was assessed by measuring variations of nitrate in plasma by capillary ion analysis. 2. Intravenous administration of the endothelium-dependent vasodilators, bradykinin (2 and 10 micrograms kg-1 min-1) or substance P (0.3-3 micrograms kg-1 min-1) caused a transient dose-dependent hypotension followed by an increase in plasma nitrate concentration (maximal increments: 33 +/- 5% and 38 +/- 6%, for bradykinin and substance P, respectively). Prior administration of L-NAME (10 mg kg-1 min-1) inhibited the hypotension and increase in plasma nitrate caused by these substances. Intravenous administration of sodium nitrate (200 micrograms kg-1) also produced a transitory elevation in plasma nitrate which was similar in magnitude as that caused by the vasodilators. A rapid and transitory increment in plasma nitrate was observed after i.v. administration of authentic NO (400 micrograms kg-1). 3. Rats receiving the endothelium-dependent vasodilators, prostacyclin (0.6 micrograms kg-1 min-1) or adenosine (3 mg kg-1 min-1) intravenously showed a drop in blood pressure paralleled by a decrease in plasma nitrate (maximal decreases: 34 +/- 5% and 24 +/- 4%, for prostacyclin and adenosine, respectively). A similar effect on the plasmatic concentration of nitrate was observed when L-NAME (10 mg kg-1 min-1, i.v.) was administered to the animals. 4. This study demonstrates that (i) changes in plasma nitrate can be detected in vivo after stimulation or inhibition of NO synthase, (ii) an increased production of NO, measured as plasma nitrate, is related to the hypotension caused by bradykinin and substance P and (iii) a diminished concentration of plasmatic nitrate is associated to the hypotension induced by adenosine or prostacyclin (endothelium-independent vasodilators), suggesting that the L-arginine: NO pathway is capable of rapid down-regulation in response to a fall in blood pressure. 相似文献
10.
I. Wiklund F. Waagstein K. Swedberg Å. Hjalmarsson 《Cardiovascular drugs and therapy / sponsored by the International Society of Cardiovascular Pharmacotherapy》1996,10(3):361-368
Summary Quality of life in heart failure patients is receiving increased attention as a reflection of a treatment's potential secondary
benefit of general well-being and daily functioning. The Metoprolol in Dilated Cardiomyopathy (MDC) trial was conducted as
a large, multicenter trial to establish the effects of metoprolol on mortality and need for heart transplantation in patients
with symptomatic idiopathic cardiomyopathy. It was found that metoprolol was well tolerated, improved symptoms and cardiac
function, and prevented clinical deterioration in patients with symptomatic idiopathic dilated cardiomyopathy. Quality of
life was evaluated as a secondary endpoint in 345 out of 383 randomized patients using a disease-specific questionnaire, the
Quality of Life in Heart Failure Questionnaire, depicting physical activity, somatic symptoms, emotions, and life satisfaction.
In a comparison of patients treated with metoprolol or placebo, patients treated with metoprolol noted a significantly more
favorable response than those treated with placebo in terms of the overall treatment evaluation (p<0.05). Additionally, an
analysis of the changes from baseline to 18 months, using 95% confidence intervals, revealed that patients treated with metoprolol
showed a significant improvement from baseline to 18 months in life satisfaction, physical activity, and the total score,
while patients treated with placebo did not change at all. The improvement in quality of life was supported by the correlations
with improvement in traditional clinical parameters. 相似文献