全文获取类型
收费全文 | 40832篇 |
免费 | 2490篇 |
国内免费 | 1359篇 |
专业分类
耳鼻咽喉 | 643篇 |
儿科学 | 998篇 |
妇产科学 | 630篇 |
基础医学 | 3997篇 |
口腔科学 | 710篇 |
临床医学 | 4101篇 |
内科学 | 6238篇 |
皮肤病学 | 1847篇 |
神经病学 | 2525篇 |
特种医学 | 993篇 |
外国民族医学 | 1篇 |
外科学 | 1750篇 |
综合类 | 5826篇 |
现状与发展 | 3篇 |
预防医学 | 4494篇 |
眼科学 | 495篇 |
药学 | 6227篇 |
31篇 | |
中国医学 | 2148篇 |
肿瘤学 | 1024篇 |
出版年
2024年 | 61篇 |
2023年 | 462篇 |
2022年 | 993篇 |
2021年 | 1438篇 |
2020年 | 1224篇 |
2019年 | 1099篇 |
2018年 | 1158篇 |
2017年 | 1184篇 |
2016年 | 1187篇 |
2015年 | 1272篇 |
2014年 | 2424篇 |
2013年 | 2807篇 |
2012年 | 2492篇 |
2011年 | 2640篇 |
2010年 | 2146篇 |
2009年 | 1989篇 |
2008年 | 2031篇 |
2007年 | 2100篇 |
2006年 | 1751篇 |
2005年 | 1649篇 |
2004年 | 1341篇 |
2003年 | 1180篇 |
2002年 | 960篇 |
2001年 | 896篇 |
2000年 | 767篇 |
1999年 | 735篇 |
1998年 | 576篇 |
1997年 | 582篇 |
1996年 | 519篇 |
1995年 | 518篇 |
1994年 | 461篇 |
1993年 | 368篇 |
1992年 | 409篇 |
1991年 | 371篇 |
1990年 | 303篇 |
1989年 | 313篇 |
1988年 | 300篇 |
1987年 | 274篇 |
1986年 | 228篇 |
1985年 | 253篇 |
1984年 | 195篇 |
1983年 | 159篇 |
1982年 | 176篇 |
1981年 | 137篇 |
1980年 | 118篇 |
1979年 | 89篇 |
1978年 | 77篇 |
1977年 | 63篇 |
1976年 | 49篇 |
1975年 | 37篇 |
排序方式: 共有10000条查询结果,搜索用时 19 毫秒
61.
M V Shestakova N A Mukhin I I Dedov V N Titov V A Warshavsky 《Journal of internal medicine》1992,231(3):213-217
The acute effects of protein loading (1.5 g kg-1) on glomerular filtration rate (GFR) and urinary albumin excretion (UAE) were investigated in 23 type-I diabetic patients with no clinical nephropathy, and in 7 healthy subjects (controls). The results were compared with renal morphology data. In controls and in 14 diabetic patients (group 1) GFR increased by 27 and 37%, respectively, corresponding to normal renal reserve, but in 9 patients (group 2) GFR decreased by 20%, indicating the absence of a renal reserve. Microalbuminuria was found in none of the patients in group 1 and in 50% of patients in group 2. Two hours after the load UAE increased in all groups, but the increase was most marked in group 2, despite the fall in GFR. The two groups of patients did not differ with regard to the duration and control of diabetes, but differed markedly in terms of baseline GFR (131 vs. 195 ml min-1, P less than 0.01, in groups 1 and 2, respectively). Renal morphology showed minimal non-specific glomerular injury in group 1, and signs of glomerulosclerosis in group 2. We conclude that the impaired renal response to protein load precedes other subclinical manifestations of diabetic renal injury, and may be useful in the diagnosis of latent diabetic nephropathy. 相似文献
62.
本文采用中和试验、沉降反应和解离试验对135例已知血型人精液中ABH血型物质的分泌强度进行了检验,并将其分为强、中、弱三型。这对区别个人血型物质含量及性犯罪的法医学鉴定均有重要意义。并证明了AB型人精液中A、B血型物质含量不均等现象,并且绝大多数人B型物质高于A型物质。 相似文献
63.
The cold pressor test: Vascular and myocardial response patterns and their stability 总被引:2,自引:0,他引:2
PATRICE G. SAAB MARIA M. LLABRE BARRY E. HURWITZ NEIL SCHNEIDERMAN WILLIAM WOHLGEMUTH LYNN A. DUREL CLIFFORD MASSIE JOACHIM NAGEL 《Psychophysiology》1993,30(4):366-373
The purposes of the present study were to compare the cardiovascular response patterns evoked by three versions of the cold pressor test (either forehead stimulation or hand or foot immersion) and to determine the reproducibility of the responses over a 2-week interval. Blood pressure, heart rate, stroke volume, cardiac output, total peripheral resistance, and systolic time intervals were obtained during rest and during the cold pressor test in 42 young men. Across conditions, the pressor response was supported by peripheral resistance increases with concomitant stroke volume decreases. Although the response panerns were generally similar across sites, exceptions were apparent for heart rate. Forehead stimulation was characterized by no significant change in heart rate, whereas limb (hand or foot) immersion was associated with significant heart rate acceleration. The responses elicited by the three cold pressor test conditions were reliable and showed little evidence of attenuation over the test-retest interval. 相似文献
64.
宣肺清热颗粒剂稳定性研究 总被引:1,自引:0,他引:1
目的:研究宣肺清热颗粒剂中橙皮甙热稳定性变化,为该颗粒剂有效期的确定、制剂生产、贮存条什提供实验参考依据。方法:采用加速实验法对橙皮甙热稳定性进行研究,用甲醇超声提取样品,HPLC进行含量测定。根据Arrhenius公式处理数据。结果:Arrhenius公式得室温下的速度常数K298=3.38×10-5/h,得出常温下该颗粒剂以橙皮甙为指标的有效期为3.6年。结论:宣肺清热颗粒剂稳定性好,初步符合中药稳定性要求。 相似文献
65.
Michael J Radcliffe George T Lewith Philip Prescott Martin K Church Stephen T Holgate 《Clinical and experimental allergy》2006,36(12):1488-1493
BACKGROUND: In the investigation of seasonal allergic rhinoconjunctivitis (SAR), quantitative skin and conjunctival allergen challenge tests are used to measure individual allergen sensitivity. These tests are reproducible and relate well to prevalence but their relationship to symptom severity is less well established. OBJECTIVE: We wished to determine if quantitative skin prick tests (QSPT) and conjunctival provocation tests (CPTs) using a single grass pollen allergen extract are reproducible and predict symptom severity in SAR. METHODS: We retrospectively analysed data from 91 participants in a previously published randomized placebo controlled study of low dosage allergen immunotherapy who were randomized to receive placebo treatment. We examined the relationship between pre-seasonal QSPT, CPT and SAR symptoms. RESULTS: We found a high level of reproducibility when repeated measures were compared for both the QSPT (P < 0.001) and the CPT (P < 0.001) and moderate correlation (0.49) between the standard skin prick test (SPT) and the QSPT (P < 0.001). We found weak negative correlation (-0.27) between the QSPT and the CPT (P < 0.001). We found no correlation between seasonal symptom, use of rescue medication or quality of life (QOL) scores and pre-seasonal QSPT or CPT. Conclusion In the assessment of seasonal rhinoconjunctivitis, quantitative skin and conjunctival allergen challenge tests are strongly reproducible, although there is no correlation between these tests and seasonal symptom, use of rescue medication or QOL scores. 相似文献
66.
Postictal Language Dysfunction in Patients with Right or Bilateral Hemispheric Language Localization 总被引:2,自引:1,他引:1
Summary: Purpose : As shown previously, when temporal lobe complex partial seizures (TLCPS) originate from the language dominant hemisphere, patients cannot read a test phrase correctly within 60 s of the end of the ictal discharge. We wished to assess whether postictal language testing results discordant with this pattern identified patients with non-left (right hemisphere or mixed) language dominance.
Methods : Since 1988, all patients undergoing video/EEG monitoring at our institution have been given a test phrase to read aloud as soon as a seizure is detected. Inclusion criteria for this study were (a) postictal language testing within 60 s of seizure end for at least one TLCPS, (b) >90% seizure reduction after anterior temporal lobectomy with 2-year minimum follow- follow- up, and (c) language localization by either intracarotid amobarbital test (IAT) or direct electrical stimulation of left hemisphere cortex.
Results : Two hundred twenty-four seizures in 64 patients were analyzed. Discordant postictal language patterns were noted in 10 of 11 patients with IAT documented non-left language dominance and in 15 of 53 with left dominance (p = 0.006; sensitivity 90.9%, specificity 71.7%).
Conclusions : Postictal language testing accurately identifies patients with non-left language dominance and may be useful in selecting appropriate patients for IAT. 相似文献
Methods : Since 1988, all patients undergoing video/EEG monitoring at our institution have been given a test phrase to read aloud as soon as a seizure is detected. Inclusion criteria for this study were (a) postictal language testing within 60 s of seizure end for at least one TLCPS, (b) >90% seizure reduction after anterior temporal lobectomy with 2-year minimum follow- follow- up, and (c) language localization by either intracarotid amobarbital test (IAT) or direct electrical stimulation of left hemisphere cortex.
Results : Two hundred twenty-four seizures in 64 patients were analyzed. Discordant postictal language patterns were noted in 10 of 11 patients with IAT documented non-left language dominance and in 15 of 53 with left dominance (p = 0.006; sensitivity 90.9%, specificity 71.7%).
Conclusions : Postictal language testing accurately identifies patients with non-left language dominance and may be useful in selecting appropriate patients for IAT. 相似文献
67.
T. Eger L. Zller H.-P. Müller S. Hoffmann D. Lobinsky 《European journal of oral sciences》1996,104(2):112-117
Actinobacillus actinomycetemcomitans has been implicated in the pathogenesis of several forms of early onset and refractory adult periodontitis. Early diagnosis of colonization of the oral cavity might be of importance in order to initiate preventive measures. The aim of the present study was to determine the potential diagnostic value of oral mucosal and salivary tests to identify, among healthy young men with no or minor periodontal disease, individuals colonized by A. actinomycetemcomitans. Two hundred and one male recruits. 18–25 yr of age, took part in the present study. Mean values of periodontal parameters suggested only minor periodontal disease. Of the sites, 64.8±17.6% (mean ± SD) had a periodonta) probing depth (PPD) of 1 or 2 mm. only 1.6±2.9% deep sites of 5 mm were detected. More than 1000 subgingival and extracrevicular samples were selectively cultivated for A. actinomycetemcomitans. The organism was isolated in 55 subjects (21%). The odds for presence of at least 1 deep site of 5 mm was increased by a factor 1.99 if A. actinomycetemcomitans could be recovered. In identifying subjects colonized by A. actinomycetemcomitans. diagnostic test parameters sensitivity and predictive value for a negative test were 74.5±5.9% and 91.1±2.3%', respectively, for both saliva and dorsum of tongue samples. In contrast, pooled subgingival plaque from mesial surfaces of 1st molars was only 34.5±6.4% sensitive: the negative predictive value was 80.2±3.0%. The results point to a high diagnostic value of oral mucosal and especially saliva samples to identify young adult individuals colonized by A. actinomycetemcomitans. 相似文献
68.
This study was designed to investigate the effect of morphine on formalin-induced nociceptive responses in streptozotocin (STZ) induced-diabetic mice, noninsulin-dependent genetically diabetic db/db mice and their respective controls (ddY and +/+). In nondiabetic (ddY and +/+) mice, morphine (1–10 mg/kg, PO) dose dependently attenuated the biphasic nociceptive responses induced by SC injection of formalin to the hindpaw, demonstrating equipotency on both the first and second phases. Para-chlorophenylalanine (800 mg/kg × 2, PO) and pindolol (1 mg/kg, IP) reduced the effect of morphine on the first phase, sulpiride (10 mg/kg, IP) abolished the effect on both phases, while ketanserin (1 mg/kg, IP) had no effect. In STZ (200 mg/kg, IP)-diabetic mice, morphine weakly attenuated the nociception in comparison to control ddY mice, whereas it had comparable effects in both the first and second phases of control +/+ mice and db/db mice. The serotonergic agonist, meta-chlorophenylpiperazine (0.32–3.2 mg/kg, PO), dose dependently attenuated the biphasic nociceptive responses to formalin in both phases of diabetic mice; however, FR64822, a dopaminergic compound (0.1–10 mg/kg, PO), had little effect. We speculate that activation of both dopaminergic (DA)- and serotonergic-mediated mechanisms are potentially responsible for the effect of morphine on the first phase, while the DA-mediated effect is involved in the second phase. The DA-mediated mechanism, but not the serotonin-mediated one, appears to be altered in both STZ-diabetic and db/db mice. These results suggest that the attenuated effects of morphine might be due to a dopaminergic dysfunction in STZ mice, and that there might be other mechanisms compensating for this attenuation of dopaminergic function in db/db mice. 相似文献
69.
为阐明课间加餐对中学生上午学习能力的影响,采用剂量作业试验,通过自身前后对比,分析了间餐与脑力工作能力的关系,结果表明间餐不仅加快了脑力工作速度,控制了末节课的错误率,而且较有效地降低了显著疲劳发生率,经logistic逐步回归分析,显示间餐及高质量早餐均为阻遏疲劳发生之保护因子。 相似文献
70.
The effect of 5-nitro-6,7-dimethyl-1,4-dihydro-2,3-quinoxalinedione (ACEA-1328), a competitive and systemically bioavailable NMDA receptor/glycine site antagonist, was examined on opioid-induced antinociception in the tail flick test. Swiss Webster mice were injected with ACEA-1328 either alone or in combination with morphine or (±)-trans-U-50488 methanesulfonate (U50,488H), a μ- and a κ-opioid receptor agonist, respectively, and tested for antinociception. Systemic administration of ACEA-1328 alone increased the tail flick latencies with an ED50of approximately 45 mg kg−1. Concurrent administration of ACEA-1328 with morphine, or U50,488H, at doses that did not affect tail flick latencies, potentiated the antinociceptive effect of the opioid analgesics and vice versa. Naloxone, an opioid receptor antagonist, while not modifying the effect of ACEA-1328, did block the augmentation, suggesting that opioid receptors might be involved in the latter effect. 5-Aza-7-chloro-4-hydroxy-3-(m-phenoxyphenyl)quinoline-2(1H)-one (ACEA-0762), a selective NMDA receptor/glycine site antagonist, also showed enhancement of the antinociceptive effect of morphine and U50,488H. However, concurrent administration of 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo[f]quinoxaline (NBQX), a selective non-NMDA receptor antagonist, with morphine did not alter the antinociceptive potency of the opioid analgesic. Overall, the data suggest that ACEA-1328 may increase the potency of the opioid analgesics by antagonising the glycine site associated with the NMDA receptor. 相似文献