全文获取类型
收费全文 | 3076篇 |
免费 | 282篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 108篇 |
儿科学 | 142篇 |
妇产科学 | 73篇 |
基础医学 | 384篇 |
口腔科学 | 45篇 |
临床医学 | 322篇 |
内科学 | 626篇 |
皮肤病学 | 49篇 |
神经病学 | 258篇 |
特种医学 | 170篇 |
外科学 | 359篇 |
综合类 | 61篇 |
一般理论 | 2篇 |
预防医学 | 353篇 |
眼科学 | 41篇 |
药学 | 224篇 |
中国医学 | 1篇 |
肿瘤学 | 180篇 |
出版年
2021年 | 42篇 |
2019年 | 29篇 |
2018年 | 47篇 |
2017年 | 28篇 |
2016年 | 34篇 |
2015年 | 50篇 |
2014年 | 56篇 |
2013年 | 106篇 |
2012年 | 99篇 |
2011年 | 100篇 |
2010年 | 67篇 |
2009年 | 63篇 |
2008年 | 111篇 |
2007年 | 109篇 |
2006年 | 124篇 |
2005年 | 108篇 |
2004年 | 101篇 |
2003年 | 109篇 |
2002年 | 97篇 |
2001年 | 104篇 |
2000年 | 85篇 |
1999年 | 100篇 |
1998年 | 47篇 |
1997年 | 29篇 |
1996年 | 42篇 |
1995年 | 49篇 |
1994年 | 29篇 |
1993年 | 38篇 |
1992年 | 74篇 |
1991年 | 75篇 |
1990年 | 80篇 |
1989年 | 90篇 |
1988年 | 65篇 |
1987年 | 94篇 |
1986年 | 79篇 |
1985年 | 69篇 |
1984年 | 60篇 |
1983年 | 39篇 |
1981年 | 30篇 |
1979年 | 60篇 |
1978年 | 40篇 |
1977年 | 36篇 |
1976年 | 38篇 |
1975年 | 27篇 |
1974年 | 30篇 |
1972年 | 28篇 |
1971年 | 50篇 |
1969年 | 25篇 |
1968年 | 27篇 |
1967年 | 25篇 |
排序方式: 共有3398条查询结果,搜索用时 21 毫秒
31.
32.
An initiative which targets resources towards chiropody patients with the greatest needs has been taking place in Nottinghamshire during the past three years. Ian Morton and Peter Pratt describe its progress and outline its new goals. 相似文献
33.
34.
William R. Crom William E. Evans Charles B. Pratt Neil Senzer Marilyn Denison Alexander A. Green F. Ann Hayes Gary C. Yee 《Cancer chemotherapy and pharmacology》1981,6(1):95-99
Summary The disposition of cisplatin was evaluated in 28 children and adolescents with cancer, as part of a phase II clinical trial. Patients received either 30 mg/m2 (11) or 90 mg/m2 (17) of cisplatin as a 6-h IV infusion. Serum samples and divided urine collections were obtained over 48 h following completion of the cisplatin infusion, and were assayed in duplicate for total platinum by atomic absorption spectrophotometry. Serum samples obtained up to 4 h after three cisplatin infusions were assayed for parent (free) cisplatin following ultrafiltration. The mean (±SE) elimination half-life of free cisplatin in serum was 1.3 (±0.4) h. Serial serum concentrations of total platinum following 90 mg/m2 dosages were adequately described by a biexponential equation. The mean (±SE) serum T1/2 of total platinum was 0.42 (±0.10) h and the mean (±SE) T1/2 was 44.43 (±8.24) h. The intercompartment distribution rate constants of a two-compartment kinetic model indicate extensive tissue accumulation of total platinum, with a rate of transport into tissue compartments (K12) that is about six times the rate of transport out of tissues (K21). The mean (±SE) renal clearance of total platinum from 0–3 h was 37.36 (±11.96) ml/min/m2 and 35.8 (±13.6) ml/min/m2 for the 30 mg/m2 and 90 mg/m2 groups, respectively. This value decreased to 3.25 (±0.94) and 2.16 (±0.4) ml/min/m2 for the two groups by the 6–12 h interval, and remained between 1 and 3 ml/min/m2 for the duration of the observation period. The ratio of total plantinum clearance to creatinine clearance decreased significantly(P<0.05) beginning 3 h post-infusion. The change in renal clearance of total platinum is apparently a function of two independent first-order processes for renal clearance of parent drug and cisplatin metabolites. 相似文献
35.
36.
An influential theory of long-term memory, in which new episodic learning is dependent upon the integrity of semantic memory, predicts that a double dissociation between episodic and semantic memory is not possible in new learning. Contrary to this view, we found, in two separate experiments, that patients with impaired semantic memory showed relatively preserved performance on tests of recognition memory if the stimuli were perceptually identical between learning and test. A significant effect of semantic memory was only seen when a perceptual manipulation was introduced in the episodic task. To account for these findings, we propose a revision to current models of long-term memory, in which sensory/perceptual information and semantic memory work in concert to support new learning. 相似文献
37.
Wayne L. Furman John H. Rodman Margaret E. Tonda Xiaolong Luo Bettye Arnold Neyssa Marina Leslie Garrison Roberta Hanna Charles B. Pratt William H. Meyer 《Cancer chemotherapy and pharmacology》1997,41(3):229-236
A hemopoietin with the ability to accelerate both platelet and granulocyte recovery after intensive chemotherapy would have
great clinical utility. The recombinant fusion protein composed of human granulocyte-macrophage colony-stimulating factor
and interleukin-3 (PIXY321), showed some promise in early adult trials. However, studies for pediatric patients are limited,
and there are no systematic data on the pharmacokinetics of PIXY321 given over prolonged periods at current dosage levels.
Purpose: To determine the safety, clinical effects and plasma concentrations of increasing doses of PIXY321 in children treated with
myelosuppressive chemotherapy. Methods: A total of 39 children with relapsed or high-risk solid tumors were enrolled in this phase I/II study. PIXY321 was administered
once or twice daily by subcutaneous injection in total doses of 500 to 1000 μg/m2 per day for 14 days after each course of chemotherapy with ifosfamide, carboplatin, and etoposide (ICE). Pharmacokinetic
studies were performed on day 1 of the first course in 33 patients and repeated on day 14 in 13 patients (once-daily schedule
only). Results: Although mild local skin reactions and fever were frequent, no dose-limiting toxicity was identified at the maximum dose
studied (1000 μg/m2 per day). There were no statistically significant differences in chemotherapy-induced hematologic toxicity with increasing
doses of PIXY321 or with twice-daily vs once-daily dosing. On day 1, the median PIXY321 clearance was 657 ml/min per m2 (range 77–1804 ml/min per m2) and the median half-life was 3.7 h (range 2.1–20.8 h). On day 14, clearance increased in all patients studied (median increase
63%), with a corresponding decrease in the median 12-h concentration (from 1.2 to 0.25 ng/ml). Maximum concentrations were
<1 ng/ml in 81% of patients, and only two patients had maximum plasma concentrations equivalent to those required for consistent
activity in vitro. Conclusions: The recombinant fusion protein PIXY321 proved safe in children treated with myelosuppressive ICE chemotherapy but had no
demonstrable clinical benefits. The pharmacokinetic studies suggest that the observed lack of hematologic benefit may be explained
by low plasma concentrations resulting from increased clearance with prolonged administration. Moreover, the significant increase
in PIXY321 systemic clearance in the absence of increased circulating myeloid cells suggests that the upregulation of either
extravascular compartment hematopoietic progenitor cells or nonhematopoietic cells may play an important role in controlling
circulating concentrations of this unique cytokine. These findings highlight the importance of a thorough assessment of the
systemic disposition of cytokines when determining the dose and schedule necessary to achieve clinical activity in patients.
Received: 29 January 1997 / Accepted: 9 May 1997 相似文献
38.
39.
Osicka TM Yu Y Panagiotopoulos S Clavant SP Kiriazis Z Pike RN Pratt LM Russo LM Kemp BE Comper WD Jerums G 《Diabetes》2000,49(1):87-93
This study examined whether the prevention of diabetes-related albuminuria by aminoguanidine (AG) or ramipril (RAM) may be mediated by a common post-glomerular basement membrane renal intracellular mechanism involving protein kinase C (PKC). The renal handling of albumin was examined over 24 weeks in control and streptozotocin (STZ)-induced diabetic rats. A radioimmunoassay (RIA) that measures intact albumin, and intravenously injected tritium-labeled rat serum albumin, was used to assess the proportion of intact albumin and albumin fragments in urine. Diabetes was induced in male Sprague-Dawley rats by the intravenous administration of STZ at a dose of 50 mg/kg. Age-matched control rats received buffer alone. Diabetes was characterized by an increase in blood glucose (>15 mmol/l), an increase in GHb (means at 24 weeks 29.3+/-1.1%; control 6.1+/-0.1%, P<0.005), an increase in glomerular filtration rate (GFR) (4.13+/-0.15 ml/min; control 3.54+/-0.19 ml/min, P<0.005), an increase in intact albumin excretion rate (expressed as geometric mean 11.64 times/divided by 2.11 mg/24 h; control 0.74 times/divided by 1.57 mg/24 h, P<0.005) as measured by RIA, and an increase in glomerular PKC activity (26.83+/-2.38 pmol x mg(-1) x min(-1); control 14.6+/-2.99 pmol x mg(-1) x min(-1), P<0.005). Treatment of diabetic rats with either AG or RAM prevented the rise in intact albuminuria and glomerular PKC activity. Renal lysosomal cathepsin activity decreased in diabetic rats and this was not prevented by AG or RAM. Neither drug affected glycemic control or GFR, but RAM reduced systolic blood pressure (BP), whereas AG did not. These data indicate that urinary excretion of intact albumin and albumin-derived fragments in diabetes may be modulated independently of glycemic control (AG and RAM) and systolic BP (RAM). While both drugs are known for their different mechanisms of action, the fact that both prevent diabetes-related increases in glomerular PKC activity and albuminuria supports the hypothesis that PKC plays a central role in the development of diabetic nephropathy. 相似文献
40.
Prescription sequence symmetry analysis: assessing risk,temporality, and consistency for adverse drug reactions across datasets in five countries 下载免费PDF全文