全文获取类型
收费全文 | 1346篇 |
免费 | 73篇 |
国内免费 | 114篇 |
专业分类
儿科学 | 68篇 |
妇产科学 | 33篇 |
基础医学 | 135篇 |
口腔科学 | 22篇 |
临床医学 | 158篇 |
内科学 | 351篇 |
皮肤病学 | 43篇 |
神经病学 | 33篇 |
特种医学 | 365篇 |
外国民族医学 | 1篇 |
外科学 | 55篇 |
综合类 | 41篇 |
预防医学 | 64篇 |
眼科学 | 12篇 |
药学 | 79篇 |
中国医学 | 1篇 |
肿瘤学 | 72篇 |
出版年
2020年 | 5篇 |
2019年 | 9篇 |
2018年 | 15篇 |
2016年 | 20篇 |
2015年 | 21篇 |
2014年 | 17篇 |
2013年 | 34篇 |
2012年 | 10篇 |
2011年 | 25篇 |
2010年 | 44篇 |
2009年 | 50篇 |
2008年 | 21篇 |
2007年 | 64篇 |
2006年 | 30篇 |
2005年 | 50篇 |
2004年 | 16篇 |
2003年 | 15篇 |
2002年 | 13篇 |
2001年 | 14篇 |
2000年 | 24篇 |
1999年 | 24篇 |
1998年 | 92篇 |
1997年 | 98篇 |
1996年 | 105篇 |
1995年 | 65篇 |
1994年 | 61篇 |
1993年 | 64篇 |
1992年 | 11篇 |
1991年 | 28篇 |
1990年 | 23篇 |
1989年 | 46篇 |
1988年 | 36篇 |
1987年 | 49篇 |
1986年 | 27篇 |
1985年 | 44篇 |
1984年 | 19篇 |
1983年 | 16篇 |
1982年 | 25篇 |
1981年 | 20篇 |
1980年 | 30篇 |
1979年 | 10篇 |
1978年 | 11篇 |
1977年 | 17篇 |
1976年 | 27篇 |
1975年 | 15篇 |
1973年 | 6篇 |
1972年 | 5篇 |
1970年 | 6篇 |
1967年 | 12篇 |
1966年 | 13篇 |
排序方式: 共有1533条查询结果,搜索用时 15 毫秒
991.
对1例中年贲门失弛缓症患者于超细胃镜直视下应用食管球囊预扩张一次的基础上,将胃镜插至胃底反转对球囊定位后再次扩张.扩张口径满意,无穿孔;症状缓解,随访1mo无复发. 相似文献
992.
993.
胃黏膜保护的基础与临床研究进展 总被引:3,自引:1,他引:3
长期以来胃黏膜保护一直是基础和临床研究的重点与热点.近年来人们对胃黏膜保护的细胞和分子机制已有了全面深入的认识,发现具有胃黏膜细胞保护作用的物质有很多种,具有细胞保护作用的器官和组织也不仅仅限于胃黏膜,在胰腺、肝脏、肾脏、心脏和脑等都发现有类似现象.因此细胞保护概念的内涵和外延都有拓展.我们对三叶因子、氧自由基、幽门螺杆菌、酒精、非甾体类抗炎药及细胞因子等研究热点与胃黏膜保护相互作用的机制进行初步的探讨. 相似文献
994.
995.
Mice of strain DBA/2J were found to produce red cells considerably more resistant to osmotic lysis than cells from C57BL/6J or the F1 hybrid between the two strains. Such strain-specific differences in osmotic fragility could be the result of genetically determined humoral or other systemic differences that indirectly influence red cell properties. Alternatively, this phenotypic variation might be an inherent property of the erythrocyte themselves and be directly controlled by their genotype. Analysis of red cells from allophenic (mosaic) mice of the strain composition C57BL/6J in equilibrium DBA/2J demonstrated that the latter possibility is the case. In such mice, erythrocytes of the DBA/2J genotype are relatively more resistant to osmotic lysis than are those of the C57BL/6J genotype; partial lysis of allophenic blood at intermediate salt concentrations results in marked enrichment for DBA/2J cells among the survivors. Future experiments designed to determine the mechanism underlying this difference can now focus on the properties of the red blood cells per se with the certainty that this property is inherent to the genotype of each cell. 相似文献
996.
Platelet-type von Willebrand's disease: characterization of a new bleeding disorder 总被引:11,自引:4,他引:11
An autosomally transmitted bleeding diathesis sharing some, but not all, features previously described in von Willebrand's disease (vWd) was studied in five patients representing three generations of a single family. Bleeding times in the upper normal range in conjunction with low-normal platelet counts, normal factor VIII coagulant activity and VIII-related antigen, decreased VIII-ristocetin cofactor activity, selective decrease of the higher molecule weight factor VIII/von Willebrand factor (VIII/vWF) multimers, and increased ristocetin- induced platelet agglutination at low ristocetin concentrations were characteristic. Binding of patient VIII/vWF to washed normal platelets was within normal limits, whereas binding of normal VIII/vWF to patient platelets was significantly increased (p less than 0.001 at 0.6 mg/ml ristocetin). This disorder accordingly appears to involve an intrinsic platelet abnormality affecting platelet-VIII/vWF interactions. It is proposed that the concept of vWD be broadened to include patients with this abnormality, which may appropriately be called "Platelet-type von Willebrand's disease." 相似文献
997.
A randomised placebo controlled trial of delipidated, deglycolipidated Mycobacterium vaccae as immunotherapy for psoriatic arthritis 下载免费PDF全文
Dalbeth N Yeoman S Dockerty JL Highton J Robinson E Tan PL Herman D McQueen FM 《Annals of the rheumatic diseases》2004,63(6):718-722
OBJECTIVES: To test the hypothesis that PVAC, delipidated, deglycolipidated heat killed Mycobacterium vaccae, is an effective and safe treatment for psoriatic arthritis (PsA). This treatment has shown promising results in psoriasis. METHODS: 36 patients with PsA in two centres were studied in this double blind, placebo controlled, randomised trial. Patients were randomised to receive two intradermal injections of 50 micro g PVAC or placebo and were followed up for 24 weeks. The primary end point was the Psoriatic Arthritis Response Criteria (PsARC), a composite measure based on changes in joint tenderness and swelling scores and physician and patient global assessments. RESULTS: The PsARC response at either 12 or 24 weeks was achieved by 9/18 (50%) placebo and 9/18 (50%) PVAC patients (p = 1.0). No significant differences in the Psoriasis Activity and Severity Index (PASI), patient or physician global assessments, CRP, or Health Assessment Questionnaire score over time were found between the two groups. However, changes in the pain visual analogue scale over time did differ between the two groups (p = 0.006): at 24 weeks the mean score in the PVAC group had declined by 19.2 mm and in the placebo group had increased by 4.8 mm. PVAC was well tolerated with no increased incidence of adverse events compared with placebo. CONCLUSIONS: PVAC was not shown to be as effective as immunotherapy for PsA. The striking response to placebo in this study reinforces the importance of adequately controlling therapeutic trials in PsA. 相似文献
998.
Cytosine arabinoside with daunorubicin or adriamycin for therapy of acute myelocytic leukemia: a CALGB study 总被引:9,自引:4,他引:9
Yates J; Glidewell O; Wiernik P; Cooper MR; Steinberg D; Dosik H; Levy R; Hoagland C; Henry P; Gottlieb A; Cornell C; Berenberg J; Hutchison JL; Raich P; Nissen N; Ellison RR; Frelick R; James GW; Falkson G; Silver RT; Haurani F; Green M; Henderson E; Leone L; Holland JF 《Blood》1982,60(2):454-462
A randomized comparison of the relative efficacy and toxicity of daunorubicin (DNR) at 30 or 45 mg/sq m or adriamycin (ADM) at 30 mg/sq m, given on the first 3 days of a 7-day continuous infusion of cytosine arabinoside (ara-C) at 100 mg/sq m/day, shows the outcome to be dependent on anthracycline, dose, and patient age. DNR 45 is significantly better than DNR 30 or ADM 30 for inducing complete remissions (CR) in patients younger than 60 yr, (72%, 59%, 58% CRs, respectively). DNR 30 is better than DNR 45 or ADM 30 for inducing CR in patients older than 60 yr (47%, 31%, 35%, respectively). There was a corresponding shift in the induction mortality for the age, dose, and anthracycline groups. Adriamycin was significantly more toxic to the gastrointestinal tract than daunorubicin. The duration of complete remission, with cyclic courses of maintenance therapy, was independent of the patient's age, the dose, or choice of anthracycline used in induction, and of whether the maintenance courses were given every 4 wk or every 8 wk. 相似文献
999.
Transplantation of CE mammary carcinoma into mice has been shown to produce marked neutrophilia. Previous studies in vivo indicated a significant increase in marrow neutrophil production in these mice, but regulatory mechanisms of this neutrophilia have not been well understood. In order to obtain information about neutrophil production mechanisms at the progenitor cell level, the profile of marrow granulocyte-macrophage progenitors in mice with neutrophilia induced by this tumor was quantitatively analyzed by cytochemical staining of in vitro colonies to distinguish colonies of neutrophils (N-colony), macrophages (M-colony), and mixed cells (NM-colony). Cell cycle kinetics of progenitors were studied by in vivo administration of cytocidal drugs. The absolute number of N-colonies in a femur increased significantly and reached three times normal three to four weeks after tumor implantation. The number of NM-colonies also increased significantly by the fourth week, but the number of M-colonies was unchanged. The number of N-colonies in a femur related directly to the degree of neutrophilia. The increased number of N-colonies from the marrow of tumor-bearing mice was not attributed to a different time course of colony growth nor to a different sensitivity to CSA; instead, a significantly larger fraction of neutrophilic progenitors from the tumor-bearing mice were in active cell cycle than were those of normal mice. The day 14 tumor-bearing mouse serum demonstrated N-colony stimulating activity while the sera of normal mice and day 7 tumor- bearing mice were inhibitory for in vitro colony growth. These studies demonstrated an increase in the numbers and turnover rate of marrow neutrophilic progenitors in CE tumor-induced neutrophilia, suggesting that this tumor stimulates proliferation of these progenitors in vivo. 相似文献
1000.
SANMIGUEL CP HAGIIKE M DELA CRUZ R PHILLIPS E CUNNEEN SA CONKLIN JL & SOFFER EE 《Neurogastroenterology and motility》2006,18(6):482-482
Cyclic vomiting syndrome (CVS) is an unexplained disorder characterized by recurrent attacks of nausea and vomiting. The aim of this study was to investigate the characteristics of gastric myoelectrical activity in patients meeting Rome II criteria for CVS and studied between cycles using cutaneous electrogastrography (EGG). Methods: 11 patients (6M, 5F, mean age: 31 years, range: 16–60) with CVS (5 symptomatic and 6 asymptomatic at the time of the study) underwent EGG between acute CVS attacks. EGG recordings were made for 30 minutes in the fasting state and for 60 minutes after ingestion of a caloric liquid meal (Boost, 360 kcal). Power spectral analysis methods were used to extract quantitative EGG parameters: EGG dominant frequency/power, change in postprandial EGG power, percentages of normal slow waves (2 to 4 cpm) and dysrythmias including tachygastria (slow‐wave frequency >4 cpm) and bradygastria (slow‐wave frequency <2 cpm) in each recording session. Patients were asked to score their symptoms of nausea, vomiting and abdominal pain (0 = none, 4 = constant) during both pre‐ and postprandial periods. Data are expressed as mean ± SE. Results: 7/11 demonstrated an abnormal EGG (dysrhythmia >30% in 4 patients and a decrease in postprandial EGG power in 6 patients). 5/11 patients had symptoms (nausea) during EGG recording and all had an abnormal EGG. The major abnormalities of EGG were tachygastria and a decrease in EGG postprandial power change. In comparison with asymptomatic patients at the time of the study, symptomatic patients had significantly more tachgastria (20.4 ± 3.9% vs. 6.7 ± 2.7%, P = 0.01) and significantly less normal slow waves (67.6 ± 2.0% vs. 86.7 ± 2.8%, P < 0.05) in the fed state. The increase in EGG postptandial power in symptomatic patients was also significantly less than asymptomatic patients (2.55 ± 1.01 dB vs. 1.14 ± 0.54 dB, P < 0.05). Conclusions: 1) Abnormalities of EGG are presented in CVS between acute episodes and could explain some of the symptoms present; 2) Abnormal gastric myoelectrical activity is part of the spectrum of the CVS patients. 相似文献