全文获取类型
收费全文 | 3544篇 |
免费 | 184篇 |
国内免费 | 109篇 |
专业分类
耳鼻咽喉 | 22篇 |
儿科学 | 59篇 |
妇产科学 | 12篇 |
基础医学 | 183篇 |
口腔科学 | 29篇 |
临床医学 | 347篇 |
内科学 | 348篇 |
皮肤病学 | 21篇 |
神经病学 | 109篇 |
特种医学 | 1303篇 |
外国民族医学 | 2篇 |
外科学 | 257篇 |
综合类 | 504篇 |
预防医学 | 50篇 |
眼科学 | 19篇 |
药学 | 337篇 |
中国医学 | 12篇 |
肿瘤学 | 223篇 |
出版年
2023年 | 18篇 |
2022年 | 38篇 |
2021年 | 66篇 |
2020年 | 61篇 |
2019年 | 64篇 |
2018年 | 60篇 |
2017年 | 54篇 |
2016年 | 55篇 |
2015年 | 57篇 |
2014年 | 121篇 |
2013年 | 145篇 |
2012年 | 112篇 |
2011年 | 143篇 |
2010年 | 149篇 |
2009年 | 200篇 |
2008年 | 186篇 |
2007年 | 188篇 |
2006年 | 227篇 |
2005年 | 187篇 |
2004年 | 178篇 |
2003年 | 174篇 |
2002年 | 141篇 |
2001年 | 131篇 |
2000年 | 130篇 |
1999年 | 107篇 |
1998年 | 76篇 |
1997年 | 87篇 |
1996年 | 82篇 |
1995年 | 79篇 |
1994年 | 69篇 |
1993年 | 57篇 |
1992年 | 60篇 |
1991年 | 50篇 |
1990年 | 44篇 |
1989年 | 51篇 |
1988年 | 35篇 |
1987年 | 32篇 |
1986年 | 38篇 |
1985年 | 22篇 |
1984年 | 3篇 |
1983年 | 9篇 |
1982年 | 9篇 |
1981年 | 11篇 |
1980年 | 11篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有3837条查询结果,搜索用时 250 毫秒
51.
目的:观察犬冠状动脉左旋支狭窄后心肌细胞对^99碍^m-甲氧基异丁基异腈(^99Tc^m-MIBI)摄取与时间变化之间的关系。方法:建立犬冠状动脉左旋支狭窄模型(12只),分别注射^99Tc^m-MIBI,剂量为185MBq(5mCi)。注射1h和4h后,各处死6只犬,取出心脏,于左室侧壁(缺血区)和前壁(正常区)分别取心肌组织约100rag,用1计数器测定其放射性计数,换算成每克组织放射性计数值,求出侧壁与前壁放射性比值。结果:注射后1h犬左心室缺血区与正常区组织放射性计数比值为0.726±O.054,4h为0.673±0.080,两者之间比较差鼻无昂薯件(t=1.3452.P〉0.05).结论.砸长时问不能摇高按血心肌对辨^99Tc^m-MIBI梧取比. 相似文献
52.
Urodilatin: a new peptide with beneficial effects in the postoperative therapy of cardiac transplant recipients 总被引:1,自引:0,他引:1
M. Hummel M. Kuhn A. Bub H. Bittner D. Kleefeld P. Marxen B. Schneider R. Hetzer W. G. Forssmann 《Journal of molecular medicine (Berlin, Germany)》1992,70(8):674-682
Summary Renal failure after heart transplantation (HTx) still remains a serious problem, especially when cyclosporin A is used for immunosuppression in the early postoperative therapy. To preserve good renal function without reducing immunosuppressive cyclosporin A treatment, we administered urodilatin (CDD/ANP-95-126) in a long-term, low-dose infusion in addition to the usual medication after heart transplantation. From November 1990 to June 1991, 51 patients (46 male and 5 female; mean age 48 years) were treated with a 620 ng/kg bw·min infusion for 96 h after HTx. The renal function and hemodynamic parameters of these urodilatin-treated patients were compared in this sequential study with 40 patients (33 male and 7 female; mean age 49 years) who had undergone HTx previously from May to November, 1990, as controls. In this phase IIa study, both groups did not differ significantly with respect to age, sex, indication for HTx, and preoperative renal function. In comparison with controls patients treated with urodilatin had a significantly better renal function: a reduction in the peak plasma creatinine (PC values day 4 : 1.5 ± 0.11 vs. 2.19 ± 0.19 mg/dl; P = 0.002), a lower peak serum urea (SU values day 4 : 109 ± 8 vs. 154.7 ± 8.94 mg/dl ; P = 0.0036), and a lower incidence of hemodialysis (6% vs. 10%) were observed. Adequate diuresis was maintained in spite of the reduction of furosemide by more than 60% (P = 0.005) on each day of urodilatin infusion in comparison with controls. The mean central venous pressure was significantly lower by about 50% (P = 0.02) during the administration of urodilatin in spite of reduced vasodilator medication with nitroglycerin. From this phase IIa study, we may conclude that urodilatin could be an important drug in intensive care treatment. For patients undergoing HTx, this peptide seems to be indicated for the improvement of renal function and cardiovascular status, especially in postoperative therapy using high-dose cyclosporin A treatment.Abbreviations ACE
angiotensin converting enzyme
- ANP
atrial natriuretic polypeptide
- ATG
antithymocyte globulin
- bpm
beats per minute
- bw
body weight
- CDD
cardiodilatin
- CDD/ANP-99-126
circulating form of vasorelaxant cardiac peptide
- CHD
coronary heart disease
- CyA
cyclosporin A
- DCM
dilated cardiomyopathy
- GLM
general linear model
- hANP
human atrial natriuretic polypeptide
- HTx
heart transplantation
- NTG
nitroglycerine
- PC
plasma creatinine
- SU
serum urea
- SAS
statistical analysing system 相似文献
53.
Harald Deckart Siegfried Ertl Annemarie Blottner Manfred Tautz 《European journal of nuclear medicine and molecular imaging》1987,13(8):429-431
Whole body retention measurements were performed in volunteers after i.v. injection of 99mTc-HM-PAO (Ceretec®). The organ accumulation was measured in mice and data were transferred to standard man according to ICRP. Absorbed dose calculations were made with these data by using the concept of absorbed fractions (MIRD method). In man, the whole body retention and the retention in the brain could be calculated by direct measurement, absorbed doses to the other organs could only be derived from animal data. The absorbed dose to the brain derived from human data (10.3 Gy/MBq) is greater by a factor of 2 than that derived from animal data. The highest absorbed dose was received by the thyroid (24.4 Gy/MBq), the absorbed dose to the ovaries, testes and whole body ranged from 2.8 to 4.2 Gy/MBq.Dedicated to Professor Dr. Guenter Liess on the occasion of his 65th anniversary 相似文献
54.
Andreas Hammermaier Ernst Reich Werner Bögl 《European journal of nuclear medicine and molecular imaging》1986,12(1):41-46
Seven99Mo/99mTc generators (using fission99Mo) obtained from seven different manufactures were studied in 1984 and 1985 to test the quality of the eluates. We present the findings concerning the elution efficiency, radionuclide purity,99Mo breakthrough, radiochemical purity, pH, and aluminium content of the eluates. One generator was overloaded with99Mo by about 40%, while one generator had99mTc yields of only about 80%. The eluates generally (although with some exceptions) exhibited a high and satisfactory radionuclidic purity and good radiochemical purity. The low-level determination of99Mo break-through using a commercially available dose calibrator with a99Mo assay shiled indicated a misleadingly high99Mo content. All of the eluates had pH values of between 5.0 and 5.5, and the aluminium content was always below the detection limit of 1 g per milliliter of eluate. The generators performed well and proved their capability of functioning as reliable sources of sodium pertechnetate Tc99m. In all cases, the pertechnetate produced met the requirements of the European Pharmacopeia.This report is based on work conducted within the scope of a research poject devised by the Ministry of the Interior of the Federal Republic of Germany (Hammermaier et al. 1985). The present report reflects the opinions of the authors and does not necessarily express the views of the Federal Ministry of the Interior 相似文献
55.
Rüdiger Schwarzrock Jörg Kotzerke Heinz Hundeshagen Klaus Böcker Burckhard Ringe 《European journal of nuclear medicine and molecular imaging》1986,12(7):346-350
The new HIDA derivative, 99mTc-dimethyl-iodine-HIDA (JODIDA), was compared with 99mTc-diisopropyl-HIDA (DISIDA) in 17 patients with jaundice by means of paired cholescintigraphic imaging studies. The following parameters were visually assessed: the extent of urinary tract visualization, biliary contrast and appearance time, and gallbladder visualization and appearance time. In the 6 patients with a total bilirubin level of between 19 and 66 mol/l (1.1 and 3.9 mg/dl), both radiopharmaceuticals gave similar results except for the moderate visualization of the urinary tract with DISIDA in contrast to JODIDA. In the remaining 11 patients with a total bilirubin level between 102 and 1303 mol/l (6 and 76 mg/dl), JODIDA showed significant advantages over DISIDA: non-visualization of the urinary tract, stronger and faster biliary contrast, and better gallbladder visualization. JODIDA thus offered substantial diagnostic advantages over DISIDA in 8 of these patients. In 4 patients, the differential diagnosis of jaundice (intrahepatic or mechanical disorder) was possible with JODIDA, whereas DISIDA either could not visualize intestinal or gallbladder activity at all or could not differentiate it from the urinary tract. In one patients, JODIDA offered faster (18 h) diagnosis. In the remaining 3 patients, other, substantially false interpretations could be avoided through the use of JODIDA. Further clinical experience with JODIDA in more than 40 patients confirmed the results of this study. We concluded that JODIDA is of significant advantage over DISIDA in clinical situations such as total bilirubin level above 80–100 mol/l (4.7 to 5.8 mg/dl), examination of small children and critically ill patients and suggestion of bile leakage. As there are also no clinical disadvantages, it could become the rediopharmaceutical of choice for hepatobiliary imaging. 相似文献
56.
Shigeru Sanada Atsushi Ando Itsuko Ando Tatsunosuke Hiraki Kinichi Hisada 《European journal of nuclear medicine and molecular imaging》1986,12(8):390-393
A single-strip miniaturized paper chromatographic method (Mini-PC) was developed using 80%–90% acetone solvent for rapid purity-control of 99mTc-radiopharmaceuticals. Routine 99mTc-radiopharmaceuticals (eight kinds of kit made agents) and diluted agents (in which radiochemical impurities might be formed) were analyzed by Mini-PC and other methods. This showed that, compared with the other methods, the Mini-PC technique is useful for the simple and rapid routine analysis of radiochemical impurities of kit made 99mTc-radiopharmaceuticals. 相似文献
57.
Summary To explore the possibility to employ99mTc-MIBI to monitor biological response of tumor cells after irradiation and to observe the relation between the radiation
doses and the uptake levels of99mTc-MIBI in tumor cells, the cells were irradiated with a single dose of 2 Gy, 10 Gy and 20 Gy respectively. The uptake of99mTc-MIBI in each dosage group was determined before and 24, 48, 72 h after irradiation respectively. Apoptosis index (AI),
plating efficiency (PE) of tumor cells was simultaneously determined. There was a positive correlation between uptake levels
of99mc-MIBI and AI(r = −0.91,P< 0.05). A negative correlation was noted between the uptake levels and PE (r = −0.86,P< 0.05). It is suggested that99mTc-MIBI may be used as a tracer to monitor the change of viability state of tumor cells after being irradiated with different
doses. 相似文献
58.
59.
Yosuke Tsuruga Toshiya Kamiyama Hirofumi Kamachi Tatsuya Orimo Shingo Shimada Akihisa Nagatsu Yoh Asahi Yuzuru Sakamoto Tatsuhiko Kakisaka Akinobu Taketomi 《World journal of gastrointestinal surgery》2021,13(2):153-163
BACKGROUNDPreoperative portal vein embolization (PVE) is a widely used strategy to enable major hepatectomy in patients with insufficient liver remnant. PVE induces hypertrophy of the future liver remnant (FLR) and a shift of the functional reserve to the FLR. However, whether the increase of the FLR volume (FLRV) corresponds to the functional transition after PVE remains unclear.AIMTo investigate the sequential relationship between the increase in FLRV and functional transition after preoperative PVE using 3-dimensional (3D) computed tomography (CT) and 99mTc-galactosyl-human serum albumin (99mTc-GSA) single-photon emission computed tomography (SPECT) fusion images. METHODSThirty-three patients who underwent major hepatectomy following PVE at the Department of Gastroenterological Surgery I, Hokkaido University Hospital between October 2013 and March 2018 were enrolled. Three-phase dynamic multidetector CT and 99mTc-GSA SPECT scintigraphy were performed at pre-PVE, and at 1 and 2 wk after PVE; 3D 99mTc-GSA SPECT CT-fused images were constructed from the Digital Imaging and Communications in Medicine data using 3D image analysis system. Functional FLRV (FFLRV) was defined as the total liver volume × (FLR volume counts/total liver volume counts) on the 3D 99mTc-GSA SPECT CT-fused images. The calculated FFLRV was compared with FLRV.RESULTSFFLRV increased by a significantly larger extent than FLRV at 1 and 2 wk after PVE (P < 0.01). The increase in FFLRV and FLRV was 55.1% ± 41.6% and 26.7% ± 17.8% (P < 0.001), respectively, at 1 wk after PVE, and 64.2% ± 33.3% and 36.8% ± 18.9% (P < 0.001), respectively, at 2 wk after PVE. In 3 of the 33 patients, FFLRV levels decreased below FLRV at 2 wk. One of the three patients showed rapidly progressive fatty changes in FLR. The biopsy at 4 wk after PVE showed macro- and micro-vesicular steatosis of more than 40%, which improved to 10%. Radical resection was performed at 13 wk after PVE. The patient recovered uneventfully without any symptoms of pos-toperative liver failure.CONCLUSIONThe functional transition lagged behind the increase in FLRV after PVE in some cases. Evaluating both volume and function is needed to determine the optimal timing of hepatectomy after PVE. 相似文献
60.